8Gb: x4, x8, x16 DDR4 SDRAM

Features

DDR4 SDRAM
MT40A2G4
MT40A1G8
MT40A512M16
Features
Options1 Marking
s VDD = VDDQ = 1.2V ά60mV s Configuration
s VPP  6 nM6 M6 n 2 Gig x 4 2G4
s On-die, internal, adjustable VREFDQ generation n 1 Gig x 8 1G8
s 1.2V pseudo open-drain I/O n 512 Meg x 16 512M16
s Refresh time of 8192-cycle at TC temperature range: s  BALL &"'! PACKAGE 0B FREE n X X
n 64ms at -40ιC to 85ιC n MM X MM n 2EV ! PM
n 32ms at >85ιC to 95ιC n MM X MM n 2EV " $ ' WE
n 16ms at >95ιC to 105ιC n MM X MM n 2EV % ( * 2 SA
s 16 internal banks (x4, x8): 4 groups of 4 banks each s  BALL &"'! PACKAGE 0B FREE n X
s 8 internal banks (x16): 2 groups of 4 banks each n MM X MM n 2EV ! HA
s 8n-bit prefetch architecture n MM X MM n 2EV " JY
s Programmable data strobe preambles n MM X MM n 2EV $ % ( LY
s Data strobe preamble training n MM X MM n 2EV * 2 TB
s Command/Address latency (CAL) s 4IMING n CYCLE TIME
s Multipurpose register READ and WRITE capability n 0.625ns @ CL = 22 (DDR4-3200) -062E
s Write leveling n 0.682ns @ CL = 21 (DDR4-2933) -068
s Self refresh mode n 0.750ns @ CL = 19 (DDR4-2666) -075
s Low-power auto self refresh (LPASR) n 0.750ns @ CL = 18 (DDR4-2666) -075E
s Temperature controlled refresh (TCR) n 0.833ns @ CL = 17 (DDR4-2400) -083
s Fine granularity refresh n 0.833ns @ CL = 16 (DDR4-2400) -083E
s Self refresh abort n 0.937ns @ CL = 15 (DDR4-2133) -093E
s Maximum power saving n 1.071ns @ CL = 13 (DDR4-1866) -107E
s Output driver calibration s Operating temperature
s Nominal, park, and dynamic on-die termination n Commercial (0ι ζ TC ζ 95ιC) None
(ODT) n )NDUSTRIAL nι ζ TC ζ 95ιC) IT
s Data bus inversion (DBI) for data bus n !UTOMOTIVE nι ζ TC ζ 105ιC) AT
s Command/Address (CA) parity s Revision :A, :B, :D, :E,
s Databus write cyclic redundancy check (CRC) :G, :H, :J, :R
s Per-DRAM addressability
s Connectivity test Notes: 1. Not all options listed can be combined to
s JEDEC JESD-79-4 compliant define an offered product. Use the part
s sPPR and hPPR capability catalog search on http://www.micron.com for
s MBIST-PPR support (Die Revision R only) available offerings.

Table 1: Key Timing Parameters

Speed Grade1 Data Rate (MT/s) Target CL-nRCD-nRP t

AA (ns) t
RCD (ns) t
RP (ns)
-062Y 3200 22-22-22 13.75 (13.32) 13.75 (13.32) 13.75 (13.32)
-062E 3200 22-22-22 13.75 13.75 13.75
-068 2933 21-21-21 14.32 (13.75) 14.32 (13.75) 14.32 (13.75)
-075E 2666 18-18-18 13.50 13.50 13.50

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
1 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
Products and specifications discussed herein are subject to change by Micron without notice.
 8Gb: x4, x8, x16 DDR4 SDRAM
Features

Table 1: Key Timing Parameters (Continued)

Speed Grade1 Data Rate (MT/s) Target CL-nRCD-nRP tAA (ns) tRCD (ns) tRP (ns)
-075 2666 19-19-19 14.25 (13.75) 14.25 (13.75) 14.25 (13.75)
-083E 2400 16-16-16 13.32 13.32 13.32
-083 2400 17-17-17 14.16 (13.75) 14.16 (13.75) 14.16 (13.75)
-093E 2133 15-15-15 14.06 (13.50) 14.06 (13.50) 14.06 (13.50)
-093 2133 16-16-16 15.00 15.00 15.00
-107E 1866 13-13-13 13.92 (13.50) 13.92 (13.50) 13.92 (13.50)

Notes: 1. Refer to the Speed Bin Tables for additional details.

Table 2: Addressing
Parameter 2048 Meg x 4 1024 Meg x 8 512 Meg x 16
Number of bank groups 4 4 2
Bank group address BG[1:0] BG[1:0] BG0
Bank count per group 4 4 4
Bank address in bank group BA[1:0] BA[1:0] BA[1:0]
Row addressing 128K (A[16:0]) 64K (A[15:0]) 64K (A[15:0])
Column addressing 1K (A[9:0]) 1K (A[9:0]) 1K (A[9:0])

Page size1 512B 1KB 2KB

Notes: 1. Page size is per bank, calculated as follows:

Page size = 2COLBITS έ ORG/8, where COLBIT = the number of column address bits and ORG = the number of DQ bits.

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
2 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
Features

Figure 1: Order Part Number Example

Example Part Number: MT40A1G8SA-062E:R

- :

MT40A Configuration Package Speed Revision

{
Configuration Die Revision
2 Gig x 4 2G4 :A, :B, :D, :G, :E, :H, :J, :R
1 Gig x 8 1G8
512 Meg x 16 512M16 Case Temperature Mark
Commercial None
Package Mark Industrial IT
78-ball 9.0mm x 13.2mm FBGA PM Extended AT
78-ball 8.0mm x 12.0mm FBGA WE
78-ball 7.5mm x 11.0mm FBGA SA Speed Cycle Time, CAS Latency
Grade
96-ball 9.0mm x 14.0mm FBGA HA
-107E tCK = 1.071ns, CL = 13
96-ball 8.0mm x 14.0mm FBGA JY
-093E tCK = 0.937ns, CL = 15
96-ball 7.5mm x 13.5mm FBGA LY
-083E tCK = 0.833ns, CL = 16
96-ball 7.5mm x 13.0mm FBGA TB
-083 tCK = 0.833ns, CL = 17
-075E tCK = 0.750ns, CL = 18
-075 tCK = 0.750ns, CL = 19
-068 tCK = 0.682ns, CL = 21
-062E tCK = 0.625ns, CL = 22

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
3 Micron Technology, Inc. reserves the right to change products or specifications without notice.
© 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM

Contents
Important Notes and Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
General Notes and Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Industrial Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Automotive Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
General Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Definitions of the Device-Pin Signal Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Definitions of the Bus Signal Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Functional Block Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Ball Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Ball Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Package Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
State Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
RESET and Initialization Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Power-Up and Initialization Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
RESET Initialization with Stable Power Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Uncontrolled Power-Down Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Programming Mode Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Mode Register 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Burst Length, Type, and Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
CAS Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Test Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Write Recovery (WR)/READ-to-PRECHARGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
DLL RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Mode Register 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
DLL Enable/DLL Disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Output Driver Impedance Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
ODT RTT(NOM) Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Additive Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Rx CTLE Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Write Leveling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Output Disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Termination Data Strobe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Mode Register 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
CAS WRITE Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Low-Power Auto Self Refresh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Dynamic ODT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Write Cyclic Redundancy Check Data Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Mode Register 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Multipurpose Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
WRITE Command Latency When CRC/DM is Enabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Fine Granularity Refresh Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Temperature Sensor Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Per-DRAM Addressability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Gear-Down Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Mode Register 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Hard Post Package Repair Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Soft Post Package Repair Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
WRITE Preamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
READ Preamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
4 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM

READ Preamble Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Temperature-Controlled Refresh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Command Address Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Internal VREF Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Maximum Power Savings Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
MBIST-PPR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Mode Register 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Data Bus Inversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Data Mask . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
CA Parity Persistent Error Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
ODT Input Buffer for Power-Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
CA Parity Error Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
CRC Error Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
CA Parity Latency Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Mode Register 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Data Rate Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
VREFDQ Calibration Enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
VREFDQ Calibration Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
VREFDQ Calibration Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Truth Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
NOP Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
DESELECT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
DLL-Off Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
DLL-On/Off Switching Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
DLL Switch Sequence from DLL-On to DLL-Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
DLL-Off to DLL-On Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Input Clock Frequency Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Write Leveling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
DRAM Setting for Write Leveling and DRAM TERMINATION Function in that Mode . . . . . . . . . . . . . . . . . . . . . . . 81
Procedure Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Write Leveling Mode Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Command Address Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Low-Power Auto Self Refresh Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Manual Self Refresh Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Multipurpose Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
MPR Reads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
MPR Readout Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
MPR Readout Serial Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
MPR Readout Parallel Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
MPR Readout Staggered Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
MPR READ Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
MPR Writes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
MPR WRITE Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
MPR REFRESH Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Gear-Down Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Maximum Power-Saving Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Maximum Power-Saving Mode Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Maximum Power-Saving Mode Entry in PDA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
CKE Transition During Maximum Power-Saving Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Maximum Power-Saving Mode Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Command/Address Parity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Per-DRAM Addressability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
VREFDQ Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
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5 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM

VREFDQ Range and Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

VREFDQ Step Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
VREFDQ Increment and Decrement Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
VREFDQ Target Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Connectivity Test Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Pin Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Minimum Terms Definition for Logic Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Logic Equations for a x4 Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Logic Equations for a x8 Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Logic Equations for a x16 Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
CT Input Timing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Excessive Row Activation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Post Package Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Post Package Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Hard Post Package Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
hPPR Row Repair - Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
H002 2OW 2EPAIR n 72! )NITIATED 2%& #OMMANDS !LLOWED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
H002 2OW 2EPAIR n 72 )NITIATED 2%& #OMMANDS ./4 !LLOWED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
sPPR Row Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
MBIST-PPR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
MBIST-PPR Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
hPPR/sPPR/MBIST-PPR Support Identifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
ACTIVATE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
PRECHARGE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
REFRESH Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Temperature-Controlled Refresh Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Normal Temperature Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Extended Temperature Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Fine Granularity Refresh Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Mode Register and Command Truth Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
t
REFI and tRFC Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Changing Refresh Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Usage with TCR Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Self Refresh Entry and Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
SELF REFRESH Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Self Refresh Abort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
Self Refresh Exit with NOP Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Power-Down Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
0OWER $OWN #LARIFICATIONS n #ASE  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Power-Down Entry, Exit Timing with CAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
ODT Input Buffer Disable Mode for Power-Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
CRC Write Data Feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
CRC Write Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
WRITE CRC DATA Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
DBI_n and CRC Both Enabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
DM_n and CRC Both Enabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
DM_n and DBI_n Conflict During Writes with CRC Enabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
CRC and Write Preamble Restrictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
CRC Simultaneous Operation Restrictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
CRC Polynomial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
CRC Combinatorial Logic Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
Burst Ordering for BL8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
CRC Data Bit Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
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6 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM

CRC Enabled With BC4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171

CRC with BC4 Data Bit Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
CRC Equations for x8 Device in BC4 Mode with A2 = 0 and A2 = 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
CRC Error Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
CRC Write Data Flow Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
Data Bus Inversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
DBI During a WRITE Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
DBI During a READ Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
Data Mask . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Programmable Preamble Modes and DQS Postambles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
WRITE Preamble Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
READ Preamble Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
READ Preamble Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
WRITE Postamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
READ Postamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
Bank Access Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
READ Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
Read Timing Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
2EAD 4IMING n #LOCK TO $ATA 3TROBE 2ELATIONSHIP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
2EAD 4IMING n $ATA 3TROBE TO $ATA 2ELATIONSHIP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
t
LZ(DQS), tLZ(DQ), tHZ(DQS), and tHZ(DQ) Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
t
RPRE Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
tRPST Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
READ Burst Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
READ Operation Followed by Another READ Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
READ Operation Followed by WRITE Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
READ Operation Followed by PRECHARGE Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
READ Operation with Read Data Bus Inversion (DBI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
READ Operation with Command/Address Parity (CA Parity) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
READ Followed by WRITE with CRC Enabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
READ Operation with Command/Address Latency (CAL) Enabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
WRITE Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
Write Timing Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
7RITE 4IMING n #LOCK TO $ATA 3TROBE 2ELATIONSHIP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
t
WPRE Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
t
WPST Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
7RITE 4IMING n $ATA 3TROBE TO $ATA 2ELATIONSHIP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
WRITE Burst Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
WRITE Operation Followed by Another WRITE Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
WRITE Operation Followed by READ Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
WRITE Operation Followed by PRECHARGE Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
WRITE Operation with WRITE DBI Enabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
WRITE Operation with CA Parity Enabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
WRITE Operation with Write CRC Enabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
Write Timing Violations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
Data Setup and Hold Violations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
Strobe-to-Strobe and Strobe-to-Clock Violations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
ZQ CALIBRATION Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
On-Die Termination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
ODT Mode Register and ODT State Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
ODT Read Disable State Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
Synchronous ODT Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
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7 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM

ODT Latency and Posted ODT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248

Timing Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
ODT During Reads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
Dynamic ODT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
Asynchronous ODT Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
Absolute Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
DRAM Component Operating Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
%LECTRICAL #HARACTERISTICS n !# AND $# /PERATING #ONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
Supply Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
Leakages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
VREFCA Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
VREFDQ Supply and Calibration Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
VREFDQ Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
%LECTRICAL #HARACTERISTICS n !# AND $# 3INGLE %NDED )NPUT -EASUREMENT ,EVELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
RESET_n Input Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
Command/Address Input Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
Command, Control, and Address Setup, Hold, and Derating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
Data Receiver Input Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
Connectivity Test (CT) Mode Input Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
%LECTRICAL #HARACTERISTICS n !# AND $# $IFFERENTIAL )NPUT -EASUREMENT ,EVELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
Differential Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
Single-Ended Requirements for CK Differential Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
Slew Rate Definitions for CK Differential Input Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
CK Differential Input Cross Point Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
DQS Differential Input Signal Definition and Swing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
DQS Differential Input Cross Point Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279
Slew Rate Definitions for DQS Differential Input Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
%LECTRICAL #HARACTERISTICS n /VERSHOOT AND 5NDERSHOOT 3PECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
Address, Command, and Control Overshoot and Undershoot Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
Clock Overshoot and Undershoot Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
Data, Strobe, and Mask Overshoot and Undershoot Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
%LECTRICAL #HARACTERISTICS n !# AND $# /UTPUT -EASUREMENT ,EVELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
Single-Ended Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
Differential Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
Reference Load for AC Timing and Output Slew Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Connectivity Test Mode Output Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
%LECTRICAL #HARACTERISTICS n !# AND $# /UTPUT $RIVER #HARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
Connectivity Test Mode Output Driver Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
Output Driver Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
Output Driver Temperature and Voltage Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
Alert Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
%LECTRICAL #HARACTERISTICS n /N $IE 4ERMINATION #HARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
ODT Levels and I-V Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
ODT Temperature and Voltage Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
ODT Timing Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298
ODT Timing Definitions and Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298
DRAM Package Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
#URRENT 3PECIFICATIONS n -EASUREMENT #ONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306
IDD, IPP, and IDDQ Measurement Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306
IDD Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
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8 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM

#URRENT 3PECIFICATIONS n 0ATTERNS AND 4EST #ONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312

Current Test Definitions and Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312
IDD Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
#URRENT 3PECIFICATIONS n ,IMITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Speed Bin Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
Backward Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
Refresh Parameters By Device Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360
AC Electrical Characteristics and AC Timing Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361
Electrical Characteristics and AC Timing Parameters: 2666 Through 3200 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374
Clock Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387
Definition for tCK(AVG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387
Definition for tCK(ABS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387
Definition for tCH(AVG) and tCL(AVG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387
Definition for tJIT(per) and tJIT(per,lck) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387
Definition for tJIT(cc) and tJIT(cc,lck) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387
Definition for tERR(nper) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 388
Jitter Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 388
Converting Time-Based Specifications to Clock-Based Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 389
Options Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 390

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
9 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM

List of Figures
Figure 1: Order Part Number Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Figure 2: 2 Gig x 4 Functional Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 3: 1 Gig x 8 Functional Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 4: 512 Meg x 16 Functional Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 5: 78-Ball x4, x8 Ball Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 6: 96-Ball x16 Ball Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 7:  "ALL &"'! n X X 0- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figure 8:  "ALL &"'! n X X 7% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Figure 9:  "ALL &"'! n X X 3! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Figure 10:  "ALL &"'! n X (! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Figure 11:  "ALL &"'! n X *9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Figure 12:  "ALL &"'! n X ,9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Figure 13:  "ALL &"'! n X 4" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Figure 14: Simplified State Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Figure 15: RESET and Initialization Sequence at Power-On Ramping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Figure 16: RESET Procedure at Power Stable Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Figure 17: tMRD Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Figure 18: tMOD Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Figure 19: DLL-Off Mode Read Timing Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Figure 20: DLL Switch Sequence from DLL-On to DLL-Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Figure 21: DLL Switch Sequence from DLL-Off to DLL-On . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Figure 22: Write Leveling Concept, Example 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Figure 23: Write Leveling Concept, Example 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Figure 24: Write Leveling Sequence (DQS Capturing CK LOW at T1 and CK HIGH at T2) . . . . . . . . . . . . . . . . . . . . . . . 82
Figure 25: Write Leveling Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Figure 26: CAL Timing Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Figure 27: CAL Timing Example (Consecutive CS_n = LOW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Figure 28: #!, %NABLE 4IMING n tMOD_CAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Figure 29: tMOD_CAL, MRS to Valid Command Timing with CAL Enabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Figure 30: CAL Enabling MRS to Next MRS Command, tMRD_CAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Figure 31: tMRD_CAL, Mode Register Cycle Time With CAL Enabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Figure 32: Consecutive READ BL8, CAL3, 1tCK Preamble, Different Bank Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Figure 33: Consecutive READ BL8, CAL4, 1tCK Preamble, Different Bank Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Figure 34: Auto Self Refresh Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Figure 35: MPR Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Figure 36: MPR READ Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Figure 37: MPR Back-to-Back READ Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Figure 38: MPR READ-to-WRITE Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Figure 39: MPR WRITE and WRITE-to-READ Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Figure 40: MPR Back-to-Back WRITE Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Figure 41: REFRESH Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Figure 42: READ-to-REFRESH Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Figure 43: WRITE-to-REFRESH Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Figure 44: Clock Mode Change from 1/2 Rate to 1/4 Rate (Initialization) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Figure 45: Clock Mode Change After Exiting Self Refresh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Figure 46: Comparison Between Gear-Down Disable and Gear-Down Enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
Figure 47: Maximum Power-Saving Mode Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Figure 48: Maximum Power-Saving Mode Entry with PDA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Figure 49: Maintaining Maximum Power-Saving Mode with CKE Transition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Figure 50: Maximum Power-Saving Mode Exit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Figure 51: Command/Address Parity Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
10 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM

Figure 52: Command/Address Parity During Normal Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Figure 53: Persistent CA Parity Error Checking Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Figure 54: #! 0ARITY %RROR #HECKING n 32% !TTEMPT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Figure 55: #! 0ARITY %RROR #HECKING n 328 !TTEMPT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Figure 56: #! 0ARITY %RROR #HECKING n 0$%0$8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Figure 57: 0ARITY %NTRY 4IMING %XAMPLE n tMRD_PAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Figure 58: 0ARITY %NTRY 4IMING %XAMPLE n tMOD_PAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Figure 59: 0ARITY %XIT 4IMING %XAMPLE n tMRD_PAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Figure 60: 0ARITY %XIT 4IMING %XAMPLE n tMOD_PAR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Figure 61: CA Parity Flow Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Figure 62: PDA Operation Enabled, BL8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Figure 63: PDA Operation Enabled, BC4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Figure 64: MRS PDA Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Figure 65: VREFDQ Voltage Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Figure 66: Example of VREF Set Tolerance and Step Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Figure 67: VREFDQ Timing Diagram for VREF,time Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Figure 68: VREFDQ Training Mode Entry and Exit Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Figure 69: VREF Step: Single Step Size Increment Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Figure 70: VREF Step: Single Step Size Decrement Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Figure 71: VREF Full Step: From VREF,min to VREF,maxCase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Figure 72: VREF Full Step: From VREF,max to VREF,minCase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Figure 73: VREFDQ Equivalent Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
Figure 74: Connectivity Test Mode Entry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
Figure 75: H002 72! n %NTRY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Figure 76: H002 72! n 2EPAIR AND %XIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
Figure 77: H002 72 n %NTRY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
Figure 78: H002 72 n 2EPAIR AND %XIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
Figure 79: S002 n %NTRY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Figure 80: S002 n 2EPAIR AND %XIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Figure 81: MBIST-PPR Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Figure 82: tRRD Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Figure 83: tFAW Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Figure 84: REFRESH Command Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
Figure 85: Postponing REFRESH Commands (Example) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
Figure 86: Pulling In REFRESH Commands (Example). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Figure 87: TCR Mode Example1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Figure 88: 4Gb with Fine Granularity Refresh Mode Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
Figure 89: OTF REFRESH Command Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Figure 90: Self Refresh Entry/Exit Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Figure 91: Self Refresh Entry/Exit Timing with CAL Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
Figure 92: Self Refresh Abort. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Figure 93: Self Refresh Exit with NOP Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
Figure 94: Active Power-Down Entry and Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Figure 95: Power-Down Entry After Read and Read with Auto Precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
Figure 96: Power-Down Entry After Write and Write with Auto Precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
Figure 97: Power-Down Entry After Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Figure 98: Precharge Power-Down Entry and Exit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Figure 99: REFRESH Command to Power-Down Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
Figure 100: Active Command to Power-Down Entry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
Figure 101: PRECHARGE/PRECHARGE ALL Command to Power-Down Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Figure 102: MRS Command to Power-Down Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Figure 103: 0OWER $OWN %NTRY%XIT #LARIFICATIONS n #ASE  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Figure 104: Active Power-Down Entry and Exit Timing with CAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
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¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM

Figure 105: REFRESH Command to Power-Down Entry with CAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164

Figure 106: ODT Power-Down Entry with ODT Buffer Disable Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
Figure 107: ODT Power-Down Exit with ODT Buffer Disable Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Figure 108: CRC Write Data Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
Figure 109: CRC Error Reporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
Figure 110: CA Parity Flow Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
Figure 111: 1tCK vs. 2tCK WRITE Preamble Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
Figure 112: 1tCK vs. 2tCK WRITE Preamble Mode, tCCD = 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
Figure 113: 1tCK vs. 2tCK WRITE Preamble Mode, tCCD = 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Figure 114: 1tCK vs. 2tCK WRITE Preamble Mode, tCCD = 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Figure 115: 1tCK vs. 2tCK READ Preamble Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
Figure 116: READ Preamble Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
Figure 117: WRITE Postamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
Figure 118: READ Postamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Figure 119: Bank Group x4/x8 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
Figure 120: READ Burst tCCD_S and tCCD_L Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
Figure 121: Write Burst tCCD_S and tCCD_L Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
Figure 122: tRRD Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
Figure 123: tWTR_S Timing (WRITE-to-READ, Different Bank Group, CRC and DM Disabled) . . . . . . . . . . . . . . . . . 190
Figure 124: tWTR_L Timing (WRITE-to-READ, Same Bank Group, CRC and DM Disabled) . . . . . . . . . . . . . . . . . . . . 190
Figure 125: Read Timing Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
Figure 126: Clock-to-Data Strobe Relationship . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
Figure 127: Data Strobe-to-Data Relationship . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
Figure 128: tLZ and tHZ Method for Calculating Transitions and Endpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
Figure 129: tRPRE Method for Calculating Transitions and Endpoints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Figure 130: tRPST Method for Calculating Transitions and Endpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
Figure 131: READ Burst Operation, RL = 11 (AL = 0, CL = 11, BL8). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
Figure 132: READ Burst Operation, RL = 21 (AL = 10, CL = 11, BL8). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
Figure 133: Consecutive READ (BL8) with 1tCK Preamble in Different Bank Group . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
Figure 134: Consecutive READ (BL8) with 2tCK Preamble in Different Bank Group . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
Figure 135: Nonconsecutive READ (BL8) with 1tCK Preamble in Same or Different Bank Group . . . . . . . . . . . . . . . 201
Figure 136: Nonconsecutive READ (BL8) with 2tCK Preamble in Same or Different Bank Group . . . . . . . . . . . . . . . 201
Figure 137: READ (BC4) to READ (BC4) with 1tCK Preamble in Different Bank Group. . . . . . . . . . . . . . . . . . . . . . . . . 202
Figure 138: READ (BC4) to READ (BC4) with 2tCK Preamble in Different Bank Group. . . . . . . . . . . . . . . . . . . . . . . . . 202
Figure 139: READ (BL8) to READ (BC4) OTF with 1tCK Preamble in Different Bank Group . . . . . . . . . . . . . . . . . . . . 203
Figure 140: READ (BL8) to READ (BC4) OTF with 2tCK Preamble in Different Bank Group . . . . . . . . . . . . . . . . . . . . 203
Figure 141: READ (BC4) to READ (BL8) OTF with 1tCK Preamble in Different Bank Group . . . . . . . . . . . . . . . . . . . . 204
Figure 142: READ (BC4) to READ (BL8) OTF with 2tCK Preamble in Different Bank Group . . . . . . . . . . . . . . . . . . . . 204
Figure 143: READ (BL8) to WRITE (BL8) with 1tCK Preamble in Same or Different Bank Group . . . . . . . . . . . . . . . . 205
Figure 144: READ (BL8) to WRITE (BL8) with 2tCK Preamble in Same or Different Bank Group . . . . . . . . . . . . . . . . 205
Figure 145: READ (BC4) OTF to WRITE (BC4) OTF with 1tCK Preamble in Same or Different Bank Group. . . . . . . 206
Figure 146: READ (BC4) OTF to WRITE (BC4) OTF with 2tCK Preamble in Same or Different Bank Group. . . . . . . 206
Figure 147: READ (BC4) Fixed to WRITE (BC4) Fixed with 1tCK Preamble in Same or Different Bank Group. . . . . 207
Figure 148: READ (BC4) Fixed to WRITE (BC4) Fixed with 2tCK Preamble in Same or Different Bank Group. . . . . 207
Figure 149: READ (BC4) to WRITE (BL8) OTF with 1tCK Preamble in Same or Different Bank Group . . . . . . . . . . . 208
Figure 150: READ (BC4) to WRITE (BL8) OTF with 2tCK Preamble in Same or Different Bank Group . . . . . . . . . . . 208
Figure 151: READ (BL8) to WRITE (BC4) OTF with 1tCK Preamble in Same or Different Bank Group . . . . . . . . . . . 209
Figure 152: READ (BL8) to WRITE (BC4) OTF with 2tCK Preamble in Same or Different Bank Group . . . . . . . . . . . 209
Figure 153: READ to PRECHARGE with 1tCK Preamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
Figure 154: READ to PRECHARGE with 2tCK Preamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
Figure 155: READ to PRECHARGE with Additive Latency and 1tCK Preamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
Figure 156: READ with Auto Precharge and 1tCK Preamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
Figure 157: READ with Auto Precharge, Additive Latency, and 1tCK Preamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
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12 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM

Figure 158: Consecutive READ (BL8) with 1tCK Preamble and DBI in Different Bank Group . . . . . . . . . . . . . . . . . . . 213
Figure 159: Consecutive READ (BL8) with 1tCK Preamble and CA Parity in Different Bank Group . . . . . . . . . . . . . . 213
Figure 160: READ (BL8) to WRITE (BL8) with 1tCK Preamble and CA Parity in Same or Different Bank Group . . . 214
Figure 161: READ (BL8) to WRITE (BL8 or BC4: OTF) with 1tCK Preamble and Write CRC in Same or Different Bank
Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
Figure 162: READ (BC4: Fixed) to WRITE (BC4: Fixed) with 1tCK Preamble and Write CRC in Same or Different Bank
Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
Figure 163: Consecutive READ (BL8) with CAL (3tCK) and 1tCK Preamble in Different Bank Group . . . . . . . . . . . . 216
Figure 164: Consecutive READ (BL8) with CAL (4tCK) and 1tCK Preamble in Different Bank Group . . . . . . . . . . . . 217
Figure 165: Write Timing Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
Figure 166: tWPRE Method for Calculating Transitions and Endpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
Figure 167: tWPST Method for Calculating Transitions and Endpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
Figure 168: Rx Compliance Mask. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
Figure 169: VCENT_DQ VREFDQ Voltage Variation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
Figure 170: Rx Mask DQ-to-DQS Timings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
Figure 171: Rx Mask DQ-to-DQS DRAM-Based Timings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224
Figure 172: Example of Data Input Requirements Without Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
Figure 173: WRITE Burst Operation, WL = 9 (AL = 0, CWL = 9, BL8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
Figure 174: WRITE Burst Operation, WL = 19 (AL = 10, CWL = 9, BL8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
Figure 175: Consecutive WRITE (BL8) with 1tCK Preamble in Different Bank Group . . . . . . . . . . . . . . . . . . . . . . . . . . 227
Figure 176: Consecutive WRITE (BL8) with 2tCK Preamble in Different Bank Group . . . . . . . . . . . . . . . . . . . . . . . . . . 227
Figure 177: Nonconsecutive WRITE (BL8) with 1tCK Preamble in Same or Different Bank Group . . . . . . . . . . . . . . 228
Figure 178: Nonconsecutive WRITE (BL8) with 2tCK Preamble in Same or Different Bank Group . . . . . . . . . . . . . . 228
Figure 179: WRITE (BC4) OTF to WRITE (BC4) OTF with 1tCK Preamble in Different Bank Group. . . . . . . . . . . . . . 229
Figure 180: WRITE (BC4) OTF to WRITE (BC4) OTF with 2tCK Preamble in Different Bank Group. . . . . . . . . . . . . . 229
Figure 181: WRITE (BC4) Fixed to WRITE (BC4) Fixed with 1tCK Preamble in Different Bank Group. . . . . . . . . . . . 230
Figure 182: WRITE (BL8) to WRITE (BC4) OTF with 1tCK Preamble in Different Bank Group . . . . . . . . . . . . . . . . . . 230
Figure 183: WRITE (BC4) OTF to WRITE (BL8) with 1tCK Preamble in Different Bank Group . . . . . . . . . . . . . . . . . . 231
Figure 184: WRITE (BL8) to READ (BL8) with 1tCK Preamble in Different Bank Group . . . . . . . . . . . . . . . . . . . . . . . . 231
Figure 185: WRITE (BL8) to READ (BL8) with 1tCK Preamble in Same Bank Group . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
Figure 186: WRITE (BC4) OTF to READ (BC4) OTF with 1tCK Preamble in Different Bank Group. . . . . . . . . . . . . . . 232
Figure 187: WRITE (BC4) OTF to READ (BC4) OTF with 1tCK Preamble in Same Bank Group . . . . . . . . . . . . . . . . . . 233
Figure 188: WRITE (BC4) Fixed to READ (BC4) Fixed with 1 tCK Preamble in Different Bank Group . . . . . . . . . . . . 233
Figure 189: WRITE (BC4) Fixed to READ (BC4) Fixed with 1tCK Preamble in Same Bank Group . . . . . . . . . . . . . . . . 234
Figure 190: WRITE (BL8/BC4-OTF) to PRECHARGE with 1tCK Preamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
Figure 191: WRITE (BC4-Fixed) to PRECHARGE with 1tCK Preamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
Figure 192: WRITE (BL8/BC4-OTF) to Auto PRECHARGE with 1tCK Preamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
Figure 193: WRITE (BC4-Fixed) to Auto PRECHARGE with 1tCK Preamble. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
Figure 194: WRITE (BL8/BC4-OTF) with 1tCK Preamble and DBI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
Figure 195: WRITE (BC4-Fixed) with 1tCK Preamble and DBI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
Figure 196: Consecutive Write (BL8) with 1tCK Preamble and CA Parity in Different Bank Group . . . . . . . . . . . . . . 238
Figure 197: Consecutive WRITE (BL8/BC4-OTF) with 1tCK Preamble and Write CRC in Same or Different Bank
Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
Figure 198: Consecutive WRITE (BC4-Fixed) with 1tCK Preamble and Write CRC in Same or Different Bank Group.
239
Figure 199: Nonconsecutive WRITE (BL8/BC4-OTF) with 1tCK Preamble and Write CRC in Same or Different Bank
Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
Figure 200: Nonconsecutive WRITE (BL8/BC4-OTF) with 2tCK Preamble and Write CRC in Same or Different Bank
Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Figure 201: WRITE (BL8/BC4-OTF/Fixed) with 1tCK Preamble and Write CRC in Same or Different Bank Group 242
Figure 202: ZQ Calibration Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
Figure 203: Functional Representation of ODT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
Figure 204: Synchronous ODT Timing with BL8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
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8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
13 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM

Figure 205: Synchronous ODT with BC4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249

Figure 206: ODT During Reads. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
Figure 207: Dynamic ODT (1t CK Preamble; CL = 14, CWL = 11, BL = 8, AL = 0, CRC Disabled) . . . . . . . . . . . . . . . . . 252
Figure 208: Dynamic ODT Overlapped with RTT(NOM) (CL = 14, CWL = 11, BL = 8, AL = 0, CRC Disabled) . . . . . . . 252
Figure 209: Asynchronous ODT Timings with DLL Off. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
Figure 210: VREFDQ Voltage Range. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
Figure 211: RESET_n Input Slew Rate Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
Figure 212: Single-Ended Input Slew Rate Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
Figure 213: DQ Slew Rate Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
Figure 214: Rx Mask Relative to tDS/tDH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
Figure 215: Rx Mask Without Write Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
Figure 216: TEN Input Slew Rate Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
Figure 217: CT Type-A Input Slew Rate Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Figure 218: CT Type-B Input Slew Rate Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Figure 219: CT Type-C Input Slew Rate Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Figure 220: CT Type-D Input Slew Rate Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
Figure 221: $IFFERENTIAL !# 3WING AND h4IME %XCEEDING !# ,EVELv tDVAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
Figure 222: Single-Ended Requirements for CK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
Figure 223: Differential Input Slew Rate Definition for CK_t, CK_c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
Figure 224: VIX(CK) Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
Figure 225: Differential Input Signal Definition for DQS_t, DQS_c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
Figure 226: DQS_t, DQS_c Input Peak Voltage Calculation and Range of Exempt non-Monotonic Signaling . . . . 278
Figure 227: VIXDQS Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279
Figure 228: Differential Input Slew Rate and Input Level Definition for DQS_t, DQS_c . . . . . . . . . . . . . . . . . . . . . . . . 280
Figure 229: ADDR, CMD, CNTL Overshoot and Undershoot Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
Figure 230: CK Overshoot and Undershoot Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
Figure 231: Data, Strobe, and Mask Overshoot and Undershoot Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Figure 232: Single-ended Output Slew Rate Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
Figure 233: Differential Output Slew Rate Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
Figure 234: Reference Load For AC Timing and Output Slew Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Figure 235: Connectivity Test Mode Reference Test Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
Figure 236: Connectivity Test Mode Output Slew Rate Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
Figure 237: Output Driver During Connectivity Test Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
Figure 238: Output Driver: Definition of Voltages and Currents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
Figure 239: Alert Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
Figure 240: ODT Definition of Voltages and Currents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
Figure 241: ODT Timing Reference Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298
Figure 242: tADC Definition with Direct ODT Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
Figure 243: tADC Definition with Dynamic ODT Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
Figure 244: tAOFAS and tAONAS Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
Figure 245: Thermal Measurement Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306
Figure 246: Measurement Setup and Test Load for IDDx, IPPx, and IDDQx. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
Figure 247: Correlation: Simulated Channel I/O Power to Actual Channel I/O Power . . . . . . . . . . . . . . . . . . . . . . . . . 308

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
14 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM

List of Tables
Table 1: Key Timing Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Table 2: Addressing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Table 3: Ball Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Table 4: State Diagram Command Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 5: Supply Power-up Slew Rate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Table 6: Address Pin Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Table 7: MR0 Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Table 8: Burst Type and Burst Order. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Table 9: Address Pin Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Table 10: MR1 Register Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Table 11: Additive Latency (AL) Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Table 12: TDQS Function Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Table 13: Address Pin Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Table 14: MR2 Register Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Table 15: Address Pin Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Table 16: MR3 Register Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Table 17: Address Pin Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Table 18: MR4 Register Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Table 19: Address Pin Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Table 20: MR5 Register Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Table 21: Address Pin Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Table 22: MR6 Register Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Table 23: 4RUTH 4ABLE n #OMMAND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Table 24: 4RUTH 4ABLE n #+% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Table 25: MR Settings for Leveling Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Table 26: DRAM TERMINATION Function in Leveling Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Table 27: Auto Self Refresh Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Table 28: MR3 Setting for the MPR Access Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Table 29: DRAM Address to MPR UI Translation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Table 30: MPR Page and MPRx Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Table 31: MPR Readout Serial Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Table 32: -02 2EADOUT n 0ARALLEL &ORMAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Table 33: MPR Readout Staggered Format, x4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Table 34: -02 2EADOUT 3TAGGERED &ORMAT X n #ONSECUTIVE 2%!$S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Table 35: MPR Readout Staggered Format, x8 and x16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Table 36: Mode Register Setting for CA Parity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Table 37: VREFDQ Range and Levels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Table 38: VREFDQ Settings (VDDQ = 1.2V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Table 39: Connectivity Mode Pin Description and Switching Levels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Table 40: MAC Encoding of MPR Page 3 MPR3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Table 41: PPR MR0 Guard Key Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Table 42: DDR4 hPPR Timing Parameters DDR4-1600 through DDR4-3200 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
Table 43: sPPR Associated Rows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Table 44: PPR MR0 Guard Key Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Table 45: DDR4 sPPR Timing Parameters DDR4-1600 Through DDR4-3200 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Table 46: MBIST-PPR Timing Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Table 47: MPR Page3 Configuration for MBIST-PPR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Table 48: DDR4 Repair Mode Support Identifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Table 49: Normal tREFI Refresh (TCR Enabled) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Table 50: MRS Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Table 51: REFRESH Command Truth Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
15 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM

Table 52: tREFI and tRFC Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

Table 53: Power-Down Entry Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Table 54: CRC Error Detection Coverage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
Table 55: CRC Data Mapping for x4 Devices, BL8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
Table 56: CRC Data Mapping for x8 Devices, BL8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
Table 57: CRC Data Mapping for x16 Devices, BL8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
Table 58: CRC Data Mapping for x4 Devices, BC4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
Table 59: CRC Data Mapping for x8 Devices, BC4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
Table 60: CRC Data Mapping for x16 Devices, BC4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
Table 61: DBI vs. DM vs. TDQS Function Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
Table 62: DBI Write, DQ Frame Format (x8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
Table 63: DBI Write, DQ Frame Format (x16) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
Table 64: DBI Read, DQ Frame Format (x8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
Table 65: DBI Read, DQ Frame Format (x16) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
Table 66: DM vs. TDQS vs. DBI Function Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Table 67: Data Mask, DQ Frame Format (x8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Table 68: Data Mask, DQ Frame Format (x16) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Table 69: CWL Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
Table 70: DDR4 Bank Group Timing Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
Table 71: Read-to-Write and Write-to-Read Command Intervals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
Table 72: Termination State Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
Table 73: Read Termination Disable Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
Table 74: ODT Latency at DDR4-1600/-1866/-2133/-2400/-2666/-3200 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
Table 75: Dynamic ODT Latencies and Timing (1tCK Preamble Mode and CRC Disabled). . . . . . . . . . . . . . . . . . . . . 251
Table 76: Dynamic ODT Latencies and Timing with Preamble Mode and CRC Mode Matrix. . . . . . . . . . . . . . . . . . . 252
Table 77: Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
Table 78: Temperature Range. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
Table 79: Recommended Supply Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
Table 80: VDD Slew Rate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
Table 81: Leakages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
Table 82: VREFDQ Specification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
Table 83: VREFDQ Range and Levels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
Table 84: RESET_n Input Levels (CMOS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
Table 85: Command and Address Input Levels: DDR4-1600 Through DDR4-2400 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
Table 86: Command and Address Input Levels: DDR4-2666. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
Table 87: Command and Address Input Levels: DDR4-2933 and DDR4-3200 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
Table 88: Single-Ended Input Slew Rates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
Table 89: #OMMAND AND !DDRESS 3ETUP AND (OLD 6ALUES 2EFERENCED n !#$# "ASED . . . . . . . . . . . . . . . . . . . . . . . . 263
Table 90: Derating Values for tIS/t)( n !#$# "ASED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
Table 91: Derating Values for tIS/t)( n !#$# "ASED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
Table 92: DQ Input Receiver Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
Table 93: Rx Mask and tDS/tDH without Write Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
Table 94: TEN Input Levels (CMOS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
Table 95: CT Type-A Input Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
Table 96: CT Type-B Input Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Table 97: CT Type-C Input Levels (CMOS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Table 98: CT Type-D Input Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Table 99: Differential Input Swing Requirements for CK_t, CK_c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
Table 100: Minimum Time AC Time tDVAC for CK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
Table 101: Single-Ended Requirements for CK. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
Table 102: CK Differential Input Slew Rate Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
Table 103: Cross Point Voltage For CK Differential Input Signals at DDR4-1600 through DDR4-2400 . . . . . . . . . . . 276
Table 104: Cross Point Voltage For CK Differential Input Signals at DDR4-2666 through DDR4-3200 . . . . . . . . . . . 276
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16 Micron Technology, Inc. reserves the right to change products or specifications without notice.
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 8Gb: x4, x8, x16 DDR4 SDRAM

Table 105: DDR4-1600 through DDR4-2400 Differential Input Swing Requirements for DQS_t, DQS_c . . . . . . . . . 277
Table 106: DDR4-2633 through DDR4-3200 Differential Input Swing Requirements for DQS_t, DQS_c . . . . . . . . . 277
Table 107: Cross Point Voltage For Differential Input Signals DQS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279
Table 108: DQS Differential Input Slew Rate Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
Table 109: DDR4-1600 through DDR4-2400 Differential Input Slew Rate and Input Levels for DQS_t, DQS_c . . . 280
Table 110: DDR4-2666 through DDR4-3200 Differential Input Slew Rate and Input Levels for DQS_t, DQS_c . . . 281
Table 111: ADDR, CMD, CNTL Overshoot and Undershoot/Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
Table 112: CK Overshoot and Undershoot/ Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
Table 113: Data, Strobe, and Mask Overshoot and Undershoot/ Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Table 114: Single-Ended Output Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
Table 115: Single-Ended Output Slew Rate Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
Table 116: Single-Ended Output Slew Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
Table 117: Differential Output Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
Table 118: Differential Output Slew Rate Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
Table 119: Differential Output Slew Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Table 120: Connectivity Test Mode Output Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Table 121: Connectivity Test Mode Output Slew Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
Table 122: Output Driver Electrical Characteristics During Connectivity Test Mode . . . . . . . . . . . . . . . . . . . . . . . . . . 291
Table 123: Strong Mode (34?) Output Driver Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292
Table 124: Weak Mode (48?) Output Driver Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
Table 125: Output Driver Sensitivity Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
Table 126: Output Driver Voltage and Temperature Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
Table 127: Alert Driver Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295
Table 128: ODT DC Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
Table 129: ODT Sensitivity Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
Table 130: ODT Voltage and Temperature Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298
Table 131: ODT Timing Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298
Table 132: Reference Settings for ODT Timing Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
Table 133: DRAM Package Electrical Specifications for x4 and x8 Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
Table 134: DRAM Package Electrical Specifications for x16 Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302
Table 135: Pad Input/Output Capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
Table 136: Thermal Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
Table 137: Basic IDD, IPP, and IDDQ Measurement Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
Table 138: IDD0 and IPP0 Measurement-Loop Pattern1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312
Table 139: IDD1 -EASUREMENT n ,OOP 0ATTERN1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
Table 140: IDD2N, IDD3N, and IPP3P -EASUREMENT n ,OOP 0ATTERN1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314
Table 141: IDD2NT -EASUREMENT n ,OOP 0ATTERN1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316
Table 142: IDD4R -EASUREMENT n ,OOP 0ATTERN1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317
Table 143: IDD4W -EASUREMENT n ,OOP 0ATTERN1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
Table 144: IDD4Wc -EASUREMENT n ,OOP 0ATTERN1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319
Table 145: IDD5R -EASUREMENT n ,OOP 0ATTERN1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
Table 146: IDD7 -EASUREMENT n ,OOP 0ATTERN1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
Table 147: Timings used for IDD, IPP, and IDDQ -EASUREMENT n ,OOP 0ATTERNS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Table 148: IDD, IPP, and IDDQ Current Limits; Die Rev. A (0— ? TC ? 85—C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Table 149: IDD, IPP, and IDDQ Current Limits; Die Rev. B (0— ? TC ? 85—C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Table 150: IDD, IPP, and IDDQ Current Limits; Die Rev. D (0— ? TC ? 85—C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
Table 151: IDD, IPP, and IDDQ Current Limits; Die Rev. E (-40— ? TC ? 85—C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Table 152: IDD, IPP, and IDDQ Current Limits; Die Rev. E (-40— ? TC ? 105—C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
Table 153: IDD, IPP, and IDDQ Current Limits; Die Rev. G (0— ? TC ? 85—C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334
Table 154: IDD, IPP, and IDDQ Current Limits; Die Rev. H (0— ? TC ? 85—C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
Table 155: IDD, IPP, and IDDQ Current Limits; Die Rev. J (-40— ? TC ? 85—C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338
Table 156: IDD, IPP, and IDDQ Current Limits; Die Rev. R (-40— ? TC ? 85—C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
Table 157: Backward Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345
CCMTD-1725822587-9875
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17 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM

Table 158: DDR4-1600 Speed Bins and Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346

Table 159: DDR4-1866 Speed Bins and Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
Table 160: DDR4-2133 Speed Bins and Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
Table 161: DDR4-2400 Speed Bins and Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352
Table 162: DDR4-2666 Speed Bins and Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354
Table 163: DDR4-2933 Speed Bins and Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Table 164: DDR4-3200 Speed Bins and Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358
Table 165: Refresh Parameters by Device Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360
Table 166: Electrical Characteristics and AC Timing Parameters: DDR4-1600 through DDR4-2400 . . . . . . . . . . . . . 361
Table 167: Electrical Characteristics and AC Timing Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374
Table 168: /PTIONS n 3PEED "ASED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 390
Table 169: /PTIONS n 7IDTH "ASED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
18 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
Important Notes and Warnings

Important Notes and Warnings

Micron Technology, Inc. ("Micron") reserves the right to make changes to information published in this document,
including without limitation specifications and product descriptions. This document supersedes and replaces all
information supplied prior to the publication hereof. You may not rely on any information set forth in this document
if you obtain the product described herein from any unauthorized distributor or other source not authorized by
Micron.
Automotive Applications. Products are not designed or intended for use in automotive applications unless specifi-
cally designated by Micron as automotive-grade by their respective data sheets. Distributor and customer/distrib-
utor shall assume the sole risk and liability for and shall indemnify and hold Micron harmless against all claims,
costs, damages, and expenses and reasonable attorneys' fees arising out of, directly or indirectly, any claim of
product liability, personal injury, death, or property damage resulting directly or indirectly from any use of
non-automotive-grade products in automotive applications. Customer/distributor shall ensure that the terms and
conditions of sale between customer/distributor and any customer of distributor/customer (1) state that Micron
products are not designed or intended for use in automotive applications unless specifically designated by Micron
as automotive-grade by their respective data sheets and (2) require such customer of distributor/customer to
indemnify and hold Micron harmless against all claims, costs, damages, and expenses and reasonable attorneys'
fees arising out of, directly or indirectly, any claim of product liability, personal injury, death, or property damage
resulting from any use of non-automotive-grade products in automotive applications.
Critical Applications. Products are not authorized for use in applications in which failure of the Micron component
could result, directly or indirectly in death, personal injury, or severe property or environmental damage ("Critical
Applications"). Customer must protect against death, personal injury, and severe property and environmental
damage by incorporating safety design measures into customer's applications to ensure that failure of the Micron
component will not result in such harms. Should customer or distributor purchase, use, or sell any Micron compo-
nent for any critical application, customer and distributor shall indemnify and hold harmless Micron and its subsid-
iaries, subcontractors, and affiliates and the directors, officers, and employees of each against all claims, costs,
damages, and expenses and reasonable attorneys' fees arising out of, directly or indirectly, any claim of product
liability, personal injury, or death arising in any way out of such critical application, whether or not Micron or its
subsidiaries, subcontractors, or affiliates were negligent in the design, manufacture, or warning of the Micron
product.
Customer Responsibility. Customers are responsible for the design, manufacture, and operation of their systems,
applications, and products using Micron products. ALL SEMICONDUCTOR PRODUCTS HAVE INHERENT
FAILURE RATES AND LIMITED USEFUL LIVES. IT IS THE CUSTOMER'S SOLE RESPONSIBILITY TO DETERMINE
WHETHER THE MICRON PRODUCT IS SUITABLE AND FIT FOR THE CUSTOMER'S SYSTEM, APPLICATION, OR
PRODUCT. Customers must ensure that adequate design, manufacturing, and operating safeguards are included in
customer's applications and products to eliminate the risk that personal injury, death, or severe property or envi-
ronmental damages will result from failure of any semiconductor component.
Limited Warranty. In no event shall Micron be liable for any indirect, incidental, punitive, special or consequential
damages (including without limitation lost profits, lost savings, business interruption, costs related to the removal
or replacement of any products or rework charges) whether or not such damages are based on tort, warranty, breach
of contract or other legal theory, unless explicitly stated in a written agreement executed by Micron's duly autho-
rized representative.

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19 Micron Technology, Inc. reserves the right to change products or specifications without notice.
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 8Gb: x4, x8, x16 DDR4 SDRAM
General Notes and Description

General Notes and Description

Description
The DDR4 SDRAM is a high-speed dynamic random-access memory internally configured as an
eight-bank DRAM for the x16 configuration and as a 16-bank DRAM for the x4 and x8 configurations.
The DDR4 SDRAM uses an 8n-prefetch architecture to achieve high-speed operation. The 8n-prefetch
architecture is combined with an interface designed to transfer two data words per clock cycle at the
I/O pins.
A single READ or WRITE operation for the DDR4 SDRAM consists of a single 8n-bit wide, four-clock
data transfer at the internal DRAM core and two corresponding n-bit wide, one-half-clock-cycle data
transfers at the I/O pins.

Industrial Temperature
An industrial temperature (IT) device option requires that the case temperature not exceed below
nιC or above 95ιC. JEDEC specifications require the refresh rate to double when TC exceeds 85ιC;
this also requires use of the high-temperature self refresh option. Additionally, ODT resistance and the
input/output impedance must be derated when operating outside of the commercial temperature
range, when TC IS BETWEEN nιC and 0ιC.

Automotive Temperature
The automotive temperature (AT) device option requires that the case temperature not exceed below
nιC or above 105ιC. The specifications require the refresh rate to 2X when TC exceeds 85ιC; 4X when
TC exceeds 95ιC. Additionally, ODT resistance and the input/output impedance must be derated when
operating temperature Tc <0ιC.

General Notes
s The functionality and the timing specifications discussed in this data sheet are for the DLL enable
mode of operation (normal operation), unless specifically stated otherwise.
s Throughout the data sheet, the various figures and text refer to DQs as "DQ." The DQ term is to be
interpreted as any and all DQ collectively, unless specifically stated otherwise.
s The terms "_t" and "_c" are used to represent the true and complement of a differential signal pair.
These terms replace the previously used notation of "#" and/or overbar characters. For example,
differential data strobe pair DQS, DQS# is now referred to as DQS_t, DQS_c.
s The term "_n" is used to represent a signal that is active LOW and replaces the previously used "#"
and/or overbar characters. For example: CS# is now referred to as CS_n.
s The terms "DQS" and "CK" found throughout the data sheet are to be interpreted as DQS_t, DQS_c
and CK_t, CK_c respectively, unless specifically stated otherwise.
s Complete functionality may be described throughout the entire document; any page or diagram may
have been simplified to convey a topic and may not be inclusive of all requirements.
s Any specific requirement takes precedence over a general statement.
s Any functionality not specifically stated here within is considered undefined, illegal, and not
supported, and can result in unknown operation.
s Addressing is denoted as BG[n] for bank group, BA[n] for bank address, and A[n] for row/col address.
s The NOP command is not allowed, except when exiting maximum power savings mode or when
entering gear-down mode, and only a DES command should be used.
s Not all features described within this document may be available on the Rev. A (first) version.

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 8Gb: x4, x8, x16 DDR4 SDRAM
General Notes and Description

s Not all specifications listed are finalized industry standards; best conservative estimates have been
provided when an industry standard has not been finalized.
s Although it is implied throughout the specification, the DRAM must be used after VDD has reached
the stable power-on level, which is achieved by toggling CKE at least once every 8192 έ tREFI.
However, in the event CKE is fixed HIGH, toggling CS_n at least once every 8192 έ tREFI is an accept-
able alternative. Placing the DRAM into self refresh mode also alleviates the need to toggle CKE.
s Not all features designated in the data sheet may be supported by earlier die revisions due to late
definition by JEDEC.
s A x16 device's DQ bus is comprised of two bytes. If only one of the bytes needs to be used, use the
lower byte for data transfers and terminate the upper byte as noted:
n Connect UDQS_t to VDDQ or VSS/ VSSQ via a resistor in the 200π range.
n Connect UDQS_c to the opposite rail via a resistor in the same 200π range.
n Connect UDM to VDDQ via a large (10,000π) pull-up resistor.
n Connect UDBI to VDDQ via a large (10,000π) pull-up resistor.
n Connect DQ [15:8] individually to VDDQ via a large (10,000π) resistors, or float DQ [15:8] .

Definitions of the Device-Pin Signal Level

s HIGH: A device pin is driving the logic 1 state.
s LOW: A device pin is driving the logic 0 state.
s High-Z: A device pin is tri-state.
s ODT: A device pin terminates with the ODT setting, which could be terminating or tri-state
depending on the mode register setting.

Definitions of the Bus Signal Level

s HIGH: One device on the bus is HIGH, and all other devices on the bus are either ODT or High-Z. The
voltage level on the bus is nominally VDDQ.
s LOW: One device on the bus is LOW, and all other devices on the bus are either ODT or High-Z. The
voltage level on the bus is nominally VOL(DC) if ODT was enabled, or VSSQ if High-Z.
s High-Z: All devices on the bus are High-Z. The voltage level on the bus is undefined as the bus is
floating.
s ODT: At least one device on the bus is ODT, and all others are High-Z. The voltage level on the bus is
nominally VDDQ.
s The specification requires 8,192 refresh commands within 64ms between 0oC and 85oC. This allows
for a tREFI of 7.8125ρs (the use of "7.8ρs" is truncated from 7.8125ρs). The specification also requires
8,192 refresh commands within 32ms between 85oC and 95oC. This allows for a tREFI of 3.90625ρs
(the use of "3.9ρs" is truncated from 3.90625ρs).

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 8Gb: x4, x8, x16 DDR4 SDRAM
Functional Block Diagrams

Functional Block Diagrams

DDR4 SDRAM is a high-speed, CMOS dynamic random access memory. It is internally configured as
an 16-bank (4-banks per Bank Group) DRAM.

Figure 2: 2 Gig x 4 Functional Block Diagram

Bank 3 Bank 3
Bank 2 CRC and ALERT
ODT To ODT/output drivers Bank 2
Bank 1 Bank 1 parity control VDDQ
Bank 0 Bank 0
ZQ CAL BG3 Bank Group 3
To ZQ Control
Bank 3 Bank 3
RESET_n VrefDQ Bank 2
Bank 2 ZQ
Control BC4 Bank 1 Bank 1 control
CKE logic OTF Bank 0 Bank 0
BG2 Bank Group 2
CK_t, CK_c CRC
ODT
Parity Bank 3 control ZQ
PAR Bank 3
Bank 2 Bank 2 ers
Sense amplifiers
Bank 1 Bank 1
TEN 2 (A12,A10)
Bank 0 Bank 0 16384 VDDQ
16384
BG1 Bank Group 1 CK_t,CK_c
CS_n Command decode
3 (A16,A15,A14) Bank 3 Bank 3 RTTp RTTn RTTw
ACT_n RAS_n, CAS_n, WE_n Bank 2 Bank 2 Sense amplifiers
Bank 1 Bank 1
Bank 0 DLL
Mode registers Bank 0
BG0 Bank Group 0
17 (0 . . . 3)
Row-
21 address 131,072 Memory
Sense amplifiers (256 Columns DQ[3:0]
17 Row- latch array x64)
address 0, 1, and 2 Read DQ[3:0]
and (131,072 x 128 x 32) 4 DQS_t / DQS_c
MUX decoder drivers
16384
16384
Refresh 17
counter
Sense amplifiers 32 READ VDDQ
FIFO
2 4 and RTTp RTTn RTTw
4096 32 BC4 DBI
4 data
2 BG 4 MUX
BC4
and 4 OTF CRC
BA (256
2 I/O gating Global
control x64) Write
DM mask logic I/O gating
A[16:0] logic drivers
BA[1:0] Address 2 CK_t,CK_c DQS_t /
21 register and
BG[1:0] input DQS_c
128 4 logic VDDQ
16
x32 32

RTTp RTTn RTTw

7 Data
Column Column interface Column 2
address decoder (BC4 nibble)
10 counter/
latch 3
VrefDQ
Columns 0, 1, and 2
DBI_n /
DM_n

Figure 3: 1 Gig x 8 Functional Block Diagram

Bank 3 Bank 3
Bank 2 CRC and ALERT
ODT To ODT/output drivers Bank 2
Bank 1 Bank 1 parity control VDDQ
Bank 0 Bank 0
ZQ CAL BG3 Bank Group 3
To ZQ Control
Bank 3 Bank 3
RESET_n VrefDQ Bank 2
Bank 2 ZQ
Control BC4 Bank 1 Bank 1 control
CKE logic OTF Bank 0 Bank 0
BG2 Bank Group 2
CK_t, CK_c CRC
ODT
Parity Bank 3 control ZQ
PAR Bank 3
Bank 2 Bank 2 ers
Sense amplifiers
Bank 1 Bank 1
TEN 2 (A12,A10)
Bank 0 Bank 0 16384 VDDQ
16384
BG1 Bank Group 1 CK_t,CK_c
CS_n Command decode
3 (A16,A15,A14) Bank 3 Bank 3 RTTp RTTn RTTw
ACT_n RAS_n, CAS_n, WE_n Bank 2 Bank 2 Sense amplifiers
Bank 1 Bank 1
Bank 0 DLL
Mode registers Bank 0
BG0 Bank Group 0
16 (0 . . . 7)
Row-
20 address 65,536 Memory
Sense amplifiers (256 Columns DQ[7:0]
16 Row- latch array x64)
address (65,536 x 128 x 64) 0, 1, and 2 Read DQ[7:0]
and 8 DQS_t / DQS_c
MUX decoder drivers
16384
16384
Refresh 16
counter
Sense amplifiers 64 READ VDDQ
FIFO
2 4 and RTTp RTTn RTTw
8192 64 BC4 DBI
4 data
2 BG 4 MUX
BC4
and 4 OTF CRC
BA (256
2 I/O gating Global
control x64) Write
DM mask logic I/O gating
A[15:0] logic drivers
BA[1:0] Address 2 CK_t,CK_c DQS_t /
20 register and
BG[1:0] input DQS_c
128 8 logic VDDQ
16
x64 64

RTTp RTTn RTTw

7 Data
Column Column interface Column 2
address decoder (BC4 nibble)
10 counter/
latch 3
VrefDQ
TDQS_c
Columns 0, 1, and 2
DBI_n /
DM_n /
TDQS_t

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 8Gb: x4, x8, x16 DDR4 SDRAM
Functional Block Diagrams

Figure 4: 512 Meg x 16 Functional Block Diagram

CRC and ALERT

ODT To ODT/output drivers parity control VDDQ

ZQ CAL To ZQ Control
RESET_n VrefDQ ZQ
Control BC4 control
CKE logic OTF
CK_t, CK_c CRC
ODT
Parity Bank 3 control ZQ
PAR Bank 3
Bank 2 Bank 2
Bank 1 Bank 1
TEN 2 (A12,A10)
Bank 0 Bank 0 VDDQ
BG1 Bank Group 1 CK_t,CK_c
CS_n Command decode
3 (A16,A15,A14) Bank 3 Bank 3 RTTp RTTn RTTw
ACT_n RAS_n, CAS_n, WE_n Bank 2 Bank 2
Bank 1 Bank 1
Bank 0 DLL
Mode registers Bank 0
BG0 Bank Group 0
16 (0 . . . 15)
Row-
19 address 65,536 Memory DQ[7:0]
Sense amplifiers Columns DQ[15:0]
16 Row- latch array
address (65,536 x 128 x 128) 0, 1, and 2 Read
and 16 LDQS_t / LDQS_c; UDQS_t / UDQS_c DQ[15:8]
MUX decoder drivers
16384
16384
Refresh 16
counter
Sense amplifiers 128 VDDQ
READ
2 4 FIFO
16384 128 and BC4 DBI RTTp RTTn RTTw
4
1 BG data
BC4
and MUX
OTF CRC
BA (256 LDQS_t /
2 I/O gating Global
control x64) Write LDQS_c
DM mask logic I/O gating
A[15:0] logic drivers
BA[1:0] Address 1 CK_t,CK_c
19 and UDQS_t /
BG[0] register
input UDQS_c
128 16 logic VDDQ
8
x128 128

RTTp RTTn RTTw

7 Data
Column Column interface Column 2
address decoder (BC4 nibble)
10 counter/
latch 3 LDBI_n /
VrefDQ
LDM_n
Columns 0, 1, and 2
UDBI_n /
UDM_n

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 8Gb: x4, x8, x16 DDR4 SDRAM
Ball Assignments

Ball Assignments
Figure 5: 78-Ball x4, x8 Ball Assignments
1 2 3 4 5 6 7 8 9
A A
VDD VSSQ NF, NF/ NF, NF/DM_n/ VSSQ VSS
TDQS_c DBI_n/TDQS_t
B B
VPP VDDQ DQS_c DQ1 VDDQ ZQ
C C
VDDQ DQ0 DQS_t VDD VSS VDDQ
D D
VSSQ NF,DQ4 DQ2 DQ3 NF,DQ5 VSSQ
E E
VSS VDDQ NF,DQ6 NF,DQ7 VDDQ VSS
F F
VDD C2/ODT1/NC ODT CK_t CK_c VDD
G G
VSS C0/CKE1/NC CKE CS_n C1/CS1_n/NC TEN/NF

H H
VDD WE_n/ ACT_n CAS_n/ RAS_n/ VSS
A14 A15 A16
J J
VREFCA BG0 A10/AP A12/BC_n BG1 VDD
K K
VSS BA0 A4 A3 BA1 VSS
L L
RESET_n A6 A0 A1 A5 ALERT_n
M M
VDD A8 A2 A9 A7 VPP
N N
VSS A11 PAR A17/NF/NC, A13 VDD
NF/NC

Notes: 1. See Ball Descriptions.

2. ! COMMA h v SEPARATES THE CONFIGURATION A SLASH hv DEFINES A MODE REGISTER SELECTABLE FUNCTION
command/address function, density, or package dependence.
3. Address bits (including bank groups) are density- and configuration-dependent (see Addressing).

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 8Gb: x4, x8, x16 DDR4 SDRAM
Ball Assignments

Figure 6: 96-Ball x16 Ball Assignments

1 2 3 4 5 6 7 8 9

A A
VDDQ VSSQ DQ8 UDQS_c VSSQ VDDQ
B B
VPP VSS VDD UDQS_t DQ9 VDD
C C
VDDQ DQ12 DQ10 DQ11 DQ13 VSSQ
D D
VDD VSSQ DQ14 DQ15 VSSQ VDDQ
E E
NF/UDM_n/ NF/LDM_n/
VSS UDBI_n
VSSQ LDBI_n VSSQ VSS
F F
VSSQ VDDQ LDQS_c DQ1 VDDQ ZQ
G G
VDDQ DQ0 LDQS_t VDD VSS VDDQ
H H
VSSQ DQ4 DQ2 DQ3 DQ5 VSSQ
J J
VDD VDDQ DQ6 DQ7 VDDQ VDD
K K
VSS CKE ODT CK_t CK_c VSS
L L
WE_n/ RAS_n/
VDD A14
ACT_n CS_n A16 VDD
M M
VREFCA BG0 A10/AP A12/BC_n CAS_n/ VSS
A15
N N
VSS BA0 A4 A3 BA1 TEN
P P
RESET_n A6 A0 A1 A5 ALERT_n

R R
VDD A8 A2 A9 A7 VPP
T T
VSS A11 PAR NF/NC A13 VDD

Notes: 1. See Ball Descriptions.

2. ! SLASH hv DEFINES A MODE REGISTER SELECTABLE FUNCTION COMMANDADDRESS FUNCTION DENSITY OR PACKAGE DEPEN-
dence.
3. Address bits (including bank groups) are density- and configuration-dependent (see Addressing).

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 8Gb: x4, x8, x16 DDR4 SDRAM
Ball Descriptions

Ball Descriptions
The pin description table below is a comprehensive list of all possible pins for DDR4 devices. All pins
listed may not be supported on the device defined in this data sheet. See the Ball Assignments section
to review all pins used on this device.

Table 3: Ball Descriptions

Symbol Type Description
A[17:0] Input Address inputs: Provide the row address for ACTIVATE commands and the column
address for READ/WRITE commands to select one location out of the memory array in
the respective bank. (A10/AP, A12/BC_n, WE_n/A14, CAS_n/A15, RAS_n/A16 have addi-
tional functions, see individual entries in this table.) The address inputs also provide
the op-code during the MODE REGISTER SET command. A16 is used on some 8Gb and
16Gb parts. A17 connection is part-number specific; Contact vendor for more informa-
tion.
A10/AP Input Auto precharge: A10 is sampled during READ and WRITE commands to determine
whether auto precharge should be performed to the accessed bank after a READ or
WRITE operation. (HIGH = auto precharge; LOW = no auto precharge.) A10 is sampled
during a PRECHARGE command to determine whether the PRECHARGE applies to one
bank (A10 LOW) or all banks (A10 HIGH). If only one bank is to be precharged, the
bank is selected by the bank group and bank addresses.
A12/BC_n Input Burst chop: A12/BC_n is sampled during READ and WRITE commands to determine if
burst chop (on-the-fly) will be performed. (HIGH = no burst chop; LOW = burst
chopped). See the Command Truth Table.
ACT_n Input Command input: ACT_n indicates an ACTIVATE command. When ACT_n (along with
CS_n) is LOW, the input pins RAS_n/A16, CAS_n/A15, and WE_n/A14 are treated as row
address inputs for the ACTIVATE command. When ACT_n is HIGH (along with CS_n
LOW), the input pins RAS_n/ A16, CAS_n/A15, and WE_n/A14 are treated as normal
commands that use the RAS_n, CAS_n, and WE_n signals. See the Command Truth
Table.
BA[1:0] Input Bank address inputs: Define the bank (within a bank group) to which an ACTIVATE,
READ, WRITE, or PRECHARGE command is being applied. Also determines which
mode register is to be accessed during a MODE REGISTER SET command.
BG[1:0] Input Bank group address inputs: Define the bank group to which an ACTIVATE, READ,
WRITE, or PRECHARGE command is being applied. Also determines which mode regis-
ter is to be accessed during a MODE REGISTER SET command. BG[1:0] are used in the
x4 and x8 configurations. BG1 is not used in the x16 configuration.
C0/CKE1, Input Stack address inputs: These inputs are used only when devices are stacked; that is,
C1/CS1_n, they are used in 2H, 4H, and 8H stacks for x4 and x8 configurations (these pins are not
C2/ODT1 used in the x16 configuration, and are NC on the x4/x8 SDP). DDR4 will support a tra-
ditional DDP package, which uses these three signals for control of the second die
(CS1_n, CKE1, ODT1). DDR4 is not expected to support a traditional QDP package. For
all other stack configurations, such as a 4H or 8H, it is assumed to be a single-load
(master/slave) type of configuration where C0, C1, and C2 are used as chip ID selects in
conjunction with a single CS_n, CKE, and ODT signal.
CK_t, Input Clock: Differential clock inputs. All address, command, and control input signals are
CK_c sampled on the crossing of the positive edge of CK_t and the negative edge of CK_c.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Ball Descriptions

Table 3: Ball Descriptions (Continued)

Symbol Type Description
CKE Input Clock enable: CKE HIGH activates and CKE LOW deactivates the internal clock sig-
nals, device input buffers, and output drivers. Taking CKE LOW provides PRECHARGE
POWER-DOWN and SELF REFRESH operations (all banks idle), or active power-down
(row active in any bank). CKE is asynchronous for self refresh exit, however, timing
parameters such as tXS are still calculated from the first rising clock edge where CKE
HIGH satisfies tIS. After VREFCA has become stable during the power-on and initializa-
tion sequence, it must be maintained during all operations (including SELF REFRESH).
CKE must be maintained HIGH throughout read and write accesses. Input buffers
(excluding CK_t, CK_c, ODT, RESET_n, and CKE) are disabled during power-down.
Input buffers (excluding CKE and RESET_n) are disabled during self refresh.
CS_n Input Chip select: All commands are masked when CS_n is registered HIGH. CS_n provides
for external rank selection on systems with multiple ranks. CS_n is considered part of
the command code.
DM_n, Input Input data mask: DM_n is an input mask signal for write data. Input data is masked
UDM_n when DM is sampled LOW coincident with that input data during a write access. DM is
LDM_n sampled on both edges of DQS. DM is not supported on x4 configurations. The
UDM_n and LDM_n pins are used in the x16 configuration: UDM_n is associated with
DQ[15:8]; LDM_n is associated with DQ[7:0]. The DM, DBI, and TDQS functions are
enabled by mode register settings. See the Data Mask section.
ODT Input On-die termination: ODT (registered HIGH) enables termination resistance internal
to the DDR4 SDRAM. When enabled, ODT (RTT) is applied only to each DQ, DQS_t,
DQS_c, DM_n/DBI_n/TDQS_t, and TDQS_c signal for the x4 and x8 configurations
(when the TDQS function is enabled via mode register). For the x16 configuration, RTT
is applied to each DQ, UDQS_t, UDQS_c, LDQS_t, LDQS_c, UDM_n, and LDM_n signal.
The ODT pin will be ignored if the mode registers are programmed to disable RTT.
PAR Input Parity for command and address: This function can be enabled or disabled via the
mode register. When enabled, the parity signal covers all command and address
inputs, including ACT_n, RAS_n/A16, CAS_n/A15, WE_n/A14, A[17:0], A10/AP,
A12/BC_n, BA[1:0], and BG[1:0] with C0, C1, and C2 on 3DS only devices. Control pins
NOT covered by the parity signal are CS_n, CKE, and ODT. Unused address pins that
are density- and configuration-specific should be treated internally as 0s by the DRAM
parity logic. Command and address inputs will have parity check performed when
commands are latched via the rising edge of CK_t and when CS_n is LOW.
RAS_n/A16, Input Command inputs: RAS_n/A16, CAS_n/A15, and WE_n/A14 (along with CS_n and
CAS_n/A15, ACT_n) define the command and/or address being entered. See the ACT_n description
WE_n/A14 in this table.
RESET_n Input Active LOW asynchronous reset: Reset is active when RESET_n is LOW, and inac-
tive when RESET_n is HIGH. RESET_n must be HIGH during normal operation. RESET_n
is a CMOS rail-to-rail signal with DC HIGH and LOW at 80% and 20% of VDD (960 mV
for DC HIGH and 240 mV for DC LOW).
TEN Input Connectivity test mode: TEN is active when HIGH and inactive when LOW. TEN
must be LOW during normal operation. TEN is a CMOS rail-to-rail signal with DC HIGH
and LOW at 80% and 20% of VDD (960mV for DC HIGH and 240mV for DC LOW). On
Micron 3DS devices, connectivity test mode is not supported and the TEN pin should
be considered NF maintained LOW at all times.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Ball Descriptions

Table 3: Ball Descriptions (Continued)

Symbol Type Description
DQ I/O Data input/output: Bidirectional data bus. DQ represents DQ[3:0], DQ[7:0], and
DQ[15:0] for the x4, x8, and x16 configurations, respectively. If write CRC is enabled
via mode register, the write CRC code is added at the end of data burst. Any one or all
of DQ0, DQ1, DQ2, and DQ3 may be used to monitor the internal V REF level during
test via mode register setting MR[4] A[4] = HIGH, training times change when
enabled. During this mode, the RTT value should be set to High-Z. This measurement is
for verification purposes and is NOT an external voltage supply pin.
DBI_n, I/O DBI input/output: Data bus inversion. DBI_n is an input/output signal used for data
UDBI_n, bus inversion in the x8 configuration. UDBI_n and LDBI_n are used in the x16 configu-
LDBI_n ration; UDBI_n is associated with DQ[15:8], and LDBI_n is associated with DQ[7:0]. The
DBI feature is not supported on the x4 configuration. DBI is not supported for 3DS
devices and should be disabled in MR5. DBI can be configured for both READ (output)
and WRITE (input) operations depending on the mode register settings. The DM, DBI,
and TDQS functions are enabled by mode register settings. See the Data Bus Inversion
section.
DQS_t, I/O Data strobe: Output with READ data, input with WRITE data. Edge-aligned with
DQS_c, READ data, centered-aligned with WRITE data. For the x16, LDQS corresponds to the
UDQS_t, data on DQ[7:0]; UDQS corresponds to the data on DQ[15:8]. For the x4 and x8 config-
UDQS_c, urations, DQS corresponds to the data on DQ[3:0] and DQ[7:0], respectively. DDR4
LDQS_t, SDRAM supports a differential data strobe only and does not support a single-ended
LDQS_c data strobe.
ALERT_n Output Alert output: This signal allows the DRAM to indicate to the system's memory con-
troller that a specific alert or event has occurred. Alerts will include the com-
mand/address parity error and the CRC data error when either of these functions is
enabled in the mode register.
TDQS_t, Output Termination data strobe: TDQS_t and TDQS_c are used by x8 DRAMs only. When
TDQS_c enabled via the mode register, the DRAM will enable the same RTT termination resis-
tance on TDQS_t and TDQS_c that is applied to DQS_t and DQS_c. When the TDQS
function is disabled via the mode register, the DM/TDQS_t pin will provide the DATA
MASK (DM) function, and the TDQS_c pin is not used. The TDQS function must be dis-
abled in the mode register for both the x4 and x16 configurations. The DM function is
supported only in x8 and x16 configurations.
VDD Supply Power supply: 1.2V ά0.060V.
VDDQ Supply DQ power supply: 1.2V ά0.060V.
VPP Supply DRAM activating power supply: 6 n6 6
VREFCA Supply Reference voltage for control, command, and address pins.
VSS Supply Ground.
VSSQ Supply DQ ground.
ZQ Reference Reference ball for ZQ calibration: This ball is tied to an external 240ȳ resistor
(RZQ), which is tied to VSSQ.
RFU n Reserved for future use.
NC n No connect: No internal electrical connection is present.
NF n No function: Internal connection is present but has no function.

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
28 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
Package Dimensions

Package Dimensions
Figure 7:  "ALL &"'! n X X 0-

0.155

Seating plane

A 0.12 A
1.8 CTR
Nonconductive
overmold

78X Ø0.47
Dimensions apply
to solder balls Ball A1 ID Ball A1 ID
post-reflow on (covered by SR)
Ø0.42 SMD ball pads.
9 8 7 3 2 1

A
B
C
D
13.2 ±0.1 E
F
9.6 CTR G
H
J
K
L
M
0.8 TYP N

0.8 TYP 1.1 ±0.1

6.4 CTR 0.28 MIN

9 ±0.1

Notes: 1. All dimensions are in millimeters.

2. Solder ball material: SAC302 (96.8% Sn, 3% Ag, 0.2% Cu).

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
29 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
Package Dimensions

Figure 8:  "ALL &"'! n X X 7%

0.155

Seating plane

A 0.12 A
1.8 CTR
nonconductive
overmold

78X Ø0.47
Dimensions apply
to solder balls post- Ball A1 ID Ball A1 ID
reflow on Ø0.42 SMD (covered by SR)
ball pads. 9 8 7 3 2 1

A
B
C
D
E
12 ±0.1 F
9.6 CTR G
H
J
K
L
M
0.8 TYP N

0.8 TYP 1.1 ±0.1

6.4 CTR 0.34 ±0.05

8 ±0.1

Notes: 1. All dimensions are in millimeters.

2. Solder ball material: SAC302 (96.8% Sn, 3% Ag, 0.2% Cu).

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
30 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
Package Dimensions

Figure 9:  "ALL &"'! n X X 3!

0.155

Seating plane

A 0.12 A
1.8 CTR
nonconductive
overmold

78X Ø0.47
Dimensions apply
to solder balls post- Ball A1 ID Ball A1 ID
reflow on Ø0.42 SMD (covered by SR)
ball pads.
9 8 7 3 2 1

A
B
C
D
E
11 ±0.1 F
9.6 CTR G
H
J
K
L
M
0.8 TYP N

0.8 TYP 1.1 ±0.1

6.4 CTR 0.34 ±0.05

7.5 ±0.1

Notes: 1. All dimensions are in millimeters.

2. Solder ball material: Die Revision E, H,J: SAC302 (96.8% Sn, 3% Ag, 0.2% Cu).
Solder ball material: Die Revision R: SAC305 (96.5% Sn, 3% Ag, 0.5% Cu).

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
31 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
Package Dimensions

Figure 10:  "ALL &"'! n X (!

0.155

Seating plane

A 0.12 A
1.8 CTR
Nonconductive
overmold

96X Ø0.47
Dimensions apply
to solder balls post- Ball A1 ID Ball A1 ID
reflow on Ø0.42 SMD (covered by SR)
ball pads. 9 8 7 3 2 1

A
B
C
D
E
F
14 ±0.1 G
H
12 CTR J
K
L
M
N
P
R
0.8 TYP T

0.8 TYP 1.1 ±0.1

6.4 CTR 0.29 MIN

9 ±0.1

Notes: 1. All dimensions are in millimeters.

2. Solder ball material: SAC302 (96.8% Sn, 3% Ag, 0.2% Cu).

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
32 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
Package Dimensions

Figure 11:  "ALL &"'! n X *9

0.155

Seating plane

A 0.12 A
1.8 CTR
Nonconductive
overmold

96X Ø0.47
Dimensions apply
to solder balls post- Ball A1 ID Ball A1 ID
reflow on Ø0.42 SMD (covered by SR)
ball pads. 9 8 7 3 2 1

A
B
C
D
E
F
14 ±0.1 G
H
12 CTR J
K
L
M
N
P
R
0.8 TYP T

0.8 TYP 1.1 ±0.1

6.4 CTR 0.34 ±0.05

8 ±0.1
Notes: 1. All dimensions are in millimeters.
2. Solder ball material: SAC302 (96.8% Sn, 3% Ag, 0.2% Cu).

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
33 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
Package Dimensions

Figure 12:  "ALL &"'! n X ,9

0.155

Seating plane

A 0.12 A

1.8 CTR
Nonconductive
overmold

96X Ø0.47
Dimensions apply
to solder balls post- Ball A1 ID Ball A1 ID
reflow on Ø0.42 (covered by SR)
SMD ball pads.
9 8 7 3 2 1

A
B
C
D
E
F
13.5 ±0.1 G
H
12 CTR J
K
L
M
N
P
R
0.8 TYP T

0.8 TYP 1.1 ±0.1

6.4 CTR 0.34 ±0.05

7.5 ±0.1
Notes: 1. All dimensions are in millimeters.
2. Solder ball material: SAC302 (96.8% Sn, 3% Ag, 0.2% Cu).

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
34 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
Package Dimensions

Figure 13:  "ALL &"'! n X 4"

0.155

Seating plane

A 0.1 A
1.8 CTR
Nonconductive
overmold

96X Ø0.47
Dimensions
apply to solder
balls post-reflow Ball A1 ID Ball A1 ID
on Ø0.42 SMD (covered by SR)
ball pads. 9 8 7 3 2 1

A
B
C
D
E
F
13 ±0.1 G
H
12 CTR
J
K
L
M
N
P
R
0.8 TYP T

0.8 TYP 1.1 ±0.1

6.4 CTR 0.34 ±0.05

7.5 ±0.1
Notes: 1. All dimensions are in millimeters.
2. Solder ball material: Die Revision J: SAC302 (96.8% Sn, 3% Ag, 0.2% Cu).
Solder ball material: Die Revision R: SAC305 (96.5% Sn, 3% Ag, 0.5% Cu).

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
35 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
State Diagram

State Diagram
This simplified state diagram provides an overview of the possible state transitions and the commands
to control them. Situations involving more than one bank, the enabling or disabling of on-die termina-
tion, and some other events are not captured in full detail.

Figure 14: Simplified State Diagram

IVREFDQ,
RTT, and
MPSM
so on
RESET SRX* = SRX with NOP
From any state
SRX*
CKE_L
MRS
Power MRS
SRX* MRS, MPR,
applied Reset write leveling, Self
Power-On RESET Initialization PDA VREFDQ training
procedure refresh
mode
TEN = 1
TEN = 1 MRS SRX
ZQCL
MRS MRS
SRE
MRS
Connectivity ZQ
test calibration
ZQCL,ZQCS
Idle
REF
Refreshing
TEN = 0
RESET
ACT PDE

CKE_L CKE_L
PDX

Active
Precharge
power- Activating power-
down
down
PDX

PDE

Bank
active
WRITE READ READ
WRITE

WRITE A READ A
READ
Writing Reading
WRITE

WRITE A READ A
WRITE A READ A

PRE, PREA
Writing PRE, PREA PRE, PREA
Reading

Precharging
Automatic
sequence
Command
sequence

CCMTD-1725822587-9875
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 8Gb: x4, x8, x16 DDR4 SDRAM
State Diagram

Table 4: State Diagram Command Definitions

Command Description
ACT Active
MPR Multipurpose register
MRS Mode register set
PDE Enter power-down
PDX Exit power-down
PRE Precharge
PREA Precharge all
READ RD, RDS4, RDS8
READ A RDA, RDAS4, RDAS8
REF Refresh, fine granularity refresh
RESET Start reset procedure
SRE Self refresh entry
SRX Self refresh exit
TEN Boundary scan mode enable
WRITE WR, WRS4, WRS8 with/without CRC
WRITE A WRA, WRAS4, WRAS8 with/without CRC
ZQCL ZQ calibration long
ZQCS ZQ calibration short

Notes: 1. See the Command Truth Table for more details.

CCMTD-1725822587-9875
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 8Gb: x4, x8, x16 DDR4 SDRAM
Functional Description

Functional Description
The DDR4 SDRAM is a high-speed dynamic random-access memory internally configured as sixteen
banks (4 bank groups with 4 banks for each bank group) for x4/x8 devices, and as eight banks for each
bank group (2 bank groups with 4 banks each) for x16 devices. The device uses double data rate (DDR)
architecture to achieve high-speed operation. DDR4 architecture is essentially an 8n-prefetch archi-
tecture with an interface designed to transfer two data words per clock cycle at the I/O pins. A single
read or write access for a device module effectively consists of a single 8n-bit-wide,
four-clock-cycle-data transfer at the internal DRAM core and eight corresponding n-bit-wide,
one-half-clock-cycle data transfers at the I/O pins.
Read and write accesses to the device are burst-oriented. Accesses start at a selected location and
continue for a burst length of eight or a chopped burst of four in a programmed sequence. Operation
begins with the registration of an ACTIVE command, which is then followed by a READ or WRITE
command. The address bits registered coincident with the ACTIVE command are used to select the
bank and row to be accessed (BG[1:0] select the bank group for x4/x8, and BG0 selects the bank group
for x16; BA[1:0] select the bank, and A[17:0] select the row. See the Addressing section for more details).
The address bits registered coincident with the READ or WRITE command are used to select the
starting column location for the burst operation, determine if the auto PRECHARGE command is to be
issued (via A10), and select BC4 or BL8 mode on-the-fly (OTF) (via A12) if enabled in the mode register.
Prior to normal operation, the device must be powered up and initialized in a predefined manner. The
following sections provide detailed information covering device reset and initialization, register defi-
nition, command descriptions, and device operation.
NOTE: The use of the NOP command is allowed only when exiting maximum power saving mode or
when entering gear-down mode.

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 8Gb: x4, x8, x16 DDR4 SDRAM
RESET and Initialization Procedure

RESET and Initialization Procedure

To ensure proper device function, the power-up and reset initialization default values for the following
mode register (MR) settings are defined as:
s Gear-down mode (MR3 A[3]): 0 = 1/2 rate
s Per-DRAM addressability (MR3 A[4]): 0 = disable
s Maximum power-saving mode (MR4 A[1]): 0 = disable
s CS to command/address latency (MR4 A[8:6]): 000 = disable
s CA parity latency mode (MR5 A[2:0]): 000 = disable
s Hard post package repair mode (MR4 A[13]): 0 = disable
s Soft post package repair mode (MR4 A[5]): 0 = disable

Power-Up and Initialization Sequence

The following sequence is required for power-up and initialization:
1. Apply power (RESET_n and TEN should be maintained below 0.2 έ VDD while supplies ramp up; all
other inputs may be undefined). When supplies have ramped to a valid stable level, RESET_n must
be maintained below 0.2 έ VDD for a minimum of tPW_RESET_L and TEN must be maintained below
0.2 έ VDD for a minimum of 700ρs. CKE is pulled LOW anytime before RESET_n is de-asserted
(minimum time of 10ns). The power voltage ramp time between 300mV to VDD,min must be no
greater than 200ms, and during the ramp, VDD must be greater than or equal to VDDQ and (VDD -
VDDQ) < 0.3V. VPP must ramp at the same time or up to 10 minutes prior to VDD, and VPP must be
equal to or higher than VDD at all times. The total time for which VPP is powered and VDD is unpow-
ered should not exceed 360 cumulative hours. After VDD has ramped and reached a stable level,
RESET_n must go high within 10 minutes. After RESET_n goes high, the initialization sequence
must be started within 3 seconds. For debug purposes, the 10 minute and 3 second delay limits may
be extended to 60 minutes each provided the DRAM is operated in this debug mode for no more
than 360 cumulative hours.
During power-up, the supply slew rate is governed by the limits stated in the table below and either
condition A or condition B listed below must be met.

Table 5: Supply Power-up Slew Rate

Symbol Min Max Unit Comment
VDD_SL, VDDQ_SL, VPP_SL 0.004 600 V/ms Measured between 300mV and 80% of supply minimum
VDD_ona N/A 200 ms VDD maximum ramp time from 300mV to VDD minimum
VDDQ_ona N/A 200 ms VDDQ maximum ramp time from 300mV to VDDQ minimum

Notes: 1. 20 MHz band-limited measurement.

n Condition A:
s Apply VPP without any slope reversal before or at the same time as VDD and VDDQ.
s VDD and VDDQ are driven from a single-power converter output and apply VDD/VDDQ without
any slope reversal before or at the same time as VTT and VREFCA.
s The voltage levels on all balls other than VDD, VDDQ, VSS, and VSSQ must be less than or equal to
VDDQ and VDD on one side and must be greater than or equal to VSSQ and VSS on the other side.
s VTT is limited to 0.76V MAX when the power ramp is complete.
s VREFCA tracks VDD/2.

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 8Gb: x4, x8, x16 DDR4 SDRAM
RESET and Initialization Procedure

n Condition B:
s Apply VPP without any slope reversal before or at the same time as VDD.
s Apply VDD without any slope reversal before or at the same time as VDDQ.
s Apply VDDQ without any slope reversal before or at the same time as VTT and VREFCA.
s The voltage levels on all pins other than VPP, VDD, VDDQ, VSS, and VSSQ must be less than or equal
to VDDQ and VDD on one side and must be larger than or equal to VSSQ and VSS on the other side.

2. After RESET_n is de-asserted, wait for a minimum of 500ρs, but no longer than 3 seconds, before
allowing CKE to be registered HIGH at clock edge Td. During this time, the device will start internal
state initialization; this will be done independently of external clocks. A reasonable attempt was
made in the design to power up with the following default MR settings: gear-down mode (MR3 A[3]):
0 = 1/2 rate; per-DRAM addressability (MR3 A[4]): 0 = disable; maximum power-down (MR4 A[1]): 0
= disable; CS to command/address latency (MR4 A[8:6]): 000 = disable; CA parity latency mode (MR5
A[2:0]): 000 = disable. However, it should be assumed that at power up the MR settings are unde-
fined and should be programmed as shown below.
3. Clocks (CK_t, CK_c) need to be started and stabilized for at least 10ns or 5 tCK (whichever is larger)
before CKE is registered HIGH at clock edge Td. Because CKE is a synchronous signal, the corre-
sponding setup time to clock (tIS) must be met. Also, a DESELECT command must be registered
(with tIS setup time to clock) at clock edge Td. After the CKE is registered HIGH after RESET, CKE
needs to be continuously registered HIGH until the initialization sequence is finished, including
expiration of tDLLK and tZQinit.
4. The device keeps its ODT in High-Z state as long as RESET_n is asserted. Further, the SDRAM keeps
its ODT in High-Z state after RESET_n de-assertion until CKE is registered HIGH. The ODT input
signal may be in an undefined state until tIS before CKE is registered HIGH. When CKE is registered
HIGH, the ODT input signal may be statically held either LOW or HIGH. If RTT(NOM) is to be enabled
in MR1, the ODT input signal must be statically held LOW. In all cases, the ODT input signal remains
static until the power-up initialization sequence is finished, including the expiration of tDLLK and
t
ZQinit.
5. After CKE is registered HIGH, wait a minimum of RESET CKE EXIT time, tXPR, before issuing the first
MRS command to load mode register (tXPR = MAX (tXS, 5 έ tCK).
6. Issue MRS command to load MR3 with all application settings, wait tMRD.
7. Issue MRS command to load MR6 with all application settings, wait tMRD.
8. Issue MRS command to load MR5 with all application settings, wait tMRD.
9. Issue MRS command to load MR4 with all application settings, wait tMRD.
10.Issue MRS command to load MR2 with all application settings, wait tMRD.
11.Issue MRS command to load MR1 with all application settings, wait tMRD.
12.Issue MRS command to load MR0 with all application settings, wait tMOD.
13.Issue a ZQCL command to start ZQ calibration.
14.Wait for tDLLK and tZQinit to complete.
15.The device will be ready for normal operation. Once the DRAM has been initialized, if the DRAM is
in an idle state longer than 960ms, then either (a) REF commands must be issued within tREFI
constraints (specification for posting allowed) or (b) CKE or CS_n must toggle once within every
960ms interval of idle time. For debug purposes, the 960ms delay limit maybe extended to 60
minutes provided the DRAM is operated in this debug mode for no more than 360 cumulative hours.
16.Optional MBIST-PPR mode can be entered by setting MR4:A0 to 1, followed by subsequent MR0
guard key sequences, then DRAM will drive ALERT_n to LOW. DRAM will drive ALERT_n to HIGH

CCMTD-1725822587-9875
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 8Gb: x4, x8, x16 DDR4 SDRAM
RESET and Initialization Procedure

to indicate that this operation is completed. MBIST-PPR mode can take place anytime after Tk. Note
that no exit sequence or re-initialization is needed after MBIST completes; As soon as ALERT_N goes
HIGH and tIS is satisfied, MR0 must be re-written to the pre guard key state, then and the DRAM is
immediately ready to receive valid commands.

A stable valid VDD level is a set DC level (0Hz to 250 KHz) and must be no less than VDD,min and no
greater than VDD,max. If the set DC level is altered anytime after initialization, the DLL reset and cali-
brations must be performed again after the new set DC level is stable. AC noise of ά60mV (greater than
250 KHz) is allowed on VDD provided the noise doesn't alter VDD to less than VDD,min or greater than
VDD,max.
A stable valid VDDQ level is a set DC level (0Hz to 250 KHz) and must be no less than VDDQ,min and no
greater than VDDQ,max. If the set DC level is altered anytime after initialization, the DLL reset and cali-
brations must be performed again after the new set DC level is stable. AC noise of ά60mV (greater than
250 KHz) is allowed on VDDQ provided the noise doesn't alter VDDQ to less than VDDQ,min or greater
than VDDQ,max.
A stable valid VPP level is a set DC level (0Hz to 250 KHz) and must be no less than VPP,min and no greater
than VPP,max. If the set DC level is altered anytime after initialization, the DLL reset and calibrations
must be performed again after the new set DC level is stable. AC noise of ά120mV (greater than 250
KHz) is allowed on VPP provided the noise doesn't alter VPP to less than VPP,min or greater than VPP,max.

Figure 15: RESET and Initialization Sequence at Power-On Ramping

Ta Tb Tc Td Te Tf Tg Th Ti Tj Tk

CK_t, CK_c

tCKSRX

VPP

VDD, VDDQ
tPW_RESET_L T = 500μs

RESET_n

tIS
T (MIN) = 10ns

CKE Valid

tDLLK

tXPR tMRD tMRD tMRD tMOD tZQinit

tIS

Command Note 1 MRS MRS MRS MRS ZQCL Note 1 Valid

BG, BA MRx MRx MRx MRx Valid

tIS
tIS

ODT Static LOW in case RTT(NOM) is enabled at time Tg, otherwise static HIGH or LOW Valid

RTT

Time Break Don’t Care

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 8Gb: x4, x8, x16 DDR4 SDRAM
RESET and Initialization Procedure

Notes: 1. From time point Td until Tk, a DES command must be applied between MRS and ZQCL commands.
2. MRS commands must be issued to all mode registers that have defined settings.
3. In general, there is no specific sequence for setting the MRS locations (except for dependent or co-related features,
such as ENABLE DLL in MR1 prior to RESET DLL in MR0, for example).
4. TEN is not shown; however, it is assumed to be held LOW.
5. Optional MBIST-PPR may be entered any time after Tk.

RESET Initialization with Stable Power Sequence

The following sequence is required for RESET at no power interruption initialization:
1. Assert RESET_n below 0.2 έ VDD any time when reset is needed (all other inputs may be undefined).
RESET_n needs to be maintained for minimum tPW_RESET. CKE is pulled LOW before RESET_n
being de-asserted (minimum time 10ns).
2. Follow Steps 2 through 10 in the Reset and Initialization Sequence at Power-On Ramping proce-
dure.

When the reset sequence is complete, all counters except the refresh counters have been reset and the
device is ready for normal operation.

Figure 16: RESET Procedure at Power Stable Condition

Ta Tb Tc Td Te Tf Tg Th Ti Tj Tk

CK_t, CK_c

tCKSRX

VPP

VDD , VDDQ
tPW_RESET_S T = 500μs

RESET_n

tIS
T (MIN) = 10ns

CKE Valid

tDLLK

tXPR tMRD tMRD tMRD tMOD tZQinit

tIS

Command Note 1 MRS MRS MRS MRS ZQCL Note 1 Valid

BG, BA MRx MRx MRx MRx Valid

tIS
tIS

ODT Static LOW in case RTT(NOM) is enabled at time Tg, otherwise static HIGH or LOW Valid

RTT

Time Break Don’t Care

Notes: 1. From time point Td until Tk, a DES command must be applied between MRS and ZQCL commands.
2. MRS commands must be issued to all mode registers that have defined settings.

CCMTD-1725822587-9875
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 8Gb: x4, x8, x16 DDR4 SDRAM
Programming Mode Registers

3. In general, there is no specific sequence for setting the MRS locations (except for dependent or co-related features,
such as ENABLE DLL in MR1 prior to RESET DLL in MR0, for example).
4. TEN is not shown; however, it is assumed to be held LOW.

Uncontrolled Power-Down Sequence

In the event of an uncontrolled ramping down of VPP supply, VPP is allowed to be less than VDD
provided the following conditions are met:
s Condition A: VPP and VDD/VDDQ are ramping down (as part of turning off) from normal operating
levels.
s Condition B: The amount that VPP may be less than VDD/VDDQ is less than or equal to 500mV.
s Condition C: The time VPP may be less than VDD is ζ10ms per occurrence with a total accumulated
time in this state ζ100ms.
s Condition D: The time VPP may be less than 2.0V and above VSS while turning off is ζ15ms per occur-
rence with a total accumulated time in this state ζ150ms.

Programming Mode Registers

For application flexibility, various functions, features, and modes are programmable in seven mode
registers (MRn) provided by the device as user defined variables that must be programmed via a MODE
REGISTER SET (MRS) command. Because the default values of the mode registers are not defined,
contents of mode registers must be fully initialized and/or re-initialized; that is, they must be written
after power-up and/or reset for proper operation. The contents of the mode registers can be altered by
re-executing the MRS command during normal operation. When programming the mode registers,
even if the user chooses to modify only a sub-set of the MRS fields, all address fields within the accessed
mode register must be redefined when the MRS command is issued. MRS and DLL RESET commands
do not affect array contents, which means these commands can be executed any time after power-up
without affecting the array contents.

The MRS command cycle time, tMRD, is required to complete the WRITE operation to the mode
register and is the minimum time required between the two MRS commands shown in the tMRD
Timing figure.
Some of the mode register settings affect address/command/control input functionality. In these
cases, the next MRS command can be allowed when the function being updated by the current MRS
COMMAND IS COMPLETED 4HESE -23 COMMANDS DONT APPLY tMRD timing to the next MRS command;
however, the input cases have unique MR setting procedures, so refer to individual function descrip-
tions:
s Gear-down mode
s Per-DRAM addressability
s CMD address latency
s CA parity latency mode
s VREFDQ training value
s VREFDQ training mode
s VREFDQ training range

Some mode register settings may not be supported because they are not required by certain speed
bins.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Programming Mode Registers

Figure 17: tMRD Timing

T0 T1 T2 Ta0 Ta1 Tb0 Tb1 Tb2 Tc0 Tc1 Tc2
CK_c
CK_t

Command Valid Valid Valid MRS2 DES DES DES DES DES MRS2 Valid

Address Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid

CKE
tMRD

Settings Old settings Updating settings

Time Break Don’t Care

Notes: 1. 4HIS TIMING DIAGRAM DEPICTS #! PARITY MODE hDISABLEDv CASE

2. tMRD applies to all MRS commands with the following exceptions:
Gear-down mode
CA parity latency mode
CMD address latency
Per-DRAM addressability mode
VREFDQ training value, VREFDQ training mode, and VREFDQ training range

The MRS command to nonMRS command delay, tMOD, is required for the DRAM to update features,
except for those noted in note 2 in figure below where the individual function descriptions may specify
a different requirement. tMOD is the minimum time required from an MRS command to a nonMRS
command, excluding DES, as shown in the tMOD Timing figure.

Figure 18: tMOD Timing

T0 T1 T2 Ta0 Ta1 Ta2 Ta3 Ta4 Tb0 Tb1 Tb2
CK_c
CK_t

Command Valid Valid Valid MRS2 DES DES DES DES DES Valid Valid

Address Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid

CKE
t
MOD

Settings Old settings Updating settings New settings

Time Break Don’t Care

Notes: 1. 4HIS TIMING DIAGRAM DEPICTS #! PARITY MODE hDISABLEDv CASE

2. tMOD applies to all MRS commands with the following exceptions:
DLL enable, DLL RESET, Gear-down mode
VREFDQ training value, internal VREF training monitor, VREFDQ training mode, and VREFDQ training range
Maximum power savings mode, Per-DRAM addressability mode, and CA parity latency mode
The mode register contents can be changed using the same command and timing requirements during
normal operation as long as the device is in idle state; that is, all banks are in the precharged state with
t
RP satisfied, all data bursts are completed, and CKE is HIGH prior to writing into the mode register. If
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 8Gb: x4, x8, x16 DDR4 SDRAM
Programming Mode Registers

the RTT(NOM) feature is enabled in the mode register prior to and/or after an MRS command, the ODT
signal must continuously be registered LOW, ensuring RTT is in an off state prior to the MRS command.
The ODT signal may be registered HIGH after tMOD has expired. If the RTT(NOM) feature is disabled in
the mode register prior to and after an MRS command, the ODT signal can be registered either LOW or
HIGH before, during, and after the MRS command. The mode registers are divided into various fields
depending on functionality and modes.

In some mode register setting cases, function updating takes longer than tMOD. This type of MRS does
not apply tMOD timing to the next valid command, excluding DES. These MRS command input cases
have unique MR setting procedures, so refer to individual function descriptions.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 0

Mode Register 0
Mode register 0 (MR0) controls various device operating modes as shown in the following register defi-
nition table. Not all settings listed may be available on a die; only settings required for speed bin
support are available. MR0 is written by issuing the MRS command while controlling the states of the
BGx, BAx, and Ax address pins. The mapping of address pins during the MRS command is shown in the
following MR0 Register Definition table.

Table 6: Address Pin Mapping

Address BG1 BG0 BA1 BA0 A17 RA CA W A1 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
bus S_ S_ E_ 3
n n n
Mode 21 20 19 18 17 n n n 13 12 11 10 9 8 7 6 5 4 3 2 1 0
register

Notes: 1. RAS_n, CAS_n, and WE_n must be LOW during MODE REGISTER SET command.

Table 7: MR0 Register Definition

Mode
Register Description
21 RFU
0 = Must be programmed to 0
1 = Reserved
20:18 MR select
000 = MR0
001 = MR1
010 = MR2
011 = MR3
100 = MR4
101 = MR5
110 = MR6
111 = DNU
17 N/A on 4Gb and 8Gb, RFU
0 = Must be programmed to 0
1 = Reserved
13,11:9 WR (WRITE recovery)/RTP (READ-to-PRECHARGE)
0000 = 10 / 5 clocks1
0001 = 12 / 6 clocks
0010 = 14 / 7 clocks1
0011 = 16 / 8 / clocks
0100 = 18 / 9 clocks1
0101 = 20 /10 clocks
0110 = 24 / 12 clocks
0111 = 22 / 11 clocks1
1000 = 26 / 13 clocks1
1001 = 28 / 14 clocks2
1010 through 1111 = Reserved
8 DLL reset
0 = No
1 = Yes

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 0

Table 7: MR0 Register Definition (Continued)

Mode
Register Description
7 4EST MODE 4- n -ANUFACTURER USE ONLY
0 = Normal operating mode, must be programmed to 0
12, 6:4, 2 #!3 LATENCY #, n $ELAY IN CLOCK CYCLES FROM THE INTERNAL 2%!$ COMMAND TO FIRST DATA OUT
00000 = 9 clocks1
00001 = 10 clocks
00010 = 11 clocks1
00011 = 12 clocks
00100 = 13 clocks1
00101 = 14 clocks
00110 = 15 clocks1
00111 = 16 clocks
01000 = 18 clocks
01001 = 20 clocks
01010 = 22 clocks
01011 = 24 clocks
01100 = 23 clocks1
01101 = 17 clocks1
01110 = 19 clocks1
01111 = 21 clocks 1
10000 = 25 clocks
10001 = 26 clocks
10011 = 28 clocks
10100 = 29 clocks1
10101 = 30 clocks
10110 = 31 clocks1
10111 = 32 clocks
3 "URST TYPE "4 n $ATA BURST ORDERING WITHIN A 2%!$ OR 72)4% BURST ACCESS
0 = Nibble sequential
1 = Interleave
1:0 "URST LENGTH ", n $ATA BURST SIZE ASSOCIATED WITH EACH READ OR WRITE ACCESS
00 = BL8 (fixed)
01 = BC4 or BL8 (on-the-fly)
10 = BC4 (fixed)
11 = Reserved

Notes: 1. Not allowed when 1/4 rate gear-down mode is enabled.

2. If WR requirement exceeds 28 clocks or RTP exceeds 14 clocks, WR should be set to 28 clocks and RTP should be set
to 14 clocks.

Burst Length, Type, and Order

Accesses within a given burst may be programmed to sequential or interleaved order. The ordering of
accesses within a burst is determined by the burst length, burst type, and the starting column address
as shown in the following table. Burst length options include fixed BC4, fixed BL8, and on-the-fly
(OTF), which allows BC4 or BL8 to be selected coincidentally with the registration of a READ or WRITE
command via A12/BC_n.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 0

Table 8: Burst Type and Burst Order

Note 1 applies to the entire table

Starting
Column
Burst READ/ Address Burst Type = Sequential Burst Type = Interleaved
Length WRITE (A[2, 1, 0]) (Decimal) (Decimal) Notes
BC4 READ 000 0, 1, 2, 3, T, T, T, T 0, 1, 2, 3, T, T, T, T 2, 3
001 1, 2, 3, 0, T, T, T, T 1, 0, 3, 2, T, T, T, T 2, 3
010 2, 3, 0, 1, T, T, T, T 2, 3, 0, 1, T, T, T, T 2, 3
011 3, 0, 1, 2, T, T, T, T 3, 2, 1, 0, T, T, T, T 2, 3
100 4, 5, 6, 7, T, T, T, T 4, 5, 6, 7, T, T, T, T 2, 3
101 5, 6, 7, 4, T, T, T, T 5, 4, 7, 6, T, T, T, T 2, 3
110 6, 7, 4, 5, T, T, T, T 6, 7, 4, 5, T, T, T, T 2, 3
111 7, 4, 5, 6, T, T, T, T 7, 6, 5, 4, T, T, T, T 2, 3
WRITE 0, V, V 0, 1, 2, 3, X, X, X, X 0, 1, 2, 3, X, X, X, X 2, 3
1, V, V 4, 5, 6, 7, X, X, X, X 4, 5, 6, 7, X, X, X, X 2, 3
BL8 READ 000 0, 1, 2, 3, 4, 5, 6, 7 0, 1, 2, 3, 4, 5, 6, 7
001 1, 2, 3, 0, 5, 6, 7, 4 1, 0, 3, 2, 5, 4, 7, 6
010 2, 3, 0, 1, 6, 7, 4, 5 2, 3, 0, 1, 6, 7, 4, 5
011 3, 0, 1, 2, 7, 4, 5, 6 3, 2, 1, 0, 7, 6, 5, 4
100 4, 5, 6, 7, 0, 1, 2, 3 4, 5, 6, 7, 0, 1, 2, 3
101 5, 6, 7, 4, 1, 2, 3, 0 5, 4, 7, 6, 1, 0, 3, 2
110 6, 7, 4, 5, 2, 3, 0, 1 6, 7, 4, 5, 2, 3, 0, 1
111 7, 4, 5, 6, 3, 0, 1, 2 7, 6, 5, 4, 3, 2, 1, 0
WRITE V, V, V 0, 1, 2, 3, 4, 5, 6, 7 0, 1, 2, 3, 4, 5, 6, 7 3

Notes: 1. 0...7 bit number is the value of CA[2:0] that causes this bit to be the first read during a burst.
2. When setting burst length to BC4 (fixed) in MR0, the internal WRITE operation starts two clock cycles earlier than
for the BL8 mode, meaning the starting point for tWR and tWTR will be pulled in by two clocks. When setting burst
length to OTF in MR0, the internal WRITE operation starts at the same time as a BL8 (even if BC4 was selected
during column time using A12/BC4_n) meaning that if the OTF MR0 setting is used, the starting point for tWR and
t
WTR will not be pulled in by two clocks as described in the BC4 (fixed) case.
3. T = Output driver for data and strobes are in High-Z.
V = Valid logic level (0 or 1), but respective buffer input ignores level on input pins.
8  h$ONT #AREv

CAS Latency
The CAS latency (CL) setting is defined in the MR0 Register Definition table. CAS latency is the delay,
in clock cycles, between the internal READ command and the availability of the first bit of output data.
The device does not support half-clock latencies. The overall read latency (RL) is defined as additive
latency (AL) + CAS latency (CL): RL = AL + CL.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 0

Test Mode
The normal operating mode is selected by MR0[7] and all other bits set to the desired values shown in
the MR0 Register Definition table. Programming MR0[7] to a value of 1 places the device into a DRAM
manufacturer-defined test mode to be used only by the manufacturer, not by the end user. No opera-
tions or functionality is specified if MR0[7] = 1.

Write Recovery (WR)/READ-to-PRECHARGE

The programmed write recovery (WR) value is used for the auto precharge feature along with tRP to
determine tDAL. WR for auto precharge (MIN) in clock cycles is calculated by dividing tWR (in ns) by
t
CK (in ns) and rounding to the next integer using the rounding algorithms found in the Converting
Time-Based Specifications to Clock-Based Requirements section. The WR value must be programmed
to be equal to or larger than tWR (MIN). When both DM and write CRC are enabled in the mode
register, the device calculates CRC before sending the write data into the array; tWR values will change
when enabled. If there is a CRC error, the device blocks the WRITE operation and discards the data.
Internal READ-to-PRECHARGE (RTP) command delay for auto precharge (MIN) in clock cycles is
calculated by dividing tRTP (in ns) by tCK (in ns) and rounding to the next integer using the rounding
algorithms found in the Converting Time-Based Specifications to Clock-Based Requirements section.
The RTP value in the mode register must be programmed to be equal to or larger than RTP (MIN). The
programmed RTP value is used with tRP to determine the ACT timing to the same bank.

DLL RESET
The DLL reset bit is self-clearing, meaning that it returns to the value of 0 after the DLL RESET function
has been issued. After the DLL is enabled, a subsequent DLL RESET should be applied. Any time the
DLL RESET function is used, tDLLK must be met before functions requiring the DLL can be used. Such
as READ commands or synchronous ODT operations, for example.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 1

Mode Register 1
Mode register 1 (MR1) controls various device operating modes as shown in the following register defi-
nition table. Not all settings listed may be available on a die; only settings required for speed bin
support are available. MR1 is written by issuing the MRS command while controlling the states of the
BGx, BAx, and Ax address pins. The mapping of address pins during the MRS command is shown in the
following MR1 Register Definition table.

Table 9: Address Pin Mapping

Address BG1 BG0 BA1 BA0 A17 RA CA WE A1 A1 A11 A10 A9 A8 A7 A6 A5 A4 A3 A A1 A0
bus S_ S_ _n 3 2 2
n n
Mode 21 20 19 18 17 n n n 13 12 11 10 9 8 7 6 5 4 3 2 1 0
register

Notes: 1. RAS_n, CAS_n, and WE_n must be LOW during MODE REGISTER SET command.

Table 10: MR1 Register Definition

Mode
Register Description
21 RFU
0 = Must be programmed to 0
1 = Reserved
20:18 MR select
000 = MR0
001 = MR1
010 = MR2
011 = MR3
100 = MR4
101 = MR5
110 = MR6
111 = DNU
17 N/A on 4Gb and 8Gb, RFU
0 = Must be programmed to 0
1 = Reserved
12 $ATA OUTPUT DISABLE 1OFF n /UTPUT BUFFER DISABLE
0 = Enabled (normal operation)
1 = Disabled (both ODI and RTT)
11 4ERMINATION DATA STROBE 4$13 n !DDITIONAL TERMINATION PINS X CONFIGURATION ONLY
0 = TDQS disabled
1 = TDQS enabled
10, 9, 8 Nominal ODT (RTT(NOM) n $ATA BUS TERMINATION SETTING
000 = RTT(NOM) disabled
001 = RZQ/4 (60 ohm)
010 = RZQ/2 (120 ohm)
011 = RZQ/6 (40 ohm)
100 = RZQ/1 (240 ohm)
101 = RZQ/5 (48 ohm)
110 = RZQ/3 (80 ohm)
111 = RZQ/7 (34 ohm)

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 1

Table 10: MR1 Register Definition (Continued)

Mode
Register Description
7 7RITE LEVELING 7, n 7RITE LEVELING MODE
0 = Disabled (normal operation)
1 = Enabled (enter WL mode)
13, 6, 5 Rx CTLE Control
000 = Vendor Default
001 = Vendor Defined
010 = Vendor Defined
011 = Vendor Defined
100 = Vendor Defined
101 = Vendor Defined
110 = Vendor Defined
111 = Vendor Defined
4, 3 !DDITIVE LATENCY !, n #OMMAND ADDITIVE LATENCY SETTING
00 = 0 (AL disabled)
01 = CL - 11
10 = CL - 2
11 = Reserved
2, 1 /UTPUT DRIVER IMPEDANCE /$) n /UTPUT DRIVER IMPEDANCE SETTING
00 = RZQ/7 (34 ohm)
01 = RZQ/5 (48 ohm)
10 = Reserved (Although not JEDEC-defined and not tested, this setting will provide RZQ/6 or 40 ohm)
11 = Reserved
0 $,, ENABLE n $,, ENABLE FEATURE
0 = DLL disabled
1 = DLL enabled (normal operation)

Notes: 1. Not allowed when 1/4 rate gear-down mode is enabled.

DLL Enable/DLL Disable

The DLL must be enabled for normal operation and is required during power-up initialization and
upon returning to normal operation after having the DLL disabled. During normal operation (DLL
enabled with MR1[0]) the DLL is automatically disabled when entering the SELF REFRESH operation
and is automatically re-enabled upon exit of the SELF REFRESH operation. Any time the DLL is
enabled and subsequently reset, tDLLK clock cycles must occur before a READ or SYNCHRONOUS
ODT command can be issued to allow time for the internal clock to be synchronized with the external
clock. Failing to wait for synchronization to occur may result in a violation of the tDQSCK, tAON, or
t
AOF parameters.

During tDLLK, CKE must continuously be registered HIGH. The device does not require DLL for any
WRITE operation, except when RTT(WR) is enabled and the DLL is required for proper ODT operation.
The direct ODT feature is not supported during DLL off mode. The ODT resistors must be disabled by
continuously registering the ODT pin LOW and/or by programming the RTT(NOM) bits MR1[9,6,2] = 000
via an MRS command during DLL off mode.
The dynamic ODT feature is not supported in DLL off mode; to disable dynamic ODT externally, use
the MRS command to set RTT(WR), MR2[10:9] = 00.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 1

Output Driver Impedance Control

The output driver impedance of the device is selected by MR1[2,1], as shown in the MR1 Register Defi-
nition table.

ODT RTT(NOM) Values

The device is capable of providing three different termination values: RTT(Park), RTT(NOM), and RTT(WR).
The nominal termination value, RTT(NOM), is programmed in MR1. A separate value, RTT(WR), may be
programmed in MR2 to enable a unique RTT value when ODT is enabled during WRITE operations. The
RTT(WR) value can be applied during WRITE commands even when RTT(NOM) is disabled. A third RTT
value, RTT(Park), is programed in MR5. RTT(Park) provides a termination value when the ODT signal is
LOW.

Additive Latency
The ADDITIVE LATENCY (AL) operation is supported to make command and data buses efficient for
sustainable bandwidths in the device. In this operation, the device allows a READ or WRITE command
(either with or without auto precharge) to be issued immediately after the ACTIVATE command. The
command is held for the time of AL before it is issued inside the device. READ latency (RL) is controlled
by the sum of the AL and CAS latency (CL) register settings. WRITE latency (WL) is controlled by the
sum of the AL and CAS WRITE latency (CWL) register settings.

Table 11: Additive Latency (AL) Settings

A4 A3 AL
0 0 0 (AL disabled)
0 1 CL - 1
1 0 CL - 2
1 1 Reserved

Notes: 1. AL has a value of CL - 1 or CL - 2 based on the CL values programmed in the MR0 register.

Rx CTLE Control
The Mode Register for Rx CTLE Control MR1[A13,A6,A5] is vendor specific. Since CTLE circuits can not
be typically bypassed a disable option is not provided. Instead, a vendor optimized setting is given. It
should be noted that the settings are not specifically linear in relationship to the vendor optimized
setting, so the host may opt to instead walk through all the provided options and use the setting that
works best in their environment.

Write Leveling
For better signal integrity, the device uses fly-by topology for the commands, addresses, control
signals, and clocks. Fly-by topology benefits from a reduced number of stubs and their lengths, but it
causes flight-time skew between clock and strobe at every DRAM on the DIMM. This makes it difficult
for the controller to maintain tDQSS, tDSS, and tDSH specifications. Therefore, the device supports a
write leveling feature that allows the controller to compensate for skew.

Output Disable
The device outputs may be enabled/disabled by MR1[12] as shown in the MR1 Register Definition
table. When MR1[12] is enabled (MR1[12] = 1) all output pins (such as DQ and DQS) are disconnected

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 1

from the device, which removes any loading of the output drivers. For example, this feature may be
useful when measuring module power. For normal operation, set MR1[12] to 0.

Termination Data Strobe

Termination data strobe (TDQS) is a feature of the x8 device and provides additional termination resis-
tance outputs that may be useful in some system configurations. Because this function is available only
in a x8 configuration, it must be disabled for x4 and x16 configurations.
While TDQS is not supported in x4 or x16 configurations, the same termination resistance function
that is applied to the TDQS pins is applied to the DQS pins when enabled via the mode register.
The TDQS, DBI, and DATA MASK (DM) functions share the same pin. When the TDQS function is
enabled via the mode register, the DM and DBI functions are not supported. When the TDQS function
is disabled, the DM and DBI functions can be enabled separately.

Table 12: TDQS Function Matrix

TDQS Data Mask (DM) WRITE DBI READ DBI
Disabled Enabled Disabled Enabled or disabled
Disabled Enabled Enabled or disabled
Disabled Disabled Enabled or disabled
Enabled Disabled Disabled Disabled

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 2

Mode Register 2
Mode register 2 (MR2) controls various device operating modes as shown in the following register defi-
nition table. Not all settings listed may be available on a die; only settings required for speed bin
support are available. MR2 is written by issuing the MRS command while controlling the states of the
BGx, BAx, and Ax address pins. The mapping of address pins during the MRS command is shown in the
following MR2 Register Definition table.

Table 13: Address Pin Mapping

Address BG1 BG0 BA1 BA0 A17 RA CA WE A13 A1 A1 A1 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
bus S_ S_ _n 2 1 0
n n
Mode 21 20 19 18 17 n n n 13 12 11 10 9 8 7 6 5 4 3 2 1 0
register

Notes: 1. RAS_n, CAS_n, and WE_n must be LOW during MODE REGISTER SET command.

Table 14: MR2 Register Definition

Mode
Register Description
21 RFU
0 = Must be programmed to 0
1 = Reserved
20:18 MR select
000 = MR0
001 = MR1
010 = MR2
011 = MR3
100 = MR4
101 = MR5
110 = MR6
111 = DNU
17 N/A on 4Gb and 8Gb, RFU
0 = Must be programmed to 0
1 = Reserved
13 RFU
0 = Must be programmed to 0
1 = Reserved
12 WRITE data bus CRC
0 = Disabled
1 = Enabled
11:9 Dynamic ODT (RTT(WR) n $ATA BUS TERMINATION SETTING DURING 72)4%S
000 = RTT(WR) disabled (WRITE does not affect RTT value)
001 = RZQ/2 (120 ohm)
010 = RZQ/1 (240 ohm)
011 = High-Z
100 = RZQ/3 (80 ohm)
101 = Reserved
110 = Reserved
111 = Reserved

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 2

Table 14: MR2 Register Definition (Continued)

Mode
Register Description
7:6 ,OW POWER AUTO SELF REFRESH ,0!32 n -ODE SUMMARY
00 = Manual mode - Normal operating temperature range (TC: -40ι#nιC)
01 = Manual mode - Reduced operating temperature range (TC: -40ι#nιC)
10 = Manual mode - Extended operating temperature range (TC: -40ι#nιC)
11 = ASR mode - Automatically switching among all modes
5:3 #!3 72)4% LATENCY #7, n $ELAY IN CLOCK CYCLES FROM THE INTERNAL 72)4% COMMAND TO FIRST DATA IN
1tCK WRITE preamble
000 = 9 (DDR4-1600)1
001 = 10 (DDR4-1866)
010 = 11 (DDR4-2133/1600)1
011 = 12 (DDR4-2400/1866)
100 = 14 (DDR4-2666/2133)
101 = 16 (DDR4-2933,3200/2400)
110 = 18 (DDR4-2666)
111 = 20 (DDR4-2933, 3200)
#!3 72)4% LATENCY #7, n $ELAY IN CLOCK CYCLES FROM THE INTERNAL 72)4% COMMAND TO FIRST DATA IN
2tCK WRITE preamble
000 = N/A
001 = N/A
010 = N/A
011 = N/A
100 = 14 (DDR4-2400)
101 = 16 (DDR4-2666/2400)
110 = 18 (DDR4-2933, 3200/2666)
111 = 20 (DDR4-2933, 3200)
8, 2 RFU
0 = Must be programmed to 0
1 = Reserved
1:0 RFU
0 = Must be programmed to 0
1 = Reserved

Notes: 1. Not allowed when 1/4 rate gear-down mode is enabled.

CAS WRITE Latency

CAS WRITE latency (CWL) is defined by MR2[5:3] as shown in the MR2 Register Definition table. CWL
is the delay, in clock cycles, between the internal WRITE command and the availability of the first bit
of input data. The device does not support any half-clock latencies. The overall WRITE latency (WL) is
defined as additive latency (AL) + parity latency (PL) + CAS WRITE latency (CWL): WL = AL +PL + CWL.

Low-Power Auto Self Refresh

Low-power auto self refresh (LPASR) is supported in the device. Applications requiring SELF REFRESH
operation over different temperature ranges can use this feature to optimize the IDD6 current for a
given temperature range as specified in the MR2 Register Definition table.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 2

Dynamic ODT
In certain applications and to further enhance signal integrity on the data bus, it is desirable to change
the termination strength of the device without issuing an MRS command. This may be done by config-
uring the dynamic ODT (RTT(WR)) settings in MR2[11:9]. In write leveling mode, only RTT(NOM) is avail-
able.

Write Cyclic Redundancy Check Data Bus

The write cyclic redundancy check (CRC) data bus feature during writes has been added to the device.
When enabled via the mode register, the data transfer size goes from the normal 8-bit (BL8) frame to a
larger 10-bit UI frame, and the extra two UIs are used for the CRC information.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 3

Mode Register 3
Mode register 3 (MR3) controls various device operating modes as shown in the following register defi-
nition table. Not all settings listed may be available on a die; only settings required for speed bin
support are available. MR3 is written by issuing the MRS command while controlling the states of the
BGx, BAx, and Ax address pins. The mapping of address pins during the MRS command is shown in the
following MR3 Register Definition table.

Table 15: Address Pin Mapping

Address BG1 BG0 BA1 BA0 A17 RA CA W A13 A1 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
bus S_ S_ E_ 2
n n n
Mode 21 20 19 18 17 n n n 13 12 11 10 9 8 7 6 5 4 3 2 1 0
register

Notes: 1. RAS_n, CAS_n, and WE_n must be LOW during MODE REGISTER SET command.

Table 16: MR3 Register Definition

Mode
Register Description
21 RFU
0 = Must be programmed to 0
1 = Reserved
20:18 MR select
000 = MR0
001 = MR1
010 = MR2
011 = MR3
100 = MR4
101 = MR5
110 = MR6
111 = DNU
17 N/A on 4Gb and 8Gb, RFU
0 = Must be programmed to 0
1 = Reserved
13 RFU
0 = Must be programmed to 0
1 = Reserved
12:11 -ULTIPURPOSE REGISTER -02 n 2EAD FORMAT
00 = Serial
01 = Parallel
10 = Staggered
11 = Reserved
10:9 WRITE CMD latency when CRC/DM enabled
00 = 4CK (DDR4-1600)
01 = 5CK (DDR4-1866/2133/2400/2666)
10 = 6CK (DDR4-2933/3200)
11 = Reserved

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 3

Table 16: MR3 Register Definition (Continued)

Mode
Register Description
8:6 Fine granularity refresh mode
000 = Normal mode (fixed 1x)
001 = Fixed 2x
010 = Fixed 4x
011 = Reserved
100 = Reserved
101 = On-the-fly 1x/2x
110 = On-the-fly 1x/4x
111 = Reserved
5 Temperature sensor status
0 = Disabled
1 = Enabled
4 Per-DRAM addressability
0 = Normal operation (disabled)
1 = Enable
3 'EAR DOWN MODE n 2ATIO OF INTERNAL CLOCK TO EXTERNAL DATA RATE
0 = [1:1]; (1/2 rate data)
1 = [2:1]; (1/4 rate data)
2 Multipurpose register (MPR) access
0 = Normal operation
1 = Data flow from MPR
1:0 MPR page select
00 = Page 0
01 = Page 1
10 = Page 2
11 = Page 3 (restricted for DRAM manufacturer use only)

Multipurpose Register
The multipurpose register (MPR) is used for several features:
s Readout of the contents of the MRn registers
s WRITE and READ system patterns used for data bus calibration
s Readout of the error frame when the command address parity feature is enabled

To enable MPR, issue an MRS command to MR3[2] = 1. MR3[12:11] define the format of read data from
the MPR. Prior to issuing the MRS command, all banks must be in the idle state (all banks precharged
and tRP met). After MPR is enabled, any subsequent RD or RDA commands will be redirected to a
specific mode register.
The mode register location is specified with the READ command using address bits. The MR is split
into upper and lower halves to align with a burst length limitation of 8. Power-down mode, SELF
REFRESH, and any other nonRD/RDA or nonWR/WRA commands are not allowed during MPR mode.
The RESET function is supported during MPR mode, which requires device re-initialization.

WRITE Command Latency When CRC/DM is Enabled

The WRITE command latency (WCL) must be set when both write CRC and DM are enabled for write
CRC persistent mode. This provides the extra time required when completing a WRITE burst when
write CRC and DM are enabled. This means at data rates less than or equal to 1600 MT/s then 4nCK is
used, 5nCK or 6nCK are not allowed; at data rates greater than 1600 MT/s and less than or equal to 2666
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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 3

MT/s then 5nCK is used, 4nCK or 6nCK are not allowed; and at data rates greater than 2666 MT/s and
less than or equal to 3200 MT/s then 6nCK is used; 4nCK or 5nCK are not allowed.

Fine Granularity Refresh Mode

This mode had been added to DDR4 to help combat the performance penalty due to refresh lockout at
high densities. Shortening tRFC and decreasing cycle time allows more accesses to the chip and allows
for increased scheduling flexibility.

Temperature Sensor Status

This mode directs the DRAM to update the temperature sensor status at MPR Page 2, MPR0 [4,3]. The
temperature sensor setting should be updated within 32ms; when an MPR read of the temperature
sensor status bits occurs, the temperature sensor status should be no older than 32ms.

Per-DRAM Addressability
This mode allows commands to be masked on a per device basis providing any device in a rank
(devices sharing the same command and address signals) to be programmed individually. As an
example, this feature can be used to program different ODT or VREF values on DRAM devices within a
given rank.

Gear-Down Mode
The device defaults in 1/2 rate (1N) clock mode and uses a low frequency MRS command followed by
a sync pulse to align the proper clock edge for operating the control lines CS_n, CKE, and ODT when in
1/4 rate (2N) mode. For operation in 1/2 rate mode, no MRS command or sync pulse is required.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 4

Mode Register 4
Mode register 4 (MR4) controls various device operating modes as shown in the following register defi-
nition table. Not all settings listed may be available on a die; only settings required for speed bin
support are available. MR4 is written by issuing the MRS command while controlling the states of the
BGx, BAx, and Ax address pins. The mapping of address pins during the MRS command is shown in the
following MR4 Register Definition table.

Table 17: Address Pin Mapping

Address BG1 BG0 BA1 BA0 A17 RA CA W A13 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
bus S_ S_ E_
n n n
Mode 21 20 19 18 17 n n n 13 12 11 10 9 8 7 6 5 4 3 2 1 0
register

Notes: 1. RAS_n, CAS_n, and WE_n must be LOW during MODE REGISTER SET (MRS) command.

Table 18: MR4 Register Definition

Mode
Register Description
21 RFU
0 = Must be programmed to 0
1 = Reserved
20:18 MR select
000 = MR0
001 = MR1
010 = MR2
011 = MR3
100 = MR4
101 = MR5
110 = MR6
111 = DNU
17 N/A on 4Gb and 8Gb, RFU
0 = Must be programmed to 0
1 = Reserved
13 Hard Post Package Repair (hPPR mode)
0 = Disabled
1 = Enabled
12 WRITE preamble setting
0 = 1tCK toggle1
1 = 2tCK toggle (When operating in 2tCK WRITE preamble mode, CWL must be programmed to a value at
least 1 clock greater than the lowest CWL setting supported in the applicable tCK range.)
11 READ preamble setting
0 = 1tCK toggle1
1 = 2tCK toggle
10 READ preamble training
0 = Disabled
1 = Enabled

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 4

Table 18: MR4 Register Definition (Continued)

Mode
Register Description
9 Self refresh abort mode
0 = Disabled
1 = Enabled
8:6 CMD (CAL) address latency
000 = 0 clocks (disabled)
001 =3 clocks1
010 = 4 clocks
011 = 5 clocks1
100 = 6 clocks
101 = 8 clocks
110 = Reserved
111 = Reserved
5 soft Post Package Repair (sPPR mode)
0 = Disabled
1 = Enabled
4 Internal VREF monitor
0 = Disabled
1 = Enabled
3 Temperature controlled refresh mode
0 = Disabled
1 = Enabled
2 Temperature controlled refresh range
0 = Normal temperature mode
1 = Extended temperature mode
1 Maximum power savings mode
0 = Normal operation
1 = Enabled
0 MBIST-PPR
0 = Disabled
1 = Enabled

Notes: 1. Not allowed when 1/4 rate gear-down mode is enabled.

Hard Post Package Repair Mode

The hard post package repair (hPPR) mode feature is JEDEC optional for 4Gb DDR4 memories.
Performing an MPR read to page 2 MPR0 [7] indicates whether hPPR mode is available (A7 = 1) or not
available (A7 = 0). hPPR mode provides a simple and easy repair method of the device after placed in
the system. One row per bank can be repaired. The repair process is irrevocable so great care should
be exercised when using.

Soft Post Package Repair Mode

The soft post package repair (sPPR) mode feature is JEDEC optional for 4Gb and 8Gb DDR4 memories.
Performing an MPR read to page 2 MPR0 [6] indicates whether sPPR mode is available (A6 = 1) or not
available (A6 = 0). sPPR mode provides a simple and easy repair method of the device after placed in
the system. One row per bank can be repaired. The repair process is revocable by either doing a reset
or power-down or by rewriting a new address in the same bank.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 4

WRITE Preamble
Programmable WRITE preamble, tWPRE, can be set to 1tCK or 2tCK via the MR4 register. The 1tCK
setting is similar to DDR3. However, when operating in 2tCK WRITE preamble mode, CWL must be
programmed to a value at least 1 clock greater than the lowest CWL setting supported in the applicable
t
CK range.
Some even settings will require addition of 2 clocks. If the alternate longer CWL was used, the addi-
tional clocks will not be required.

READ Preamble
Programmable READ preamble tRPRE can be set to 1tCK or 2tCK via the MR4 register. Both the 1tCK
and 2tCK DDR4 preamble settings are different from that defined for the DDR3 SDRAM. Both DDR4
READ preamble settings may require the memory controller to train (or read level) its data strobe
receivers using the READ preamble training.

READ Preamble Training

Programmable READ preamble training can be set to 1tCK or 2tCK. This mode can be used by the
memory controller to train or READ level its data strobe receivers.

Temperature-Controlled Refresh
When temperature-controlled refresh mode is enabled, the device may adjust the internal refresh
period to be longer than tREFI of the normal temperature range by skipping external REFRESH
commands with the proper gear ratio. For example, the DRAM temperature sensor detected less than
45ιC. Normal temperature mode covers the range of -40ιC to 85ιC, while the extended temperature
range covers -40ιC to 105ιC.

Command Address Latency

COMMAND ADDRESS LATENCY (CAL) is a power savings feature and can be enabled or disabled via
the MRS setting. CAL is defined as the delay in clock cycles (tCAL) between a CS_n registered LOW and
its corresponding registered command and address. The value of CAL (in clocks) must be programmed
into the mode register according to the tCAL(ns)/tCK(ns) rounding algorithms found in the Converting
Time-Based Specifications to Clock-Based Requirements section.

Internal VREF Monitor

This mode enables output of internally generated VREFDQ for monitoring on DQ0, DQ1, DQ2, and DQ3.
May be used during VREFDQ training and test. While in this mode, RTT should be set to High-Z. VREF_-
time must be increased by 10ns if DQ load is 0pF, plus an additional 15ns per pF of loading. This
measurement is for verification purposes and is NOT an external voltage supply pin.

Maximum Power Savings Mode

This mode provides the lowest power mode where data retention is not required. When the device is
in the maximum power saving mode, it does not need to guarantee data retention or respond to any
external command (except the MAXIMUM POWER SAVING MODE EXIT command and during the
assertion of RESET_n signal LOW).

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 4

MBIST-PPR
This mode is JEDEC optional and allows for a self-contained DRAM test and repair. Please refer to the
Features list on page 1 for a list of die revisions that support MBIST-PPR.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 5

Mode Register 5
Mode register 5 (MR5) controls various device operating modes as shown in the following register defi-
nition table. Not all settings listed may be available on a die; only settings required for speed bin
support are available. MR5 is written by issuing the MRS command while controlling the states of the
BGx, BAx, and Ax address pins. The mapping of address pins during the MRS command is shown in the
following MR5 Register Definition table.

Table 19: Address Pin Mapping

Address BG1 BG0 BA1 BA0 A17 RA CA WE A13 A1 A1 A1 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
bus S_ S_ _n 2 1 0
n n
Mode 21 20 19 18 17 n n n 13 12 11 10 9 8 7 6 5 4 3 2 1 0
register

Notes: 1. RAS_n, CAS_n, and WE_n must be LOW during MODE REGISTER SET command.

Table 20: MR5 Register Definition

Mode
Register Description
21 RFU
0 = Must be programmed to 0
1 = Reserved
20:18 MR select
000 = MR0
001 = MR1
010 = MR2
011 = MR3
100 = MR4
101 = MR5
110 = MR6
111 = DNU
17 N/A on 4Gb and 8Gb, RFU
0 = Must be programmed to 0
1 = Reserved
13 RFU
0 = Must be programmed to 0
1 = Reserved
12 $ATA BUS INVERSION $") n 2%!$ $") ENABLE
0 = Disabled
1 = Enabled
11 $ATA BUS INVERSION $") n 72)4% $") ENABLE
0 = Disabled
1 = Enabled
10 Data mask (DM)
0 = Disabled
1 = Enabled
9 CA parity persistent error mode
0 = Disabled
1 = Enabled

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 5

Table 20: MR5 Register Definition (Continued)

Mode
Register Description
8:6 Parked ODT value (RTT(Park))
000 = RTT(Park) disabled
001 = RZQ/4 (60 ohm)
010 = RZQ/2 (120 ohm)
011 = RZQ/6 (40 ohm)
100 = RZQ/1 (240 ohm)
101 = RZQ/5 (48 ohm)
110 = RZQ/3 (80 ohm)
111 = RZQ/7 (34 ohm)
5 ODT input buffer for power-down
0 = Buffer enabled
1 = Buffer disabled
4 CA parity error status
0 = Clear
1 = Error
3 CRC error status
0 = Clear
1 = Error
2:0 CA parity latency mode
000 = Disable
001 = 4 clocks (DDR4-1600/1866/2133)
010 = 5 clocks (DDR4-2400/2666)1
011 = 6 clocks (DDR4-2933/3200)
100 = Reserved
101 = Reserved
110 = Reserved
111 = Reserved

Notes: 1. Not allowed when 1/4 rate gear-down mode is enabled.

Data Bus Inversion

The DATA BUS INVERSION (DBI) function has been added to the device and is supported only for x8
and x16 configurations (x4 is not supported). The DBI function shares a common pin with the DM and
TDQS functions. The DBI function applies to both READ and WRITE operations; Write DBI cannot be
enabled at the same time the DM function is enabled. Refer to the TDQS Function Matrix table for valid
configurations for all three functions (TDQS/DM/DBI). DBI is not allowed during MPR READ opera-
tion; during an MPR read, the DRAM ignores the read DBI enable setting in MR5 bit A12.
DBI is not supported for 3DS devices and should be disabled in MR5.

Data Mask
The DATA MASK (DM) function, also described as a partial write, has been added to the device and is
supported only for x8 and x16 configurations (x4 is not supported). The DM function shares a common
pin with the DBI and TDQS functions. The DM function applies only to WRITE operations and cannot
be enabled at the same time the write DBI function is enabled. Refer to the TDQS Function Matrix table
for valid configurations for all three functions (TDQS/DM/DBI).

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 5

CA Parity Persistent Error Mode

Normal CA parity mode (CA parity persistent mode disabled) no longer performs CA parity checking
while the parity error status bit remains set at 1. However, with CA parity persistent mode enabled, CA
parity checking continues to be performed when the parity error status bit is set to a 1.

ODT Input Buffer for Power-Down

This feature determines whether the ODT input buffer is on or off during power-down. If the input
buffer is configured to be on (enabled during power-down), the ODT input signal must be at a valid
logic level. If the input buffer is configured to be off (disabled during power-down), the ODT input
signal may be floating and the device does not provide RTT(NOM) termination. However, the device may
provide RTT(Park) termination depending on the MR settings. This is primarily for additional power
savings.

CA Parity Error Status

The device will set the error status bit to 1 upon detecting a parity error. The parity error status bit
remains set at 1 until the device controller clears it explicitly using an MRS command.

CRC Error Status

The device will set the error status bit to 1 upon detecting a CRC error. The CRC error status bit remains
set at 1 until the device controller clears it explicitly using an MRS command.

CA Parity Latency Mode

CA parity is enabled when a latency value, dependent on tCK, is programmed; this accounts for parity
calculation delay internal to the device. The normal state of CA parity is to be disabled. If CA parity is
enabled, the device must ensure there are no parity errors before executing the command. CA parity
signal (PAR) covers ACT_n, RAS_n/A16, CAS_n/A15, WE_n/A14, and the address bus including bank
address and bank group bits. The control signals CKE, ODT, and CS_n are not included in the parity
calculation.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 6

Mode Register 6
Mode register 6 (MR6) controls various device operating modes as shown in the following register defi-
nition table. Not all settings listed may be available on a die; only settings required for speed bin
support are available. MR6 is written by issuing the MRS command while controlling the states of the
BGx, BAx, and Ax address pins. The mapping of address pins during the MRS command is shown in the
following MR6 Register Definition table.

Table 21: Address Pin Mapping

Address BG1 BG0 BA1 BA0 A17 RA CA WE A1 A12 A11 A1 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
bus S_ S_ _n 3 0
n n
Mode 21 20 19 18 17 n n n 13 12 11 10 9 8 7 6 5 4 3 2 1 0
register

Notes: 1. RAS_n, CAS_n, and WE_n must be LOW during MODE REGISTER SET command.

Table 22: MR6 Register Definition

Mode
Register Description
21 RFU
0 = Must be programmed to 0
1 = Reserved
20:18 MR select
000 = MR0
001 = MR1
010 = MR2
011 = MR3
100 = MR4
101 = MR5
110 = MR6
111 = DNU
17 NA on 4Gb and 8Gb, RFU
0 = Must be programmed to 0
1 = Reserved
12:10 Data rate
000 = Data rateζ 1333 Mb/s (1333 Mb/s)
001 = 1333 Mb/s < Data rate ζ 1866 Mb/s (1600, 1866 Mb/s)
010 = 1866 Mb/s < Data rate ζ 2400 Mb/s (2133, 2400 Mb/s)
011 = 2400 Mb/s < Data rate ζ 2666 Mb/s (2666 Mb/s)
100 = 2666 Mb/s < Data rate ζ 3200 Mb/s (2933, 3200 Mb/s)
101 = Reserved
110 = Reserved
111 = Reserved

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 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 6

Table 22: MR6 Register Definition (Continued)

Mode
Register Description
13, 9, 8 RFU
Default = 000; Must be programmed to 000
001 = Reserved
010 = Reserved
011 = Reserved
100 = Reserved
101 = Reserved
110 = Reserved
111 = Reserved
7 VREF Calibration Enable
0 = Disable
1 = Enable
6 VREF Calibration Range
0 = Range 1
1 = Range 2
5:0 VREF Calibration Value
See the VREFDQ Range and Levels table in the VREFDQ Calibration section

Data Rate Programming

The device controller must program the correct data rate according to the operating frequency.

VREFDQ Calibration Enable

VREFDQ calibration is where the device internally generates its own VREFDQ to be used by the DQ input
receivers. The VREFDQ value will be output on any DQ of DQ[3:0] for evaluation only. The device
controller is responsible for setting and calibrating the internal VREFDQ level using an MRS protocol
(adjust up, adjust down, and so on). It is assumed that the controller will use a series of writes and reads
in conjunction with VREFDQ adjustments to optimize and verify the data eye. Enabling VREFDQ calibra-
tion must be used whenever values are being written to the MR6[6:0] register.

VREFDQ Calibration Range

The device defines two VREFDQ calibration ranges: Range 1 and Range 2. Range 1 supports VREFDQ
between 60% and 92% of VDDQ while Range 2 supports VREFDQ between 45% and 77% of VDDQ, as seen
in VREFDQ Specification table. Although not a restriction, Range 1 was targeted for module-based
designs and Range 2 was added to target point-to-point designs.

VREFDQ Calibration Value

Fifty settings provide approximately 0.65% of granularity steps sizes for both Range 1 and Range 2 of
VREFDQ, as seen in VREFDQ Range and Levels table in the VREFDQ Calibration section.

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 Truth Tables
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Table 23: Truth Table n Command

Notes 1n5 apply to the entire table; Note 6 applies to all READ/WRITE commands

CAS_n/A15
RAS_n/A16

WE_n/A14

A12/BC_n

A[13,11]
BA [1:0]
Symbol

A10/AP
BG[1:0]
ACT_n

A[9:0]
C[2:0]
CS_n
Prev. Pres.
Function CKE CKE Notes
MODE REGISTER SET MRS H H L H L L L BG BA V OP code 7
REFRESH REF H H L H L L H V V V V V V V
Self refresh entry SRE H L L H L L H V V V V V V V 8, 9, 10
Self refresh exit SRX L H H X X X X X X X X X X X 8, 9, 10,
11
L H H H H V V V V V V V
Single-bank PRECHARGE PRE H H L H L H L BG BA V V V L V
PRECHARGE all banks PREA H H L H L H L V V V V V H V
Reserved for future use RFU H H L H L H H RFU
Bank ACTIVATE ACT H H L L Row address (RA) BG BA V Row address (RA)
69

WRITE BL8 fixed, BC4 WR H H L H H L L BG BA V V V L CA

fixed
BC4OTF WRS4 H H L H H L L BG BA V L V L CA
Micron Technology, Inc. reserves the right to change products or specifications without notice.

BL8OTF WRS8 H H L H H L L BG BA V H V L CA
WRITE BL8 fixed, BC4 WRA H H L H H L L BG BA V V V H CA

8Gb: x4, x8, x16 DDR4 SDRAM

with fixed
auto
BC4OTF H H L H H L L BG BA V L V H CA
pre-
WRAS
charge
4
BL8OTF H H L H H L L BG BA V H V H CA
¥ 2015 Micron Technology, Inc. All rights reserved.

WRAS
8

Mode Register 6
READ BL8 fixed, BC4 RD H H L H H L H BG BA V V V L CA
fixed
BC4OTF RDS4 H H L H H L H BG BA V L V L CA
BL8OTF RDS8 H H L H H L H BG BA V H V L CA
 CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

CAS_n/A15
RAS_n/A16

WE_n/A14

A12/BC_n

A[13,11]
BA [1:0]
Symbol

A10/AP
BG[1:0]
ACT_n

A[9:0]
C[2:0]
CS_n
Prev. Pres.
Function CKE CKE Notes
READ BL8 fixed, BC4 RDA H H L H H L H BG BA V V V H CA
with fixed
auto
BC4OTF H H L H H L H BG BA V L V H CA
pre-
RDAS4
charge
BL8OTF H H L H H L H BG BA V H V H CA
RDAS8
NO OPERATION NOP H H L H H H H V V V V V V V 12
Device DESELECTED DES H H H X X X X X X X X X X X 13
Power-down entry PDE H L H X X X X X X X X X X X 10, 14
Power-down exit PDX L H H X X X X X X X X X X X 10, 14
ZQ CALIBRATION LONG ZQCL H H L H H H L X X X X X H X
ZQ CALIBRATION SHORT ZQCS H H L H H H L X X X X X L X

s BG = Bank group address

70

s BA = Bank address
s RA = Row address
s CA = Column address
Micron Technology, Inc. reserves the right to change products or specifications without notice.

s BC_n = Burst chop

s X = hDont Carev
s V = Valid

8Gb: x4, x8, x16 DDR4 SDRAM

2. All DDR4 SDRAM commands are defined by states of CS_n, ACT_n, RAS_n/A16, CAS_n/A15, WE_n/A14, and CKE at the rising edge of the clock.
The MSB of BG, BA, RA, and CA are device density- and configuration-dependent. When ACT_n = H, pins RAS_n/A16, CAS_n/A15, and WE_n/A14
are used as command pins RAS_n, CAS_n, and WE_n, respectively. When ACT_n = L, pins RAS_n/A16, CAS_n/A15, and WE_n/A14 are used as
address pins A16, A15, and A14, respectively.
3. RESET_n is enabled LOW and is used only for asynchronous reset and must be maintained HIGH during any function.
¥ 2015 Micron Technology, Inc. All rights reserved.

4. Bank group addresses (BG) and bank addresses (BA) determine which bank within a bank group is being operated upon. For MRS commands,
the BG and BA selects the specific mode register location.

Mode Register 6
5. V means HIGH or LOW (but a defined logic level), and X means either defined or undefined (such as floating) logic level.
6. READ or WRITE bursts cannot be terminated or interrupted, and fixed/on-the-fly (OTF) BL will be defined by MRS.
7. During an MRS command, A17 is RFU and is device density- and configuration-dependent.
8. The state of ODT does not affect the states described in this table. The ODT function is not available during self refresh.
9. VPP and VREF (VREFCA) must be maintained during SELF REFRESH operation.
10. Refer to the Truth Table n CKE table for more details about CKE transition.
11. Controller guarantees self refresh exit to be synchronous. DRAM implementation has the choice of either synchronous or asynchronous.
12. The NO OPERATION (NOP) command may be used only when exiting maximum power saving mode or when entering gear-down mode.
 8Gb: x4, x8, x16 DDR4 SDRAM
Mode Register 6
13. The NOP command may not be used in place of the DESELECT command.
14. The power-down mode does not perform any REFRESH operation.
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 Table 24: Truth Table n CKE
CCMTD-1725822587-9875
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Notes 1n7, 9, and 20 apply to the entire table

CKE
Previous Cycle
Current State (n - 1) Present Cycle (n) Command (n) Action (n) Notes
Power-down L L X Maintain power-down 8, 10, 11
L H DES Power-down exit 8, 10, 12
Self refresh L L X Maintain self refresh 11, 13
L H DES Self refresh exit 8, 13, 14, 15
Bank(s) active H L DES Active power-down entry 8, 10, 12, 16
Reading H L DES Power-down entry 8, 10, 12, 16, 17
Writing H L DES Power-down entry 8, 10, 12, 16, 17
Precharging H L DES Power-down entry 8, 10, 12, 16, 17
Refreshing H L DES Precharge power-down entry 8, 12
All banks idle H L DES Precharge power-down entry 8, 10, 12, 16, 18
H L REFRESH Self refresh 16, 18, 19
72

Notes: 1. Current state is defined as the state of the DDR4 SDRAM immediately prior to clock edge n.
2. CKE (n) is the logic state of CKE at clock edge n; CKE (n-1) was the state of CKE at the previous clock edge.
3. COMMAND (n) is the command registered at clock edge n, and ACTION (n) is a result of COMMAND (n); ODT is not included here.
4. All states and sequences not shown are illegal or reserved unless explicitly described elsewhere in this document.
Micron Technology, Inc. reserves the right to change products or specifications without notice.

5. The state of ODT does not affect the states described in this table. The ODT function is not available during self refresh.
6. During any CKE transition (registration of CKE H->L or CKE H->L), the CKE level must be maintained until 1 nCK prior to tCKE (MIN) being satis-

8Gb: x4, x8, x16 DDR4 SDRAM

fied (at which time CKE may transition again).
7. DESELECT and NOP are defined in the Truth Table n Command table.
8. For power-down entry and exit parameters, see the Power-Down Modes section.
9. CKE LOW is allowed only if tMRD and tMOD are satisfied.
10. The power-down mode does not perform any REFRESH operations.
11. X = "Dont Care" (including floating around VREF) in self refresh and power-down. X also applies to address pins.
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12. The DESELECT command is the only valid command for power-down entry and exit.
13. VPP and VREFCA must be maintained during SELF REFRESH operation.

Mode Register 6
14. On self refresh exit, the DESELECT command must be issued on every clock edge occurring during the tXS period. READ or ODT commands may
be issued only after tXSDLL is satisfied.
15. The DESELECT command is the only valid command for self refresh exit.
16. Self refresh cannot be entered during READ or WRITE operations. For a detailed list of restrictions see the SELF REFRESH Operation and
Power-Down Modes sections.
17. If all banks are closed at the conclusion of the READ, WRITE, or PRECHARGE command, then precharge power-down is entered; otherwise,
active power-down is entered.
 18. Idle state is defined as all banks are closed (tRP, tDAL, and so on, satisfied), no data bursts are in progress, CKE is HIGH, and all timings from
CCMTD-1725822587-9875
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previous operations are satisfied (tMRD, tMOD, tRFC, tZQinit, tZQoper, tZQCS, and so on), as well as all self refresh exit and power-down exit
parameters are satisfied (tXS, tXP, tXSDLL, and so on).
19. Self refresh mode can be entered only from the all banks idle state.
20. For more details about all signals, see the Truth Table n Command table; must be a legal command as defined in the table.
73
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8Gb: x4, x8, x16 DDR4 SDRAM

¥ 2015 Micron Technology, Inc. All rights reserved.

Mode Register 6
 8Gb: x4, x8, x16 DDR4 SDRAM
NOP Command

NOP Command
The NO OPERATION (NOP) command was originally used to instruct the selected DDR4 SDRAM to
perform a NOP (CS_n = LOW and ACT_n, RAS_n/A16, CAS_n/A15, and WE_n/A14 = HIGH). This
prevented unwanted commands from being registered during idle or wait states. NOP command
general support has been removed and the command should not be used unless specifically allowed,
which is when exiting maximum power-saving mode or when entering gear-down mode.

DESELECT Command
The deselect function (CS_n HIGH) prevents new commands from being executed; therefore, with this
command, the device is effectively deselected. Operations already in progress are not affected.

DLL-Off Mode
DLL-off mode is entered by setting MR1 bit A0 to 0, which will disable the DLL for subsequent opera-
tions until the A0 bit is set back to 1. The MR1 A0 bit for DLL control can be switched either during
initialization or during self refresh mode. Refer to the Input Clock Frequency Change section for more
details.

The maximum clock frequency for DLL-off mode is specified by the parameter tCKDLL_OFF.
Due to latency counter and timing restrictions, only one CL value and CWL value (in MR0 and MR2
respectively) are supported. The DLL-off mode is only required to support setting both CL = 10 and
CWL = 9.

DLL-off mode will affect the read data clock-to-data strobe relationship (tDQSCK), but not the data
strobe-to-data relationship (tDQSQ,tQH). Special attention is needed to line up read data to the
controller time domain.

Compared with DLL-on mode, where tDQSCK starts from the rising clock edge (AL + CL) cycles after
the READ command, the DLL-off mode tDQSCK starts (AL + CL - 1) cycles after the READ command.
Another difference is that tDQSCK may not be small compared totCK (it might even be larger than tCK),
and the difference between tDQSCK (MIN) and tDQSCK (MAX) is significantly larger than in DLL-on
mode. The tDQSCK (DLL-off) values are undefined and the user is responsible for training to the
data-eye.
The timing relations on DLL-off mode READ operation are shown in the following diagram, where CL
= 10, AL = 0, and BL = 8.

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 8Gb: x4, x8, x16 DDR4 SDRAM
DLL-Off Mode

Figure 19: DLL-Off Mode Read Timing Operation

T0 (( T1 T6 T7 T8 T9 T10 T11 T12 T13 T14
CK_c ))
((
))
CK_t ((
))
((
))
Command RD (( DES DES DES DES DES DES DES DES DES DES
))
((
))
((
))
((
Address A RD ))
((
)) RL (DLL-on) = AL + CL = 10
(( CL = 10, AL = 0
DQS_t, DQS_c ))
(DLL-on)
tDQSCK (MIN) tDQSCK (MAX)
((
DQS_c )) DIN DIN DIN DIN DIN DIN DIN DIN
(DLL-on) b b+1 b+2 b+3 b+4 b+5 b+6 b+7

RL (DLL-off) = AL + (CL - 1) = 9
CL = 10, AL = 0 tDQSCK (DLL-off) MIN
DQS_t, DQS_c ((
))
(DLL-off)

DQS_c ((
)) DIN DIN DIN DIN DIN DIN DIN DIN
(DLL-off)
b b+1 b+2 b+3 b+4 b+5 b+6 b+7

tDQSCK (DLL-off) MAX

DQS_t, DQS_c ((
(DLL-off) ))

DQS_c ((
(DLL-off) )) DIN DIN DIN DIN DIN DIN DIN DIN
b b+1 b+2 b+3 b+4 b+5 b+6 b+7

Transitioning data Don’t Care

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 8Gb: x4, x8, x16 DDR4 SDRAM
DLL-On/Off Switching Procedures

DLL-On/Off Switching Procedures

The DLL-off mode is entered by setting MR1 bit A0 to 0; this will disable the DLL for subsequent oper-
ations until the A0 bit is set back to 1.

DLL Switch Sequence from DLL-On to DLL-Off

To switch from DLL-on to DLL-off requires the frequency to be changed during self refresh, as outlined
in the following procedure:
1. Starting from the idle state (all banks pre-charged, all timings fulfilled, and, to disable the DLL, the
DRAM on-die termination resistors, RTT(NOM), must be in High-Z before MRS to MR1.)
2. Set MR1 bit A0 to 1 to disable the DLL.
3. Wait tMOD.
4. Enter self refresh mode; wait until tCKSRE/tCKSRE_PAR is satisfied.
5. Change frequency, following the guidelines in the Input Clock Frequency Change section.
6. Wait until a stable clock is available for at least tCKSRX at device inputs.
7. Starting with the SELF REFRESH EXIT command, CKE must continuously be registered HIGH until
all tMOD timings from any MRS command are satisfied. In addition, if any ODT features were
enabled in the mode registers when self refresh mode was entered, the ODT signal must continu-
ously be registered LOW until all tMOD timings from any MRS command are satisfied. If RTT(NOM)
was disabled in the mode registers when self refresh mode was entered, the ODT signal is "Don't
Care."
8. Wait tXS_FAST, tXS_ABORT, or tXS, and then set mode registers with appropriate values (an update
of CL, CWL, and WR may be necessary; a ZQCL command can also be issued after tXS_FAST).
n tXS_FAST: ZQCL, ZQCS, and MRS commands. For MRS commands, only CL and WR/RTP registers
in MR0, the CWL register in MR2, and gear-down mode in MR3 may be accessed provided the
device is not in per-DRAM addressability mode. Access to other device mode registers must satisfy
t
XS timing.
n tXS_ABORT: If MR4 [9] is enabled, then the device aborts any ongoing refresh and does not incre-
ment the refresh counter. The controller can issue a valid command after a delay of tXS_ABORT.
Upon exiting from self refresh, the device requires a minimum of one extra REFRESH command
before it is put back into self refresh mode. This requirement remains the same regardless of the
MRS bit setting for self refresh abort.
n tXS: ACT, PRE, PREA, REF, SRE, PDE, WR, WRS4, WRS8, WRA, WRAS4, WRAS8, RD, RDS4, RDS8,
RDA, RDAS4, and RDAS8.

9. Wait tMOD to complete.

The device is ready for the next command.

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 8Gb: x4, x8, x16 DDR4 SDRAM
DLL-On/Off Switching Procedures

Figure 20: DLL Switch Sequence from DLL-On to DLL-Off

Ta Tb0 Tb1 Tc Td Te0 Te1 Tf Tg Th
CK_c

CK_t
tCKSRE/tCKSRE_PAR Note 4 tCKSRX5

tIS
tCPDED

CKE Valid Valid Valid

tXS_FAST

Command MRS2 SRE3 DES SRX6 Valid 7 Valid 8 Valid 9

Address Valid Valid Valid

tRP tXS_ABORT

tIS tCKESR/tCKESR_PAR tXS

ODT Valid

Enter self refresh Exit self refresh

Time Break Don’t Care

Notes: 1. Starting in the idle state. RTT in stable state.

2. Disable DLL by setting MR1 bit A0 to 0.
3. Enter SR.
4. Change frequency.
5. Clock must be stable tCKSRX.
6. Exit SR.
7. Update mode registers allowed with DLL-off settings met.

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 8Gb: x4, x8, x16 DDR4 SDRAM
DLL-On/Off Switching Procedures

DLL-Off to DLL-On Procedure

To switch from DLL-off to DLL-on (with required frequency change) during self refresh:
1. Starting from the idle state (all banks pre-charged, all timings fulfilled, and DRAM ODT resistors
(RTT(NOM)) must be in High-Z before self refresh mode is entered.)
2. Enter self refresh mode; wait until tCKSRE/tCKSRE_PAR are satisfied.
3. Change frequency (following the guidelines in the Input Clock Frequency Change section).
4. Wait until a stable clock is available for at least tCKSRX at device inputs.
5. Starting with the SELF REFRESH EXIT command, CKE must continuously be registered HIGH until
t
DLLK timing from the subsequent DLL RESET command is satisfied. In addition, if any ODT
features were enabled in the mode registers when self refresh mode was entered, the ODT signal
must continuously be registered LOW or HIGH until tDLLK timing from the subsequent DLL RESET
command is satisfied. If RTT(NOM) disabled in the mode registers when self refresh mode was
entered, the ODT signal is "Don't Care."
6. Wait tXS or tXS_ABORT, depending on bit 9 in MR4, then set MR1 bit A0 to 0 to enable the DLL.
7. Wait tMRD, then set MR0 bit A8 to 1 to start DLL reset.
8. Wait tMRD, then set mode registers with appropriate values; an update of CL, CWL, and WR may be
necessary. After tMOD is satisfied from any proceeding MRS command, a ZQCL command can also
be issued during or after tDLLK.
9. Wait for tMOD to complete. Remember to wait tDLLK after DLL RESET before applying any
command requiring a locked DLL. In addition, wait for tZQoper in case a ZQCL command was
issued.

The device is ready for the next command.

Figure 21: DLL Switch Sequence from DLL-Off to DLL-On

Ta Tb0 Tb1 Tc Td Te0 Te1 Tf Tg Th
CK_c

CK_t
Note 1 tCKSRE/tCKSRE_PAR Note 4 tCKSRX5

tIS
tCPDED

CKE Valid Valid Valid

tXS_ABORT

Command MRS2 SRE3 DES SRX6 Valid 7 Valid 7 Valid 7

Address Valid Valid Valid

tRP tXS tMRD

tIS
tCKESR/tCKESR_PAR

ODT Valid

Enter self refresh Exit self refresh

Time Break Don’t Care

Notes: 1. Starting in the idle state.

2. Enter SR.
3. Change frequency.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Input Clock Frequency Change

4. Clock must be stable tCKSRX.

5. Exit SR.
6. Set DLL to on by setting MR1 to A0 = 0.
7. Update mode registers.
8. Issue any valid command.

Input Clock Frequency Change

After the device is initialized, it requires the clock to be stable during almost all states of normal oper-
ation. This means that after the clock frequency has been set and is in the stable state, the clock period
is not allowed to deviate except for what is allowed by the clock jitter and spread spectrum clocking
(SSC) specifications. The input clock frequency can be changed from one stable clock rate to another
stable clock rate only when in self refresh mode. Outside of self refresh mode, it is illegal to change the
clock frequency.

After the device has been successfully placed in self refresh mode and tCKSRE/tCKSRE_PAR have been
SATISFIED THE STATE OF THE CLOCK BECOMES A $ONT #ARE &OLLOWING A $ONT #ARE  CHANGING THE CLOCK
frequency is permissible, provided the new clock frequency is stable prior to tCKSRX. When entering
and exiting self refresh mode for the sole purpose of changing the clock frequency, the self refresh entry
and exit specifications must still be met as outlined in SELF REFRESH Operation.
For the new clock frequency, additional MRS commands to MR0, MR2, MR3, MR4, MR5, and MR6 may
need to be issued to program appropriate CL, CWL, gear-down mode, READ and WRITE preamble,
Command Address Latency, and data rate values.
When the clock rate is being increased (faster), the MR settings that require additional clocks should
be updated prior to the clock rate being increased. In particular, the PL latency must be disabled when
the clock rate changes, ie. while in self refresh mode. For example, if changing the clock rate from
DDR4-2133 to DDR4-2933 with CA parity mode enabled, MR5[2:0] must first change from PL = 4 to PL
= disable prior to PL = 6. The correct procedure would be to (1) change PL = 4 to disable via MR5 [2:0],
(2) enter self refresh mode, (3) change clock rate from DDR4-2133 to DDR4-2933, (4) exit self refresh
mode, (5) Enable CA parity mode setting PL = 6 vis MR5 [2:0].
If the MR settings that require additional clocks are updated after the clock rate has been increased, for
example. after exiting self refresh mode, the required MR settings must be updated prior to removing
the DRAM from the IDLE state, unless the DRAM is RESET. If the DRAM leaves the IDLE state to enter
self refresh mode or ZQ Calibration, the updating of the required MR settings may be deferred to the
next time the DRAM enters the IDLE state.
If MR6 is issued prior to self refresh entry for the new data rate value, DLL will relock automatically at
self refresh exit. However, if MR6 is issued after self refresh entry, MR0 must be issued to reset the DLL.
The device input clock frequency can change only within the minimum and maximum operating
frequency specified for the particular speed grade. Any frequency change below the minimum oper-
ating frequency would require the use of DLL-on mode to DLL-off mode transition sequence (see
DLL-On/Off Switching Procedures).

Write Leveling
For better signal integrity, DDR4 memory modules use fly-by topology for the commands, addresses,
control signals, and clocks. Fly-by topology has benefits from the reduced number of stubs and their
length, but it also causes flight-time skew between clock and strobe at every DRAM on the DIMM. This
makes it difficult for the controller to maintain tDQSS,tDSS, and tDSH specifications. Therefore, the
device supports a write leveling feature to allow the controller to compensate for skew. This feature

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 8Gb: x4, x8, x16 DDR4 SDRAM
Write Leveling

may not be required under some system conditions, provided the host can maintain the tDQSS, tDSS,
and tDSH specifications.
The memory controller can use the write leveling feature and feedback from the device to adjust the
DQS (DQS_t, DQS_c) to CK (CK_t, CK_c) relationship. The memory controller involved in the leveling
must have an adjustable delay setting on DQS to align the rising edge of DQS with that of the clock at
the DRAM pin. The DRAM asynchronously feeds back CK, sampled with the rising edge of DQS,
through the DQ bus. The controller repeatedly delays DQS until a transition from 0 to 1 is detected. The
DQS delay established though this exercise would ensure the tDQSS specification. Besides tDQSS, tDSS
and tDSH specifications also need to be fulfilled. One way to achieve this is to combine the actual
t
DQSS in the application with an appropriate duty cycle and jitter on the DQS signals. Depending on
the actual tDQSS in the application, the actual values for tDQSL and tDQSH may have to be better than
the absolute limits provided in the AC Timing Parameters section in order to satisfy tDSS and tDSH
specifications. A conceptual timing of this scheme is shown below.

Figure 22: Write Leveling Concept, Example 1

T0 T1 T2 T3 T4 T5 T6 T7
CK_c
Source
CK_t

diff_DQS

Tn T0 T1 T2 T3 T4 T5 T6
CK_c
Destination
CK_t

diff_DQS

DQ 0 or 1 0 0 0

Push DQS to capture

diff_DQS the 0-1 transition

DQ 0 or 1 1 1 1

DQS driven by the controller during leveling mode must be terminated by the DRAM based on the
ranks populated. Similarly, the DQ bus driven by the DRAM must also be terminated at the controller.
All data bits carry the leveling feedback to the controller across the DRAM configurations: x4, x8, and
x16. On a x16 device, both byte lanes should be leveled independently. Therefore, a separate feedback
mechanism should be available for each byte lane. The upper data bits should provide the feedback of
the upper diff_DQS(diff_UDQS)-to-clock relationship; the lower data bits would indicate the lower
diff_DQS(diff_LDQS)-to-clock relationship.
The figure below is another representative way to view the write leveling procedure. Although it shows
the clock varying to a static strobe, this is for illustrative purpose only; the clock does not actually
change phase, the strobe is what actually varies. By issuing multiple WL bursts, the DQS strobe can be
varied to capture with fair accuracy the time at which the clock edge arrives at the DRAM clock input
buffer.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Write Leveling

Figure 23: Write Leveling Concept, Example 2

tWLS
CK_c
1 1 1 111 1 1 11 1 1 1 1 1 1 1 1
CK_t
tWLH
CK_c
0 000 000 000 000
CK_t
tWLS tWLH

CK_c
CK_t
0 000 000 X XX X X X 11 1 1 1 1 1 1 1 1
DQS_t/
DQS_c
tWLO

DQ (CK 0 to 1)

DQ (CK 1 to 0)

DRAM Setting for Write Leveling and DRAM TERMINATION Function in that Mode
The DRAM enters into write leveling mode if A7 in MR1 is HIGH. When leveling is finished, the DRAM
exits write leveling mode if A7 in MR1 is LOW (see the MR Leveling Procedures table). Note that in write
leveling mode, only DQS terminations are activated and deactivated via the ODT pin, unlike normal
operation (see DRAM DRAM TERMINATION Function in Leveling Mode table).

Table 25: MR Settings for Leveling Procedures

Function MR1 Enable Disable
Write leveling enable A7 1 0
Output buffer mode (Q off) A12 0 1

Table 26: DRAM TERMINATION Function in Leveling Mode

ODT Pin at DRAM DQS_t/DQS_c Termination DQ Termination
RTT(NOM) with ODT HIGH On Off
RTT(Park) with ODT LOW On Off

Notes: 1. In write leveling mode, with the mode's output buffer either disabled (MR1[bit7] = 1 and MR1[bit12] = 1) or with
its output buffer enabled (MR1[bit7] = 1 and MR1[bit12] = 0), all RTT(NOM) and RTT(Park) settings are supported.
2. RTT(WR) is not allowed in write leveling mode and must be set to disable prior to entering write leveling mode.

Procedure Description
The memory controller initiates the leveling mode of all DRAM by setting bit 7 of MR1 to 1. When
entering write leveling mode, the DQ pins are in undefined driving mode. During write leveling mode,
only the DESELECT command is supported, other than MRS commands to change the Qoff bit
(MR1[A12]) and to exit write leveling (MR1[A7]). Upon exiting write leveling mode, the MRS command
performing the exit (MR1[A7] = 0) may also change the other MR1 bits. Because the controller levels

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 8Gb: x4, x8, x16 DDR4 SDRAM
Write Leveling

one rank at a time, the output of other ranks must be disabled by setting MR1 bit A12 to 1. The
controller may assert ODT after tMOD, at which time the DRAM is ready to accept the ODT signal,
unless DODTLon or DODTLoff have been altered (the ODT internal pipe delay is increased when
increasing WRITE latency [WL] or READ latency [RL] by the previous MR command), then ODT asser-
tion should be delayed by DODTLon after tMOD is satisfied, which means the delay is now tMOD +
DODTLon.

The controller may drive DQS_t LOW and DQS_c HIGH after a delay of tWLDQSEN, at which time the
DRAM has applied ODT to these signals. After tDQSL and tWLMRD, the controller provides a single
DQS_t, DQS_c edge, which is used by the DRAM to sample CK driven from the controller. tWLMRD
(MAX) timing is controller dependent.
The DRAM samples CK status with the rising edge of DQS and provides feedback on all the DQ bits
asynchronously after tWLO timing. There is a DQ output uncertainty of tWLOE defined to allow
mismatch on DQ bits. The tWLOE period is defined from the transition of the earliest DQ bit to the
corresponding transition of the latest DQ bit. There are no read strobes (DQS_t, DQS_c) needed for
these DQs. The controller samples incoming DQ and either increments or decrements DQS delay
setting and launches the next DQS pulse after some time, which is controller dependent. After a 0-to-1
transition is detected, the controller locks the DQS delay setting, and write leveling is achieved for the
device. The following figure shows the timing diagram and parameters for the overall write leveling
procedure.

Figure 24: Write Leveling Sequence (DQS Capturing CK LOW at T1 and CK HIGH at T2)
T1 T2
tWLH tWLH
tWLS tWLS

CK_c5
CK_t

Command MRS2 DES3 DES DES DES DES DES NOP DES DES DES DES DES
tMOD

ODT
tWLDQSEN tDQSL6 tDQSH6 tDQSL6 tDQSH6

diff_DQS4
tWLMRD
tWLO tWLO

Late Prime DQ1

tWLOE

Early Prime DQ1

tWLO tWLO
tWLOE

Undefined Driving Mode Time Break Don’t Care

Notes: 1. The device drives leveling feedback on all DQs.

2. MRS: Load MR1 to enter write leveling mode.
3. diff_DQS is the differential data strobe. Timing reference points are the zero crossings. DQS_t is shown with a solid
line; DQS_c is shown with a dotted line.
4. CK_t is shown with a solid dark line; CK_c is shown with a dotted line.
5. DQS needs to fulfill minimum pulse width requirements, tDQSH (MIN) and tDQSL (MIN), as defined for regular
WRITEs; the maximum pulse width is system dependent.
6. tWLDQSEN must be satisfied following equation when using ODT:
s DLL = Enable, then tWLDQSEN > tMOD (MIN) + DODTLon + tADC
s DLL = Disable, then tWLDQSEN > tMOD (MIN) + tAONAS

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 8Gb: x4, x8, x16 DDR4 SDRAM
Write Leveling

Write Leveling Mode Exit

Write leveling mode should be exited as follows:
1. After the last rising strobe edge (see ~T0), stop driving the strobe signals (see ~Tc0). Note that from
this point on, DQ pins are in undefined driving mode and will remain undefined, until tMOD after
the respective MR command (Te1).
2. Drive ODT pin LOW (tIS must be satisfied) and continue registering LOW (see Tb0).
3. After RTT is switched off, disable write leveling mode via the MRS command (see Tc2).
4. After tMOD is satisfied (Te1), any valid command can be registered. (MR commands can be issued
after tMRD [Td1]).

Figure 25: Write Leveling Exit

T0 T1 T2 Ta0 Tb0 Tc0 Tc1 Tc2 Td0 Td1 Te0 Te1
CK_c
CK_t

Command DES DES DES DES DES DES DES DES DES Valid DES Valid
tMRD

Address MR1 Valid Valid

tIS tMOD

ODT

ODTL (OFF) tADC (MIN)

RTT(DQS_t)
RTT(NON) RTT(Park)
RTT(DQS_c)
tADC (MAX)
DQS_t,
DQS_c

RTT(DQ)
tWLO

DQ1 result = 1

Undefined Driving Mode Transitioning Time Break Don’t Care

Notes: 1. The DQ result = 1 between Ta0 and Tc0 is a result of the DQS signals capturing CK_t HIGH just after the T0 state.
2. See previous figure for specific tWLO timing.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Command Address Latency

Command Address Latency

DDR4 supports the command address latency (CAL) function as a power savings feature. This feature
can be enabled or disabled via the MRS setting. CAL timing is defined as the delay in clock cycles (tCAL)
between a CS_n registered LOW and its corresponding registered command and address. The value of
CAL in clocks must be programmed into the mode register (see MR1 Register Definition table) and is
based on the tCAL(ns)/tCK(ns) rounding algorithms found in the Converting Time-Based Specifica-
tions to Clock-Based Requirements section.

Figure 26: CAL Timing Definition

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
CLK

CS_n

CMD/ADDR
tCAL

CAL gives the DRAM time to enable the command and address receivers before a command is issued.
After the command and the address are latched, the receivers can be disabled if CS_n returns to HIGH.
For consecutive commands, the DRAM will keep the command and address input receivers enabled
for the duration of the command sequence.

Figure 27: CAL Timing Example (Consecutive CS_n = LOW)

1 2 3 4 5 6 7 8 9 10 11 12
CLK

CS_n

CMD/ADDR

When the CAL mode is enabled, additional time is required for the MRS command to complete. The
earliest the next valid command can be issued is tMOD_CAL, which should be equal to tMOD + tCAL.
The two following figures are examples.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Command Address Latency

Figure 28: #!, %NABLE 4IMING n tMOD_CAL

T0 T1 Ta0 Ta1 Ta2 Ta3 Ta4 Tb0 Tb1 Tb2 Tb3
CK_c
CK_t

Command Valid MRS DES DES DES DES DES DES DES Valid Valid

Address Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid

CS_n
tCAL
tMOD_CAL

Settings Old settings Updating settings New settings

Time Break Don’t Care

Note: 1. CAL mode is enabled at T1.

Figure 29: tMOD_CAL, MRS to Valid Command Timing with CAL Enabled
T0 T1 Ta0 Ta1 Ta2 Tb0 Tb1 Tb2 Tc0 Tc1 Tc2
CK_c
CK_t

Command Valid DES DES MRS DES DES DES DES DES Valid Valid

tCAL tCAL

Address Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid

CS_n
tMOD_CAL

Settings Old settings Updating settings New settings

Time Break Don’t Care

Note: 1. MRS at Ta1 may or may not modify CAL, tMOD_CAL is computed based on new tCAL setting if modified.
When the CAL mode is enabled or being enabled, the earliest the next MRS command can be issued is
t
MRD_CAL is equal to tMOD + tCAL. The two following figures are examples.

Figure 30: CAL Enabling MRS to Next MRS Command, tMRD_CAL

T0 T1 Ta0 Ta1 Ta2 Ta3 Ta4 Tb0 Tb1 Tb2 Tb3
CK_c
CK_t

Command Valid MRS DES DES DES DES DES DES DES MRS DES

tCAL

Address Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid

CS_n
tMRD_CAL

Settings Old settings Updating settings Updating settings

Time Break Don’t Care

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 8Gb: x4, x8, x16 DDR4 SDRAM
Command Address Latency

Note: 1. Command address latency mode is enabled at T1.

Figure 31: tMRD_CAL, Mode Register Cycle Time With CAL Enabled
T0 T1 Ta0 Ta1 Ta2 Tb0 Tb1 Tb2 Tc0 Tc1 Tc2
CK_c
CK_t

Command Valid DES DES MRS DES DES DES DES DES MRS DES

t CAL t CAL

Address Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid

CS_n
t MRD_CAL

Settings Old settings Updating settings New settings

Time Break Don’t Care

Note: 1. MRS at Ta1 may or may not modify CAL, tMRD_CAL is computed based on new tCAL setting if modified.

CAL Examples: Consecutive READ BL8 with two different CALs and 1tCK preamble in different bank
group shown in the following figures.

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 Figure 32: Consecutive READ BL8, CAL3, 1tCK Preamble, Different Bank Group
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T0 T1 T2 T3 T4 T5 T6 T7 T13 T14 T15 T16 T17 T18 T19 T20 T21 T22
CK_c
CK_t

CS_n
t t
CAL = 3 CAL = 3

Command DES DES READ DES DES READ DES DES DES DES DES DES DES DES DES DES
t
CCD_S = 4
Bank Group BG a BG b
Address
Bank, Bank,
Address Col n Col b

tRPST
tRPRE (1nCK)
DQS_t, DQS_c

DQ DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT
RL = 11 n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+7 b+2 b+3 b+4 b+5 b+6 b+7

RL = 11
Transitioning Data Don’t Care

Notes: 1. BL = 8, AL = 0, CL = 11, CAL = 3, Preamble = 1tCK.

2. DOUT n = data-out from column n; DOUT b = data-out from column b.
3. DES commands are shown for ease of illustration, other commands may be valid at these times.
4. BL8 setting activated by either MR0[A1:0 = 00] or MR0[A1:0 = 01] and A12 = 1 during READ command at T3 and T7.
5. CA parity = Disable, CS to CA latency = Enable, Read DBI = Disable.
6. Enabling CAL mode does not impact ODT control timings. ODT control timings should be maintained with the same timing relationship relative
to the command/address bus as when CAL is disabled.

Figure 33: Consecutive READ BL8, CAL4, 1tCK Preamble, Different Bank Group
87

T0 T1 T2 T3 T4 T5 T6 T7 T8 T14 T15 T16 T17 T18 T19 T20 T21 T22 T23
CK_c
CK_t

CS_n
t t
CAL = 4 CAL = 4

Command DES DES DES READ DES DES DES READ DES DES DES DES DES DES DES DES DES DES
Micron Technology, Inc. reserves the right to change products or specifications without notice.

t
CCD_S = 4
Bank Group BG a BG b
Address
Bank, Bank,
Address Col n Col b

t RPST
t RPRE (1nCK)

8Gb: x4, x8, x16 DDR4 SDRAM

DQS_t, DQS_c

DQ DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT
RL = 11 n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+7 b+2 b+3 b+4 b+5 b+6 b+7

Command Address Latency

RL = 11
Transitioning Data Don’t Care

Notes: 1. BL = 8, AL = 0, CL = 11, CAL = 4, Preamble = 1tCK.

2. DOUT n = data-out from column n; DOUT b = data-out from column b.
¥ 2015 Micron Technology, Inc. All rights reserved.

3. DES commands are shown for ease of illustration, other commands may be valid at these times.
4. BL8 setting activated by either MR0[A1:0 = 00] or MR0[A1:0 = 01] and A12 = 1 during READ command at T4 and T8.
5. CA parity = Disable, CS to CA latency = Enable, Read DBI = Disable.
6. Enabling CAL mode does not impact ODT control timings. ODT control timings should be maintained with the same timing relationship relative
to the command/address bus as when CAL is disabled.
 8Gb: x4, x8, x16 DDR4 SDRAM
Low-Power Auto Self Refresh Mode

Low-Power Auto Self Refresh Mode

An auto self refresh mode is provided for application ease. Auto self refresh mode is enabled by setting
MR2[6] = 1 and MR2[7] = 1. The device will manage self refresh entry over the supported temperature
range of the DRAM. In this mode, the device will change its self refresh rate as the DRAM operating
temperature changes, going lower at low temperatures and higher at high temperatures.

Manual Self Refresh Mode

If auto self refresh mode is not enabled, the low-power auto self refresh mode register must be manu-
ally programmed to one of the three self refresh operating modes. This mode provides the flexibility to
select a fixed self refresh operating mode at the entry of the self refresh, according to the system
memory temperature conditions. The user is responsible for maintaining the required memory
temperature condition for the mode selected during the SELF REFRESH operation. The user may
change the selected mode after exiting self refresh and before entering the next self refresh. If the
temperature condition is exceeded for the mode selected, there is a risk to data retention resulting in
loss of data.

Table 27: Auto Self Refresh Mode

Low-Power Operating Temperature
Auto Self Refresh Range for Self Refresh Mode
MR2[7] MR2[6] Mode SELF REFRESH Operation (DRAM TCASE)
0 0 Normal Variable or fixed normal self refresh rate -40ιC to 85ιC
maintains data retention at the normal oper-
ating temperature. User is required to ensure
that 85ιC DRAM TCASE (MAX) is not exceeded
to avoid any risk of data loss.
1 0 Extended Variable or fixed high self refresh rate opti- -40ιC to 105ιC
temperature mizes data retention to support the
extended temperature range.
0 1 Reduced Variable or fixed self refresh rate or any -40ιC to 45ιC
temperature other DRAM power consumption reduction
control for the reduced temperature range.
User is required to ensure 45ιC DRAM TCASE
(MAX) is not exceeded to avoid any risk of
data loss.
1 1 Auto self refresh Auto self refresh mode enabled. Self refresh All of the above
power consumption and data retention are
optimized for any given operating tempera-
ture condition.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Low-Power Auto Self Refresh Mode

Figure 34: Auto Self Refresh Ranges

IDD6

2x refresh rate

1x refresh rate

Extended
temperature
range
1/2x refresh rate

Reduced Normal
temperature temperature
range range
Tc
-40°C 45°C 85°C 105°C

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 8Gb: x4, x8, x16 DDR4 SDRAM
Multipurpose Register

Multipurpose Register
The MULTIPURPOSE REGISTER (MPR) function, MPR access mode, is used to write/read specialized
data to/from the DRAM. The MPR consists of four logical pages, MPR Page 0 through MPR Page 3, with
each page having four 8-bit registers, MPR0 through MPR3. Page 0 can be read by any of three readout
modes (serial, parallel, or staggered) while Pages 1, 2, and 3 can be read by only the serial readout
mode. Page 3 is for DRAM vendor use only. MPR mode enable and page selection is done with MRS
commands. Data bus inversion (DBI) is not allowed during MPR READ operation.
Once the MPR access mode is enabled (MR3[2] = 1), only the following commands are allowed: MRS,
RD, RDA WR, WRA, DES, REF, and RESET; RDA/WRA have the same functionality as RD/WR which
means the auto precharge part of RDA/WRA is ignored. Power-down mode and SELF REFRESH
command are not allowed during MPR enable mode. No other command can be issued within tRFC
after a REF command has been issued; 1x refresh (only) is to be used during MPR access mode. While
in MPR access mode, MPR read or write sequences must be completed prior to a REFRESH command.

Figure 35: MPR Block Diagram

Memory core
(all banks precharged)

Four multipurpose registers (pages),

MR3 [2] = 1 each with four 8-bit registers:

Data patterns (RD/WR)

Error log (RD)
Mode registers (RD)
flow
data DRAM manufacture only (RD)
PR
M

DQ,s DM_n/DBI_n, DQS_t, DQS_c

Table 28: MR3 Setting for the MPR Access Mode

Address Operation Mode Description
A[12:11] MPR data read format 00 = Serial ........... 01 = Parallel
10 = Staggered .... 11 = Reserved
A2 MPR access 0 = Standard operation (MPR not enabled)
1 = MPR data flow enabled
A[1:0] MPR page selection 00 = Page 0 .... 01 = Page 1
10 = Page 2 .... 11 = Page 3

Table 29: DRAM Address to MPR UI Translation

MPR Location [7] [6] [5] [4] [3] [2] [1] [0]
$2!- ADDRESS n !x A7 A6 A5 A4 A3 A2 A1 A0
-02 5) n 5)x UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7

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 8Gb: x4, x8, x16 DDR4 SDRAM
Multipurpose Register

Table 30: MPR Page and MPRx Definitions

Address MPR Location [7] [6] [5] [4] [3] [2] [1] [0] Note
-02 0AGE  n 2EAD OR 7RITE $ATA 0ATTERNS
BA[1:0] 00 = MPR0 0 1 0 1 0 1 0 1 Read/
Write
01 = MPR1 0 0 1 1 0 0 1 1
(default
10 = MPR2 0 0 0 0 1 1 1 1 value
11 = MPR3 0 0 0 0 0 0 0 0 listed)

-02 0AGE  n 2EAD ONLY %RROR ,OG

BA[1:0] 00 = MPR0 A7 A6 A5 A4 A3 A2 A1 A0 Read-
only
01 = MPR1 CAS_n/A WE_n/A A13 A12 A11 A10 A9 A8
15 14
10 = MPR2 PAR ACT_n BG1 BG0 BA1 BA0 A17 RAS_n/A
16
11 = MPR3 CRC CA parity error status CA C2 C1 C0
error parity latency: [5] = MR5[2],
status [4] = MR5[1], [3] = MR5[0]
-02 0AGE  n 2EAD ONLY -23 2EADOUT
BA[1:0] 00 = MPR0 hPPR sPPR RTT(WR) Temperature sen- CRC write RTT(WR) MR2[10:9] Read-
support support MR2[11] sor status2 enable only
MR2[12]
01 = MPR1 VREFDQ trainging range MR6[6]VREFDQ training value: [6:1] = Gear-
MR6[5:0] down
enable
MR3[3]
10 = MPR2CAS latency: [7:3] = MR0[6:4,2,12] CAS write latency [2:0] =
MR2[5:3]
11 = MPR3RTT(NOM): [7:5] = MR1[10:8] RTT(Park): [4:2] = MR5[8:6] RON: [1:0] =
MR1[2:1]
-02 0AGE  n 2EAD ONLY 2ESTRICTED EXCEPT FOR -02 ;=
BA[1:0] 00 = MPR0 DC DC DC DC DC DC DC DC Read-
only
01 = MPR1 DC DC DC DC DC DC DC DC
10 = MPR2 DC DC DC DC DC DC DC DC
11 = MPR3 MBIST-P DCMBIST-PPR MAC MAC MAC MAC
PR Sup- Transparency
port

Notes: 1. DC = "Don't Care"

2. MPR[4:3] 00 = Sub 1X refresh; MPR[4:3] 01 = 1X refresh; MPR[4:3] 10 = 2X refresh; MPR[4:3] 11 = Reserved

MPR Reads
MPR reads are supported using BL8 and BC4 modes. Burst length on-the-fly is not supported for MPR
reads. Data bus inversion (DBI) is not allowed during MPR READ operation; the device will ignore the
Read DBI enable setting in MR5 [12] when in MPR mode. READ commands for BC4 are supported with
a starting column address of A[2:0] = 000 or 100. After power-up, the content of MPR Page 0 has the
default values, which are defined in . MPR page 0 can be rewritten via an MPR WRITE command. The

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 8Gb: x4, x8, x16 DDR4 SDRAM
Multipurpose Register

device maintains the default values unless it is rewritten by the DRAM controller. If the DRAM
controller does overwrite the default values (Page 0 only), the device will maintain the new values
unless re-initialized or there is power loss.
Timing in MPR mode:
s Reads (back-to-back) from Page 0 may use tCCD_S or tCCD_L timing between READ commands
s Reads (back-to-back) from Pages 1, 2, or 3 may not use tCCD_S timing between READ commands;
t
CCD_L must be used for timing between READ commands

The following steps are required to use the MPR to read out the contents of a mode register (MPR Page
x, MPRy).
1. The DLL must be locked if enabled.
2. Precharge all; wait until tRP is satisfied.
3. MRS command to MR3[2] = 1 (Enable MPR data flow), MR3[12:11] = MPR read format, and MR3[1:0]
MPR page.
a) MR3[12:11] MPR read format:
i) 00 = Serial read format
ii) 01 = Parallel read format
iii) 10 = staggered read format
iv) 11 = RFU

b) MR3[1:0] MPR page:

i) 00 = MPR Page 0
ii) 01 = MPR Page 1
iii) 10 = MPR Page 2
iv) 11 = MPR Page 3

4. tMRD and tMOD must be satisfied.

5. Redirect all subsequent READ commands to specific MPRx location.
6. Issue RD or RDA command.
a) BA1 and BA0 indicate MPRx location:
i) 00 = MPR0
ii) 01 = MPR1
iii) 10 = MPR2
iv) 11 = MPR3

b) A12/BC = 0 or 1; BL8 or BC4 fixed-only, BC4 OTF not supported.

i) If BL = 8 and MR0 A[1:0] = 01, A12/BC must be set to 1 during MPR READ commands.
c) A2 = burst-type dependant:
i) BL8: A2 = 0 with burst order fixed at 0, 1, 2, 3, 4, 5, 6, 7
ii) BL8: A2 = 1 not allowed
iii) BC4: A2 = 0 with burst order fixed at 0, 1, 2, 3, T, T, T, T
iv) BC4: A2 = 1 with burst order fixed at 4, 5, 6, 7, T, T, T, T
d) A[1:0] = 00, data burst is fixed nibble start at 00.
e) 2EMAINING ADDRESS INPUTS INCLUDING ! AND "' AND "' ARE $ONT #ARE

7. After RL = AL + CL, DRAM bursts data from MPRx location; MPR readout format determined by
MR3[A12,11,1,0].
8. Steps 5 through 7 may be repeated to read additional MPRx locations.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Multipurpose Register

9. After the last MPRx READ burst, tMPRR must be satisfied prior to exiting.
10.Issue MRS command to exit MPR mode; MR3[2] = 0.
11.After the tMOD sequence is completed, the DRAM is ready for normal operation from the core (such
as ACT).

MPR Readout Format

The MPR read data format can be set to three different settings: serial, parallel, and staggered.

MPR Readout Serial Format

The serial format is required when enabling the MPR function to read out the contents of an MRx,
temperature sensor status, and the command address parity error frame. However, data bus calibra-
tion locations (four 8-bit registers) can be programmed to read out any of the three formats. The DRAM
is required to drive associated strobes with the read data similar to normal operation (such as using
MRS preamble settings).
Serial format implies that the same pattern is returned on all DQ lanes, as shown the table below, which
uses values programmed into the MPR via [7:0] as 0111 1111.

Table 31: MPR Readout Serial Format

Serial UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7
x4 Device
DQ0 0 1 1 1 1 1 1 1
DQ1 0 1 1 1 1 1 1 1
DQ2 0 1 1 1 1 1 1 1
DQ3 0 1 1 1 1 1 1 1
x8 Device
DQ0 0 1 1 1 1 1 1 1
DQ1 0 1 1 1 1 1 1 1
DQ2 0 1 1 1 1 1 1 1
DQ3 0 1 1 1 1 1 1 1
DQ4 0 1 1 1 1 1 1 1
DQ5 0 1 1 1 1 1 1 1
DQ6 0 1 1 1 1 1 1 1
DQ7 0 1 1 1 1 1 1 1
x16 Device
DQ0 0 1 1 1 1 1 1 1
DQ1 0 1 1 1 1 1 1 1
DQ2 0 1 1 1 1 1 1 1
DQ3 0 1 1 1 1 1 1 1
DQ4 0 1 1 1 1 1 1 1
DQ5 0 1 1 1 1 1 1 1
DQ6 0 1 1 1 1 1 1 1
DQ7 0 1 1 1 1 1 1 1

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 8Gb: x4, x8, x16 DDR4 SDRAM
Multipurpose Register

Table 31: MPR Readout Serial Format (Continued)

Serial UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7
DQ8 0 1 1 1 1 1 1 1
DQ9 0 1 1 1 1 1 1 1
DQ10 0 1 1 1 1 1 1 1
DQ11 0 1 1 1 1 1 1 1
DQ12 0 1 1 1 1 1 1 1
DQ13 0 1 1 1 1 1 1 1
DQ14 0 1 1 1 1 1 1 1
DQ15 0 1 1 1 1 1 1 1

MPR Readout Parallel Format

Parallel format implies that the MPR data is returned in the first data UI and then repeated in the
remaining UIs of the burst, as shown in the table below. Data pattern location 0 is the only location
used for the parallel format. RD/RDA from data pattern locations 1, 2, and 3 are not allowed with
parallel data return mode. In this example, the pattern programmed in the data pattern location 0 is
0111 1111. The x4 configuration only outputs the first four bits (0111 in this example). For the x16
configuration, the same pattern is repeated on both the upper and lower bytes.

Table 32: -02 2EADOUT n 0ARALLEL &ORMAT

Parallel UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7
x4 Device
DQ0 0 0 0 0 0 0 0 0
DQ1 1 1 1 1 1 1 1 1
DQ2 1 1 1 1 1 1 1 1
DQ3 1 1 1 1 1 1 1 1
x8 Device
DQ0 0 0 0 0 0 0 0 0
DQ1 1 1 1 1 1 1 1 1
DQ2 1 1 1 1 1 1 1 1
DQ3 1 1 1 1 1 1 1 1
DQ4 1 1 1 1 1 1 1 1
DQ5 1 1 1 1 1 1 1 1
DQ6 1 1 1 1 1 1 1 1
DQ7 1 1 1 1 1 1 1 1
x16 Device
DQ0 0 0 0 0 0 0 0 0
DQ1 1 1 1 1 1 1 1 1
DQ2 1 1 1 1 1 1 1 1
DQ3 1 1 1 1 1 1 1 1
DQ4 1 1 1 1 1 1 1 1

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 8Gb: x4, x8, x16 DDR4 SDRAM
Multipurpose Register

Table 32: -02 2EADOUT n 0ARALLEL &ORMAT

Parallel UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7
DQ5 1 1 1 1 1 1 1 1
DQ6 1 1 1 1 1 1 1 1
DQ7 1 1 1 1 1 1 1 1
DQ8 0 0 0 0 0 0 0 0
DQ9 1 1 1 1 1 1 1 1
DQ10 1 1 1 1 1 1 1 1
DQ11 1 1 1 1 1 1 1 1
DQ12 1 1 1 1 1 1 1 1
DQ13 1 1 1 1 1 1 1 1
DQ14 1 1 1 1 1 1 1 1
DQ15 1 1 1 1 1 1 1 1

MPR Readout Staggered Format

Staggered format of data return is defined as the staggering of the MPR data across the lanes. In this
mode, an RD/RDA command is issued to a specific data pattern location and then the data is returned
on the DQ from each of the different data pattern locations. For the x4 configuration, an RD/RDA to
data pattern location 0 will result in data from location 0 being driven on DQ0, data from location 1
being driven on DQ1, data from location 2 being driven on DQ2, and so on, as shown below. Similarly,
an RD/RDA command to data pattern location 1 will result in data from location 1 being driven on
DQ0, data from location 2 being driven on DQ1, data from location 3 being driven on DQ2, and so on.
Examples of different starting locations are also shown.

Table 33: MPR Readout Staggered Format, x4

x4 READ MPR0 Command x4 READ MPR1 Command x4 READ MPR2 Command x4 READ MPR3 Command
Stagger UI[7:0] Stagger UI[7:0] Stagger UI[7:0] Stagger UI[7:0]
DQ0 MPR0 DQ0 MPR1 DQ0 MPR2 DQ0 MPR3
DQ1 MPR1 DQ1 MPR2 DQ1 MPR3 DQ1 MPR0
DQ2 MPR2 DQ2 MPR3 DQ2 MPR0 DQ2 MPR1
DQ3 MPR3 DQ3 MPR0 DQ3 MPR1 DQ3 MPR2

It is expected that the DRAM can respond to back-to-back RD/RDA commands to the MPR for all DDR4
frequencies so that a sequence (such as the one that follows) can be created on the data bus with no
bubbles or clocks between read data. In this case, the system memory controller issues a sequence of
RD(MPR0), RD(MPR1), RD(MPR2), RD(MPR3), RD(MPR0), RD(MPR1), RD(MPR2), and RD(MPR3).

Table 34: -02 2EADOUT 3TAGGERED &ORMAT X n #ONSECUTIVE 2%!$S

Stagger UI[7:0] UI[15:8] UI[23:16] UI[31:24] UI[39:32] UI[47:40] UI[55:48] UI[63:56]
DQ0 MPR0 MPR1 MPR2 MPR3 MPR0 MPR1 MPR2 MPR3
DQ1 MPR1 MPR2 MPR3 MPR0 MPR1 MPR2 MPR3 MPR0
DQ2 MPR2 MPR3 MPR0 MPR1 MPR2 MPR3 MPR0 MPR1
DQ3 MPR3 MPR0 MPR1 MPR2 MPR3 MPR0 MPR1 MPR2

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 8Gb: x4, x8, x16 DDR4 SDRAM
Multipurpose Register

For the x8 configuration, the same pattern is repeated on the lower nibble as on the upper nibble.
READs to other MPR data pattern locations follow the same format as the x4 case. A read example to
MPR0 for x8 and x16 configurations is shown below.

Table 35: MPR Readout Staggered Format, x8 and x16

x8 READ MPR0 Command x16 READ MPR0 Command x16 READ MPR0 Command
Stagger UI[7:0] Stagger UI[7:0] Stagger UI[7:0]
DQ0 MPR0 DQ0 MPR0 DQ8 MPR0
DQ1 MPR1 DQ1 MPR1 DQ9 MPR1
DQ2 MPR2 DQ2 MPR2 DQ10 MPR2
DQ3 MPR3 DQ3 MPR3 DQ11 MPR3
DQ4 MPR0 DQ4 MPR0 DQ12 MPR0
DQ5 MPR1 DQ5 MPR1 DQ13 MPR1
DQ6 MPR2 DQ6 MPR2 DQ14 MPR2
DQ7 MPR3 DQ7 MPR3 DQ15 MPR3

MPR READ Waveforms

The following waveforms show MPR read accesses.

Figure 36: MPR READ Timing

T0 Ta0 Ta1 Tb0 Tc0 Tc1 Tc2 Tc3 Td0 Td1 Te0 Tf0 Tf1
CK_c
CK_t
MPE Enable MPE Disable
Command PREA MRS1 DES READ DES DES DES DES DES DES MRS3 Valid 4 DES
tRP tMOD tMPRR tMOD

Address Valid Valid Valid Add2 Valid Valid Valid Valid Valid Valid Valid Valid Valid

CKE

PL5 + AL + CL

DQS_t,
DQS_c

DQ UI0 UI1 UI2 UI5 UI6 UI7

Time Break Don’t Care

Notes: 1. tCCD_S = 4tCK, Read Preamble = 1tCK.

2. Address setting:
A[1:0] = 00b (data burst order is fixed starting at nibble, always 00b here)
A2 = 0b (for BL = 8, burst order is fixed at 0, 1, 2, 3, 4, 5, 6, 7)
BA1 and BA0 indicate the MPR location
! AND OTHER ADDRESS PINS ARE $ONT #ARE  INCLUDING "' AND "' ! IS $ONT #ARE WHEN -2 !;=  
or 10 and must be 1b when MR0 A[1:0] = 01
3. Multipurpose registers read/write disable (MR3 A2 = 0).
4. Continue with regular DRAM command.
5. Parity latency (PL) is added to data output delay when CA parity latency mode is enabled.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Multipurpose Register

Figure 37: MPR Back-to-Back READ Timing

T0 T1 T2 T3 T4 T5 T6 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Ta8 Ta9 Ta10
CK_c
CK_t

Command DES READ DES DES DES READ DES DES DES DES DES DES DES DES DES DES DES DES
tCCD_S1

Address Valid Add2 Valid Add2 Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid

CKE
PL3 + AL + CL

DQS_t,
DQS_c

DQ UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7 UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7

DQS_t,
DQS_c

DQ UI0 UI1 UI2 UI3 UI0 UI1 UI2 UI3

Time Break Don’t Care

Notes: 1. tCCD_S = 4tCK, Read Preamble = 1tCK.

2. Address setting:
A[1:0] = 00b (data burst order is fixed starting at nibble, always 00b here)
A2 = 0b (for BL = 8, burst order is fixed at 0, 1, 2, 3, 4, 5, 6, 7; for BC = 4, burst order is fixed at 0, 1, 2, 3, T, T, T, T)
BA1 and BA0 indicate the MPR location
! AND OTHER ADDRESS PINS ARE $ONT #ARE  INCLUDING "' AND "' ! IS $ONT #ARE WHEN -2 !;=  
or 10 and must be 1b when MR0 A[1:0] = 01
3. Parity latency (PL) is added to data output delay when CA parity latency mode is enabled.

Figure 38: MPR READ-to-WRITE Timing

T0 T1 T2 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Tb0 Tb1 Tb2
CK_c
CK_t

Command READ DES DES DES DES DES DES DES DES DES WRITE DES DES
tMPRR

Address Add1 Valid Valid Valid Valid Valid Valid Valid Valid Valid Add2 Valid Valid

CKE

PL3 + AL + CL

DQS_t,
DQS_c

DQ UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7

Time Break Don’t Care

Notes: 1. Address setting:

A[1:0] = 00b (data burst order is fixed starting at nibble, always 00b here)
A2 = 0b (for BL = 8, burst order is fixed at 0, 1, 2, 3, 4, 5, 6, 7)
BA1 and BA0 indicate the MPR location
! AND OTHER ADDRESS PINS ARE $ONT #ARE  INCLUDING "' AND "' ! IS $ONT #ARE WHEN -2 !;=  
and must be 1b when MR0 A[1:0] = 01
2. Address setting:
BA1 and BA0 indicate the MPR location
A[7:0] = data for MPR
BA1 and BA0 indicate the MPR location
! AND OTHER ADDRESS PINS ARE $ONT #ARE
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 8Gb: x4, x8, x16 DDR4 SDRAM
Multipurpose Register

3. Parity latency (PL) is added to data output delay when CA parity latency mode is enabled.

MPR Writes
MPR access mode allows 8-bit writes to the MPR Page 0 using the address bus A[7:0]. Data bus inver-
sion (DBI) is not allowed during MPR WRITE operation. The DRAM will maintain the new written
values unless re-initialized or there is power loss.
The following steps are required to use the MPR to write to mode register MPR Page 0.
1. The DLL must be locked if enabled.
2. Precharge all; wait until tRP is satisfied.
3. MRS command to MR3[2] = 1 (enable MPR data flow) and MR3[1:0] = 00 (MPR Page 0); writes to 01,
10, and 11 are not allowed.
4. tMRD and tMOD must be satisfied.
5. Redirect all subsequent WRITE commands to specific MPRx location.
6. Issue WR or WRA command:
a) BA1 and BA0 indicate MPRx location
i) 00 = MPR0
ii) 01 = MPR1
iii) 10 = MPR2
iv) 11 = MPR3

b) A[7:0] = data for MPR Page 0, mapped A[7:0] to UI[7:0].

c) 2EMAINING ADDRESS INPUTS INCLUDING ! AND "' AND "' ARE $ONT #ARE

7. tWR_MPR must be satisfied to complete MPR WRITE.

8. Steps 5 through 7 may be repeated to write additional MPRx locations.
9. After the last MPRx WRITE, tMPRR must be satisfied prior to exiting.
10.Issue MRS command to exit MPR mode; MR3[2] = 0.
11.When the tMOD sequence is completed, the DRAM is ready for normal operation from the core
(such as ACT).

MPR WRITE Waveforms

The following waveforms show MPR write accesses.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Multipurpose Register

Figure 39: MPR WRITE and WRITE-to-READ Timing

T0 Ta0 Ta1 Tb0 Tc0 Tc1 Tc2 Td0 Td1 Td2 Td3 Td4 Td5
CK_c
CK_t
MPR Enable
Command PREA MRS1 DES WRITE DES DES READ DES DES DES DES DES DES
tRP tMOD tWR_MPR

Address Valid Valid Valid Add2 Valid Valid Add Valid Valid Valid Add2 Valid Valid

CKE

PL3 + AL + CL

DQS_t,
DQS_c

DQ UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7

Time Break Don’t Care

Notes: 1. Multipurpose registers read/write enable (MR3 A2 = 1).

2. Address setting:
BA1 and BA0 indicate the MPR location
! AND OTHER ADDRESS PINS ARE $ONT #ARE
3. Parity latency (PL) is added to data output delay when CA parity latency mode is enabled.

Figure 40: MPR Back-to-Back WRITE Timing

T0 T1 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Ta8 Ta9 Ta10
CK_c
CK_t

Command WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES
tWR_MPR

Address Add1 Valid Valid Add1 Valid Valid Add Valid Valid Valid Valid Valid Valid

CKE

DQS_t,
DQS_c

DQ

Time Break Don’t Care

Note: 1. Address setting:

BA1 and BA0 indicate the MPR location
A[7:0] = data for MPR
! AND OTHER ADDRESS PINS ARE $ONT #ARE

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 8Gb: x4, x8, x16 DDR4 SDRAM
Multipurpose Register

MPR REFRESH Waveforms

The following waveforms show MPR accesses interaction with refreshes.

Figure 41: REFRESH Timing

T0 Ta0 Ta1 Tb0 Tb1 Tb2 Tb3 Tb4 Tc0 Tc1 Tc2 Tc3 Tc4
CK_c
CK_t
MPR Enable
Command PREA MRS1 DES REF2 DES DES DES DES DES DES Valid Valid Valid
tRP tMOD tRFC

Address Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid

Time Break Don’t Care

Notes: 1. Multipurpose registers read/write enable (MR3 A2 = 1). Redirect all subsequent read and writes to MPR locations.
2. 1x refresh is only allowed when MPR mode is enabled.

Figure 42: READ-to-REFRESH Timing

T0 T1 T2 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Ta8 Ta9
CK_c
CK_t

Command READ DES DES DES DES DES DES DES DES DES REF2 DES DES

Address Add1 Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid

CKE

PL + AL + CL (4 + 1) Clocks tRFC

BL = 8
DQS_t, DQS_c

DQ UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7

BC = 4
DQS_t, DQS_c

DQ UI0 UI1 UI2 UI3

Time Break Don’t Care

Notes: 1. Address setting:

A[1:0] = 00b (data burst order is fixed starting at nibble, always 00b here)
A2 = 0b (for BL = 8, burst order is fixed at 0, 1, 2, 3, 4, 5, 6, 7)
BA1 and BA0 indicate the MPR location
! AND OTHER ADDRESS PINS ARE $ONT #ARE  INCLUDING "' AND "' ! IS $ONT #ARE WHEN -2 !;=  
or 10, and must be 1b when MR0 A[1:0] = 01
2. 1x refresh is only allowed when MPR mode is enabled.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Multipurpose Register

Figure 43: WRITE-to-REFRESH Timing

T0 T1 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Ta8 Ta9 Ta10
CK_c
CK_t

Command WRITE DES DES DES REF2 DES DES DES DES DES DES DES DES
tWR_MPR tRFC

Address Add1 Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid

CKE

DQS_t,
DQS_c

DQ

Time Break Don’t Care

Notes: 1. Address setting:

BA1 and BA0 indicate the MPR location
A[7:0] = data for MPR
! AND OTHER ADDRESS PINS ARE $ONT #ARE
2. 1x refresh is only allowed when MPR mode is enabled.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Gear-Down Mode

Gear-Down Mode
The DDR4 SDRAM defaults in 1/2 rate (1N) clock mode and uses a low-frequency MRS command (the
MRS command has relaxed setup and hold) followed by a sync pulse (first CS pulse after MRS setting)
to align the proper clock edge for operating the control lines CS_n, CKE, and ODT when in 1/4 rate (2N)
mode. Gear-down mode is only supported at DDR4-2666 and faster. For operation in 1/2 rate mode,
neither an MRS command or a sync pulse is required. Gear-down mode may only be entered during
initialization or self refresh exit and may only be exited during self refresh exit. CAL mode and CA parity
mode must be disabled prior to gear-down mode entry. The two modes may be enabled after tSYN-
C_GEAR and tCMD_GEAR periods have been satisfied. The general sequence for operation in 1/4 rate
during initialization is as follows:
1. The device defaults to a 1N mode internal clock at power-up/reset.
2. Assertion of reset.
3. Assertion of CKE enables the DRAM.
4. MRS is accessed with a low-frequency N έ tCK gear-down MRS command. (NtCK static MRS
command is qualified by 1N CS_n. )
5. The memory controller will send a 1N sync pulse with a low-frequency N έ tCK NOP command.
t
SYNC_GEAR is an even number of clocks. The sync pulse is on an even edge clock boundary from
the MRS command.
6. Initialization sequence, including the expiration of tDLLK and tZQinit, starts in 2N mode after
t
CMD_GEAR from 1N sync pulse.

The device resets to 1N gear-down mode after entering self refresh. The general sequence for operation
in gear-down after self refresh exit is as follows:
1. MRS is set to 1, via MR3[3], with a low-frequency N έ tCK gear-down MRS command.
a) The NtCK static MRS command is qualified by 1N CS_n, which meets tXS or tXS_ABORT.
b) Only a REFRESH command may be issued to the DRAM before the NtCK static MRS command.

2. The DRAM controller sends a 1N sync pulse with a low-frequency N έ tCK NOP command.
a) tSYNC_GEAR is an even number of clocks.
b) The sync pulse is on even edge clock boundary from the MRS command.

3. A valid command not requiring locked DLL is available in 2N mode after tCMD_GEAR from the 1N
sync pulse.
a) A valid command requiring locked DLL is available in 2N mode after tXSDLL or tDLLK from the
1N sync pulse.
4. If operation is in 1N mode after self refresh exit, N έ tCK MRS command or sync pulse is not required
during self refresh exit. The minimum exit delay to the first valid command is tXS, or tXS_ABORT.
The DRAM may be changed from 2N to 1N by entering self refresh mode, which will reset to 1N mode.
Changing from 2N to by any other means can result in loss of data and make operation of the DRAM
uncertain.
When operating in 2N gear-down mode, the following MR settings apply:
s CAS latency (MR0[6:4,2]): Even number of clocks
s Write recovery and read to precharge (MR0[11:9]): Even number of clocks
s Additive latency (MR1[4:3]): CL - 2
s CAS WRITE latency (MR2 A[5:3]): Even number of clocks
s CS to command/address latency mode (MR4[8:6]): Even number of clocks
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 8Gb: x4, x8, x16 DDR4 SDRAM
Gear-Down Mode

s CA parity latency mode (MR5[2:0]): Even number of clocks

Figure 44: Clock Mode Change from 1/2 Rate to 1/4 Rate (Initialization)
TdkN1 TdkN + Neven2

CK_c
CK_t
tCKSRX

DRAM
internal CLK

RESET_n

CKE
tXPR_GEAR tSYNC_GEAR tCMD_GEAR

1N sync pulse 2N mode

CS_n
tGEAR_setup tGEAR_hold tGEAR_setup tGEAR_hold

Command MRS NOP Valid

Configure DRAM
to 1/4 rate Time Break Don’t Care

Notes: 1. After tSYNC_GEAR from GEAR-DOWN command, internal clock rate is changed at TdkN.
2. After tSYNC_GEAR + tCMD_GEAR from GEAR-DOWN command, both internal clock rate and command cycle are
changed at TdkN + Neven.

Figure 45: Clock Mode Change After Exiting Self Refresh

TdkN1 TdkN + Neven2

CK_c
L

CK_t

DRAM
internal CLK

CKE
tXPR_GEAR tSYNC_GEAR tCMD_GEAR

1N sync pulse 2N mode

CS_n
tGEAR_setup tGEAR_hold tGEAR_setup tGEAR_hold

Command MRS NOP Valid

Configure DRAM
to 1/4 rate Time Break Don’t Care

Notes: 1. After tSYNC_GEAR from GEAR-DOWN command, internal clock rate is changed at TdkN.
2. After tSYNC_GEAR + tCMD_GEAR from GEAR-DOWN command, both internal clock rate and command cycle are
changed at TdkN + Neven.

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 Figure 46: Comparison Between Gear-Down Disable and Gear-Down Enable
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T0 T1 T2 T3 T15 T16 T17 T18 T19 T30 T31 T32 T33 T34 T35 T36 T37 T38
CK_c
CK_t
AL = 0 (geardown = disable)

Command ACT DES DES DES DES READ DES DES DES DES DES DES DES DES DES DES DES DES

DQ DO DO DO DO DO DO DO DO
n n+ 1 n+ 2 n+ 3 n+ 4 n+ 5 n+ 6 n+ 7
tRCD = 16 RL =CL= 16 (AL = 0)

AL = CL - 1 (geardown = disable) READ

Command ACT READ DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES

DQ DO DO DO DO DO DO DO DO
n n+ 1 n+ 2 n+ 3 n+ 4 n+ 5 n+ 6 n+ 7
RL = AL + CL = 31 (AL = CL - 1 = 15)

READ
Command ACT READ DES DES DES DES DES DES DES

DQ DO DO DO DO DO DO DO DO
n n+ 1 n+ 2 n+ 3 n+ 4 n+ 5 n+ 6 n+ 7
AL + CL = RL = 30 (AL = CL - 2 = 14)

Time Break Transitioning Data Don’t Care

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Gear-Down Mode
 8Gb: x4, x8, x16 DDR4 SDRAM
Maximum Power-Saving Mode

Maximum Power-Saving Mode

Maximum power-saving mode provides the lowest power mode where data retention is not required.
When the device is in the maximum power-saving mode, it does not maintain data retention or
respond to any external command, except the MAXIMUM POWER SAVING MODE EXIT command
AND DURING THE ASSERTION OF 2%3%4?N SIGNAL ,/7 4HIS MODE IS MORE LIKE A hHIBERNATE MODEv THAN A
typical power-saving mode. The intent is to be able to park the DRAM at a very low-power state; the
device can be switched to an active state via the per-DRAM addressability (PDA) mode.

Maximum Power-Saving Mode Entry

Maximum power-saving mode is entered through an MRS command. For devices with shared
control/address signals, a single DRAM device can be entered into the maximum power-saving mode
using the per-DRAM addressability MRS command. Large CS_n hold time to CKE upon the mode exit
could cause DRAM malfunction; as a result, CA parity, CAL, and gear-down modes must be disabled
prior to the maximum power-saving mode entry MRS command.
The MRS command may use both address and DQ information, as defined in the Per-DRAM Address-
ability section. As illustrated in the figure below, after tMPED from the mode entry MRS command, the
DRAM is not responsive to any input signals except CKE, CS_n, and RESET_n. All other inputs are
disabled (external input signals may become High-Z). The system will provide a valid clock until
t
CKMPE expires, at which time clock inputs (CK) should be disabled (external clock signals may
become High-Z).

Figure 47: Maximum Power-Saving Mode Entry

Ta0 Ta1 Ta2 Tb0 Tb1 Tb3 Tc0 Tc1 Tc2 Tc3 Tc4 Tc5 Tc6 Tc7 Tc8 Tc9 Tc10 Tc11
CK_c
CK_t
tCKMPE

MR4[A1=1]
MPSM Enable)
Command DES MRS DES DES DES
tMPED

Address Valid

CS_n

CKE CKE LOW makes CS_n a care; CKE LOW followed by CS_n LOW followed by CKE HIGH exits mode

RESET_n

Time Break Don’t Care

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 8Gb: x4, x8, x16 DDR4 SDRAM
Maximum Power-Saving Mode

Maximum Power-Saving Mode Entry in PDA

The sequence and timing required for the maximum power-saving mode with the per-DRAM address-
ability enabled is illustrated in the figure below.

Figure 48: Maximum Power-Saving Mode Entry with PDA

Ta0 Ta1 Ta2 Tb0 Tb1 Tb3 Tb4 Tb5 Tb6 Tb7 Tb8 Tb9 Tc0 Tc1 Tc2 Td0 Td1 Td2
CK_c
CK_t

MR4[A1 = 1]
MPSM Enable)
Command DES MRS DES DES DES DES DES DES DES DES DES DES DES DES

tCKMPE

CS_n

CKE
AL + CWL tMPED

DQS_t
DQS_c tPDA_S tPDA_H

DQ0

RESET_n

Time Break Don’t Care

CKE Transition During Maximum Power-Saving Mode

The following figure shows how to maintain maximum power-saving mode even though the CKE input
may toggle. To prevent the device from exiting the mode, CS_n should be HIGH at the CKE
LOW-to-HIGH edge, with appropriate setup (tMPX_S) and hold (tMPX_H) timings.

Figure 49: Maintaining Maximum Power-Saving Mode with CKE Transition

CLK

CMD

CS_n
tMPX_S tMPX_HH

CKE

RESET_n

Don’t Care

Maximum Power-Saving Mode Exit

To exit the maximum power-saving mode, CS_n should be LOW at the CKE LOW-to-HIGH transition,
with appropriate setup (tMPX_S) and hold (tMPX_LH) timings, as shown in the figure below. Because
the clock receivers (CK_t, CK_c) are disabled during this mode, CS_n = LOW is captured by the rising
edge of the CKE signal. If the CS_n signal level is detected LOW, the DRAM clears the maximum
power-saving mode MRS bit and begins the exit procedure from this mode. The external clock must be
restarted and be stable by tCKMPX before the device can exit the maximum power-saving mode.
During the exit time (tXMP), only NOP and DES commands are allowed: NOP during tMPX_LH and

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 8Gb: x4, x8, x16 DDR4 SDRAM
Maximum Power-Saving Mode

DES the remainder of tXMP. After tXMP expires, valid commands not requiring a locked DLL are
allowed; after tXMP_DLL expires, valid commands requiring a locked DLL are allowed.

Figure 50: Maximum Power-Saving Mode Exit

Ta0 Ta1 Ta2 Ta3 Tb0 Tb1 Tb2 Tb3 Tc0 Tc1 Tc2 Tc4 Td0 Td1 Td2 Td3 Te0 Te1
CK_c
CK_t
tCKMPX

Command NOP NOP NOP NOP NOP DES DES DES DES Valid DES DES
tMPX_LH

CS_n

tMPX_S

CKE
tXMP

tXMP_DLL

RESET_n

Time Break Don’t Care

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 8Gb: x4, x8, x16 DDR4 SDRAM
Command/Address Parity

Command/Address Parity
Command/address (CA) parity takes the CA parity signal (PAR) input carrying the parity bit for the
generated address and commands signals and matches it to the internally generated parity from the
captured address and commands signals. CA parity is supported in the DLL enabled state only; if the
DLL is disabled, CA parity is not supported.

Figure 51: Command/Address Parity Operation

DRAM Controller DRAM

CMD/ADDR CMD/ADDR

Even parity CMD/ADDR Even parity

GEN GEN
Even parity bit

Even parity bit

Compare
parity
bit

CA parity is disabled or enabled via an MRS command. If CA parity is enabled by programming a

non-zero value to CA parity latency in the MR, the DRAM will ensure that there is no parity error before
executing commands. There is an additional delay required for executing the commands versus when
parity is disabled. The delay is programmed in the MR when CA parity is enabled (parity latency) and
applied to all commands which are registered by CS_n (rising edge of CK_t and falling CS_n). The
command is held for the time of the parity latency (PL) before it is executed inside the device. The
command captured by the input clock has an internal delay before executing and is determined with
PL. ALERT_n will go active when the DRAM detects a CA parity error.
CA parity covers ACT_n, RAS_n/A16, CAS_n/A15, WE_n/A14, the address bus including bank address
and bank group bits, and C[2:0] on 3DS devices; the control signals CKE, ODT, and CS_n are not
covered. For example, for a 4Gb x4 monolithic device, parity is computed across BG[1:0], BA[1:0],
A16/RAS_n, A15/CAS_n, A14/ WE_n, A[13:0], and ACT_n. The DRAM treats any unused address pins
internally as zeros; for example, if a common die has stacked pins but the device is used in a monolithic
application, then the address pins used for stacking and not connected are treated internally as zeros.
The convention for parity is even parity; for example, valid parity is defined as an even number of ones
across the inputs used for parity computation combined with the parity signal. In other words, the
parity bit is chosen so that the total number of ones in the transmitted signal, including the parity bit,
is even.
If a DRAM device detects a CA parity error in any command qualified by CS_n, it will perform the
following steps:
1. Ignore the erroneous command. Commands in the MAX NnCK window (tPAR_UNKNOWN) prior to
the erroneous command are not guaranteed to be executed. When a READ command in this NnCK
window is not executed, the device does not activate DQS outputs. If WRITE CRC is enabled and a
WRITE CRC occurs during the tPAR_UNKNOWN window, the WRITE CRC Error Status Bit located
at MR5[3] may or may not get set. When CA Parity and WRITE CRC are both enabled and a CA Parity
occurs, the WRITE CRC Error Status Bit should be reset.
2. Log the error by storing the erroneous command and address bits in the MPR error log.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Command/Address Parity

3. Set the parity error status bit in the mode register to 1. The parity error status bit must be set before
the ALERT_n signal is released by the DRAM (that is, tPAR_ALERT_ON + tPAR_ALERT_PW (MIN)).
4. Assert the ALERT_n signal to the host (ALERT_n is active LOW) within tPAR_ALERT_ON time.
5. Wait for all in-progress commands to complete. These commands were received tPAR_UNKOWN
before the erroneous command.
6. Wait for tRAS (MIN) before closing all the open pages. The DRAM is not executing any commands
during the window defined by (tPAR_ALERT_ON + tPAR_ALERT_PW).
7. After tPAR_ALERT_PW (MIN) has been satisfied, the device may de-assert ALERT_n.
a) When the device is returned to a known precharged state, ALERT_n is allowed to be de-asserted.
8. After (tPAR_ALERT_PW (MAX)) the DRAM is ready to accept commands for normal operation.
Parity latency will be in effect; however, parity checking will not resume until the memory controller
has cleared the parity error status bit by writing a zero. The DRAM will execute any erroneous
commands until the bit is cleared; unless persistent mode is enabled.

s It is possible that the device might have ignored a REFRESH command during tPAR_ALERT_PW or
the REFRESH command is the first erroneous frame, so it is recommended that extra REFRESH
cycles be issued, as needed.
s The parity error status bit may be read anytime after tPAR_ALERT_ON + tPAR_ALERT_PW to deter-
mine which DRAM had the error. The device maintains the error log for the first erroneous command
until the parity error status bit is reset to a zero or a second CA parity occurs prior to resetting.
The mode register for the CA parity error is defined as follows: CA parity latency bits are write only, the
parity error status bit is read/write, and error logs are read-only bits. The DRAM controller can only
program the parity error status bit to zero. If the DRAM controller illegally attempts to write a 1 to the
parity error status bit, the DRAM can not be certain that parity will be checked; the DRAM may opt to
block the DRAM controller from writing a 1 to the parity error status bit.
The device supports persistent parity error mode. This mode is enabled by setting MR5[9] = 1; when
enabled, CA parity resumes checking after the ALERT_n is de-asserted, even if the parity error status
bit remains a 1. If multiple errors occur before the error status bit is cleared the error log in MPR Page
 SHOULD BE TREATED AS $ONT #ARE )N PERSISTENT PARITY ERROR MODE THE !,%24?N PULSE WILL BE ASSERTED
and de-asserted by the DRAM as defined with the MIN and MAX value tPAR_ALERT_PW. The DRAM
controller must issue DESELECT commands once it detects the ALERT_n signal, this response time is
defined as tPAR_ALERT_RSP. The following figures capture the flow of events on the CA bus and the
ALERT_n signal.

Table 36: Mode Register Setting for CA Parity

CA Parity Latency Erroneous CA
MR5[2:0]1 Applicable Speed Bin Parity Error Status Parity Persistent Mode Frame
000 = Disabled N/A
001 = 4 clocks 1600, 1866, 2133
010 = 5 clocks 2400, 2666 C[2:0], ACT_n, BG1,
011 = 6 clocks 2933, 3200 BG0, BA[1:0], PAR,
MR5 [4] 0 = Clear MR5 [9] 0 = Disabled-
A17, A16/RAS_n,
100 = 8 clocks RFU MR5 [4] 1 = Error MR5 [9] 1 = Enabled
A15/CAS_n,
101 = Reserved RFU A14/WE_n, A[13:0]

110 = Reserved RFU

111 = Reserved RFU

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 8Gb: x4, x8, x16 DDR4 SDRAM
Command/Address Parity

Notes: 1. Parity latency is applied to all commands.

2. Parity latency can be changed only from a CA parity disabled state; for example, a direct change from PL = 3 to PL
= 4 is not allowed. The correct sequence is PL = 3 to disabled to PL = 4.
3. Parity latency is applied to WRITE and READ latency. WRITE latency = AL + CWL + PL. READ latency = AL + CL + PL.

Figure 52: Command/Address Parity During Normal Operation

T0 T1 Ta0 Ta1 Ta2 Tb0 Tc0 Tc1 Td0 Te0 Te1
CK_c
CK_t

Command/
Valid 2 Valid 2 Valid 2 Error Valid Valid Valid DES2 DES2 Valid 3 Valid 3
Address
t > 2nCK tRP

tPAR_UNKNOWN 2 tPAR_ALERT_ON tPAR_ALERT_PW 1

ALERT_n

Valid 2 DES2 Command execution unknown

Error Valid Command not executed Don’t Care Time Break

Valid 3 Command executed

Notes: 1. DRAM is emptying queues. Precharge all and parity checking are off until parity error status bit is cleared.
2. Command execution is unknown; the corresponding DRAM internal state change may or may not occur. The
DRAM controller should consider both cases and make sure that the command sequence meets the specifications.
If WRITE CRC is enabled and a WRITE CRC occurs during the tPAR_UNKNOWN window, the WRITE CRC Error Status
Bit located at MR5[3] may or may not get set.
3. Normal operation with parity latency (CA parity persistent error mode disabled). Parity checking is off until parity
error status bit is cleared.

Figure 53: Persistent CA Parity Error Checking Operation

T0 T1 Ta0 Ta1 Ta2 Tb0 Tc0 Tc1 Td0 Te0 Te1
CK_c
CK_t

Command/
Valid 2 Valid 2 Valid 2 Error Valid Valid Valid DES DES DES Valid 3
Address
tPAR_ALERT_RSP t > 2nCK tRP

tPAR_UNKNOWN 2 tPAR_ALERT_ON tPAR_ALERT_PW 1

ALERT_n

Valid 2 DES Command execution unknown

Error Valid Command not executed
Valid 3 Command executed Don’t Care Time Break

Notes: 1. DRAM is emptying queues. Precharge all and parity check re-enable finished by tPAR_ALERT_PW.
2. Command execution is unknown; the corresponding DRAM internal state change may or may not occur. The
DRAM controller should consider both cases and make sure that the command sequence meets the specifications.
If WRITE CRC is enabled and a WRITE CRC occurs during the tPAR_UNKNOWN window, the WRITE CRC Error Status
Bit located at MR5[3] may or may not get set
3. Normal operation with parity latency and parity checking (CA parity persistent error mode enabled).

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 8Gb: x4, x8, x16 DDR4 SDRAM
Command/Address Parity

Figure 54: #! 0ARITY %RROR #HECKING n 32% !TTEMPT

T0 T1 Ta0 Ta1 Tb0 Tb1 Tc0 Tc1 Td0 Td1 Td2 Td3 Te0 Te1
CK_c
CK_t
tCPDED + PL tXP + PL

Command/
DES1, 5 Error2 DES1 DES6 DES6 DES5 Valid 3
Address
tIS tIS

CKE
t > 2nCK tRP
tIH
tPAR_ALERT_ON
Note 4 tPAR_ALERT_PW 1

ALERT_n

DES1, 5 DES6 DES5 Command execution unknown

Error2 DES1 Command not executed
Valid 3 Command executed Don’t Care Time Break

Notes: 1. Only DESELECT command is allowed.

2. SELF REFRESH command error. The DRAM masks the intended SRE command and enters precharge power-down.
3. Normal operation with parity latency (CA parity persistent error mode disabled). Parity checking is off until the
parity error status bit cleared.
4. The controller cannot disable the clock until it has been capable of detecting a possible CA parity error.
5. Command execution is unknown; the corresponding DRAM internal state change may or may not occur. The
DRAM controller should consider both cases and make sure that the command sequence meets the specifications.
6. Only a DESELECT command is allowed; CKE may go HIGH prior to Tc2 as long as DES commands are issued.

Figure 55: #! 0ARITY %RROR #HECKING n 328 !TTEMPT

T0 Ta0 Ta1 Tb0 Tb1 Tc0 Tc1 Tc2 Td0 Td1 Te0 Tf0
CK_c
CK_t

Command/
SRX1 DES DES Error2 Valid 2 Valid 2 Valid 2 DES2, 3 DES2, 3 Valid 2, 4, 5 Valid 2, 4, 6 Valid 2, 4, 7
Address
t > 2nCK tRP
tIS

CKE
tPAR_UNKNOWN tPAR_ALERT_ON tPAR_ALERT_PW

ALERT_n
tXS_FAST 8

tXS

tXSDLL

SRX1 DES Valid 3, 5 Command execution unknown

Error Valid Command not executed Time Break Don’t Care

Valid 4,5,6,7 Command executed

Notes: 1. Self refresh abort = disable: MR4 [9] = 0.

2. Input commands are bounded by tXSDLL, tXS, tXS_ABORT, and tXS_FAST timing.
3. Command execution is unknown; the corresponding DRAM internal state change may or may not occur. The
DRAM controller should consider both cases and make sure that the command sequence meets the specifications.
4. Normal operation with parity latency (CA parity persistent error mode disabled). Parity checking off until parity
error status bit cleared.
5. Only an MRS (limited to those described in the SELF REFRESH Operation section), ZQCS, or ZQCL command is
allowed.
6. Valid commands not requiring a locked DLL.
7. Valid commands requiring a locked DLL.
8. This figure shows the case from which the error occurred after tXS_FAST. An error may also occur after tXS_ABORT
and tXS.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Command/Address Parity

Figure 56: #! 0ARITY %RROR #HECKING n 0$%0$8

T0 T1 Ta0 Ta1 Tb0 Tb1 Tc0 Tc1 Td0 Td1 Td2 Td3 Te0 Te1
CK_c
CK_t
tCPDED + PL tXP + PL

Command/
Error2 DES1 DES1 DES5 DES5 DES4 Valid 3
Address
tIS tIS

CKE
t > 2nCK tRP
tIH
tPAR_ALERT_ON tPAR_ALERT_PW 1

ALERT_n

DES4 DES5 Command execution unknown

Error2 DES1 Command not executed
Valid 3 Command executed Don’t Care Time Break

Notes: 1. Only DESELECT command is allowed.

2. Error could be precharge or activate.
3. Normal operation with parity latency (CA parity persistent error mode disabled). Parity checking is off until parity
error status bit cleared.
4. Command execution is unknown; the corresponding DRAM internal state change may or may not occur. The
DRAM controller should consider both cases and make sure that the command sequence meets the specifications.
5. Only a DESELECT command is allowed; CKE may go HIGH prior to Td2 as long as DES commands are issued.

Figure 57: 0ARITY %NTRY 4IMING %XAMPLE n tMRD_PAR

Ta0 Ta1 Ta2 Tb0 Tb1 Tb2
CK_c
CK_t

Command DES MRS DES DES MRS DES

Parity latency PL = 0 Updating setting PL = N

tMRD_PAR

Enable
parity
Time Break Don’t Care

Note: 1. tMRD_PAR = tMOD + N; where N is the programmed parity latency.

Figure 58: 0ARITY %NTRY 4IMING %XAMPLE n tMOD_PAR

Ta0 Ta1 Ta2 Tb0 Tb1 Tb2
CK_c
CK_t

Command DES MRS DES DES Valid DES

Parity latency PL = 0 Updating setting PL = N

tMOD_PAR

Enable
parity
Time Break Don’t Care

t
Note: 1. MOD_PAR = tMOD + N; where N is the programmed parity latency.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Command/Address Parity

Figure 59: 0ARITY %XIT 4IMING %XAMPLE n tMRD_PAR

Ta0 Ta1 Ta2 Tb0 Tb1 Tb2
CK_c
CK_t

Command DES MRS DES DES MRS DES

Parity latency PL = N Updating setting

tMRD_PAR

Disable
parity
Time Break Don’t Care

t
Note: 1. MRD_PAR = tMOD + N; where N is the programmed parity latency.

Figure 60: 0ARITY %XIT 4IMING %XAMPLE n tMOD_PAR

Ta0 Ta1 Ta2 Tb0 Tb1 Tb2
CK_c
CK_t

Command DES MRS DES DES Valid DES

Parity latency PL = N Updating setting

tMOD_PAR

Disable
parity
Time Break Don’t Care

t
Note: 1. MOD_PAR = tMOD + N; where N is the programmed parity latency.

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 Figure 61: CA Parity Flow Diagram
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CA MR5[2:0] set parity latency (PL)

process start MR5[4] set parity error status to 0
MR5[9] enable/disable persistent mode

CA
latched in

Yes Persistent Yes Yes

CA parity CA parity
mode
enabled error
enabled

No No
No
Command
Good CA Ignore
MR5[4] = 0 Yes Yes execution
CA parity processed bad CMD
@ ADDR/CMD unknown
latched error

No
No

Command ALERT_n LOW MR5[4] = 0 Yes Log error/

Good CA Ignore @ ADDR/CMD
execution 44 to 144 CKs set parity status
processed bad CMD latched
unknown
Yes No
CA error
ALERT_n LOW Log error/ Internal
44 to 144 CKs set parity status precharge all
No
114

Good CA Bad CA
processed processed Internal
ALERT_n HIGH
precharge all

Normal
operation ready Operation ready?
Micron Technology, Inc. reserves the right to change products or specifications without notice.

Command
ALERT_n HIGH execution
unknown

8Gb: x4, x8, x16 DDR4 SDRAM

Command Normal operation ready
execution MR5[4] reset to 0 if desired
unknown

Command/Address Parity
Normal operation ready
MR5[4] reset to 0 if desired
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
Per-DRAM Addressability

Per-DRAM Addressability
DDR4 allows programmability of a single, specific DRAM on a rank. As an example, this feature can be
used to program different ODT or VREF values on each DRAM on a given rank. Because per-DRAM
addressability (PDA) mode may be used to program optimal VREF for the DRAM, the data set up for first
DQ0 transfer or the hold time for the last DQ0 transfer cannot be guaranteed. The DRAM may sample
DQ0 on either the first falling or second rising DQS transfer edge. This supports a common implemen-
tation between BC4 and BL8 modes on the DRAM. The DRAM controller is required to drive DQ0 to a
stable LOW or HIGH state during the length of the data transfer for BC4 and BL8 cases. Note, both fixed
and on-the-fly (OTF) modes are supported for BC4 and BL8 during PDA mode.
1. Before entering PDA mode, write leveling is required.
n BL8 or BC4 may be used.
2. Before entering PDA mode, the following MR settings are possible:
n RTT(Park) MR5 A[8:6] = Enable
n RTT(NOM) MR1 A[10:8] = Enable

3. Enable PDA mode using MR3 [4] = 1. (The default programed value of MR3[4] = 0.)
4. In PDA mode, all MRS commands are qualified with DQ0. The device captures DQ0 by using DQS
signals. If the value on DQ0 is LOW, the DRAM executes the MRS command. If the value on DQ0 is
HIGH, the DRAM ignores the MRS command. The controller can choose to drive all the DQ bits.
5. Program the desired DRAM and mode registers using the MRS command and DQ0.
6. In PDA mode, only MRS commands are allowed.
7. The MODE REGISTER SET command cycle time in PDA mode, AL + CWL + BL/2 - 0.5tCK +
t
MRD_PDA + PL, is required to complete the WRITE operation to the mode register and is the
minimum time required between two MRS commands.
8. Remove the device from PDA mode by setting MR3[4] = 0. (This command requires DQ0 = 0.)

Note: Removing the device from PDA mode will require programming the entire MR3 when the MRS
command is issued. This may impact some PDA values programmed within a rank as the EXIT
command is sent to the rank. To avoid such a case, the PDA enable/disable control bit is located in a
mode register that does not have any PDA mode controls.
In PDA mode, the device captures DQ0 using DQS signals the same as in a normal WRITE operation;
however, dynamic ODT is not supported. Extra care is required for the ODT setting. If RTT(NOM) MR1
[10:8] = enable, device data termination needs to be controlled by the ODT pin, and applies the same
timing parameters (defined below).

Symbol Parameter
DODTLon Direct ODT turnon latency
DODTLoff Direct ODT turn off latency
t
ADC RTT change timing skew
t
AONAS Asynchronous RTT(NOM) turn-on delay
t
AOFAS Asynchronous RTT(NOM) turn-off delay

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 8Gb: x4, x8, x16 DDR4 SDRAM
Per-DRAM Addressability

Figure 62: PDA Operation Enabled, BL8

CK_c
CK_t

MR3 A4 = 1
(PDA enable) MRS MRS MRS
t MOD CWL+AL+PL t MRD_PDA

DQS_t
DQS_c

DQ0

t PDA_S t PDA_H

DODTLoff = WL-3

ODT

DODTLon = WL-3

RTT RTT(Park) RTT(NOM) RTT(Park)

Note: 1. RTT(Park) = Enable; RTT(NOM) = Enable; WRITE preamble set = 2tCK; and DLL = On.

Figure 63: PDA Operation Enabled, BC4

CK_c
CK_t

MR3 A4 = 1
(PDA enable) MRS MRS MRS
tMOD CWL+AL+PL tMRD_PDA

DQS_t
DQS_c

DQ0

tPDA_S tPDA_H

DODTLoff = WL-3

ODT

DODTLon = WL-3

RTT RTT(Park) RTT(NOM) RTT(Park)

Note: 1. RTT(Park) = Enable; RTT(NOM) = Enable; WRITE preamble set = 2tCK; and DLL = On.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Per-DRAM Addressability

Figure 64: MRS PDA Exit

CK_c
CK_t

MR3 A4 = 0
(PDA disable) MRS Valid
CWL+AL+PL t MOD_PDA

DQS_t
DQS_c

DQ0

t PDA_S t PDA_H

DODTLoff = WL - 3

ODT

DODTLon = WL - 3

RTT RTT(Park) RTT(NOM) RTT(Park)

Note: 1. RTT(Park) = Enable; RTT(NOM) = Enable; WRITE preamble set = 2tCK; and DLL = On.

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 8Gb: x4, x8, x16 DDR4 SDRAM
VREFDQ Calibration

VREFDQ Calibration
The VREFDQ level, which is used by the DRAM DQ input receivers, is internally generated. The DRAM
VREFDQ does not have a default value upon power-up and must be set to the desired value, usually via
VREFDQ calibration mode. If PDA or PPR modes (hPPR or sPPR) are used prior to VREFDQ calibration,
VREFDQ should initially be set at the midpoint between the VDD,max, and the LOW as determined by the
driver and ODT termination selected with wide voltage swing on the input levels and setup and hold
times of approximately 0.75UI. The memory controller is responsible for VREFDQ calibration to deter-
mine the best internal VREFDQ level. The VREFDQ calibration is enabled/disabled via MR6[7], MR6[6]
selects Range 1 (60% to 92.5% of VDDQ) or Range 2 (45% to 77.5% of VDDQ), and an MRS protocol using
MR6[5:0] to adjust the VREFDQ level up and down. MR6[6:0] bits can be altered using the MRS
command if MR6[7] is enabled. The DRAM controller will likely use a series of writes and reads in
conjunction with VREFDQ adjustments to obtain the best VREFDQ, which in turn optimizes the data eye.
The internal VREFDQ specification parameters are voltage range, step size, VREF step time, VREF full step
time, and VREF valid level. The voltage operating range specifies the minimum required VREF setting
range for DDR4 SDRAM devices. The minimum range is defined by VREFDQ,min and VREFDQ,max. As
noted, a calibration sequence, determined by the DRAM controller, should be performed to adjust
VREFDQand optimize the timing and voltage margin of the DRAM data input receivers. The internal
VREFDQ voltage value may not be exactly within the voltage range setting coupled with the VREF set
tolerance; the device must be calibrated to the correct internal VREFDQ voltage.

Figure 65: VREFDQ Voltage Range

VDDQ

VREF,max

VREF
range

VREF,min

VSWING small System variance

VSWING large Total range

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 8Gb: x4, x8, x16 DDR4 SDRAM
VREFDQ Calibration

VREFDQ Range and Levels

Table 37: VREFDQ Range and Levels

MR6[5:0] Range 1 MR6[6] 0 Range 2 MR6[6] 1 MR6[5:0] Range 1 MR6[6] 0 Range 2 MR6[6] 1
00 0000 60.00% 45.00% 01 1010 76.90% 61.90%
00 0001 60.65% 45.65% 01 1011 77.55% 62.55%
00 0010 61.30% 46.30% 01 1100 78.20% 63.20%
00 0011 61.95% 46.95% 01 1101 78.85% 63.85%
00 0100 62.60% 47.60% 01 1110 79.50% 64.50%
00 0101 63.25% 48.25% 01 1111 80.15% 65.15%
00 0110 63.90% 48.90% 10 0000 80.80% 65.80%
00 0111 64.55% 49.55% 10 0001 81.45% 66.45%
00 1000 65.20% 50.20% 10 0010 82.10% 67.10%
00 1001 65.85% 50.85% 10 0011 82.75% 67.75%
00 1010 66.50% 51.50% 10 0100 83.40% 68.40%
00 1011 67.15% 52.15% 10 0101 84.05% 69.05%
00 1100 67.80% 52.80% 10 0110 84.70% 69.70%
00 1101 68.45% 53.45% 10 0111 85.35% 70.35%
00 1110 69.10% 54.10% 10 1000 86.00% 71.00%
00 1111 69.75% 54.75% 10 1001 86.65% 71.65%
01 0000 70.40% 55.40% 10 1010 87.30% 72.30%
01 0001 71.05% 56.05% 10 1011 87.95% 72.95%
01 0010 71.70% 56.70% 10 1100 88.60% 73.60%
01 0011 72.35% 57.35% 10 1101 89.25% 74.25%
01 0100 73.00% 58.00% 10 1110 89.90% 74.90%
01 0101 73.65% 58.65% 10 1111 90.55% 75.55%
01 0110 74.30% 59.30% 11 0000 91.20% 76.20%
01 0111 74.95% 59.95% 11 0001 91.85% 76.85%
01 1000 75.60% 60.60% 11 0010 92.50% 77.50%
01 1001 76.25% 61.25% 11 0011 to 11 1111 = Reserved

VREFDQ Step Size

The VREF step size is defined as the step size between adjacent steps. VREF step size ranges from 0.5%
VDDQ to 0.8% VDDQ. However, for a given design, the device has one value for VREF step size that falls
within the range.
The VREF set tolerance is the variation in the VREF voltage from the ideal setting. This accounts for accu-
mulated error over multiple steps. There are two ranges for VREF set tolerance uncertainty. The range
of VREF set tolerance uncertainty is a function of number of steps n.
The VREF set tolerance is measured with respect to the ideal line, which is based on the MIN and MAX
VREF value endpoints for a specified range. The internal VREFDQ voltage value may not be exactly within
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 8Gb: x4, x8, x16 DDR4 SDRAM
VREFDQ Calibration

the voltage range setting coupled with the VREF set tolerance; the device must be calibrated to the
correct internal VREFDQ voltage.

Figure 66: Example of VREF Set Tolerance and Step Size

Actual VREF
output
Straight line
(endpoint fit)
VREF

VREF set
tolerance

VREF set
tolerance

VREF
step size

Digital Code

Note: 1. Maximum case shown.

VREFDQ Increment and Decrement Timing

The VREF increment/decrement step times are defined by VREF,time. VREF,time is defined from t0 to t1,
where t1 is referenced to the VREF voltage at the final DC level within the VREF valid tolerance
(VREF,val_tol). The VREF valid level is defined by VREF,val tolerance to qualify the step time t1. This param-
eter is used to insure an adequate RC time constant behavior of the voltage level change after any VREF
increment/decrement adjustment.

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 8Gb: x4, x8, x16 DDR4 SDRAM
VREFDQ Calibration

Figure 67: VREFDQ Timing Diagram for VREF,time Parameter

CK_c
CK_t

Command MRS

VREF setting
adjustment

DQ VREF Old VREF setting Updating VREF setting New VREF setting

VREF_time

t0 t1

Don’t Care

Note: 1. t0 is referenced to the MRS command clock

t1 is referenced to VREF,tol
VREFDQ calibration mode is entered via an MRS command, setting MR6[7] to 1 (0 disables VREFDQ cali-
bration mode) and setting MR6[6] to either 0 or 1 to select the desired range (MR6[5:0] are "Don't
Care"). After VREFDQ calibration mode has been entered, VREFDQ calibration mode legal commands
may be issued once tVREFDQE has been satisfied. Legal commands for VREFDQ calibration mode are
ACT, WR, WRA, RD, RDA, PRE, DES, and MRS to set VREFDQ values, and MRS to exit VREFDQ calibration
mode. Also, after VREFDQ CALIBRATION MODE HAS BEEN ENTERED hDUMMYv 72)4% COMMANDS ARE ALLOWED
prior to adjusting the VREFDQ value the first time VREFDQ calibration is performed after initialization.
Setting VREFDQ values requires MR6[7] be set to 1 and MR6[6] be unchanged from the initial range
selection; MR6[5:0] may be set to the desired VREFDQ values. If MR6[7] is set to 0, MR6[6:0] are not
written. VREF,time-short or VREF,time-long must be satisfied after each MR6 command to set VREFDQ value
before the internal VREFDQ value is valid.
If PDA mode is used in conjunction with VREFDQ calibration, the PDA mode requirement that only MRS
commands are allowed while PDA mode is enabled is not waived. That is, the only VREFDQ calibration
mode legal commands noted above that may be used are the MRS commands: MRS to set VREFDQ
values and MRS to exit VREFDQ calibration mode.
The last MR6[6:0] setting written to MR6 prior to exiting VREFDQ calibration mode is the range and
value used for the internal VREFDQ setting. VREFDQ calibration mode may be exited when the DRAM is
in idle state. After the MRS command to exit VREFDQ calibration mode has been issued, DES must be
issued until tVREFDQX has been satisfied where any legal command may then be issued. VREFDQ
setting should be updated if the die temperature changes too much from the calibration temperature.
The following are typical script when applying the above rules for VREFDQ calibration routine when
performing VREFDQ calibration in Range 1:
s MR6[7:6]10 [5:0]XXXXXXX.
n Subsequent legal commands while in VREFDQ calibration mode: ACT, WR, WRA, RD, RDA, PRE,
DES, and MRS (to set VREFDQ values and exit VREFDQ calibration mode).
s All subsequent VREFDQ calibration MR setting commands are MR6[7:6]10 [5:0]VVVVVV.
n "VVVVVV" are desired settings for VREFDQ.

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 8Gb: x4, x8, x16 DDR4 SDRAM
VREFDQ Calibration

s Issue ACT/WR/RD looking for pass/fail to determine VCENT (midpoint) as needed.

s To exit VREFDQ calibration, the last two VREFDQ calibration MR commands are:
n MR6[7:6]10 [5:0]VVVVVV* where VVVVVV* = desired value for VREFDQ.
n MR6[7]0 [6:0]XXXXXXX to exit VREFDQ calibration mode.

The following are typical script when applying the above rules for VREFDQ calibration routine when
performing VREFDQ calibration in Range 2:
s MR6[7:6]11 [5:0]XXXXXXX.
n Subsequent legal commands while in VREFDQ calibration mode: ACT, WR, WRA, RD, RDA, PRE,
DES, and MRS (to set VREFDQ values and exit VREFDQ calibration mode).
s All subsequent VREFDQ calibration MR setting commands are MR6[7:6]11 [5:0]VVVVVV.
n "VVVVVV" are desired settings for VREFDQ.
s Issue ACT/WR/RD looking for pass/fail to determine VCENT (midpoint) as needed.
s To exit VREFDQ calibration, the last two VREFDQ calibration MR commands are:
n MR6[7:6]11 [5:0]VVVVVV* where VVVVVV* = desired value for VREFDQ.
n MR6[7]0 [6:0]XXXXXXX to exit VREFDQ calibration mode.

Note: Range may only be set or changed when entering VREFDQ calibration mode; changing range
while in or exiting VREFDQ calibration mode is illegal.

Figure 68: VREFDQ Training Mode Entry and Exit Timing Diagram
T0 T1 Ta0 Ta1 Tb0 Tb1 Tc0 Tc1 Td0 Td1 Td2
CK_c
CK_t

Command DES MRS DES CMD DES CMD DES MRS1,2 DES WR DES

tVREFDQE tVREFDQX

VREFDQ training on New VREFDQ New VREFDQ VREFDQ training off

value or write value or write
Don’t Care

Notes: 1. New VREFDQ values are not allowed with an MRS command during calibration mode entry.
2. Depending on the step size of the latest programmed VREF value, VREF must be satisfied before disabling VREFDQ
training mode.

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 8Gb: x4, x8, x16 DDR4 SDRAM
VREFDQ Calibration

Figure 69: VREF Step: Single Step Size Increment Case

VREF
Voltage
VREF
(VDDQ(DC))

VREF,val_tol
Step size

t1

Time
Figure 70: VREF Step: Single Step Size Decrement Case

VREF
Voltage
t1

Step size
VREF,val_tol

VREF
(VDDQ(DC))

Time

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 8Gb: x4, x8, x16 DDR4 SDRAM
VREFDQ Calibration

Figure 71: VREF Full Step: From VREF,min to VREF,maxCase

VREF VREF
Voltage VREF,max (VDDQ(DC))
VREF,val_tol

Full range
t1
step

VREF,min

Time
Figure 72: VREF Full Step: From VREF,max to VREF,minCase

VREF,max
VREF
Voltage

Full range
step t1

VREF,val_tol
VREF,min
VREF
(VDDQ(DC))

Time

VREFDQ Target Settings

The VREFDQ initial settings are largely dependant on the ODT termination settings. The table below
shows all of the possible initial settings available for VREFDQ training; it is unlikely the lower ODT
settings would be used in most cases.

Table 38: VREFDQ Settings (VDDQ = 1.2V)

RON ODT 6X n 6IN LOW (mV) VREFDQ (mv) VREFDQ (%VDDQ)

34 ohm 600 900 75%
40 ohm 550 875 73%
48 ohm 500 850 71%
34 ohm 60 ohm 435 815 68%
80 ohm 360 780 65%
120 ohm 265 732 61%
240 ohm 150 675 56%

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 8Gb: x4, x8, x16 DDR4 SDRAM
VREFDQ Calibration

Table 38: VREFDQ Settings (VDDQ = 1.2V)

RON ODT 6X n 6IN LOW (mV) VREFDQ (mv) VREFDQ (%VDDQ)

34 ohm 700 950 79%
40 ohm 655 925 77%
48 ohm 600 900 75%
48 ohm 60 ohm 535 865 72%
80 ohm 450 825 69%
120 ohm 345 770 64%
240 ohm 200 700 58%

Figure 73: VREFDQ Equivalent Circuit

VDDQ VDDQ

ODT

RXer
Vx

RON VREFDQ
(internal)

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 8Gb: x4, x8, x16 DDR4 SDRAM
Connectivity Test Mode

Connectivity Test Mode

Connectivity test (CT) mode is similar to boundary scan testing but is designed to significantly speed
up the testing of electrical continuity of pin interconnections between the device and the memory
controller on the PC boards. Designed to work seamlessly with any boundary scan device, CT mode is
supported in all έ4, έ8, and έ16 non-3DS devices (JEDEC states CT mode for έ4 and έ8 is not required
on 4Gb and is an optional feature on 8Gb and above). 3DS devices do not support CT mode and the
TEN pin should be considered RFU maintained LOW at all times.
Contrary to other conventional shift-register-based test modes, where test patterns are shifted in and
out of the memory devices serially during each clock, the CT mode allows test patterns to be entered
on the test input pins in parallel and the test results to be extracted from the test output pins of the
device in parallel. These two functions are also performed at the same time, significantly increasing the
speed of the connectivity check. When placed in CT mode, the device appears as an asynchronous
device to the external controlling agent. After the input test pattern is applied, the connectivity test
results are available for extraction in parallel at the test output pins after a fixed propagation delay
time.
Note: A reset of the device is required after exiting CT mode (see RESET and Initialization Procedure).

Pin Mapping
Only digital pins can be tested using the CT mode. For the purposes of a connectivity check, all the pins
used for digital logic in the device are classified as one of the following types:
s Test enable (TEN): When asserted HIGH, this pin causes the device to enter CT mode. In CT mode,
the normal memory function inside the device is bypassed and the I/O pins appear as a set of test
input and output pins to the external controlling agent. Additionally, the device will set the internal
VREFDQ to VDDQ έ 0.5 during CT mode (this is the only time the DRAM takes direct control over
setting the internal VREFDQ). The TEN pin is dedicated to the connectivity check function and will not
be used during normal device operation.
s Chip select (CS_n): When asserted LOW, this pin enables the test output pins in the device. When
de-asserted, these output pins will be High-Z. The CS_n pin in the device serves as the CS_n pin in
CT mode.
s Test input: A group of pins used during normal device operation designated as test input pins. These
pins are used to enter the test pattern in CT mode.
s Test output: A group of pins used during normal device operation designated as test output pins.
These pins are used for extraction of the connectivity test results in CT mode.
s RESET_n: This pin must be fixed high level during CT mode, as in normal function.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Connectivity Test Mode

Table 39: Connectivity Mode Pin Description and Switching Levels

CT Mode
Pins Pin Name During Normal Memory Operation Switching Level Notes
Test enable TEN CMOS (20%/80% VDD) 1, 2
Chip select CS_n VREFCA ά200mV 3
BA[1:0], BG[1:0], A[9:0], A10/AP, A11, A12/BC_n, A13, WE_n/A14, VREFCA ά200mV 3
A
CAS_n/A15, RAS_n/A16, A17, CKE, ACT_n, ODT, CLK_t, CLK_c, PAR
Test B LDM_n/LDBI_n, UDM_n/UDBI_n; DM_n/DBI_n VREFDQ ά200mV 4
input
C ALERT_n CMOS (20%/80% VDD) 2, 5

D RESET_n CMOS (20%/80% VDD) 2

Test DQ[15:0], UDQS_t, UDQS_c, LDQS_t, LDQS_c; DQS_t, DQS_c VTT ά100mV 6
output

Notes: 1. TEN: Connectivity test mode is active when TEN is HIGH and inactive when TEN is LOW. TEN must be LOW during
normal operation.
2. CMOS is a rail-to-rail signal with DC HIGH at 80% and DC LOW at 20% of VDD (960mV for DC HIGH and 240mV for
DC LOW.)
3. VREFCA should be VDD/2.
4. VREFDQ should be VDDQ/2.
5. ALERT_n switching level is not a final setting.
6. VTT should be set to VDD/2.

Minimum Terms Definition for Logic Equations

The test input and output pins are related by the following equations, where INV denotes a logical
inversion operation and XOR a logical exclusive OR operation:
MT0 = XOR (A1, A6, PAR)
MT1 = XOR (A8, ALERT_n, A9)
MT2 = XOR (A2, A5, A13) or XOR (A2, A5, A13, A17)
MT3 = XOR (A0, A7, A11)
MT4 = XOR (CK_c, ODT, CAS_n/A15)
MT5 = XOR (CKE, RAS_n/A16, A10/AP)
MT6 = XOR (ACT_n, A4, BA1)
MT7 = έ16: XOR (DMU_n/DBIU_n, DML_n/DBIL_n, CK_t)
= x8: XOR (BG1, DML_n/DBIL_n, CK_t)
= x4: XOR (BG1, CK_t)
MT8 = XOR (WE_n/A14, A12 / BC, BA0)
MT9 = XOR (BG0, A3, RESET_n and TEN)

Logic Equations for a x4 Device

DQ0 = XOR (MT0, MT1)

DQ1 = XOR (MT2, MT3)
DQ2 = XOR (MT4, MT5)
DQ3 = XOR (MT6, MT7)
DQS_t = MT8
DQS_c = MT9

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 8Gb: x4, x8, x16 DDR4 SDRAM
Connectivity Test Mode

Logic Equations for a x8 Device

DQ0 = MT0 DQ5 = MT5

DQ1 = MT1 DQ6 = MT6
DQ2 = MT2 DQ7 = MT7
DQ3 = MT3 DQS_t = MT8
DQ4 = MT4 DQS_c = MT9

Logic Equations for a x16 Device

DQ0 = MT0 DQ10 = INV DQ2
DQ1 = MT1 DQ11 = INV DQ3
DQ2 = MT2 DQ12 = INV DQ4
DQ3 = MT3 DQ13 = INV DQ5
DQ4 = MT4 DQ14 = INV DQ6
DQ5 = MT5 DQ15 = INV DQ7
DQ6 = MT6 LDQS_t = MT8
DQ7 = MT7 LDQS_c = MT9
DQ8 = INV DQ0 UDQS_t = INV LDQS_t
DQ9 = INV DQ1 UDQS_c = INV LDQS_c

CT Input Timing Requirements

Prior to the assertion of the TEN pin, all voltage supplies, including VREFCA, must be valid and stable
and RESET_n registered high prior to entering CT mode. Upon the assertion of the TEN pin HIGH with
RESET_n, CKE, and CS_n held HIGH; CLK_t, CLK_c, and CKE signals become test inputs within
tCTECT_Valid. The remaining CT inputs become valid tCT_Enable after TEN goes HIGH when CS_n

allows input to begin sampling, provided inputs were valid for at least tCT_Valid. While in CT mode,
refresh activities in the memory arrays are not allowed; they are initiated either externally (auto
refresh) or internally (self refresh).
The TEN pin may be asserted after the DRAM has completed power-on. After the DRAM is initialized
and VREFDQ is calibrated, CT mode may no longer be used. The TEN pin may be de-asserted at any time
in CT mode. Upon exiting CT mode, the states and the integrity of the original content of the memory
array are unknown. A full reset of the memory device is required.

After CT mode has been entered, the output signals will be stable within tCT_Valid after the test inputs
have been applied as long as TEN is maintained HIGH and CS_n is maintained LOW.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Connectivity Test Mode

Figure 74: Connectivity Test Mode Entry

Ta Tb Tc Td

CK_t
Valid input Valid input
CK_c

tCKSRX tCT_IS

T = 10ns tIS tCT_IS

CKE Valid input Valid input

tCTCKE_Valid

T = 200μs T = 500μs

RESET_n
tCT_IS

TEN

tCTCKE_Valid>10ns
tCT_Enable
tCT_IS >0ns

CS_n

tCT_IS

CT Inputs Valid input Valid input

tCT_Valid tCT_Valid

tCT_Valid

CT Outputs Valid Valid

Don’t Care

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 8Gb: x4, x8, x16 DDR4 SDRAM
Excessive Row Activation

Excessive Row Activation

Rows can be accessed a limited number of times within a certain time period before adjacent rows
require refresh. The maximum activate count (MAC) is the maximum number of activates that a single
row can sustain within a time interval of equal to or less than the maximum activate window (tMAW)
before the adjacent rows need to be refreshed, regardless of how the activates are distributed over
t
MAW.
Micron's DDR4 devices automatically perform a type of TRR mode in the background and provide an
MPR Page 3 MPR3[3:0] of 1000, indicating there is no restriction to the number of ACTIVATE
commands to a given row in a refresh period provided DRAM timing specifications are not violated.
However, specific attempts to by-pass TRR may result in data disturb.

Table 40: MAC Encoding of MPR Page 3 MPR3

[7] [6] [5] [4] [3] [2] [1] [0] MAC Comments
x x x x 0 0 0 0 Untested The device has not been tested for MAC.
x x x x 0 0 0 1 t
MAC = 700K
x x x x 0 0 1 0 t
MAC = 600K
x x x x 0 0 1 1 t
MAC = 500K
x x x x 0 1 0 0 t
MAC = 400K
x x x x 0 1 0 1 t
MAC = 300K
x x x x 0 1 1 0 Reserved
x x x x 0 1 1 1 t
MAC = 200K
x x x x 1 0 0 0 Unlimited There is no restriction to the number of ACTIVATE com-
mands to a given row in a refresh period provided DRAM
timing specifications are not violated.
x x x x 1 0 0 1 Reserved
x x x x : : : : Reserved
x x x x 1 1 1 1 Reserved

Notes: 1. MAC encoding in MPR Page 3 MPR3.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Post Package Repair

Post Package Repair

Post Package Repair
JEDEC defines two modes of Post Package Repair (PPR): soft Post Package Repair (sPPR) and hard Post
Package Repair (hPPR). sPPR is non-persistent so the repair row maybe altered; that is, sPPR is NOT a
permanent repair and even though it will repair a row, the repair can be reversed, reassigned via
another sPPR, or made permanent via hPPR. Hard Post Package Repair is persistent so once the repair
row is assigned for a hPPR address, further PPR commands to a previous hPPR section should not be
performed, that is, hPPR is a permanent repair; once repaired, it cannot be reversed. The controller
provides the failing row address in the hPPR/sPPR sequence to the device to perform the row repair.
hPPR Mode and sPPR Mode may not be enabled at the same time.
JEDEC states hPPR is optional for 4Gb and sPPR is optional for 4Gb and 8Gb parts however Micron 4Gb
and 8Gb DDR4 DRAMs should have both sPPR and hPPR support. The hPPR support is identified via
an MPR read from MPR Page 2, MPR0[7] and sPPR support is identified via an MPR read from MPR
Page 2, MPR0[6].
The JEDEC minimum support requirement for DDR4 PPR (hPPR or sPPR) is to provide one row of
repair per bank group (BG), x4/x8 have 4 BG and x16 has 2 BG; this is a total of 4 repair rows available
on x4/x8 and 2 repair rows available on x16. Micron PPR support exceeds the JEDEC minimum require-
ments; Micron DDR4 DRAMs have at least one row of repair for each bank which is essentially 4 row
repairs per BG for a total of 16 repair rows for x4 and x8 and 8 repair rows for x16; a 4x increase in repair
rows.
JEDEC requires the user to have all sPPR row repair addresses reset and cleared prior to enabling hPPR
Mode. Micron DDR4 PPR does not have this restriction, the existing sPPR row repair addresses are not
required to be cleared prior to entering hPPR mode. Each bank in a BG is PPR independent: sPPR or
hPPR issued to a bank will not alter a sPPR row repair existing in a different bank.
sPPR followed by sPPR to same bank
When PPR is issued to a bank for the first time and is a sPPR command, the repair row will be a sPPR.
When a subsequent sPPR is issued to the same bank, the previous sPPR repair row will be cleared and
used for the subsequent sPPR address as the sPPR operation is non-persistent.
sPPR followed by hPPR to same bank
When a PPR is issued to a bank for the first time and is a sPPR command, the repair row will be a sPPR.
When a subsequent hPPR is issued to the same bank, the initial sPPR repair row will be cleared and
used for the hPPR address1. If a further subsequent PPR (hPPR or sPPR) is issued to the same bank, the
further subsequent PPR ( hPPR or sPPR) repair row will not clear or overwrite the previous hPPR
address as the hPPR operation is persistent.
hPPR followed by hPPR or sPPR to same bank
When a PPR is issued to a bank for the first time and is a hPPR command, the repair row will be a hPPR.
When a subsequent PPR (hPPR or sPPR) is issued to the same bank, the subsequent PPR ( hPPR or
sPPR) repair row will not clear or overwrite the initial hPPR address as the initial hPPR is persistent.
Note: Newer Micron DDR4 designs may not guarantee that an sPPR followed by an hPPR to the same
bank will result the same repair row being used. Contact factory for more information.

Hard Post Package Repair

All banks must be precharged and idle. DBI and CRC modes must be disabled. Both sPPR and hPPR
must be disabled. sPPR is disabled with MR4[5] = 0. hPPR is disabled with MR4[13] = 0, which is the

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 8Gb: x4, x8, x16 DDR4 SDRAM
Hard Post Package Repair

normal state, and hPPR is enabled with MR4 [13]= 1, which is the hPPR enabled state. There are two
forms of hPPR mode. Both forms of hPPR have the same entry requirement as defined in the sections
below. The first command sequence uses a WRA command and supports data retention with a
REFRESH operation except for the bank containing the row that is being repaired; JEDEC has relaxed
this requirement and allows BA[0] to be a Don't Care regarding the banks which are not required to
maintain data a REFRESH operation during hPPR. The second command sequence uses a WR
command (a REFRESH operation can't be performed in this command sequence). The second
command sequence doesn't support data retention for the target DRAM.

hPPR Row Repair - Entry

As stated above, all banks must be precharged and idle. DBI and CRC modes must be disabled, and all
timings must be followed as shown in the timing diagram that follows.
All other commands except those listed in the following sequences are illegal.
1. Issue MR4[13] 1 to enter hPPR mode enable.
a) All DQ are driven HIGH.
2. Issue four consecutive guard key commands (shown in the table below) to MR0 with each command
separated by tMOD. The PPR guard key settings are the same whether performing sPPR or hPPR
mode.
a) Any interruption of the key sequence by other commands, such as ACT, WR, RD, PRE, REF, ZQ,
and NOP, are not allowed.
b) If the guard key bits are not entered in the required order or interrupted with other MR
commands, hPPR will not be enabled, and the programming cycle will result in a NOP.
c) When the hPPR entry sequence is interrupted and followed by ACT and WR commands, these
commands will be conducted as normal DRAM commands.
d) JEDEC allows A6:0 to be Don't Care on 4Gb and 8Gb devices from a supplier perspective and the
user should rely on vendor datasheet.

Table 41: PPR MR0 Guard Key Settings

MR0 BG1:0 BA1:0 A17:12 A11 A10 A9 A8 A7 A6:0
First guard key 0 0 xxxxxx 1 1 0 0 1 1111111
Second guard key 0 0 xxxxxx 0 1 1 1 1 1111111
Third Guard key 0 0 xxxxxx 1 0 1 1 1 1111111
Fourth guard key 0 0 xxxxxx 0 0 1 1 1 1111111

H002 2OW 2EPAIR n 72! )NITIATED 2%& #OMMANDS !LLOWED

1. Issue an ACT command with failing BG and BA with the row address to be repaired.
2. Issue a WRA command with BG and BA of failing row address.
a) The address must be at valid levels, but the address is Don't Care.
3. All DQ of the target DRAM should be driven LOW for 4nCK (bit 0 through bit 7) after WL (WL = CWL
+ AL + PL) in order for hPPR to initiate repair.
a) Repair will be initiated to the target DRAM only if all DQ during bit 0 through bit 7 are LOW. The
bank under repair does not get the REFRESH command applied to it.
b) Repair will not be initiated to the target DRAM if any DQ during bit 0 through bit 7 is HIGH.
i) JEDEC states: All DQs of target DRAM should be LOW for 4tCK. If HIGH is driven to all DQs of
a DRAM consecutively for equal to or longer than 2tCK, then DRAM does not conduct hPPR

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132 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
Hard Post Package Repair

and retains data if REF command is properly issued; if all DQs are neither LOW for 4tCK nor
HIGH for equal to or longer than 2tCK, then hPPR mode execution is unknown.
c) DQS should function normally.

4. REF command may be issued anytime after the WRA command followed by WL + 4nCK + tWR + tRP.
a) Multiple REF commands are issued at a rate of tREFI or tREFI/2, however back-to-back REF
commands must be separated by at least tREFI/4 when the DRAM is in hPPR mode.
b) All banks except the bank under repair will perform refresh.

5. Issue PRE after tPGM time so that the device can repair the target row during tPGM time.
a) Wait tPGM_Exit after PRE to allow the device to recognize the repaired target row address.
6. Issue MR4[13] 0 command to hPPR mode disable.
a) Wait tPGMPST for hPPR mode exit to complete.
b) After tPGMPST has expired, any valid command may be issued.
The entire sequence from hPPR mode enable through hPPR mode disable may be repeated if more
than one repair is to be done.
After completing hPPR mode, MR0 must be re-programmed to a prehPPR mode state if the device is to
be accessed.
After hPPR mode has been exited, the DRAM controller can confirm if the target row was repaired
correctly by writing data into the target row and reading it back.

Figure 75: H002 72! n %NTRY

T0 T1 Ta0 Ta1 Tb0 Tb1 Tc0 Tc1 Td0 Td1 Te0 Tf0 Tg0
CK_c
CK_t
CMD MRS4 DES MRS0 DES MRS0 DES MRS0 DES MRS0 DES ACT WRA DES

BG Valid N/A 00 N/A 00 N/A 00 N/A 00 N/A BGf BGf N/A

BA Valid N/A 00 N/A 00 N/A 00 N/A 00 N/A BAf BAf N/A

Valid
ADDR (A13=1) N/A 1st Key N/A 2nd Key N/A 3rd Key N/A 4th Key N/A Valid Valid N/A

CKE

DQS_t
DQS_c

DQs1

All Banks t MOD t MOD t MOD t MOD t MOD t RCD

Precharged
and idle state

Normal hPPR Entry 1st Guard Key Validate 2nd Guard Key Validate 3rd Guard Key Validate 4th Guard Key Validate hPPR Repair
Mode

Don’t Care

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 8Gb: x4, x8, x16 DDR4 SDRAM
Hard Post Package Repair

Figure 76: H002 72! n 2EPAIR AND %XIT

Te0 Tf0 Tg0 Tg1 Th0 Th1 Tj0 Tj1 Tj2 Tk0 Tk1 Tm0 Tm1 Tn0
CK_c
CK_t
CMD ACT WRA DES DES DES DES DES REF/DES REF/DES PRE REF/DES MRSx DES Valid

BG BGf BGf N/A N/A N/A N/A N/A N/A N/A Valid N/A Valid N/A Valid

BA BAf BAf N/A N/A N/A N/A N/A N/A N/A Valid N/A Valid N/A Valid

Valid Valid N/A N/A N/A N/A N/A N/A N/A Valid N/A Valid N/A Valid
ADDR (A13 = 0)

CKE

WL = CWL+AL+PL 4nCK tWR +tRP + 1nCK

DQS_t
DQS_c

DQs1
bit 0 bit 1 bit 6 bit 7
tRCD tPGM tPGM_Exit tPGMPST
All Banks
Precharged
and idle state

hPPR Recognition hPPR Exit Normal

hPPR Repair hPPR Repair hPPR Repair mode

Don’t Care

H002 2OW 2EPAIR n 72 )NITIATED 2%& #OMMANDS ./4 !LLOWED

1. Issue an ACT command with failing BG and BA with the row address to be repaired.
2. Issue a WR command with BG and BA of failing row address.
a) The address must be at valid levels, but the address is Don't Care.
3. All DQ of the target DRAM should be driven LOW for 4nCK (bit 0 through bit 7) after WL (WL = CWL
+ AL + PL) in order for hPPR to initiate repair.
a) Repair will be initiated to the target DRAM only if all DQ during bit 0 through bit 7 are LOW.
b) Repair will not be initiated to the target DRAM if any DQ during bit 0 through bit 7 is HIGH.
i) JEDEC states: All DQs of target DRAM should be LOW for 4tCK. If HIGH is driven to all DQs of
a DRAM consecutively for equal to or longer than 2tCK, then DRAM does not conduct hPPR
and retains data if REF command is properly issued; if all DQs are neither LOW for 4tCK nor
HIGH for equal to or longer than 2tCK, then hPPR mode execution is unknown.
c) DQS should function normally.

4. REF commands may NOT be issued at anytime while in PPT mode.

5. Issue PRE after tPGM time so that the device can repair the target row during tPGM time.
a) Wait tPGM_Exit after PRE to allow the device to recognize the repaired target row address.
6. Issue MR4[13] 0 command to hPPR mode disable.
a) Wait tPGMPST for hPPR mode exit to complete.
b) After tPGMPST has expired, any valid command may be issued.
The entire sequence from hPPR mode enable through hPPR mode disable may be repeated if more
than one repair is to be done.
After completing hPPR mode, MR0 must be re-programmed to a prehPPR mode state if the device is to
be accessed.
After hPPR mode has been exited, the DRAM controller can confirm if the target row was repaired
correctly by writing data into the target row and reading it back.

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 8Gb: x4, x8, x16 DDR4 SDRAM
sPPR Row Repair

Figure 77: H002 72 n %NTRY

T0 T1 Ta0 Ta1 Tb0 Tb1 Tc0 Tc1 Td0 Td1 Te0 Tf0 Tg0
CK_c
CK_t
CMD MRS4 DES MRS0 DES MRS0 DES MRS0 DES MRS0 DES ACT WR DES

BG Valid N/A 00 N/A 00 N/A 00 N/A 00 N/A BGf BGf N/A

BA Valid N/A 00 N/A 00 N/A 00 N/A 00 N/A BAf BAf N/A

Valid
ADDR (A13 = 1) N/A 1st Key N/A 2nd Key N/A 3rd Key N/A 4th Key N/A Valid Valid N/A

CKE

WL = CWL +
DQS_t
DQS_c

DQs1

All Banks t MOD t MOD t MOD t MOD t MOD t RCD

Precharged
and idle state

Normal hPPR Entry 1st Guard Key Validate 2nd Guard Key Validate 3rd Guard Key Validate 4th Guard Key Validate hPPR Repair
Mode

Don’t Care

Figure 78: H002 72 n 2EPAIR AND %XIT

Te0 Tf0 Tg0 Tg1 Th0 Th1 Tj0 Tj1 Tj2 Tk0 Tk1 Tm0 Tm1 Tn0
CK_c
CK_t
CMD ACT WR DES DES DES DES DES DES DES PRE DES MRSx DES Valid

BG BGf BGf N/A N/A N/A N/A N/A N/A N/A Valid N/A Valid N/A Valid

BA BAf BAf N/A N/A N/A N/A N/A N/A N/A Valid N/A Valid N/A Valid

Valid Valid N/A N/A N/A N/A N/A N/A N/A Valid N/A Valid N/A Valid
ADDR (A13 = 0)

CKE

WL = CWL + AL + PL 4nCK
DQS_t
DQS_c

DQs1
bit 0 bit 1 bit 6 bit 7
tRCD tPGM tPGM_Exit tPGMPST
All Banks
Precharged
and idle state

hPPR Recognition hPPR Exit Normal

hPPR Repair hPPR Repair hPPR Repair mode

Don’t Care

Table 42: DDR4 hPPR Timing Parameters DDR4-1600 through DDR4-3200

Parameter Symbol Min Max Unit
hPPR programming time t
PGM έ4, έ8 1000 n ms
έ16 2000 n ms
hPPR precharge exit time t
PGM_Exit 15 n ns

hPPR exit time t

PGMPST 50 n ρs

sPPR Row Repair

Soft post package repair (sPPR) is a way to quickly, but temporarily, repair a row element in a bank on
a DRAM device, where hPPR takes longer but permanently repairs a row element. sPPR mode is
entered in a similar fashion as hPPR, sPPR uses MR4[5] while hPPR uses MR4[13]. sPPR is disabled with
MR4[5] = 0, which is the normal state, and sPPR is enabled with MR4[5] = 1, which is the sPPR enabled
state.
sPPR requires the same guard key sequence as hPPR to qualify the MR4 PPR entry. After sPPR entry, an
ACT command will capture the target bank and target row, herein seed row, where the row repair will
be made. After tRCD time, a WR command is used to select the individual DRAM, through the DQ bits,

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 8Gb: x4, x8, x16 DDR4 SDRAM
sPPR Row Repair

to transfer the repair address into an internal register in the DRAM. After a write recovery time and PRE
command, the sPPR mode can be exited and normal operation can resume.
The DRAM will retain the soft repair information as long as VDD remains within the operating region
unless rewritten by a subsequent sPPR entry to the same bank. If DRAM power is removed or the DRAM
is reset, the soft repair will revert to the unrepaired state. hPPR and sPPR should not be enabled at the
same time; Micron sPPR does not have to be disabled and cleared prior to entering hPPR mode, but
sPPR must be disabled and cleared prior to entering MBIST-PPR mode.
With sPPR, Micron DDR4 can repair one row per bank. When a subsequent sPPR request is made to the
same bank, the subsequently issued sPPR address will replace the previous sPPR address. When the
hPPR resource for a bank is used up, the bank should be assumed to not have available resources for
sPPR. If a repair sequence is issued to a bank with no repair resource available, the DRAM will ignore
the programming sequence.
The bank receiving sPPR change is expected to retain memory array data in all rows except for the seed
row and its associated row addresses. If the data in the memory array in the bank under sPPR repair is
NOT REQUIRED TO BE RETAINED THEN THE HANDLING OF THE SEED ROWS ASSOCIATED ROW ADDRESSES IS NOT OF
interest and can be ignored. If the data in the memory array is required to be retained in the bank under
sPPR mode, then prior to executing the sPPR mode, the seed row and its associated row addresses
should be backed up and subsequently restored after sPPR has been completed. sPPR associated seed
row addresses are specified in the Table below; BA0 is not required by Micron DRAMs however it is
JEDEC reserved.

Table 43: sPPR Associated Rows

sPPR Associated Row Address
BA0* A17 A16 A15 A14 A13 A1 A0

All banks must be precharged and idle. DBI and CRC modes must be disabled, and all sPPR timings
must be followed as shown in the timing diagram that follows.
All other commands except those listed in the following sequences are illegal.
1. Issue MR4[5] 1 to enter sPPR mode enable.
a) All DQ are driven HIGH.
2. Issue four consecutive guard key commands (shown in the table below) to MR0 with each command
separated by tMOD. Please note that JEDEC recently added the four guard key entry used for hPPR
to sPPR entry; early DRAMs may not require four guard key entry code. A prudent controller design
should accommodate either option in case an earlier DRAM is used.
a) Any interruption of the key sequence by other commands, such as ACT, WR, RD, PRE, REF, ZQ,
and NOP, are not allowed.
b) If the guard key bits are not entered in the required order or interrupted with other MR
commands, sPPR will not be enabled, and the programming cycle will result in a NOP.
c) When the sPPR entry sequence is interrupted and followed by ACT and WR commands, these
commands will be conducted as normal DRAM commands.
d) JEDEC allows A6:0 to be "Don't Care" on 4Gb and 8Gb devices from a supplier perspective and
the user should rely on vendor datasheet.

Table 44: PPR MR0 Guard Key Settings

MR0 BG1:0 BA1:0 A17:12 A11 A10 A9 A8 A7 A6:0
First guard key 0 0 xxxxxx 1 1 0 0 1 1111111
Second guard key 0 0 xxxxxx 0 1 1 1 1 1111111

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 8Gb: x4, x8, x16 DDR4 SDRAM
sPPR Row Repair

Table 44: PPR MR0 Guard Key Settings (Continued)

MR0 BG1:0 BA1:0 A17:12 A11 A10 A9 A8 A7 A6:0
Third guard key 0 0 xxxxxx 1 0 1 1 1 1111111
Fourth guard key 0 0 xxxxxx 0 0 1 1 1 1111111

3. After tMOD, issue an ACT command with failing BG and BA with the row address to be repaired.
4. After tRCD, issue a WR command with BG and BA of failing row address.
a) The address must be at valid levels, but the address is a "Don't Care."
5. All DQ of the target DRAM should be driven LOW for 4nCK (bit 0 through bit 7) after WL (WL = CWL
+ AL + PL) in order for sPPR to initiate repair.
a) Repair will be initiated to the target DRAM only if all DQ during bit 0 through bit 7 are LOW.
b) Repair will not be initiated to the target DRAM if any DQ during bit 0 through bit 7 is HIGH.
i) JEDEC states: All DQs of target DRAM should be LOW for 4tCK. If HIGH is driven to all DQs of
a DRAM consecutively for equal to or longer than the first 2tCK, then DRAM does not conduct
hPPR and retains data if REF command is properly issued; if all DQs are neither LOW for 4tCK
nor HIGH for equal to or longer than the first 2tCK, then hPPR mode execution is unknown.
c) DQS should function normally.

6. REF command may NOT be issued at anytime while in sPPR mode.

7. Issue PRE after tWR time so that the device can repair the target row during tWR time.
a) Wait tPGM_Exit_s after PRE to allow the device to recognize the repaired target row address.
8. Issue MR4[5] 0 command to sPPR mode disable.
a) Wait tPGMPST_s for sPPR mode exit to complete.
b) After tPGMPST_s has expired, any valid command may be issued.
The entire sequence from sPPR mode enable through sPPR mode disable may be repeated if more than
one repair is to be done.
After sPPR mode has been exited, the DRAM controller can confirm if the target row was repaired
correctly by writing data into the target row and reading it back.

Figure 79: S002 n %NTRY

T0 T1 Ta0 Ta1 Tb0 Tb1 Tc0 Tc1 Td0 Td1 Te0 Tf0 Tg0
CK_c
CK_t
CMD MRS4 DES MRS0 DES MRS0 DES MRS0 DES MRS0 DES ACT WR DES

BG Valid N/A 00 N/A 00 N/A 00 N/A 00 N/A BGf BGf N/A

BA Valid N/A 00 N/A 00 N/A 00 N/A 00 N/A BAf BAf N/A

Valid
ADDR (A5=1) N/A 1st Key N/A 2nd Key N/A 3rd Key N/A 4th Key N/A Valid Valid N/A

CKE

DQS_t
DQS_c

DQs1

All Banks t MOD t MOD t MOD t MOD t MOD t RCD

Precharged
and idle state

Normal sPPR Entry 1st Guard Key Validate 2nd Guard Key Validate 3rd Guard Key Validate 4th Guard Key Validate sPPR Repair
Mode

Don’t Care

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 8Gb: x4, x8, x16 DDR4 SDRAM
MBIST-PPR

Figure 80: S002 n 2EPAIR AND %XIT

Te0 Tf0 Tg0 Tg1 Th0 Th1 Tj0 Tj1 Tj2 Tk0 Tk1 Tm0 Tm1 Tn0
CK_c
CK_t
CMD ACT WR DES DES DES DES DES DES DES PRE DES MRS4 DES Valid

BG BGf BGf N/A N/A N/A N/A N/A N/A N/A Valid N/A Valid N/A Valid

BA BAf BAf N/A N/A N/A N/A N/A N/A N/A Valid N/A Valid N/A Valid

Valid Valid N/A N/A N/A N/A N/A N/A N/A Valid N/A Valid N/A Valid
ADDR (A5=0)

CKE

WL = CWL + AL + PL 4nCK tWR

DQS_t
DQS_c

DQs1
bit 0 bit 1 bit 6 bit 7
tRCD tPGM_s tPGM_Exit_s tPGMPST_s
All Banks
Precharged
and idle state

sPPR Recognition sPPR Exit Normal

sPPR Repair sPPR Repair sPPR Repair sPPR Repair Mode

Don’t Care

Table 45: DDR4 sPPR Timing Parameters DDR4-1600 Through DDR4-3200

Parameter Symbol Min Max Unit
sPPR programming time tPGM_s tRCD(MIN)+ WL + 4nCK + tWR(MIN) n ns

sPPR precharge exit time tPGM_Exit_s 20 n ns

sPPR exit time t

PGMPST_s t
MOD n ns

MBIST-PPR
DDR4 devices can support optional memory built-in self-test post-package repair (MBIST-PPR) to
help with hard failures such as single-bit or multi-bit failures in a single device so that weak cells can
be scanned and repaired during the initialization phase. The DRAM will use vendor-specific patterns
to investigate the status of all cell arrays and automatically perform PPR for weak bits during this oper-
ation. This operation introduces proactive, automated PPR by the DRAM, and it is recommended to be
DONE FOR A VERY FIRST BOOT UP AT LEAST !FTER THAT IT IS AT THE CONTROLLERS DISCRETION WHETHER TO ACTIVATE
MBIST. MBIST mode can only be entered from the all banks idle state. The DLL is required to be
enabled and locked prior to MBIST-PPR execution.
MBIST-PPR resources are separated from normal hPPR/sPPR resources. MBIST-PPR resources are
typically used for initial scan and repair, and hPPR/sPPR resources must still satisfy the number of
repair elements, one per BG, specified in the DDR4 Bank Group Timing Examples 1. Once the
MBIST-PPR is completed, the DRAM will update the status flag in MPR3[7] of MPR page 3. Detailed
status is described in the MPR Page and MPRx Definitions .
The test time of MBIST-PPR will not exceed 10 seconds for all mono-die DRAM densities. For DDP
devices, test time will be 20 seconds.
The controller is required to inject an MRS command to enter this operation. The controller sets
MR4:A0 to 1, followed by MR0 commands for the guard key. Then the DRAM enters MBIST-PPR oper-
ation. The ALERT_n signal notifies the host of the status of this operation. When the controller sets
MR4:A0 to 1, followed by the MR0 guard key sequence, the DRAM drives ALERT_n to 0. Once the

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 8Gb: x4, x8, x16 DDR4 SDRAM
MBIST-PPR

MBIST-PPR is completed, the DRAM drives ALERT_n to 1 to notify the controller that this operation is
completed. DRAM data will not be guaranteed after the MBIST-PPR operation.

Table 46: MBIST-PPR Timing Parameter

Value
Parameter Min Max Unit
tSELFHEAL Monolithic n 10 s
DDP n 20

MBIST-PPR Procedure
The following sequences are required for MBIST-PPR and are shown in the figure below.
1. The DRAM needs to finalize initialization, MR training, and ZQ calibration prior to entering
MBIST-PPR.
2. Four consecutive guard key commands must be issued to MR0, with each command separated by
t
MOD. The PPR guard key settings are the same whether performing sPPR, hPPR, or MBIST-PPR
mode.
3. Anytime after Tk in the Read Termination Disable Window 15, the host must set MR4:A0 to 1,
followed by subsequent MR0 guard key sequences (which is identical to typical hPPR/sPPR guard
key sequences and specified in Table 73) to start MBIST-PPR operation, and the DRAM drives the
ALERT_n signal to 0.
4. During MBIST-PPR mode, only DESELECT commands are allowed.
5. The ODT pin must be driven LOW during MBIST-PPR to satisfy DODTLoff from time Tb0 until Tc2.
The DRAM may or may not provide RTT_PARK termination during MBIST-PPR regardless of
whether RTT_PARK is enabled in MR5.

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 8Gb: x4, x8, x16 DDR4 SDRAM
MBIST-PPR

Figure 81: MBIST-PPR Sequence

T0 T1 Ta0 Ta1 Tb0 Tb1 Tb2
CK_c
CK_t
CMD MRS4 DES MRS0 DES DES Valid DES

BG Valid N/A 00 N/A N/A Valid N/A

BA Valid N/A 00 N/A N/A Valid N/A

Valid
ADDR (A0=1) N/A 4th Key N/A N/A Valid N/A

CKE

t IS
ALERT_N

All Banks 5 x t MOD t SELFHEAL

Precharged Follow Guard Key Entry Sequence
and idle state

Normal MBIST-PPR Entry MBIST-PPR Normal

NormalOperation
Operation
Mode

Table 47: MPR Page3 Configuration for MBIST-PPR

Address MPR Location [7] [6] [5] [4] [3] [2] [1] [0] Note
BA[1:0] 00 = MPR0 DC DC DC DC DC DC DC DC Read-
only
01 = MPR1 DC DC DC DC DC DC DC DC
10 = MPR2 DC DC DC DC DC DC DC DC
11 = MPR3 MBIST- DC MBIST-PPR MAC MAC MAC MAC
PPR Transparency
Support

MPR Location Address Bit Function Data Notes

0: Don't Support
11 = MPR3 7 MBIST-PPR Support 1
1: Support
00B: MBIST-PPR hasn't run since init OR no fails found
1, 2
during most recent MBIST-PPR
MBIST-PPR 01B: Repaired all found fails during most recent run 1
11 = MPR3 5:4
Transparency
10B: Unrepairable fails found during most recent run 1
11B: MBIST-PPR should be run again 1, 3

Notes: 1. MPR bits are cleared either by a power-up sequence or re-initialization by RESET_n signal
2. The host should track whether MBIST-PPR has run since INIT. If MBIST-PPR is performed and it finds no fails, this
transparency state will remain set to 00B
3. This state does not imply that MBIST-PPR is required to run again. This implies that additional repairable fails were
found during the most recent MBIST-PPR beyond what could be repaired in the tSELFHEAL window.

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 8Gb: x4, x8, x16 DDR4 SDRAM
hPPR/sPPR/MBIST-PPR Support Identifier

hPPR/sPPR/MBIST-PPR Support Identifier

Table 48: DDR4 Repair Mode Support Identifier

A7 A6 A5 A4 A3 A2 A1 A0
MPR Page 2
UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7
MPR0 hPPR1 sPPR2 RTT_WR Temp sensor CRC RTT_WR

A7 A6 A5 A4 A3 A2 A1 A0
MPR Page 3
UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7
MBIST-PPR
MPR3 Don't Care MBIST-PPR Transparency MAC MAC MAC MAC
Support3

Notes: 1. 0 = hPPR mode is not available, 1 = hPPR mode is available.

2. 0 = sPPR mode is not available, 1 = sPPR mode is available.
3. 0 = MBIST-PPR mode is not available, 1 = MBIST-PPR mode is available.
4. Gray shaded areas are for reference only.

ACTIVATE Command
The ACTIVATE command is used to open (activate) a row in a particular bank for subsequent access.
The values on the BG[1:0] inputs select the bank group, the BA[1:0] inputs select the bank within the
bank group, and the address provided on inputs A[17:0] selects the row within the bank. This row
remains active (open) for accesses until a PRECHARGE command is issued to that bank. A
PRECHARGE command must be issued before opening a different row in the same bank.
Bank-to-bank command timing for ACTIVATE commands uses two different timing parameters,
depending on whether the banks are in the same or different bank group. tRRD_S (short) is used for
timing between banks located in different bank groups. tRRD_L (long) is used for timing between
banks located in the same bank group. Another timing restriction for consecutive ACTIVATE
commands [issued at tRRD (MIN)] is tFAW (four activate window). Because there is a maximum of four
banks in a bank group, the tFAW parameter applies across different bank groups (five ACTIVATE
commands issued at tRRD_L (MIN) to the same bank group would be limited by tRC).

Figure 82: tRRD Timing

T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11
CK_c
CK_t

Command ACT DES DES DES ACT DES DES DES DES DES ACT DES
tRRD_S tRRD_L

Bank
Group BG a BG b BG b
(BG)

Bank Bank c Bank c Bank d

Address Row n Row n Row n

Don’t Care

Notes: 1. tRRD_S; ACTIVATE-to-ACTIVATE command period (short); applies to consecutive ACTIVATE commands to different

bank groups (that is, T0 and T4).

2. tRRD_L; ACTIVATE-to-ACTIVATE command period (long); applies to consecutive ACTIVATE commands to the
different banks in the same bank group (that is, T4 and T10).

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 8Gb: x4, x8, x16 DDR4 SDRAM
PRECHARGE Command

Figure 83: tFAW Timing

CK_c T0 Ta0 Tb0 Tc0 Tc1 Tc2 Td0 Td1
CK_t

Command ACT Valid ACT Valid ACT Valid ACT Valid Valid Valid ACT NOP

tRRD tRRD tRRD

tFAW
Bank
Group Valid Valid Valid Valid Valid
(BG)

Bank Valid Valid Valid Valid Valid

Address Valid Valid Valid Valid Valid

Don’t Care Time Break

t
Note: 1. FAW; four activate windows.

PRECHARGE Command
The PRECHARGE command is used to deactivate the open row in a particular bank or the open row in
all banks. The bank(s) will be available for a subsequent row activation for a specified time (tRP) after
the PRECHARGE command is issued. An exception to this is the case of concurrent auto precharge,
where a READ or WRITE command to a different bank is allowed as long as it does not interrupt the
data transfer in the current bank and does not violate any other timing parameters.
After a bank is precharged, it is in the idle state and must be activated prior to any READ or WRITE
commands being issued to that bank. A PRECHARGE command is allowed if there is no open row in
that bank (idle state) or if the previously open row is already in the process of precharging. However,
the precharge period will be determined by the last PRECHARGE command issued to the bank.
The auto precharge feature is engaged when a READ or WRITE command is issued with A10 HIGH. The
auto precharge feature uses the RAS lockout circuit to internally delay the PRECHARGE operation until
the ARRAY RESTORE operation has completed. The RAS lockout circuit feature allows the
PRECHARGE operation to be partially or completely hidden during burst READ cycles when the auto
precharge feature is engaged. The PRECHARGE operation will not begin until after the last data of the
burst write sequence is properly stored in the memory array.

REFRESH Command
The REFRESH command (REF) is used during normal operation of the device. This command is
nonpersistent, so it must be issued each time a refresh is required. The device requires REFRESH cycles
at an average periodic interval of tREFI. When CS_n, RAS_n/A16, and CAS_n/A15 are held LOW and
WE_n/A14 HIGH at the rising edge of the clock, the device enters a REFRESH cycle. All banks of the
SDRAM must be precharged and idle for a minimum of the precharge time, tRP (MIN), before the
REFRESH command can be applied. The refresh addressing is generated by the internal DRAM refresh
CONTROLLER 4HIS MAKES THE ADDRESS BITS h$ONT #AREv DURING A 2%&2%3( COMMAND !N INTERNAL ADDRESS
counter supplies the addresses during the REFRESH cycle. No control of the external address bus is
required once this cycle has started. When the REFRESH cycle has completed, all banks of the SDRAM
will be in the precharged (idle) state. A delay between the REFRESH command and the next valid
command, except DES, must be greater than or equal to the minimum REFRESH cycle time tRFC
(MIN), as shown in .

NOTE: The tRFC timing parameter depends on memory density.

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 8Gb: x4, x8, x16 DDR4 SDRAM
REFRESH Command

In general, a REFRESH command needs to be issued to the device regularly every tREFI interval. To
allow for improved efficiency in scheduling and switching between tasks, some flexibility in the abso-
lute refresh interval is provided for postponing and pulling-in the REFRESH command. A limited
number REFRESH commands can be postponed depending on refresh mode: a maximum of 8
REFRESH commands can be postponed when the device is in 1X refresh mode; a maximum of 16
REFRESH commands can be postponed when the device is in 2X refresh mode; and a maximum of 32
REFRESH commands can be postponed when the device is in 4X refresh mode.
When 8 consecutive REFRESH commands are postponed, the resulting maximum interval between the
surrounding REFRESH commands is limited to 9 έ tREFI (see ). For both the 2X and 4X refresh modes,
the maximum interval between surrounding REFRESH commands allowed is limited to 17 έ tREFI2
and 33 έ tREFI4, respectively.
A limited number REFRESH commands can be pulled-in as well. A maximum of 8 additional REFRESH
COMMANDS CAN BE ISSUED IN ADVANCE OR hPULLED INv IN 8 REFRESH MODE A MAXIMUM OF  ADDITIONAL
REFRESH commands can be issued when in advance in 2X refresh mode, and a maximum of 32 addi-
tional REFRESH commands can be issued in advance when in 4X refresh mode. Each of these
REFRESH commands reduces the number of regular REFRESH commands required later by one. The
resulting maximum interval between two surrounding REFRESH commands is limited to 9 έ tREFI ( ),
17 έ tRFEI2, or 33 έ tREFI4. At any given time, a maximum of 16 REF commands can be issued within 2
έ tREFI, 32 REF2 commands can be issued within 4 έ tREFI2, and 64 REF4 commands can be issued
within 8 έ tREFI4 (larger densities are limited by tRFC1, tRFC2, and tRFC4, respectively, which must
still be met).

Figure 84: REFRESH Command Timing

T0 T1 Ta0 Ta1 Tb0 Tb1 Tb2 Tb3 Tc0 Tc1 Tc2 Tc3
CK_c
CK_t

Command REF DES DES REF DES DES Valid Valid Valid Valid Valid REF Valid Valid Valid
tRFC tRFC (MIN)
tREFI (MAX 9 × tREFI)

DRAM must be idle DRAM must be idle

Time Break Don’t Care

Notes: 1. Only DES commands are allowed after a REFRESH command is registered until tRFC (MIN) expires.
2. Time interval between two REFRESH commands may be extended to a maximum of 9 έ tREFI.

Figure 85: Postponing REFRESH Commands (Example)

tREFI
9 × tREFI

t
tRFC

8 REF-Commands postponed

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 8Gb: x4, x8, x16 DDR4 SDRAM
REFRESH Command

Figure 86: Pulling In REFRESH Commands (Example)

tREFI 9 × tREFI

t
tRFC

8 REF-Commands pulled-in

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 8Gb: x4, x8, x16 DDR4 SDRAM
Temperature-Controlled Refresh Mode

Temperature-Controlled Refresh Mode

During normal operation, temperature-controlled refresh (TCR) mode disabled, the device must have
a REFRESH command issued once every tREFI, except for what is allowed by posting (see REFRESH
Command section). This means a REFRESH command must be issued once every 7.8ρs if TC is less
than or equal to 85ιC, once every 3.9ρs if TC is greater than 85ιC, once every 1.95ρs if TC is greater than
95ιC, regardless of which Temperature Mode is selected (MR4[2]). TCR mode is disabled by setting
MR4[3] = 0 while TCR mode is enabled by setting MR4[3] = 1. When TCR mode is enabled (MR4[3] = 1),
the Temperature Mode must be selected where MR4[2] = 0 enables the Normal Temperature Mode
while MR4[2] = 1 enables the Extended Temperature Mode.
When TCR mode is enabled, the device will register the externally supplied REFRESH command and
adjust the internal refresh period to be longer than tREFI of the normal temperature range, when
allowed, by skipping REFRESH commands with the proper gear ratio. TCR mode has two Temperature
Modes to select between the normal temperature range and the extended temperature range; the
correct Temperature Mode must be selected so the internal control operates correctly. The DRAM
must have the correct refresh rate applied externally; the internal refresh rate is determined by the
DRAM based upon the temperature.

Normal Temperature Mode

REFRESH commands should be issued to the device with the refresh period equal to tREFI of normal
temperature range (-40ιC to 85ιC). The system must guarantee that the TC does not exceed 85ιC when
t
REFI of the normal temperature range is used. The device may adjust the internal refresh period to be
longer than tREFI of the normal temperature range by skipping external REFRESH commands with the
proper gear ratio when TC is below 85ιC. The internal refresh period is automatically adjusted inside
the DRAM, and the DRAM controller does not need to provide any additional control.

Extended Temperature Mode

REFRESH commands should be issued to the device with the refresh period equal to tREFI of extended
temperature range (85ιC to 95ιC, or 95ιC to 105ιC) . The system must guarantee that the TC does not
exceed 95ιC, or 105ιC. Even though the external refresh supports the extended temperature range, the
device may adjust its internal refresh period to be equal to or longer than tREFI of the normal tempera-
ture range (-40ιC to 85ιC) by skipping external REFRESH commands with the proper gear ratio when
TC is equal to or below 85ιC. The internal refresh period is automatically adjusted inside the DRAM,
and the DRAM controller does not need to provide any additional control.

Table 49: Normal tREFI Refresh (TCR Enabled)

Normal Temperature Mode Extended Temperature Mode
External Refresh Internal Refresh External Refresh Internal Refresh
Temperature Period Period Period Period
TC ζ 85ιC 7.8ρs η7.8ρs 3.9ρs1 η7.8ρs

85ιC < TC ζ 95ιC 3.9ρs

95ιC < TC ζ 105ιC 1.95ρs

Notes: 1. If the external refresh period is slower than 3.9ρs, the device will refresh internally at too slow of a refresh rate
and will violate refresh specifications.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Temperature-Controlled Refresh Mode

Figure 87: TCR Mode Example1

Controller 85°C < TC ” 95°C TC ” 85°C

REFRESH REFRESH REFRESH

External Internal
tREFI tREFI
3.9μs 3.9μs Internal
REFRESH REFRESH tREFI
•7.8μs

REFRESH REFRESH REFRESH

REFRESH REFRESH

REFRESH REFRESH REFRESH

REFRESH REFRESH

REFRESH REFRESH REFRESH

Controller issues REFRESH External REFRESH At least every other

commands at extended commands are not external REFRESH
temperature rate ignored ignored

Note: 1. TCR enabled with Extended Temperature Mode selected.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Fine Granularity Refresh Mode

Fine Granularity Refresh Mode

Mode Register and Command Truth Table
The REFRESH cycle time (tRFC) and the average refresh interval (tREFI) can be programmed by the
MRS command. The appropriate setting in the mode register will set a single set of REFRESH cycle
times and average refresh interval for the device (fixed mode), or allow the dynamic selection of one of
two sets of REFRESH cycle times and average refresh interval for the device (on-the-fly mode [OTF]).
OTF mode must be enabled by MRS before any OTF REFRESH command can be issued.

Table 50: MRS Definition

MR3[
8] MR3[7] MR3[6] Refresh Rate Mode
0 0 0 Normal mode (fixed 1x)
0 0 1 Fixed 2x
0 1 0 Fixed 4x
0 1 1 Reserved
1 0 0 Reserved
1 0 1 On-the-fly 1x/2x
1 1 0 On-the-fly 1x/4x
1 1 1 Reserved

There are two types of OTF modes (1x/2x and 1x/4x modes) that are selectable by programming the
appropriate values into the mode register MR3 [8:6]. When either of the two OTF modes is selected, the
device evaluates the BG0 bit when a REFRESH command is issued, and depending on the status of BG0,
it dynamically switches its internal refresh configuration between 1x and 2x (or 1x and 4x) modes, and
then executes the corresponding REFRESH operation.

Table 51: REFRESH Command Truth Table

A[9:0],
RAS_n/A CAS_n/A WE_n/ A10/ A[12:11], MR3[8:6
Refresh CS_n ACT_n 15 14 A13 BG1 BG0 AP A[20:16] ]
Fixed rate L H L L H V V V V 0vv
OTF: 1x L H L L H V L V V 1vv
OTF: 2x L H L L H V H V V 101
OTF: 4x L H L L H V H V V 110

t
REFI and tRFC Parameters
The default refresh rate mode is fixed 1x mode where REFRESH commands should be issued with the
normal rate; that is, tREFI1 = tREFI(base) (for TC ζ 85ιC), and the duration of each REFRESH command
is the normal REFRESH cycle time (tRFC1). In 2x mode (either fixed 2x or OTF 2x mode), REFRESH
commands should be issued to the device at the double frequency (tREFI2 = tREFI(base)/2) of the
normal refresh rate. In 4x mode, the REFRESH command rate should be quadrupled (tREFI4 =
t
REFI(base)/4). Per each mode and command type, the tRFC parameter has different values as defined
in the following table.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Fine Granularity Refresh Mode

For discussion purposes, the REFRESH command that should be issued at the normal refresh rate and
has the normal REFRESH cycle duration may be referred to as an REF1x command. The REFRESH
command that should be issued at the double frequency (tREFI2 = tREFI(base)/2) may be referred to
as a REF2x command. Finally, the REFRESH command that should be issued at the quadruple rate
(tREFI4 = tREFI(base)/4) may be referred to as a REF4x command.
In the fixed 1x refresh rate mode, only REF1x commands are permitted. In the fixed 2x refresh rate
mode, only REF2x commands are permitted. In the fixed 4x refresh rate mode, only REF4x commands
are permitted. When the on-the-fly 1x/2x refresh rate mode is enabled, both REF1x and REF2x
commands are permitted. When the OTF 1x/4x refresh rate mode is enabled, both REF1x and REF4x
commands are permitted.

Table 52: tREFI and tRFC Parameters

Refresh
Mode Parameter 2Gb 4Gb 8Gb 16Gb Units
t
REFI (base) 7.8 7.8 7.8 7.8 ρs

1x mode tREFI1 -40ιC ζ TC ζ 85ιC tREFI(base) tREFI(base) tREFI(base) tREFI(base) ρs

85ιC ζ TC ζ 95ιC t
REFI(base)/2 t
REFI(base)/2 t
REFI(base)/2 t
REFI(base)/2 ρs

95ιC ζ TC ζ 105ιC t
REFI(base)/4 t
REFI(base)/4 t
REFI(base)/4 t
REFI(base)/4 ρs
t
RFC1 160 260 350 350 ns

2x mode t
REFI2 -40ιC ζ TC ζ 85ιC t
REFI(base)/2 t
REFI(base)/2 t
REFI(base)/2 t
REFI(base)/2 ρs

85ιC ζ TC ζ 95ιC t
REFI(base)/4 t
REFI(base)/4 t
REFI(base)/4 t
REFI(base)/4 ρs

95ιC ζ TC ζ 105ιC tREFI(base)/8 tREFI(base)/8 tREFI(base)/8 tREFI(base)/8 ρs

t
RFC2 110 160 260 260 ns

4x mode t
REFI4 -40ιC ζ TC ζ 85ιC t
REFI(base)/4 t
REFI(base)/4 t
REFI(base)/4 t
REFI(base)/4 ρs

85ιC ζ TC ζ 95ιC t
REFI(base)/8 t
REFI(base)/8 t
REFI(base)/8 t
REFI(base)/8 ρs

95ιC ζ TC ζ 105ιC t
REFI(base)/1 t
REFI(base)/1 t
REFI(base)/1 t
REFI(base)/1 ρs
6 6 6 6
t
RFC4 90 110 160 160 ns

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 Figure 88: 4Gb with Fine Granularity Refresh Mode Example
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Normal Temperature Operation – -40°C to 85°C Extended Temperature Operation – -40°C to 105°C

1x Mode 2x Mode 4x Mode 1x Mode 2x Mode 4x Mode

(-40°C to 85°C) (-40°C to 85°C) (-40°C to 85°C) (-40°C to 105°C) (-40°C to 105°C) (-40°C to 105°C)

s
5μ
REF@260ns REF@160ns REF@110ns REF@260ns REF@160ns REF@110ns

97
0.
μs

μs

=
95

95

FI
Rt E
1.

1.

s
5μ
=

=
REF@110ns

FI

FI

97
Rt E

Rt E

0.
s

=
9μ

9μ

FI
3.

3.

Rt E

s
=

5μ
REF@110ns REF@160ns REF@110ns

FI

FI

97
Rt E

Rt E

0.
μs

μs

=
95

95

FI
Rt E
1.

1.

s
5μ
=

=
REF@110ns

FI

FI

97
Rt E

Rt E

0.
=
FI
Rt E
s
8μ

s
5μ
REF@160ns REF@110ns REF@260ns REF@160ns REF@110ns
7.

97
=

0.
FI

μs

μs

=
Rt E

95

95

FI
Rt E
1.

1.

s
5μ
=

=
REF@110ns

FI

FI

97
Rt E

Rt E

0.
=
s

s
9μ

9μ

FI
3.

3.

Rt E

s
=

5μ
REF@110ns REF@160ns REF@110ns
FI

FI

97
Rt E

Rt E

0.
μs

μs

=
FI
95

95

Rt E
1.

1.

s
5μ
=

=
REF@110ns

97
FI

FI
Rt E

Rt E

0.
=
FI
Rt E

s
5μ
REF@260ns REF@160ns REF@110ns REF@260ns REF@160ns REF@110ns

97
0.
=
μs

μs

FI
95

95
149

Rt E
1.

1.

s
5μ
=

=
REF@110ns

97
FI

FI
Rt E

Rt E

0.
=
s

s
9μ

9μ

FI
Rt E
3.

3.

s
5μ
=

=
REF@110ns REF@160ns REF@110ns
FI

FI

97
Rt E

Rt E

0.
=
μs

μs

FI
95

95

Rt E
1.

1.

s
Micron Technology, Inc. reserves the right to change products or specifications without notice.

5μ
s
8μ

=
REF@110ns

97
FI

FI
7.

0.
Rt E

Rt E
=

=
FI

FI
Rt E

Rt E

s
5μ
REF@160ns REF@110ns REF@260ns REF@160ns REF@110ns

97

Fine Granularity Refresh Mode

0.
=
μs

μs

8Gb: x4, x8, x16 DDR4 SDRAM

FI
95

95

Rt E

s
1.

1.

5μ
=

=
REF@110ns

97
FI

FI

0.
Rt E

Rt E

=
s

s
9μ

9μ

FI
Rt E
3.

3.

s
5μ
=

=
REF@110ns REF@160ns REF@110ns
FI

FI

97
Rt E

Rt E

0.
=
μs

μs

FI
95

95

Rt E

s
1.

1.

5μ
REF@110ns
=

97
FI

FI

0.
Rt E

Rt E

=
FI
¥ 2015 Micron Technology, Inc. All rights reserved.

Rt E
REF@260ns REF@160ns REF@110ns REF@260ns REF@160ns REF@110ns
 8Gb: x4, x8, x16 DDR4 SDRAM
Fine Granularity Refresh Mode

Changing Refresh Rate

If the refresh rate is changed by either MRS or OTF. New tREFI and tRFC parameters will be applied
from the moment of the rate change. When the REF1x command is issued to the DRAM, tREF1 and
t
RFC1 are applied from the time that the command was issued; when the REF2x command is issued,
tREF2 and tRFC2 should be satisfied.

Figure 89: OTF REFRESH Command Timing

CK_c
CK_t
Command DES REF1 DES DES DES Valid Valid REF2 DES DES Valid DES REF2 DES
tRFC1 (MIN) tRFC2 (MIN)

tREFI1 tREFI2

Don’t Care

The following conditions must be satisfied before the refresh rate can be changed. Otherwise, data
retention cannot be guaranteed.
s In the fixed 2x refresh rate mode or the OTF 1x/2x refresh mode, an even number of REF2x
commands must be issued because the last change of the refresh rate mode with an MRS command
before the refresh rate can be changed by another MRS command.
s In the OTF1x/2x refresh rate mode, an even number of REF2x commands must be issued between
any two REF1x commands.
s In the fixed 4x refresh rate mode or the OTF 1x/4x refresh mode, a multiple-of-four number of REF4x
commands must be issued because the last change of the refresh rate with an MRS command before
the refresh rate can be changed by another MRS command.
s In the OTF1x/4x refresh rate mode, a multiple-of-four number of REF4x commands must be issued
between any two REF1x commands.
There are no special restrictions for the fixed 1x refresh rate mode. Switching between fixed and OTF
modes keeping the same rate is not regarded as a refresh rate change.

Usage with TCR Mode

If the temperature controlled refresh mode is enabled, only the normal mode (fixed 1x mode, MR3[8:6]
= 000) is allowed. If any other refresh mode than the normal mode is selected, the temperature
controlled refresh mode must be disabled.

Self Refresh Entry and Exit

The device can enter self refresh mode anytime in 1x, 2x, and 4x mode without any restriction on the
number of REFRESH commands that have been issued during the mode before the self refresh entry.
However, upon self refresh exit, extra REFRESH command(s) may be required, depending on the
condition of the self refresh entry.
The conditions and requirements for the extra REFRESH command(s) are defined as follows:
s In the fixed 2x refresh rate mode or the enable-OTF 1x/2x refresh rate mode, it is recommended there
be an even number of REF2x commands before entry into self refresh after the last self refresh exit,
REF1x command, or MRS command that set the refresh mode. If this condition is met, no additional
REFRESH commands are required upon self refresh exit. In the case that this condition is not met,
either one extra REF1x command or two extra REF2x commands must be issued upon self refresh
exit. These extra REFRESH commands are not counted toward the computation of the average
refresh interval (tREFI).

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 8Gb: x4, x8, x16 DDR4 SDRAM
Fine Granularity Refresh Mode

s In the fixed 4x refresh rate mode or the enable-OTF 1x/4x refresh rate mode, it is recommended there
be a multiple-of-four number of REF4x commands before entry into self refresh after the last self
refresh exit, REF1x command, or MRS command that set the refresh mode. If this condition is met,
no additional refresh commands are required upon self refresh exit. When this condition is not met,
either one extra REF1x command or four extra REF4x commands must be issued upon self refresh
exit. These extra REFRESH commands are not counted toward the computation of the average
refresh interval (tREFI).
There are no special restrictions on the fixed 1x refresh rate mode.
This section does not change the requirement regarding postponed REFRESH commands. The
requirement for the additional REFRESH command(s) described above is independent of the require-
ment for the postponed REFRESH commands.

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 8Gb: x4, x8, x16 DDR4 SDRAM
SELF REFRESH Operation

SELF REFRESH Operation

The SELF REFRESH command can be used to retain data in the device, even if the rest of the system is
powered down. When in self refresh mode, the device retains data without external clocking. The
device has a built-in timer to accommodate SELF REFRESH operation. The SELF REFRESH command
is defined by having CS_n, RAS_n, CAS_n, and CKE held LOW with WE_n and ACT_n HIGH at the rising
edge of the clock.
Before issuing the SELF REFRESH ENTRY command, the device must be idle with all banks in the
precharge state and tRP satisfied. Idle state is defined as: All banks are closed (tRP, tDAL, and so on,
satisfied), no data bursts are in progress, CKE is HIGH, and all timings from previous operations are
satisfied (tMRD, tMOD, tRFC, tZQinit, tZQoper, tZQCS, and so on). After the SELF REFRESH ENTRY
command is registered, CKE must be held LOW to keep the device in self refresh mode. The DRAM
automatically disables ODT termination, regardless of the ODT pin, when it enters self refresh mode
and automatically enables ODT upon exiting self refresh. During normal operation (DLL_on), the DLL
is automatically disabled upon entering self refresh and is automatically enabled (including a DLL
reset) upon exiting self refresh.
When the device has entered self refresh mode, all of the external control signals, except CKE and
2%3%4?N ARE h$ONT #AREv &OR PROPER 3%,& 2%&2%3( OPERATION ALL POWER SUPPLY AND REFERENCE PINS
(VDD, VDDQ, VSS, VSSQ, VPP, and VREFCA) must be at valid levels. The DRAM internal VREFDQ generator
circuitry may remain on or be turned off depending on the MR6 bit 7 setting. If the internal VREFDQ
circuit is on in self refresh, the first WRITE operation or first write-leveling activity may occur after tXS
time after self refresh exit. If the DRAM internal VREFDQ circuitry is turned off in self refresh, it ensures
that the VREFDQ generator circuitry is powered up and stable within the tXSDLL period when the DRAM
exits the self refresh state. The first WRITE operation or first write-leveling activity may not occur
earlier than tXSDLL after exiting self refresh. The device initiates a minimum of one REFRESH
command internally within the tCKE period once it enters self refresh mode.
The clock is internally disabled during a SELF REFRESH operation to save power. The minimum time
that the device must remain in self refresh mode is tCKESR/tCKESR_PAR. The user may change the
external clock frequency or halt the external clock tCKSRE/tCKSRE_PAR after self refresh entry is regis-
tered; however, the clock must be restarted and tCKSRX must be stable before the device can exit SELF
REFRESH operation.
The procedure for exiting self refresh requires a sequence of events. First, the clock must be stable prior
to CKE going back HIGH. Once a SELF REFRESH EXIT command (SRX, combination of CKE going
HIGH and DESELECT on the command bus) is registered, the following timing delay must be satisfied:
Commands that do not require locked DLL:
s tXS = ACT, PRE, PREA, REF, SRE, and PDE.
s tXS_FAST = ZQCL, ZQCS, and MRS commands. For an MRS command, only DRAM CL, WR/RTP
register, and DLL reset in MR0; RTT(NOM) register in MR1; the CWL and RTT(WR) registers in MR2; and
gear-down mode register in MR3; WRITE and READ preamble registers in MR4; RTT(PARK) register in
MR5; Data rate and VREFDQ calibration value registers in MR6 may be accessed provided the DRAM
is not in per-DRAM mode. Access to other DRAM mode registers must satisfy tXS timing. WRITE
commands (WR, WRS4, WRS8, WRA, WRAS4, and WRAS8) that require synchronous ODT and
dynamic ODT controlled by the WRITE command require a locked DLL.

Commands that require locked DLL in the normal operating range:

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 8Gb: x4, x8, x16 DDR4 SDRAM
SELF REFRESH Operation

s t83$,, n 2$ 2$3 2$3 2$! 2$!3 AND 2$!3 UNLIKE $$2 72 723 723 72! 72!3
and WRAS8 because synchronous ODT is required).
Depending on the system environment and the amount of time spent in self refresh, ZQ CALIBRATION
commands may be required to compensate for the voltage and temperature drift described in the ZQ
CALIBRATION Commands section. To issue ZQ CALIBRATION commands, applicable timing require-
ments must be satisfied (see the ZQ Calibration Timing figure).

CKE must remain HIGH for the entire self refresh exit period tXSDLL for proper operation except for
self refresh re-entry. Upon exit from self refresh, the device can be put back into self refresh mode or
power-down mode after waiting at least tXS period and issuing one REFRESH command (refresh
period of tRFC). The DESELECT command must be registered on each positive clock edge during the
self refresh exit interval tXS. ODT must be turned off during tXSDLL.
The use of self refresh mode introduces the possibility that an internally timed refresh event can be
missed when CKE is raised for exit from self refresh mode. Upon exit from self refresh, the device
requires a minimum of one extra REFRESH command before it is put back into self refresh mode.

Figure 90: Self Refresh Entry/Exit Timing

T0 T1 Ta0 Tb0 Tc0 Td0 Td1 Te0 Tf0 Tg0
CK_c
CK_t
tCKSRE/tCKSRE_PAR tCKSRX

tIS tCPDED

CKE Valid Valid Valid

tCKESR/tCKESR_PAR

ODT Valid

tXS_FAST

Command DES SRE DES SRX Valid 1 Valid 2 Valid 3

ADDR Valid Valid Valid

tRP tXS

tXSDLL

Enter Self Refresh Exit Self Refresh

Don’t Care Time Break

Notes: 1. Only MRS (limited to those described in the SELF REFRESH Operation section), ZQCS, or ZQCL commands are
allowed.
2. Valid commands not requiring a locked DLL.
3. Valid commands requiring a locked DLL.

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 8Gb: x4, x8, x16 DDR4 SDRAM
SELF REFRESH Operation

Figure 91: Self Refresh Entry/Exit Timing with CAL Mode

T0 T1 T3 T4 T7 T8 T11 Ta0 Ta7 Ta8 Ta9 Ta10 Tb0 Tb1 Tb3
CK_c
CK_t
t
t
CKSRE CKSRX

CS_n

Note 2 Note 3
Command DES DES SRE DES DES SRX DES DES DES DES Valid
w/o CS_n

ADDR Valid Valid

t t t t
CAL CPDED XS_FAST CAL

CKE

Don’t Care

Notes: 1. tCAL = 3nCK, tCPDED = 4nCK, tCKSRE/tCKSRE_PAR = 8nCK, tCKSRX = 8nCK, tXS_FAST = tREFC4 (MIN) + 10ns.
2. CS_n = HIGH, ACT_n = "Don't Care," RAS_n/A16 = "Don't Care," CAS_n/A15 = "Don't Care," WE_n/A14 = "Don't
Care."
3. Only MRS (limited to those described in the SELF REFRESH Operations section), ZQCS, or ZQCL commands are
allowed.
4. The figure only displays tXS_FAST timing, but tCAL must also be added to any tXS and tXSDLL associated commands
during CAL mode.

Self Refresh Abort

The exit timing from self refresh exit to the first valid command not requiring a locked DLL is tXS. The
value of tXS is (tRFC1 + 10ns). This delay allows any refreshes started by the device time to complete.
t
RFC continues to grow with higher density devices, so tXS will grow as well. An MRS bit enables the self
refresh abort mode. If the bit is disabled, the controller uses tXS timings (location MR4, bit 9). If the bit
is enabled, the device aborts any ongoing refresh and does not increment the refresh counter. The
controller can issue a valid command not requiring a locked DLL after a delay of tXS_ABORT. Upon exit
from self refresh, the device requires a minimum of one extra REFRESH command before it is put back
into self refresh mode. This requirement remains the same irrespective of the setting of the MRS bit for
self refresh abort.

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 8Gb: x4, x8, x16 DDR4 SDRAM
SELF REFRESH Operation

Figure 92: Self Refresh Abort

T0 T1 Ta0 Tb0 Tc0 Td0 Td1 Te0 Tf0 Tg0
CK_c
CK_t
tCKSRE/tCKSRE_PAR tCKSRX

tIS tCPDED

CKE Valid Valid Valid

tCKESR/tCKESR_PAR

ODT Valid

tXS_FAST

Command DES SRE DES SRX Valid 1 Valid 2 Valid 3

ADDR Valid Valid Valid

tRP tXS_ABORT

tXSDLL

Enter Self Refresh Exit Self Refresh

Don’t Care Time Break

Notes: 1. Only MRS (limited to those described in the SELF REFRESH Operation section), ZQCS, or ZQCL commands are
allowed.
2. Valid commands not requiring a locked DLL with self refresh abort mode enabled in the mode register.
3. Valid commands requiring a locked DLL.

Self Refresh Exit with NOP Command

Exiting self refresh mode using the NO OPERATION command (NOP) is allowed under a specific
system application. This special use of NOP allows for a common command/address bus between
active DRAM devices and DRAM(s) in maximum power saving mode. Self refresh mode may exit with
NOP commands provided:
s The device entered self refresh mode with CA parity, CAL, and gear-down disabled.
s tMPX_S and tMPX_LH are satisfied.
s NOP commands are only issued during tMPX_LH window.

No other command is allowed during the tMPX_LH window after an SELF REFRESH EXIT (SRX)
command is issued.

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 8Gb: x4, x8, x16 DDR4 SDRAM
SELF REFRESH Operation

Figure 93: Self Refresh Exit with NOP Command

Ta0 Ta1 Ta2 Ta3 Tb0 Tb1 Tb2 Tb3 Tc0 Tc1 Tc2 Tc3 Tc4 Td0 Td1 Td2 Td3 Te0 Te1
CK_c
CK_t
t
CKSRX

CKE

ODT
Valid

t t
MPX_S MPX_LH

CS_n

Note 1, 2 Note 3
Command SRX NOP NOP NOP NOP DES DES DES DES DES Valid DES Valid

ADDR Valid Valid Valid Valid Valid Valid Valid

t
XS
t
XS + t XSDLL

Don’t Care

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 8Gb: x4, x8, x16 DDR4 SDRAM
Power-Down Mode

Power-Down Mode
Power-down is synchronously entered when CKE is registered LOW (along with a DESELECT
command). CKE is not allowed to go LOW when the following operations are in progress: MRS
command, MPR operations, ZQCAL operations, DLL locking, or READ/WRITE operations. CKE is
allowed to go LOW while any other operations, such as ROW ACTIVATION, PRECHARGE or auto
precharge, or REFRESH, are in progress, but the power-down IDD specification will not be applied until
those operations are complete. The timing diagrams that follow illustrate power-down entry and exit.
For the fastest power-down exit timing, the DLL should be in a locked state when power-down is
entered. If the DLL is not locked during power-down entry, the DLL must be reset after exiting
power-down mode for proper READ operation and synchronous ODT operation. DRAM design
provides all AC and DC timing and voltage specification as well as proper DLL operation with any CKE
intensive operations as long as the controller complies with DRAM specifications.
During power-down, if all banks are closed after any in-progress commands are completed, the device
will be in precharge power-down mode; if any bank is open after in-progress commands are
completed, the device will be in active power-down mode.
Entering power-down deactivates the input and output buffers, excluding CK, CKE, and RESET_n. In
power-down mode, DRAM ODT input buffer deactivation is based on Mode Register 5, bit 5 (MR5[5]).
If it is configured to 0b, the ODT input buffer remains on and the ODT input signal must be at valid
logic level. If it is configured to 1b, the ODT input buffer is deactivated and the DRAM ODT input signal
may be floating and the device does not provide RTT(NOM) termination. Note that the device continues
to provide RTT(Park) termination if it is enabled in MR5[8:6]. To protect internal delay on the CKE line
to block the input signals, multiple DES commands are needed during the CKE switch off and on
cycle(s); this timing period is defined as tCPDED. CKE LOW will result in deactivation of command and
address receivers after tCPDED has expired.

Table 53: Power-Down Entry Definitions

Power-Down
DRAM Status DLL Exit Relevant Parameters
Active On Fast t
XP to any valid command.
(a bank or more open)
Precharged On Fast t
XP to any valid command.
(all banks precharged)

The DLL is kept enabled during precharge power-down or active power-down. In power-down mode,
CKE is LOW, RESET_n is HIGH, and a stable clock signal must be maintained at the inputs of the
device. ODT should be in a valid state, but all other input signals are "Don't Care." (If RESET_n goes
LOW during power-down, the device will be out of power-down mode and in the reset state.) CKE LOW
must be maintained until tCKE has been satisfied. Power-down duration is limited by 9 έ tREFI.
The power-down state is synchronously exited when CKE is registered HIGH (along with DES
command). CKE HIGH must be maintained until tCKE has been satisfied. The ODT input signal must
be at a valid level when the device exits from power-down mode, independent of MR1 bit [10:8] if
RTT(NOM) is enabled in the mode register. If RTT(NOM) is disabled, the ODT input signal may remain
floating. A valid, executable command can be applied with power-down exit latency, tXP, after CKE
goes HIGH. Power-down exit latency is defined in the AC Specifications table.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Power-Down Mode

Figure 94: Active Power-Down Entry and Exit

T0 T1 T2 Ta0 Ta1 Tb0 Tb1 Tc0
CK_c
CK_t

Command Valid DES DES DES DES DES Valid

tPD
tIS
tIH
CKE Valid Valid
tCKE
tIH tIS

ODT (ODT buffer enabled - MR5[5] = 0)2

Refer to ODT Power-Down Entry/Exit

ODT (ODT buffer disabled - MR5[5] = 1)3 with ODT Buffer Disable Mode figures

Address Valid Valid

tCPDED tXP

Enter Exit
power-down power-down
mode mode
Time Break Don’t Care

Notes: 1. Valid commands at T0 are ACT, DES, or PRE with one bank remaining open after completion of the PRECHARGE
command.
2. ODT pin driven to a valid state; MR5[5] = 0 (normal setting).
3. ODT pin drive/float timing requirements for the ODT input buffer disable option (for additional power savings
during active power-down) is described in the section for ODT Input Buffer Disable Mode for Power-Down;
MR5[5] = 1.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Power-Down Mode

Figure 95: Power-Down Entry After Read and Read with Auto Precharge
T0 T1 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Ta8 Tb0 Tb1
CK_c
CK_t
RD or DES DES DES DES DES DES DES DES DES Valid
Command RDA DES DES

tIS tCPDED

CKE Valid

Address Valid Valid

RL = AL + CL tPD

DQS_t, DQS_c

DI DI DI DI DI DI DI DI
DQ BL8 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

DQ BC4 DI DI DI DI
n n+1 n+2 n+3

tRDPDEN

Power-Down
entry

Transitioning Data Time Break Don’t Care

Note: 1. DI n (or b) = data-in from column n (or b).

Figure 96: Power-Down Entry After Write and Write with Auto Precharge
T0 T1 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Tb0 Tb1 Tb2 Tc0 Tc1
CK_c
CK_t

Command WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES Valid

tIS tCPDED

CKE Valid

Address Bank, Valid

Col n

A10

WL = AL + CWL WR tPD

DQS_t, DQS_c

DI DI DI DI DI DI DI DI
DQ BL8 b b+1 b+2 b+3 b+4 b+5 b+6 b+7
Start internal
precharge
DI DI DI DI
DQ BC4 n n+1 n+2 n+3
tWRAPDEN

Power-Down
entry

Transitioning Data Time Break Don’t Care

Notes: 1. DI n (or b) = data-in from column n (or b).

2. Valid commands at T0 are ACT, DES, or PRE with one bank remaining open after completion of the PRECHARGE
command.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Power-Down Mode

Figure 97: Power-Down Entry After Write

T0 T1 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Tb0 Tb1 Tb2 Tc0 Tc1
CK_c
CK_t

Command WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES Valid

tIS tCPDED

CKE Valid

Bank,
Address Col n Valid

A10

WL = AL + CWL tWR tPD

DQS_t, DQS_c

DI DI DI DI DI DI DI DI
DQ BL8 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

DI DI DI DI
DQ BC4 n n+1 n+2 n+3
tWRPDEN

Power-Down
entry

Transitioning Data Time Break Don’t Care

Note: 1. DI n (or b) = data-in from column n (or b).

Figure 98: Precharge Power-Down Entry and Exit

T0 T1 T2 Ta0 Ta1 Tb0 Tb1 Tc0
CK_c
CK_t

Command DES DES DES DES DES DES Valid

tCPDED tCKE

tIS tIH

CKE Valid Valid

tPD tIS tXP

Enter Exit
power-down power-down
mode mode
Time Break Don’t Care

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 8Gb: x4, x8, x16 DDR4 SDRAM
Power-Down Mode

Figure 99: REFRESH Command to Power-Down Entry

T0 T1 T2 Ta0 Tb0 Tb1
CK_c
CK_t

Command REF DES DES DES DES

Address Valid
tCPDED

tIS tPD tCKE

CKE Valid

tREFPDEN

Time Break Don’t Care

Figure 100: Active Command to Power-Down Entry

T0 T1 T2 Ta0 Tb0 Tb1
CK_c
CK_t

Command ACT DES DES DES DES

Address Valid
tCPDED

tIS tPD tCKE

CKE Valid

tACTPDEN

Time Break Don’t Care

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 8Gb: x4, x8, x16 DDR4 SDRAM
Power-Down Mode

Figure 101: PRECHARGE/PRECHARGE ALL Command to Power-Down Entry

T0 T1 T2 Ta0 Tb0 Tb1
CK_c
CK_t

Command PRE or
PREA DES DES DES Valid

Address Valid
tCPDED

tIS tPD tCKE

CKE

tPREPDEN

Time Break Don’t Care

Figure 102: MRS Command to Power-Down Entry

T0 T1 Ta0 Ta1 Tb0 Tb1
CK_c
CK_t

Command MRS DES DES DES DES

Address Valid
tCPDED

tIS tPD tCKE

CKE Valid

tMRSPDEN

Time Break Don’t Care

0OWER $OWN #LARIFICATIONS n #ASE 

When CKE is registered LOW for power-down entry, tPD (MIN) must be satisfied before CKE can be
registered HIGH for power-down exit. The minimum value of parameter tPD (MIN) is equal to the
minimum value of parameter tCKE (MIN) as shown in the Timing Parameters by Speed Bin table. A
detailed example of Case 1 follows.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Power-Down Mode

Figure 103: 0OWER $OWN %NTRY%XIT #LARIFICATIONS n #ASE 

T0 T1 T2 Ta0 Ta1 Tb0 Tb1 Tb2
CK_c
CK_t

Command Valid DES DES DES DES DES DES

tPD tPD

tIS tIH tIS

CKE
tIH tIS tCKE

Address Valid
tCPDED tCPDED

Enter Exit Enter

power-down power-down power-down
mode mode mode

Time Break Don’t Care

Power-Down Entry, Exit Timing with CAL

Command/Address latency is used and additional timing restrictions are required when entering
power-down, as noted in the following figures.

Figure 104: Active Power-Down Entry and Exit Timing with CAL
T0 T1 Ta0 Ta1 Ta2 Tb0 Tb1 Tc0 Tc1 Td0 Td1 Te0
CK_c
CK_t

CS_n

Command DES DES Valid DES DES DES DES DES DES DES Valid

Address Valid Valid

t CAL tIH t CPDED t XP t CAL

t IH t IS
t IS t PD

CKE

Time Break Don’t Care

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 8Gb: x4, x8, x16 DDR4 SDRAM
Power-Down Mode

Figure 105: REFRESH Command to Power-Down Entry with CAL

T0 T1 Ta0 Tb0 Tb1 Tc0 Tc1 Td0 Td1 Te0 Te1 Tf0
CK_c
CK_t

CS_n

Command DES DES REF DES DES DES DES DES DES DES Valid

Address Valid Valid

t CAL t REFPDEN t CPDED t XP t CAL

t IH t IS
t IS t PD

CKE tIH

Time Break Don’t Care

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 8Gb: x4, x8, x16 DDR4 SDRAM
ODT Input Buffer Disable Mode for Power-Down

ODT Input Buffer Disable Mode for Power-Down

DRAM does not provide RTT_NOM termination during power-down when ODT input buffer deactiva-
tion mode is enabled in MR5 bit A5.
To account for DRAM internal delay on CKE line to disable the ODT buffer and block the sampled
output, the host controller must continuously drive ODT to either low or high when entering power
down (from tDODTLoff+1 prior to CKE low till tCPDED after CKE low).

The ODT signal is allowed to float after tCPDEDmin has expired. In this mode, RTT_NOM termination
corresponding to sampled ODT at the input when CKE is registered low (and tANPD before that) may
be either RTT_NOM or RTT_PARK. tANPD is equal to (WL-1) and is counted backwards from PDE.

Figure 106: ODT Power-Down Entry with ODT Buffer Disable Mode

diff_CK

CKE

tDODTLoff +1 tCPDED (MIN)

ODT Floating

tADC (MIN)
DRAM_RTT_sync
RTT(NOM) RTT(Park)
(DLL enabled)
CA parity disabled tCPDED
DODTLoff (MIN) + tADC (MAX)

DRAM_RTT_async
RTT(NOM) RTT(Park)
(DLL disabled)
tAONAS (MIN)

tCPDED (MIN) + tAOFAS (MAX)

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 8Gb: x4, x8, x16 DDR4 SDRAM
ODT Input Buffer Disable Mode for Power-Down

Figure 107: ODT Power-Down Exit with ODT Buffer Disable Mode

diff_CK

CKE

ODT_A Floating
(DLL enabled)
tADC (MAX)
tXP

DRAM_RTT_A RTT(Park) RTT(NOM)

DODTLon
tADC (MIN)

ODT_B Floating
(DLL disabled)
tXP

DRAM_RTT_B RTT(Park) RTT(NOM)

tAONAS (MIN)
tAOFAS (MAX)

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 8Gb: x4, x8, x16 DDR4 SDRAM
CRC Write Data Feature

CRC Write Data Feature

CRC Write Data
The CRC write data feature takes the CRC generated data from the DRAM controller and compares it
to the internally CRC generated data and determines whether the two match (no CRC error) or do not
match (CRC error).

Figure 108: CRC Write Data Operation

DRAM Controller DRAM

Data Data

CRC CRC CRC

engine Data Code engine

CRC Code CRC Code

Compare
CRC

WRITE CRC DATA Operation

A DRAM controller generates a CRC checksum using a 72-bit CRC tree and forms the write data frames,
as shown in the following CRC data mapping tables for the x4, x8, and x16 configurations. A x4 device
has a CRC tree with 32 input data bits used, and the remaining upper 40 bits D[71:32] being 1s. A x8
device has a CRC tree with 64 input data bits used, and the remaining upper 8 bits dependant upon
whether DM_n/DBI_n is used (1s are sent when not used). A x16 device has two identical CRC trees
each, one for the lower byte and one for the upper byte, with 64 input data bits used by each, and the
remaining upper 8 bits on each byte dependant upon whether DM_n/DBI_n is used (1s are sent when
not used). For a x8 and x16 DRAMs, the DRAM memory controller must send 1s in transfer 9 location
whether or not DM_n/DBI_n is used.
The DRAM checks for an error in a received code word D[71:0] by comparing the received checksum
against the computed checksum and reports errors using the ALERT_n signal if there is a mismatch.
The DRAM can write data to the DRAM core without waiting for the CRC check for full writes when DM
is disabled. If bad data is written to the DRAM core, the DRAM memory controller will try to overwrite
the bad data with good data; this means the DRAM controller is responsible for data coherency when
DM is disabled. However, in the case where both CRC and DM are enabled via MRS (that is, persistent
mode), the DRAM will not write bad data to the core when a CRC error is detected.

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 8Gb: x4, x8, x16 DDR4 SDRAM
CRC Write Data Feature

DBI_n and CRC Both Enabled

The DRAM computes the CRC for received written data D[71:0]. Data is not inverted back based on DBI
before it is used for computing CRC. The data is inverted back based on DBI before it is written to the
DRAM core.

DM_n and CRC Both Enabled

When both DM and write CRC are enabled in the DRAM mode register, the DRAM calculates CRC
before sending the write data into the array. If there is a CRC error, the DRAM blocks the WRITE oper-
ation and discards the data. If a CRC error is encountered from a WRITE with auto precharge (WRA),
the DRAM will not block the precharge. The Nonconsecutive WRITE (BL8/BC4-OTF) with 2tCK
Preamble and Write CRC in Same or Different Bank Group and the WRITE (BL8/BC4-OTF/Fixed) with
1tCK Preamble and Write CRC in Same or Different BankGroup figures in the WRITE Operation section
show timing differences when DM is enabled.

DM_n and DBI_n Conflict During Writes with CRC Enabled

Both write DBI_n and DM_n can not be enabled at the same time; read DBI_n and DM_n can be
enabled at the same time.

CRC and Write Preamble Restrictions

When write CRC is enabled:
s And 1tCK WRITE preamble mode is enabled, a tCCD_S or tCCD_L of 4 clocks is not allowed.
s And 2tCK WRITE preamble mode is enabled, a tCCD_S or tCCD_L of 6 clocks is not allowed.

CRC Simultaneous Operation Restrictions

When write CRC is enabled, neither MPR writes nor per-DRAM mode is allowed.

CRC Polynomial
The CRC polynomial used by DDR4 is the ATM-8 HEC, X8 + X2 + X1 + 1.
A combinatorial logic block implementation of this 8-bit CRC for 72 bits of data includes 272 two-input
XOR gates contained in eight 6-XOR-gate-deep trees.
The CRC polynomial and combinatorial logic used by DDR4 is the same as used on GDDR5.
The error coverage from the DDR4 polynomial used is shown in the following table.

Table 54: CRC Error Detection Coverage

Error Type Detection Capability
Random single-bit errors 100%
Random double-bit errors 100%
Random odd count errors 100%
Random multibit UI vertical column error 100%
detection excluding DBI bits

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 8Gb: x4, x8, x16 DDR4 SDRAM
CRC Write Data Feature

CRC Combinatorial Logic Equations

module CRC8_D72;
// polynomial: (0 1 2 8)
// data width: 72
// convention: the first serial data bit is D[71]
//initial condition all 0 implied
// "^" = XOR
function [7:0]
nextCRC8_D72;
input [71:0] Data;
input [71:0] D;
reg [7:0] CRC;
begin
D = Data;

CRC[0] =
D[69]^D[68]^D[67]^D[66]^D[64]^D[63]^D[60]^D[56]^D[54]^D[53]^D[52]^D[50]^D[49]^D[48]^D[45]
^D[43]^D[40]^D[39]^D[35]^D[34]^D[31]^D[30]^D[28]^D[23]^D[21]^D[19]^D[18]^D[16]^D[14]^D[1
2]^D[8]^D[7]^D[6]^D[0];

CRC[1] =
D[70]^D[66]^D[65]^D[63]^D[61]^D[60]^D[57]^D[56]^D[55]^D[52]^D[51]^D[48]^D[46]^D[45]^D[44]
^D[43]^D[41]^D[39]^D[36]^D[34]^D[32]^D[30]^D[29]^D[28]^D[24]^D[23]^D[22]^D[21]^D[20]^D[1
8]^D[17]^D[16]^D[15]^D[14]^D[13]^D[12]^D[9]^D[6]^D[1]^D[0];

CRC[2] =
D[71]^D[69]^D[68]^D[63]^D[62]^D[61]^D[60]^D[58]^D[57]^D[54]^D[50]^D[48]^D[47]^D[46]^D[44]
^D[43]^D[42]^D[39]^D[37]^D[34]^D[33]^D[29]^D[28]^D[25]^D[24]^D[22]^D[17]^D[15]^D[13]^D[1
2]^D[10]^D[8]^D[6]^D[2]^D[1]^D[0];

CRC[3] =
D[70]^D[69]^D[64]^D[63]^D[62]^D[61]^D[59]^D[58]^D[55]^D[51]^D[49]^D[48]^D[47]^D[45]^D[44]
^D[43]^D[40]^D[38]^D[35]^D[34]^D[30]^D[29]^D[26]^D[25]^D[23]^D[18]^D[16]^D[14]^D[13]^D[1
1]^D[9]^D[7]^D[3]^D[2]^D[1];

CRC[4] =
D[71]^D[70]^D[65]^D[64]^D[63]^D[62]^D[60]^D[59]^D[56]^D[52]^D[50]^D[49]^D[48]^D[46]^D[45]
^D[44]^D[41]^D[39]^D[36]^D[35]^D[31]^D[30]^D[27]^D[26]^D[24]^D[19]^D[17]^D[15]^D[14]^D[1
2]^D[10]^D[8]^D[4]^D[3]^D[2];

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 8Gb: x4, x8, x16 DDR4 SDRAM
CRC Write Data Feature

CRC[5] =
D[71]^D[66]^D[65]^D[64]^D[63]^D[61]^D[60]^D[57]^D[53]^D[51]^D[50]^D[49]^D[47]^D[46]^D[45]
^D[42]^D[40]^D[37]^D[36]^D[32]^D[31]^D[28]^D[27]^D[25]^D[20]^D[18]^D[16]^D[15]^D[13]^D[1
1]^D[9]^D[5]^D[4]^D[3];

CRC[6] =
D[67]^D[66]^D[65]^D[64]^D[62]^D[61]^D[58]^D[54]^D[52]^D[51]^D[50]^D[48]^D[47]^D[46]^D[43]
^D[41]^D[38]^D[37]^D[33]^D[32]^D[29]^D[28]^D[26]^D[21]^D[19]^D[17]^D[16]^D[14]^D[12]^D[1
0]^D[6]^D[5]^D[4];

CRC[7] =
D[68]^D[67]^D[66]^D[65]^D[63]^D[62]^D[59]^D[55]^D[53]^D[52]^D[51]^D[49]^D[48]^D[47]^D[44]
^D[42]^D[39]^D[38]^D[34]^D[33]^D[30]^D[29]^D[27]^D[22]^D[20]^D[18]^D[17]^D[15]^D[13]^D[1
1]^D[7]^D[6]^D[5];

nextCRC8_D72 = CRC;

Burst Ordering for BL8

DDR4 supports fixed WRITE burst ordering [A2:A1:A0 = 0:0:0] when write CRC is enabled in BL8 (fixed).

CRC Data Bit Mapping

Table 55: CRC Data Mapping for x4 Devices, BL8

Transfer
Function 0 1 2 3 4 5 6 7 8 9
DQ0 D0 D1 D2 D3 D4 D5 D6 D7 CRC0 CRC4
DQ1 D8 D9 D10 D11 D12 D13 D14 D15 CRC1 CRC5
DQ2 D16 D17 D18 D19 D20 D21 D22 D23 CRC2 CRC6
DQ3 D24 D25 D26 D27 D28 D29 D30 D31 CRC3 CRC7

Table 56: CRC Data Mapping for x8 Devices, BL8

Transfer
Function 0 1 2 3 4 5 6 7 8 9
DQ0 D0 D1 D2 D3 D4 D5 D6 D7 CRC0 1
DQ1 D8 D9 D10 D11 D12 D13 D14 D15 CRC1 1
DQ2 D16 D17 D18 D19 D20 D21 D22 D23 CRC2 1
DQ3 D24 D25 D26 D27 D28 D29 D30 D31 CRC3 1
DQ4 D32 D33 D34 D35 D36 D37 D38 D39 CRC4 1

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 8Gb: x4, x8, x16 DDR4 SDRAM
CRC Write Data Feature

Table 56: CRC Data Mapping for x8 Devices, BL8 (Continued)

Transfer
Function 0 1 2 3 4 5 6 7 8 9
DQ5 D40 D41 D42 D43 D44 D45 D46 D47 CRC5 1
DQ6 D48 D49 D50 D51 D52 D53 D54 D55 CRC6 1
DQ7 D56 D57 D58 D59 D60 D61 D62 D63 CRC7 1
DM_n/DB D64 D65 D66 D67 D68 D69 D70 D71 1 1
I_n

A x16 device is treated as two x8 devices; a x16 device will have two identical CRC trees implemented.
CRC[7:0] covers data bits D[71:0], and CRC[15:8] covers data bits D[143:72].

Table 57: CRC Data Mapping for x16 Devices, BL8

Transfer
Function 0 1 2 3 4 5 6 7 8 9
DQ0 D0 D1 D2 D3 D4 D5 D6 D7 CRC0 1
DQ1 D8 D9 D10 D11 D12 D13 D14 D15 CRC1 1
DQ2 D16 D17 D18 D19 D20 D21 D22 D23 CRC2 1
DQ3 D24 D25 D26 D27 D28 D29 D30 D31 CRC3 1
DQ4 D32 D33 D34 D35 D36 D37 D38 D39 CRC4 1
DQ5 D40 D41 D42 D43 D44 D45 D46 D47 CRC5 1
DQ6 D48 D49 D50 D51 D52 D53 D54 D55 CRC6 1
DQ7 D56 D57 D58 D59 D60 D61 D62 D63 CRC7 1
LDM_n/LD D64 D65 D66 D67 D68 D69 D70 D71 1 1
BI_n
DQ8 D72 D73 D74 D75 D76 D77 D78 D79 CRC8 1
DQ9 D80 D81 D82 D83 D84 D85 D86 D87 CRC9 1
DQ10 D88 D89 D90 D91 D92 D93 D94 D95 CRC10 1
DQ11 D96 D97 D98 D99 D100 D101 D102 D103 CRC11 1
DQ12 D104 D105 D106 D107 D108 D109 D110 D111 CRC12 1
DQ13 D112 D113 D114 D115 D116 D117 D118 D119 CRC13 1
DQ14 D120 D121 D122 D123 D124 D125 D126 D127 CRC14 1
DQ15 D128 D129 D130 D131 D132 D133 D134 D135 CRC15 1
UDM_n/U D136 D137 D138 D139 D140 D141 D142 D143 1 1
DBI_n

CRC Enabled With BC4

If CRC and BC4 are both enabled, then address bit A2 is used to transfer critical data first for BC4 writes.

CRC with BC4 Data Bit Mapping

For a x4 device, the CRC tree inputs are 16 data bits, and the inputs for the remaining bits are 1.

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 8Gb: x4, x8, x16 DDR4 SDRAM
CRC Write Data Feature

When A2 = 1, data bits D[7:4] are used as inputs for D[3:0], D[15:12] are used as inputs to D[11:8], and
so forth, for the CRC tree.

Table 58: CRC Data Mapping for x4 Devices, BC4

Transfer
Function 0 1 2 3 4 5 6 7 8 9
A2 = 0
DQ0 D0 D1 D2 D3 1 1 1 1 CRC0 CRC4
DQ1 D8 D9 D10 D11 1 1 1 1 CRC1 CRC5
DQ2 D16 D17 D18 D19 1 1 1 1 CRC2 CRC6
DQ3 D24 D25 D26 D27 1 1 1 1 CRC3 CRC7
A2 = 1
DQ0 D4 D5 D6 D7 1 1 1 1 CRC0 CRC4
DQ1 D12 D13 D14 D15 1 1 1 1 CRC1 CRC5
DQ2 D20 D21 D22 D23 1 1 1 1 CRC2 CRC6
DQ3 D28 D29 D30 D31 1 1 1 1 CRC3 CRC7

For a x8 device, the CRC tree inputs are 36 data bits.

When A2 = 0, the input bits D[67:64]) are used if DBI_n or DM_n functions are enabled; if DBI_n and
DM_n are disabled, then D[67:64]) are 1.
When A2 = 1, data bits D[7:4] are used as inputs for D[3:0], D[15:12] are used as inputs to D[11:8], and
so forth, for the CRC tree. The input bits D[71:68]) are used if DBI_n or DM_n functions are enabled; if
DBI_n and DM_n are disabled, then D[71:68]) are 1.

Table 59: CRC Data Mapping for x8 Devices, BC4

Transfer
Function 0 1 2 3 4 5 6 7 8 9
A2 = 0
DQ0 D0 D1 D2 D3 1 1 1 1 CRC0 1
DQ1 D8 D9 D10 D11 1 1 1 1 CRC1 1
DQ2 D16 D17 D18 D19 1 1 1 1 CRC2 1
DQ3 D24 D25 D26 D27 1 1 1 1 CRC3 1
DQ4 D32 D33 D34 D35 1 1 1 1 CRC4 1
DQ5 D40 D41 D42 D43 1 1 1 1 CRC5 1
DQ6 D48 D49 D50 D51 1 1 1 1 CRC6 1
DQ7 D56 D57 D58 D59 1 1 1 1 CRC7 1
DM_n/DBI_n D64 D65 D66 D67 1 1 1 1 1 1
A2 = 1
DQ0 D4 D5 D6 D7 1 1 1 1 CRC0 1
DQ1 D12 D13 D14 D15 1 1 1 1 CRC1 1
DQ2 D20 D21 D22 D23 1 1 1 1 CRC2 1
DQ3 D28 D29 D30 D31 1 1 1 1 CRC3 1

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 8Gb: x4, x8, x16 DDR4 SDRAM
CRC Write Data Feature

Table 59: CRC Data Mapping for x8 Devices, BC4 (Continued)

Transfer
Function 0 1 2 3 4 5 6 7 8 9
DQ4 D36 D37 D38 D39 1 1 1 1 CRC4 1
DQ5 D44 D45 D46 D47 1 1 1 1 CRC5 1
DQ6 D52 D53 D54 D55 1 1 1 1 CRC6 1
DQ7 D60 D61 D62 D63 1 1 1 1 CRC7 1
DM_n/DBI_n D68 D69 D70 D71 1 1 1 1 1 1

There are two identical CRC trees for x16 devices, each have CRC tree inputs of 36 bits.
When A2 = 0, input bits D[67:64] are used if DBI_n or DM_n functions are enabled; if DBI_n and DM_n
are disabled, then D[67:64] are 1s. The input bits D[139:136] are used if DBI_n or DM_n functions are
enabled; if DBI_n and DM_n are disabled, then D[139:136] are 1s.
When A2 = 1, data bits D[7:4] are used as inputs for D[3:0], D[15:12] are used as inputs for D[11:8], and
so forth, for the CRC tree. Input bits D[71:68] are used if DBI_n or DM_n functions are enabled; if DBI_n
and DM_n are disabled, then D[71:68] are 1s. The input bits D[143:140] are used if DBI_n or DM_n
functions are enabled; if DBI_n and DM_n are disabled, then D[143:140] are 1s.

Table 60: CRC Data Mapping for x16 Devices, BC4

Transfer
Function 0 1 2 3 4 5 6 7 8 9
A2 = 0
DQ0 D0 D1 D2 D3 1 1 1 1 CRC0 1
DQ1 D8 D9 D10 D11 1 1 1 1 CRC1 1
DQ2 D16 D17 D18 D19 1 1 1 1 CRC2 1
DQ3 D24 D25 D26 D27 1 1 1 1 CRC3 1
DQ4 D32 D33 D34 D35 1 1 1 1 CRC4 1
DQ5 D40 D41 D42 D43 1 1 1 1 CRC5 1
DQ6 D48 D49 D50 D51 1 1 1 1 CRC6 1
DQ7 D56 D57 D58 D59 1 1 1 1 CRC7 1
LDM_n/LDBI_ D64 D65 D66 D67 1 1 1 1 1 1
n
DQ8 D72 D73 D74 D75 1 1 1 1 CRC8 1
DQ9 D80 D81 D82 D83 1 1 1 1 CRC9 1
DQ10 D88 D89 D90 D91 1 1 1 1 CRC10 1
DQ11 D96 D97 D98 D99 1 1 1 1 CRC11 1
DQ12 D104 D105 D106 D107 1 1 1 1 CRC12 1
DQ13 D112 D113 D114 D115 1 1 1 1 CRC13 1
DQ14 D120 D121 D122 D123 1 1 1 1 CRC14 1
DQ15 D128 D129 D130 D131 1 1 1 1 CRC15 1
UDM_n/UDBI D136 D137 D138 D139 1 1 1 1 1 1
_n

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 8Gb: x4, x8, x16 DDR4 SDRAM
CRC Write Data Feature

Table 60: CRC Data Mapping for x16 Devices, BC4 (Continued)
Transfer
Function 0 1 2 3 4 5 6 7 8 9
A2 = 1
DQ0 D4 D5 D6 D7 1 1 1 1 CRC0 1
DQ1 D12 D13 D14 D15 1 1 1 1 CRC1 1
DQ2 D20 D21 D22 D23 1 1 1 1 CRC2 1
DQ3 D28 D29 D30 D31 1 1 1 1 CRC3 1
DQ4 D36 D37 D38 D39 1 1 1 1 CRC4 1
DQ5 D44 D45 D46 D47 1 1 1 1 CRC5 1
DQ6 D52 D53 D54 D55 1 1 1 1 CRC6 1
DQ7 D60 D61 D62 D63 1 1 1 1 CRC7 1
LDM_n/LDBI_ D68 D69 D70 D71 1 1 1 1 1 1
n
DQ8 D76 D77 D78 D79 1 1 1 1 CRC8 1
DQ9 D84 D85 D86 D87 1 1 1 1 CRC9 1
DQ10 D92 D93 D94 D95 1 1 1 1 CRC10 1
DQ11 D100 D101 D102 D103 1 1 1 1 CRC11 1
DQ12 D108 D109 D110 D111 1 1 1 1 CRC12 1
DQ13 D116 D117 D118 D119 1 1 1 1 CRC13 1
DQ14 D124 D125 D126 D127 1 1 1 1 CRC14 1
DQ15 D132 D133 D134 D135 1 1 1 1 CRC15 1
UDM_n/UDBI D140 D141 D142 D143 1 1 1 1 1 1
_n

CRC Equations for x8 Device in BC4 Mode with A2 = 0 and A2 = 1

The following example is of a CRC tree when x8 is used in BC4 mode (x4 and x16 CRC trees have similar
differences).
CRC[0], A2=0 =
1^1^D[67]^D[66]^D[64]^1^1^D[56]^1^1^1^D[50]^D[49]^D[48]^1^D[43]^D[40]^1^D[35]^D[34]^1^1^1^1^1^
D[19]^D[18]^D[16]^1^1^D[8] ^1^1^ D[0] ;
CRC[0], A2=1=
1^1^D[71]^D[70]^D[68]^1^1^D[60]^1^1^1^D[54]^D[53]^D[52]^1^D[47]^D[44]^1^D[39]^D[38]^1^1^1^1^1^
D[23]^D[22]^D[20]^1^1^D[12]^1^1^D[4] ;

CRC[1], A2=0 =
1^D[66]^D[65]^1^1^1^D[57]^D[56]^1^1^D[51]^D[48]^1^1^1^D[43]^D[41]^1^1^D[34]^D[32]^1^1^1^D[24]^
1^1^1^1^D[18]^D[17]^D[16]^1^1^1^1^D[9] ^1^ D[1]^D[0];
CRC[1], A2=1 =
1^D[70]^D[69]^1^1^1^D[61]^D[60]^1^1^D[55]^D[52]^1^1^1^D[47]^D[45]^1^1^D[38]^D[36]^1^1^1^D[28]^
1^1^1^1^D[22]^D[21]^D[20]^1^1^1^1^D[13]^1^D[5]^D[4];

CRC[2], A2=0=
1^1^1^1^1^1^1^D[58]^D[57]^1^D[50]^D[48]^1^1^1^D[43]^D[42]^1^1^D[34]^D[33]^1^1^D[25]^D[24]^1^D[
17]^1^1^1^D[10]^D[8] ^1^D[2]^D[1]^D[0];

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 8Gb: x4, x8, x16 DDR4 SDRAM
CRC Write Data Feature

CRC[2], A2=1=
1^1^1^1^1^1^1^D[62]^D[61]^1^D[54]^D[52]^1^1^1^D[47]^D[46]^1^1^D[38]^D[37]^1^1^D[29]^D[28]^1^D[
21]^1^1^1^D[14]^D12]^1^D[6]^D[5]^D[4];

CRC[3], A2=0 =
1^1^D[64]^1^1^1^D[59]^D[58]^1^D[51]^D[49]^D[48]^1^1^1^D[43]^D[40]^1^D[35]^D[34]^1^1^D[26]^D[25]
^1^D[18]^D[16]^1^1^D[11]^D[9] ^1^D[3]^D[2]^D[1];
CRC[3], A2=1 =
1^1^D[68]^1^1^1^D[63]^D[62]^1^D[55]^D[53]^D[52]^1^1^1^D[47]^D[44]^1^D[39]^D[38]^1^1^D[30]^D[29]
^1^D[22]^D[20]^1^1^D[15]^D[13]^1^D[7]^D[6]^D[5];

CRC[4], A2=0 =
1^1^D[65]^D[64]^1^1^1^D[59]^D[56]^1^D[50]^D[49]^D[48]^1^1^1^D[41]^1^1^D[35]^1^1^D[27]^D[26]^D[2
4]^D[19]^D[17]^1^1^1^D[10]^D[8] ^1^D[3]^D[2];
CRC[4], A2=1 =
1^1^D[69]^D[68]^1^1^1^D[63]^D[60]^1^D[54]^D[53]^D[52]^1^1^1^D[45]^1^1^D[39]^1^1^D[31]^D[30]^D[2
8]^D[23]^D[21]^1^1^1^D[14]^D[12]^1^D[7]^D[6];

CRC[5], A2=0 =
1^D[66]^D[65]^D[64]^1^1^1^D[57]^1^D[51]^D[50]^D[49]^1^1^1^D[42]^D[40]^1^1^D[32]^1^1^D[27]^D[25]^1
^D[18]^D[16]^1^1^D[11]^D[9] ^1^1^D[3];
CRC[5], A2=1 =
1^D[70]^D[69]^D[68]^1^1^1^D[61]^1^D[55]^D[54]^D[53]^1^1^1^D[46]^D[44]^1^1^D[36]^1^1^D[31]^D[29]
^1^D[22]^D[20]^1^1^D[15]^D[13]^1^1^D[7];

CRC[6], A2=0 =
D[67]^D[66]^D[65]^D[64]^1^1^D[58]^1^1^D[51]^D[50]^D[48]^1^1^D[43]^D[41]^1^1^D[33]^D[32]^1^1^D[2
6]^1^D[19]^D[17]^D[16]^1^1^D[10]^1^1^1;
CRC[6], A2=1 =
D[71]^D[70]^D[69]^D[68]^1^1^D[62]^1^1^D[55]^D[54]^D[52]^1^1^D[47]^D[45]^1^1^D[37]^D[36]^1^1^D[3
0]^1^D[23]^D[21]^D[20]^1^1^D[14]^1^1^1;

CRC[7], A2=0=
1^D[67]^D[66]^D[65]^1^1^D[59]^1^1^1^D[51]^D[49]^D[48]^1^1^D[42]^1^1^D[34]^D[33]^1^1^D[27]^1^1^
D[18]^D[17]^1^1^D[11]^1^1^1;
CRC[7], A2=1 =
1^D[71]^D[70]^D[69]^1^1^D[63]^1^1^1^D[55]^D[53]^D[52]^1^1^D[46]^1^1^D[38]^D[37]^1^1^D[31]^1^1^
D[22]^D[21]^1^1^D[15]^1^1^1;

CRC Error Handling

The CRC error mechanism shares the same ALERT_n signal as CA parity for reporting write errors to
the DRAM. The controller has two ways to distinguish between CRC errors and CA parity errors: 1)
Read DRAM mode/MPR registers, and 2) Measure time ALERT_n is LOW. To speed up recovery for
CRC errors, CRC errors are only sent back as a "short" pulse; the maximum pulse width is roughly ten
clocks (unlike CA parity where ALERT_n is LOW longer than 45 clocks). The ALERT_n LOW could be
longer than the maximum limit at the controller if there are multiple CRC errors as the ALERT_n signals
are connected by a daisy chain bus. The latency to ALERT_n signal is defined as tCRC_ALERT in the
following figure.
The DRAM will set the error status bit located at MR5[3] to a 1 upon detecting a CRC error, which will
subsequently set the CRC error status flag in the MPR error log HIGH (MPR Page1, MPR3[7]). The CRC
error status bit (and CRC error status flag) remains set at 1 until the DRAM controller clears the CRC
error status bit using an MRS command to set MR5[3] to a 0. The DRAM controller, upon seeing an
error as a pulse width, will retry the write transactions. The controller should consider the worst-case
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 8Gb: x4, x8, x16 DDR4 SDRAM
CRC Write Data Feature

delay for ALERT_n (during initialization) and backup the transactions accordingly. The DRAM
controller may also be made more intelligent and correlate the write CRC error to a specific rank or a
transaction.

Figure 109: CRC Error Reporting

T0 T1 T2 T3 T4 T5 T6 Ta0 Ta1 Ta2 Ta3 Tb0 Tb1
CK_c
CK_t

DQIN
Dx Dx+1 Dx+2 Dx+3 Dx+4 Dx+5 Dx+6 Dx+7 CRCy 1

CRC ALERT_PW (MAX)

tCRC_ALERT

ALERT_n
CRC ALERT_PW (MIN)

Transition Data Don’t Care

Notes: 1. D[71:1] CRC computed by DRAM did not match CRC[7:0] at T5 and started error generating process at T6.
2. CRC ALERT_PW is specified from the point where the DRAM starts to drive the signal LOW to the point where the
DRAM driver releases and the controller starts to pull the signal up.
3. Timing diagram applies to x4, x8, and x16 devices.

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 CRC Write Data Flow Diagram
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Figure 110: CA Parity Flow Diagram

DRAM write MR2 12 enable CRC
process start MR5 3 set CRC error clear to 0
MR5 10 enable/disable DM
MR3[10:9] WCL if DM enabled

Capture data

Persistent DRAM
CRC Yes Yes CRC same as No
mode
enabled controller
enabled
CRC
No Yes
No

Transfer Data Transfer data Transfer data

Internally internally internally

Yes DRAM
CRC same as No MR5[3] = 0 Yes MR5[3] = 0 Yes
CA error controller at WRITE at WRITE
CRC
Yes ALERT_n LOW No Set error flag ALERT_n LOW No Set error flag
No 6 to 10 CKs MR5[A3] = 1 6 to 10 CKs MR5[A3] = 1
MR5[A3] and MR5[A3] and
PAGE1 MPR3[7] PAGE1 MPR3[7]
remain set to 1 Set error status remain set to 1 Set error status
ALERT_n HIGH ALERT_n HIGH
PAGE1 MPR3[7] = 1 PAGE1 MPR3[7] = 1
177

WRITE burst WRITE burst WRITE burst WRITE burst WRITE burst WRITE burst
completed completed completed completed completed rejected
Bad data written Bad data not written
MR5 3 reset to 0 if desired MR5 3 reset to 0 if desired
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8Gb: x4, x8, x16 DDR4 SDRAM

CRC Write Data Feature
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 8Gb: x4, x8, x16 DDR4 SDRAM
Data Bus Inversion

Data Bus Inversion

The DATA BUS INVERSION (DBI) function is supported only for x8 and x16 configurations (it is not
supported on x4 devices). DBI opportunistically inverts data bits, and in conjunction with the DBI_n
I/O, less than half of the DQs will switch LOW for a given DQS strobe edge. The DBI function shares a
common pin with the DATA MASK (DM) and TDQS functions. The DBI function applies to either or
both READ and WRITE operations: Write DBI cannot be enabled at the same time the DM function is
enabled, and DBI is not allowed during MPR READ operation. Valid configurations for TDQS, DM, and
DBI functions are shown below.

Table 61: DBI vs. DM vs. TDQS Function Matrix

Read DBI Write DBI Data Mask (DM) TDQS (x8 only)
Enabled (or Disabled) Disabled Disabled Disabled
MR5[12]=1 (or MR5[12] = 0) MR5[11] = 0 MR5[10] = 0 MR1[11] = 0
Enabled Disabled Disabled
MR5[11] = 1 MR5[10] = 0 MR1[11] = 0
Disabled Enabled Disabled
MR5[11] = 0 MR5[10] = 1 MR1[11] = 0
Disabled Disabled Disabled Enabled
MR5[12] = 0 MR5[11] = 0 MR5[10] = 0 MR1[11] = 1

DBI During a WRITE Operation

If DBI_n is sampled LOW on a given byte lane during a WRITE operation, the DRAM inverts write data
received on the DQ inputs prior to writing the internal memory array. If DBI_n is sampled HIGH on a
given byte lane, the DRAM leaves the data received on the DQ inputs noninverted. The write DQ frame
format is shown below for x8 and x16 configurations (the x4 configuration does not support the DBI
function).

Table 62: DBI Write, DQ Frame Format (x8)

Transfer
Function 0 1 2 3 4 5 6 7
DQ[7:0] Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7
DM_n or DM0 or DM1 or DM2 or DM3 or DM4 or DM5 or DM6 or DM7 or
DBI_n DBI0 DBI1 DBI2 DBI3 DBI4 DBI5 DBI6 DBI7

Table 63: DBI Write, DQ Frame Format (x16)

Transfer, Lower (L) and Upper(U)
Function 0 1 2 3 4 5 6 7
DQ[7:0] LByte 0 LByte 1 LByte 2 LByte 3 LByte 4 LByte 5 LByte 6 LByte 7
LDM_n or LDM0 or LDM1 or LDM2 or LDM3 or LDM4 or LDM5 or LDM6 or LDM7 or
LDBI_n LDBI0 LDBI1 LDBI2 LDBI3 LDBI4 LDBI5 LDBI6 LDBI7
DQ[15:8] UByte 0 UByte 1 UByte 2 UByte 3 UByte 4 UByte 5 UByte 6 UByte 7
UDM_n or UDM0 or UDM1 or UDM2 or UDM3 or UDM4 or UDM5 or UDM6 or UDM7 or
UDBI_n UDBI0 UDBI1 UDBI2 UDBI3 UDBI4 UDBI5 UDBI6 UDBI7

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 8Gb: x4, x8, x16 DDR4 SDRAM
Data Bus Inversion

DBI During a READ Operation

If the number of 0 data bits within a given byte lane is greater than four during a READ operation, the
DRAM inverts read data on its DQ outputs and drives the DBI_n pin LOW; otherwise, the DRAM does
not invert the read data and drives the DBI_n pin HIGH. The read DQ frame format is shown below for
x8 and x16 configurations (the x4 configuration does not support the DBI function).

Table 64: DBI Read, DQ Frame Format (x8)

Transfer Byte
Function 0 1 2 3 4 5 6 7
DQ[7:0] Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7
DBI_n DBI0 DBI1 DBI2 DBI3 DBI4 DBI5 DBI6 DBI7

Table 65: DBI Read, DQ Frame Format (x16)

Transfer Byte, Lower (L) and Upper(U)
Function 0 1 2 3 4 5 6 7
DQ[7:0] LByte 0 LByte 1 LByte 2 LByte 3 LByte 4 LByte 5 LByte 6 LByte 7
LDBI_n LDBI0 LDBI1 LDBI2 LDBI3 LDBI4 LDBI5 LDBI6 LDBI7
DQ[15:8] UByte 0 UByte 1 UByte 2 UByte 3 UByte 4 UByte 5 UByte 6 UByte 7
UDBI_n UDBI0 UDBI1 UDBI2 UDBI3 UDBI4 UDBI5 UDBI6 UDBI7

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 8Gb: x4, x8, x16 DDR4 SDRAM
Data Mask

Data Mask
The DATA MASK (DM) function, also described as PARTIAL WRITE, is supported only for x8 and x16
configurations (it is not supported on x4 devices). The DM function shares a common pin with the
DBI_n and TDQS functions. The DM function applies only to WRITE operations and cannot be enabled
at the same time the WRITE DBI function is enabled. The valid configurations for the TDQS, DM, and
DBI functions are shown here.

Table 66: DM vs. TDQS vs. DBI Function Matrix

Data Mask (DM) TDQS (x8 only) Write DBI Read DBI
Enabled Disabled Disabled Enabled or Disabled
MR5[10] = 1 MR1[11] = 0 MR5[11] = 0 MR5[12] = 1 or MR5[12] = 0
Disabled Enabled Disabled Disabled
MR5[10] = 0 MR1[11] = 1 MR5[11] = 0 MR5[12] = 0
Disabled Enabled Enabled or Disabled
MR1[11] = 0 MR5[11] = 1 MR5[12] = 1 or MR5[12] = 0
Disabled Disabled Enabled (or Disabled)
MR1[11] = 0 MR5[11] = 0 MR5[12] = 1 (or MR5[12] = 0)

When enabled, the DM function applies during a WRITE operation. If DM_n is sampled LOW on a
given byte lane, the DRAM masks the write data received on the DQ inputs. If DM_n is sampled HIGH
on a given byte lane, the DRAM does not mask the data and writes this data into the DRAM core. The
DQ frame format for x8 and x16 configurations is shown below. If both CRC write and DM are enabled
(via MRS), the CRC will be checked and valid prior to the DRAM writing data into the DRAM core. If a
CRC error occurs while the DM feature is enabled, CRC write persistent mode will be enabled and data
will not be written into the DRAM core. In the case of CRC write enabled and DM disabled (via MRS),
that is, CRC write nonpersistent mode, data is written to the DRAM core even if a CRC error occurs.

Table 67: Data Mask, DQ Frame Format (x8)

Transfer
Function 0 1 2 3 4 5 6 7
DQ[7:0] Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7
DM_n or DM0 or DM1 or DM2 or DM3 or DM4 or DM5 or DM6 or DM7 or
DBI_n DBI0 DBI1 DBI2 DBI3 DBI4 DBI5 DBI6 DBI7

Table 68: Data Mask, DQ Frame Format (x16)

Transfer, Lower (L) and Upper (U)
Function 0 1 2 3 4 5 6 7
DQ[7:0] LByte 0 LByte 1 LByte 2 LByte 3 LByte 4 LByte 5 LByte 6 LByte 7
LDM_n or LDM0 or LDM1 or LDM2 or LDM3 or LDM4 or LDM5 or LDM6 or LDM7 or
LDBI_n LDBI0 LDBI1 LDBI2 LDBI3 LDBI4 LDBI5 LDBI6 LDBI7
DQ[15:8] UByte 0 UByte 1 UByte 2 UByte 3 UByte 4 UByte 5 UByte 6 UByte 7
UDM_n or UDM0 or UDM1 or UDM2 or UDM3 or UDM4 or UDM5 or UDM6 or UDM7 or
UDBI_n UDBI0 UDBI1 UDBI2 UDBI3 UDBI4 UDBI5 UDBI6 UDBI7

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 8Gb: x4, x8, x16 DDR4 SDRAM
Programmable Preamble Modes and DQS Postambles

Programmable Preamble Modes and DQS Postambles

The device supports programmable WRITE and READ preamble modes, either the normal 1tCK
preamble mode or special 2tCK preamble mode. The 2tCK preamble mode places special timing
constraints on many operational features as well as being supported for data rates of DDR4-2400 and
faster. The WRITE preamble 1tCK or 2tCK mode can be selected independently from READ preamble
1tCK or 2tCK mode.
READ preamble training is also supported; this mode can be used by the DRAM controller to train or
"read level" the DQS receivers.

There are tCCD restrictions under some circumstances:

s When 2tCK READ preamble mode is enabled, a tCCD_S or tCCD_L of 5 clocks is not allowed.
s When 2tCK WRITE preamble mode is enabled and write CRC is not enabled, a tCCD_S or tCCD_L of
5 clocks is not allowed.
s When 2tCK WRITE preamble mode is enabled and write CRC is enabled, a tCCD_S or tCCD_L of 6
clocks is not allowed.

WRITE Preamble Mode

MR4[12] = 0 selects 1tCK WRITE preamble mode while MR4[12] = 1 selects 2tCK WRITE preamble
mode. Examples are shown in the figures below.

Figure 111: 1tCK vs. 2tCK WRITE Preamble Mode

1tCK Mode
WR
WL
CK_c
CK_t
Preamble
DQS_t,
DQS_c

DQ D0 D1 D2 D3 D4 D5 D6 D7

2tCK Mode
WR
WL
CK_c
CK_t
Preamble
DQS_t,
DQS_c

DQ D0 D1 D2 D3 D4 D5 D6 D7

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 8Gb: x4, x8, x16 DDR4 SDRAM
Programmable Preamble Modes and DQS Postambles

CWL has special considerations when in the 2tCK WRITE preamble mode. The CWL value selected in
MR2[5:3], as seen in table below, requires at least one additional clock when the primary CWL value
and 2tCK WRITE preamble mode are used; no additional clocks are required when the alternate CWL
value and 2tCK WRITE preamble mode are used.

Table 69: CWL Selection

CWL - Primary Choice CWL - Alternate Choice
Speed Bin 1tCK Preamble 2tCK Preamble 1tCK Preamble 2tCK Preamble
DDR4-1600 9 N/A 11 N/A
DDR4-1866 10 N/A 12 N/A
DDR4-2133 11 N/A 14 N/A
DDR4-2400 12 14 16 16
DDR4-2666 14 16 18 18
DDR4-2933 16 18 20 20
DDR4-3200 16 18 20 20

Note: 1. CWL programmable requirement for MR2[5:3].

When operating in 2tCK WRITE preamble mode, tWTR (command based) and tWR (MR0[11:9]) must
be programmed to a value 1 clock greater than the tWTR and tWR setting normally required for the
applicable speed bin to be JEDEC compliant; however, Micron's DDR4 DRAMs do not require these
additional tWTR and tWR clocks. The CAS_n-to-CAS_n command delay to either a different bank group
(tCCD_S) or the same bank group (tCCD_L) have minimum timing requirements that must be satisfied
between WRITE commands and are stated in the Timing Parameters by Speed Bin tables.

Figure 112: 1tCK vs. 2tCK WRITE Preamble Mode, tCCD = 4

1tCK Mode

CMD WRITE WRITE

CK_c
CK_t
tCCD =4 WL

DQS_t,
DQS_c Preamble

DQ D0 D1 D2 D3 D4 D5 D6 D7 D0 D1 D2 D3

2tCK Mode

CMD WRITE WRITE

CK_c
CK_t
tCCD =4 WL

DQS_t,
DQS_c Preamble

DQ D0 D1 D2 D3 D4 D5 D6 D7 D0 D1

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 8Gb: x4, x8, x16 DDR4 SDRAM
Programmable Preamble Modes and DQS Postambles

Figure 113: 1tCK vs. 2tCK WRITE Preamble Mode, tCCD = 5

1tCK Mode

CMD WRITE WRITE

CK_c
CK_t
tCCD =5 WL

DQS_t,
DQS_c Preamble
Preamble

DQ D0 D1 D2 D3 D4 D5 D6 D7 D0 D1 D2 D3

2tCK Mode: tCCD = 5 is not allowed in 2tCK mode.

t
Note: 1. CCD_S and tCCD_L = 5 tCKs is not allowed when in 2tCK WRITE preamble mode.

Figure 114: 1tCK vs. 2tCK WRITE Preamble Mode, tCCD = 6

1tCK Mode

CMD WRITE WRITE

CK_c
CK_t
tCCD =6 WL

DQS_t,
DQS_c Preamble
Preamble

DQ D0 D1 D2 D3 D4 D5 D6 D7 D0 D1 D2 D3

2tCK Mode

CMD WRITE WRITE

CK_c
CK_t
tCCD =6 WL

DQS_t,
DQS_c Preamble
Preamble

DQ D0 D1 D2 D3 D4 D5 D6 D7 D0 D1 D2 D3

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 8Gb: x4, x8, x16 DDR4 SDRAM
Programmable Preamble Modes and DQS Postambles

READ Preamble Mode

MR4[11] = 0 selects 1tCK READ preamble mode and MR4[11] = 1 selects 2tCK READ preamble mode.
Examples are shown in the following figure.

Figure 115: 1tCK vs. 2tCK READ Preamble Mode

1tCK Mode
RD
CL
CK_c
CK_t
Preamble
DQS_t,
DQS_c

DQ D0 D1 D2 D3 D4 D5 D6 D7

2tCK Mode
RD
CL
CK_c
CK_t
Preamble
DQS_t,
DQS_c

DQ D0 D1 D2 D3 D4 D5 D6 D7

READ Preamble Training

DDR4 supports READ preamble training via MPR reads; that is, READ preamble training is allowed
only when the DRAM is in the MPR access mode. The READ preamble training mode can be used by
the DRAM controller to train or "read level" its DQS receivers. READ preamble training is entered via
an MRS command (MR4[10] = 1 is enabled and MR4[10] = 0 is disabled). After the MRS command is
issued to enable READ preamble training, the DRAM DQS signals are driven to a valid level by the time
t
SDO is satisfied. During this time, the data bus DQ signals are held quiet, that is, driven HIGH. The
DQS_t signal remains driven LOW and the DQS_c signal remains driven HIGH until an MPR Page0
READ command is issued (MPR0 through MPR3 determine which pattern is used), and when CAS
latency (CL) has expired, the DQS signals will toggle normally depending on the burst length setting.
To exit READ preamble training mode, an MRS command must be issued, MR4[10] = 0.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Programmable Preamble Modes and DQS Postambles

Figure 116: READ Preamble Training

CMD MRS MPR RD

tSDO CL
DQS_t
DQS_c,

DQs (Quiet/Driven HIGH) D0 D1 D2 D3 D4 D5 D6 D7

WRITE Postamble
Whether the 1tCK or 2tCK WRITE preamble mode is selected, the WRITE postamble remains the same
AT tCK.

Figure 117: WRITE Postamble

1tCK Mode
WR
WL
CK_c
CK_t
Postamble

DQS_t,
DQS_c

DQ D0 D1 D2 D3 D4 D5 D6 D7

2tCK Mode
WR
WL
CK_c
CK_t
Postamble

DQS_t,
DQS_c

DQ D0 D1 D2 D3 D4 D5 D6 D7

READ Postamble
Whether the 1tCK or 2tCK READ preamble mode is selected, the READ postamble remains the same at
t
CK.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Programmable Preamble Modes and DQS Postambles

Figure 118: READ Postamble

1tCK Mode
RD
CL
CK_c
CK_t
Postamble

DQS_t,
DQS_c

DQ D0 D1 D2 D3 D4 D5 D6 D7

2tCK Mode
RD
CL
CK_c
CK_t
Postamble

DQS_t,
DQS_c

DQ D0 D1 D2 D3 D4 D5 D6 D7

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 8Gb: x4, x8, x16 DDR4 SDRAM
Bank Access Operation

Bank Access Operation

DDR4 supports bank grouping: x4/x8 DRAMs have four bank groups (BG[1:0]), and each bank group is
comprised of four subbanks (BA[1:0]); x16 DRAMs have two bank groups (BG[0]), and each bank group
is comprised of four subbanks. Bank accesses to different banks' groups require less time delay
between accesses than bank accesses to within the same bank's group. Bank accesses to different bank
groups require tCCD_S (or short) delay between commands while bank accesses within the same bank
group require tCCD_L (or long) delay between commands.

Figure 119: Bank Group x4/x8 Block Diagram

Bank 3 Bank 3 Bank 3 Bank 3
Bank 2 Bank 2 Bank 2 Bank 2
Bank 1 Bank 1 Bank 1 Bank 1
Bank 0 Bank 0 Bank 0 Bank 0
Memory Array Memory Array Memory Array Memory Array

Bank Group 0 Bank Group 1 Bank Group 2 Bank Group 3

CMD/ADDR CMD/ADDR
register

Sense amplifiers Sense amplifiers Sense amplifiers Sense amplifiers

Local I/O gating Local I/O gating Local I/O gating Local I/O gating

Global I/O gating

Data I/O

Notes: 1. Bank accesses to different bank groups require tCCD_S.

2. Bank accesses within the same bank group require tCCD_L.
Splitting the banks into bank groups with subbanks improved some bank access timings and
increased others. However, considering DDR4 did not increase the prefetch from 8n to 16n, the penalty
for staying 8n prefetch was significantly mitigated by using bank groups. The table below summarizes
the timings affected (values listed as xnCK or yns means the larger of the two values).

Table 70: DDR4 Bank Group Timing Examples

Parameter DDR4-1600 DDR4-2133 DDR4-2400
t 4nCK 4nCK 4nCK
CCD_S
tCCD_L 4nCK or 6.25ns 4nCK or 5.355ns 4nCK or 5ns

t 4nCK or 5ns 4nCK or 3.7ns 4nCK or 3.3ns

22$?3 ž+
t 4nCK or 6ns 4nCK or 5.3ns 4nCK or 4.9ns
22$?, ž+

t 4nCK or 5ns 4nCK or 3.7ns 4nCK or 3.3ns

RRD_S (1K)
tRRD_L (1K) 4nCK or 6ns 4nCK or 5.3ns 4nCK or 4.9ns

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 8Gb: x4, x8, x16 DDR4 SDRAM
Bank Access Operation

Table 70: DDR4 Bank Group Timing Examples (Continued)

Parameter DDR4-1600 DDR4-2133 DDR4-2400
tRRD_S (2K) 4nCK or 6ns 4nCK or 5.3ns 4nCK or 5.3ns
t 4nCK or 7.5ns 4nCK or 6.4ns 4nCK or 6.4ns
RRD_L (2K)

t
WTR_S 2nCK or 2.5ns 2nCK or 2.5ns 2nCK or 2.5ns
t
WTR_L 4nCK or 7.5ns 4nCK or 7.5ns 4nCK or 7.5ns

Notes: 1. Refer to Timing Tables for actual specification values, these values are shown for reference only and are not veri-
fied for accuracy.
2. Timings with both nCK and ns require both to be satisfied; that is, the larger time of the two cases must be satis-
fied.

Figure 120: READ Burst tCCD_S and tCCD_L Examples

T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11
CK_c
CK_t
Command READ DES DES DES READ DES DES DES DES DES READ DES
tCCD_S tCCD_L

Bank Group
BG a BG b BG b
(BG)

Bank Bank c Bank c Bank c

Address Col n Col n Col n

Don’t Care

Notes: 1. tCCD_S;CAS_n-to-CAS_n delay (short). Applies to consecutive CAS_n to different bank groups (T0 to T4).
t
2. CCD_L; CAS_n-to-CAS_n delay (long). Applies to consecutive CAS_n to the same bank group (T4 to T10).

Figure 121: Write Burst tCCD_S and tCCD_L Examples

T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11
CK_c
CK_t
Command WRITE DES DES DES WRITE DES DES DES DES DES WRITE DES
tCCD_S tCCD_L

Bank Group
BG a BG b BG b
(BG)

Bank Bank c Bank c Bank c

Address Coln Coln Coln

Don’t Care

t
Notes: 1. CCD_S; CAS_n-to-CAS_n delay (short). Applies to consecutive CAS_n to different bank groups (T0 to T4).
t
2. CCD_L; CAS_n-to-CAS_n delay (long). Applies to consecutive CAS_n to the same bank group (T4 to T10).

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 8Gb: x4, x8, x16 DDR4 SDRAM
Bank Access Operation

Figure 122: tRRD Timing

T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11
CK_c
CK_t

Command ACT DES DES DES ACT DES DES DES DES DES ACT DES
tRRD_S tRRD_L

Bank
Group BG a BG b BG b
(BG)

Bank Bank c Bank c Bank d

Address Row n Row n Row n

Don’t Care

t
Notes: 1. RRD_S; ACTIVATE-to-ACTIVATE command period (short); applies to consecutive ACTIVATE commands to different
bank groups (T0 and T4).
2. tRRD_L; ACTIVATE-to-ACTIVATE command period (long); applies to consecutive ACTIVATE commands to the
different banks in the same bank group (T4 and T10).

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 8Gb: x4, x8, x16 DDR4 SDRAM
Bank Access Operation

Figure 123: tWTR_S Timing (WRITE-to-READ, Different Bank Group, CRC and DM Disabled)
T0 T1 T2 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Tb0 Tb1
CK_c
CK_t

Command WRITE Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid READ Valid
tWTR_S

Bank BGa BGb

Group

Bank Bank c Bank c

Address Col n Col n

tWPRE
tWPST

DQS, DQS_c

DQ DI DI DI DI DI DI DI DI
n n+ 1 n+ 2 n+ 3 n+ 4 n+ 5 n+ 6 n+ 7
WL RL

Time Break Transitioning Data Don’t Care

t
Note: 1. WTR_S: delay from start of internal write transaction to internal READ command to a different bank group.

Figure 124: tWTR_L Timing (WRITE-to-READ, Same Bank Group, CRC and DM Disabled)
T0 T1 T2 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Tb0 Tb1
CK_c
CK_t

Command WRITE Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid READ Valid
tWTR_L

Bank BGa BGa

Group

Bank Bank c Bank c

Address Col n Col n

tWPRE
tWPST

DQS, DQS_c

DQ DI DI DI DI DI DI DI DI
n n+ 1 n+ 2 n+ 3 n+ 4 n+ 5 n+ 6 n+ 7
WL RL

Time Break Transitioning Data Don’t Care

t
Note: 1. WTR_L: delay from start of internal write transaction to internal READ command to the same bank group.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

READ Operation
Read Timing Definitions
The read timings shown below are applicable in normal operation mode, that is, when the DLL is
enabled and locked.

Note:tDQSQ = both rising/falling edges of DQS; no tAC defined.

Rising data strobe edge parameters:
s tDQSCK (MIN)/(MAX) describes the allowed range for a rising data strobe edge relative to CK.
s tDQSCK is the actual position of a rising strobe edge relative to CK.
s tQSH describes the DQS differential output HIGH time.
s tDQSQ describes the latest valid transition of the associated DQ pins.
s tQH describes the earliest invalid transition of the associated DQ pins.
Falling data strobe edge parameters:
s tQSL describes the DQS differential output LOW time.
s tDQSQ describes the latest valid transition of the associated DQ pins.
s tQH describes the earliest invalid transition of the associated DQ pins.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

Figure 125: Read Timing Definition

CK_c

CK_t

tDQSCK (MIN) tDQSCK (MAX) tDQSCK (MIN) tDQSCK (MAX)

tDQSCKi tDQSCKi

tDQSCK Rising strobe Rising strobe

MAX region region
window window

tDQSCKi tDQSCKi

tDQSCK Rising strobe Rising strobe

center region region
window window

tDQSCKi tDQSCKi

tDQSCK Rising strobe Rising strobe

MIN region region
window window

tDQSCK tDQSCK

tQSH/DQS_c tQSH/DQS_t

DQS_c

DQS_t
tQH tQH

tDQSQ tDQSQ

Associated
DQ Pins

Table 71: Read-to-Write and Write-to-Read Command Intervals

Access Type Bank Group Timing Parameters Note
Same CL - CWL + RBL/2 + 1tCK + tWPRE 1, 2
Read-to-Write, mini-
mum Different 1, 2
CL - CWL + RBL/2 + 1tCK + tWPRE
Same CWL + WBL/2 + tWTR_L 1, 3
Write-to-Read, mini-
mum Different 1, 3
CWL + WBL/2 + tWTR_S

Notes: 1. These timings require extended calibrations times tZQinit and tZQCS.
2. RBL: READ burst length associated with READ command, RBL = 8 for fixed 8 and on-the-fly mode 8 and RBL = 4 for
fixed BC4 and on-the-fly mode BC4.
3. WBL: WRITE burst length associated with WRITE command, WBL = 8 for fixed 8 and on-the-fly mode 8 or BC4 and
WBL = 4 for fixed BC4 only.

2EAD 4IMING n #LOCK TO $ATA 3TROBE 2ELATIONSHIP

The clock-to-data strobe relationship shown below is applicable in normal operation mode, that is,
when the DLL is enabled and locked.
Rising data strobe edge parameters:

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READ Operation

s tDQSCK (MIN)/(MAX) describes the allowed range for a rising data strobe edge relative to CK.
s tDQSCK is the actual position of a rising strobe edge relative to CK.
s tQSH describes the data strobe high pulse width.
s tHZ(DQS) DQS strobe going to high, nondrive level (shown in the postamble section of the figure
below).

Falling data strobe edge parameters:

s tQSL describes the data strobe low pulse width.
s tLZ(DQS) DQS strobe going to low, initial drive level (shown in the preamble section of the figure
below).

Figure 126: Clock-to-Data Strobe Relationship

RL measured
to this point

CK_t
CK_c
tDQSCK (MIN) tDQSCK (MIN) tDQSCK (MIN) tDQSCK (MIN)
tHZ(DQS) MIN

tLZ(DQS) MIN tQSH tQSL tQSH tQSL tQSH tQSL

DQS_t, DQS_c
Early Strobe Bit 0 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7

tRPRE tRPST
tHZ(DQS) MAX

tDQSCK (MAX) tDQSCK (MAX) tDQSCK (MAX) tDQSCK (MAX)

tRPST
tLZ(DQS) MAX

DQS_t, DQS_c
Late Strobe Bit 0 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7

tRPRE tQSH tQSL tQSH tQSL

Notes: 1. Within a burst, the rising strobe edge will vary within tDQSCKi while at the same voltage and temperature.
However, when the device, voltage, and temperature variations are incorporated, the rising strobe edge variance
window can shift between tDQSCK (MIN) and tDQSCK (MAX).
A timing of this window's right edge (latest) from rising CK_t, CK_c is limited by a device's actual tDQSCK (MAX).
A timing of this window's left inside edge (earliest) from rising CK_t, CK_c is limited by tDQSCK (MIN).
2. Notwithstanding Note 1, a rising strobe edge with tDQSCK (MAX) at T(n) can not be immediately followed by a
rising strobe edge with tDQSCK (MIN) at T(n + 1) because other timing relationships (tQSH, tQSL) exist: if tDQSCK(n
+ 1) < 0: tDQSCK(n) < 1.0 tCK - (tQSH (MIN) + tQSL (MIN)) - |tDQSCK(n + 1) |.
3. The DQS_t, DQS_c differential output HIGH time is defined by tQSH, and the DQS_t, DQS_c differential output LOW
time is defined by tQSL.
4. tLZ(DQS) MIN and tHZ(DQS) MIN are not tied to tDQSCK (MIN) (early strobe case), and tLZ(DQS) MAX and tHZ(DQS)
MAX are not tied to tDQSCK (MAX) (late strobe case).
5. The minimum pulse width of READ preamble is defined by tRPRE (MIN).
6. The maximum READ postamble is bound by tDQSCK (MIN) plus tQSH (MIN) on the left side and tHZDSQ (MAX) on
the right side.
7. The minimum pulse width of READ postamble is defined by tRPST (MIN).
8. The maximum READ preamble is bound by tLZDQS (MIN) on the left side and tDQSCK (MAX) on the right side.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

2EAD 4IMING n $ATA 3TROBE TO $ATA 2ELATIONSHIP

The data strobe-to-data relationship is shown below and is applied when the DLL is enabled and
locked.

Note:tDQSQ: both rising/falling edges of DQS; no tAC defined.

Rising data strobe edge parameters:
s tDQSQ describes the latest valid transition of the associated DQ pins.
s tQH describes the earliest invalid transition of the associated DQ pins.
Falling data strobe edge parameters:
s tDQSQ describes the latest valid transition of the associated DQ pins.
s tQH describes the earliest invalid transition of the associated DQ pins.
Data valid window parameters:
s tDVWd is the Data Valid Window per device per UI and is derived from [tQH - tDQSQ] of each UI on
a given DRAM
s tDVWp is the Data Valid Window per pin per UI and is derived [tQH - tDQSQ] of each UI on a pin of
a given DRAM

Figure 127: Data Strobe-to-Data Relationship

T0 T1 T2 T9 T10 T11 T12 T13 T14 T15 T16
CK_c
CK_t

Command3 READ DES DES DES DES DES DES DES DES DES DES

RL = AL + CL

Bank,
Address4 Col n
tDQSQ (MAX) tDQSQ (MAX)
tRPST
tRPRE (1nCK)

DQS_t, DQS_c
tQH tQH

DQ2 DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT

(Last data ) n n+1 n+2 n+3 n+4 n+5 n+6 n+7
tDVWp

DQ2 DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT

n n+1 n+2 n+3 n+4 n+5 n+6 n+7
(First data no longer)
tDVWp
DOUT DOUT DOUT DOUT DOUT DOUT DOUT DOUT
All DQ collectively n n+1 n+2 n+3 n+4 n+5 n+6 n+7

tDVWd tDVWd
Don’t Care

Notes: 1. BL = 8, RL = 11 (AL = 0, CL = 1), Premable = 1tCK.

2. DOUT n = data-out from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[A1:0 = 00] or MR0[A1:0 = 01] and A12 = 1 during READ commands at T0.
5. Output timings are referenced to VDDQ, and DLL on for locking.
6. tDQSQ defines the skew between DQS to data and does not define DQS to clock.
7. Early data transitions may not always happen at the same DQ. Data transitions of a DQ can vary (either early or
late) within a burst.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

t
LZ(DQS), tLZ(DQ), tHZ(DQS), and tHZ(DQ) Calculations
t
HZ and tLZ transitions occur in the same time window as valid data transitions. These parameters are
referenced to a specific voltage level that specifies when the device output is no longer driving
t
HZ(DQS) and tHZ(DQ), or begins driving tLZ(DQS) and tLZ(DQ). The figure below shows a method to
calculate the point when the device is no longer driving tHZ(DQS) and tHZ(DQ), or begins driving
t
LZ(DQS) and tLZ(DQ), by measuring the signal at two different voltages. The actual voltage measure-
ment points are not critical as long as the calculation is consistent. tLZ(DQS), tLZ(DQ), tHZ(DQS), and
t
HZ(DQ) are defined as singled-ended parameters.

Figure 128: tLZ and tHZ Method for Calculating Transitions and Endpoints
tLZ(DQ): CK_t, CK_c rising crossing at RL tHZ(DQ) with BL8: CK_t, CK_c rising crossing at RL + 4CK
tHZ(DQ) with BC4: CK_t, CK_c rising crossing at RL + 2CK

CK_t

CK_c
tLZ tHZ
Begin point:
Extrapolated point at VDDQ
VDDQ
DQ VDDQ DQ

VSW2 VSW2
0.7 × VDDQ 0.7 × VDDQ
VSW1 VSW1

0.4 × VDDQ 0.4 × VDDQ

Begin point: Extrapolated point (low level)

Notes: 1. Vsw1 = (0.70 - 0.04) έ VDDQ for both tLZ and tHZ.
2. Vsw2 = (0.70 + 0.04) έ VDDQ for both tLZ and tHZ.
3. Extrapolated point (low level) = VDDQ/(50 + 34) έ 34 = 0.4 έ VDDQ
Driver impedance = RZQ/7 = 34ȳ
VTT test load = 50ȳ to VDDQ.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

t
RPRE Calculation

Figure 129: tRPRE Method for Calculating Transitions and Endpoints

CK_t

VDD /2

CK_c

Single-ended signal provided as background information

DQS_t VDDQ

0.7 × VDDQ

0.4 × VDDQ
DQS_c
VDDQ

0.7 × VDDQ

0.4 × VDDQ

DQS_t DQS_t VDDQ

DQS_c
0.7 × VDDQ

DQS_c 0.4 × VDD

Resulting differential signal relevant for tRPRE specification

0.6 × VDDQ

VSW2
0.3 × VDDQ
VSW1

DQS_t, DQS_c 0V
t t t
RPRE begins ( 1) RPRE ends (t2)

Notes: 1. Vsw1 = (0.3 - 0.04) έ VDDQ.

2. Vsw2 = (0.30 + 0.04) έ VDDQ.
3. DQS_t and DQS_c low level = VDDQ/(50 + 34) έ 34 = 0.4 έ VDDQ
Driver impedance = RZQ/7 = 34ȳ
VTT test load = 50ȳ to VDDQ.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

t
RPST Calculation

Figure 130: tRPST Method for Calculating Transitions and Endpoints

CK_t

VDD /2

CK_c

Single-ended signal provided as background information

VDDQ

0.7 × VDDQ

DQS_t 0.4 × VDDQ

DQS_c VDDQ

0.7 × VDDQ

0.4 × VDDQ

DQS_c VDDQ

0.7 × VDDQ

DQS_t

Resulting differential signal relevant fortRPST specification

tRPST beginst(1)

0V
VSW2
–0.3 × VDDQ
VSW1

DQS_t, DQS_c –0.6 × VDDQ

tRPST ends t(2)

Notes: 1. Vsw1  n  έ VDDQ.

2. Vsw2  n  έ VDDQ.
3. DQS_t and DQS_c low level = VDDQ/(50 + 34) έ 34 = 0.4 έ VDDQ
Driver impedance = RZQ/7 = 34ȳ
VTT test load = 50ȳ to VDDQ.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

READ Burst Operation

DDR4 READ commands support bursts of BL8 (fixed), BC4 (fixed), and BL8/BC4 on-the-fly (OTF); OTF
uses address A12 to control OTF when OTF is enabled:
s A12 = 0, BC4 (BC4 = burst chop)
s A12 = 1, BL8

READ commands can issue precharge automatically with a READ with auto precharge command
(RDA), and is enabled by A10 HIGH:
s READ command with A10 = 0 (RD) performs standard read, bank remains active after READ burst.
s READ command with A10 = 1 (RDA) performs read with auto precharge, bank goes in to precharge
after READ burst.

Figure 131: READ Burst Operation, RL = 11 (AL = 0, CL = 11, BL8)

T0 T1 T2 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Ta8 Ta9
CK_c
CK_t

Command READ DES DES DES DES DES DES DES DES DES DES DES DES

Bank Group
BGa
Address

Address Bank
col n
tRPRE tRPST

DQS_t
DQS_c

DQ DO DO DO DO DO DO DO DO
n n+ 1 n+ 2 n+ 3 n+ 4 n+ 5 n+ 6 n+ 7
CL = 11
RL = AL + CL

Time Break Transitioning Data Don’t Care

Notes: 1. BL8, RL = 0, AL = 0, CL = 11, Preamble = 1tCK.

2. DO n = data-out from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ command at T0.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

Figure 132: READ Burst Operation, RL = 21 (AL = 10, CL = 11, BL8)

T0 T1 Ta0 Ta1 Ta2 Ta3 Tb0 Tb1 Tb2 Tb3 Tb4 Tb5 Tb6
CK_c
CK_t

Command READ DES DES DES DES DES DES DES DES DES DES DES DES

Bank Group
BGa
Address

Address Bank
col n
tRPRE tRPST

DQS_t
DQS_c

DQ DO DO DO DO DO DO DO DO
n n+ 1 n+ 2 n+ 3 n+ 4 n+ 5 n+ 6 n+ 7
AL = 10 CL = 11
RL = AL + CL

Time Break Transitioning Data Don’t Care

Notes: 1. BL8, RL = 21, AL = (CL - 1), CL = 11, Preamble = 1tCK.

2. DO n = data-out from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ command at T0.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

READ Operation Followed by Another READ Operation

Figure 133: Consecutive READ (BL8) with 1tCK Preamble in Different Bank Group
T0 T1 T2 T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21
CK_c
CK_t

Command READ DES DES DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES

tCCD_S =4

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tRPRE tRPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DO DO DO DO DO DO DO DO DO DO DO DO
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

RL = 11

Time Break Transitioning Data Don’t Care

Notes: 1. BL8, AL = 0, CL = 11, Preamble = 1tCK.

2. DO n (or b) = data-out from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T0 and T4.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.

Figure 134: Consecutive READ (BL8) with 2tCK Preamble in Different Bank Group
T0 T1 T2 T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21
CK_c
CK_t

Command READ DES DES DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES

tCCD_S =4

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tRPRE tRPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DO DO DO DO DO DO DO DO DO DO DO DO
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

RL = 11

Time Break Transitioning Data Don’t Care

Notes: 1. BL8, AL = 0, CL = 11, Preamble = 2tCK.

2. DO n (or b) = data-out from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T0 and T4.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

Figure 135: Nonconsecutive READ (BL8) with 1tCK Preamble in Same or Different Bank Group
T0 T1 T2 T3 T4 T5 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21
CK_c
CK_t

Command READ DES DES DES DES READ DES DES DES DES DES DES DES DES DES DES DES DES

tCCD_S/L =5

Bank Group
BGa BGb
Address

Address Bank Bank

Col n Col b
tRPRE tRPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DO DO DO DO DO DO DO DO DO DO DO DO
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

RL = 11

Time Break Transitioning Data Don’t Care

Notes: 1. BL8, AL = 0, CL = 11, Preamble = 1tCK, tCCD_S/L = 5.

2. DO n (or b) = data-out from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T0 and T5.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.

Figure 136: Nonconsecutive READ (BL8) with 2tCK Preamble in Same or Different Bank Group
T0 T1 T2 T5 T6 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21
CK_c
CK_t

Command READ DES DES DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES

tCCD_S/L =6

Bank Group BGa BGa or

Address BGb

Address Bank Bank

Col n Col b
tRPRE tRPRE tRPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DO DO DO DO DO DO DO DO DO DO DO DO
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

RL = 11

Time Break Transitioning Data Don’t Care

Notes: 1. BL8, AL = 0, CL = 11, Preamble = 2tCK, tCCD_S/L = 6.

2. DO n (or b) = data-out from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[A1:0 = 00] or MR0[A1:0 = 01] and A12 = 1 during READ commands at T0 and T6.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.
6. 6 t##$?3,   ISNT ALLOWED IN tCK preamble mode.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

Figure 137: READ (BC4) to READ (BC4) with 1tCK Preamble in Different Bank Group
T0 T1 T2 T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21
CK_c
CK_t

Command READ DES DES DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES

tCCD_S =4

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tRPRE tRPST tRPRE tRPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DO DO DO DO
n n+1 n+2 n+3 b b+1 b+2 b+3

RL = 11

Time Break Transitioning Data Don’t Care

Notes: 1. BL8, AL = 0, CL = 11, Preamble = 1tCK.

2. DO n (or b) = data-out from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by either MR0[1:0] = 10 or MR0[1:0] = 01 and A12 = 0 during READ commands at T0 and T4.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.

Figure 138: READ (BC4) to READ (BC4) with 2tCK Preamble in Different Bank Group
T0 T1 T2 T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21
CK_c
CK_t

Command READ DES DES DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES

tCCD_S =4

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tRPRE tRPRE tRPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DO DO DO DO
n n+1 n+2 n+3 b b+1 b+2 b+3

RL = 11

Time Break Transitioning Data Don’t Care

Notes: 1. BL8, AL = 0, CL = 11, Preamble = 2tCK.

2. DO n (or b) = data-out from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by either MR0[1:0] = 10 or MR0[1:0] = 01 and A12 = 0 during READ commands at T0 and T4.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

Figure 139: READ (BL8) to READ (BC4) OTF with 1tCK Preamble in Different Bank Group
T0 T1 T2 T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21
CK_c
CK_t

Command READ DES DES DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES

tCCD_S =4

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
t RPRE tRPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DO DO DO DO DO DO DO DO
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3

RL = 11

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, AL = 0, CL = 11, Preamble = 1tCK.

2. DO n (or b) = data-out from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during READ commands at T0. BC4 setting activated by
MR0[1:0] = 01 and A12 = 0 during READ commands at T4.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.

Figure 140: READ (BL8) to READ (BC4) OTF with 2tCK Preamble in Different Bank Group
T0 T1 T2 T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21
CK_c
CK_t

Command READ DES DES DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES

tCCD_S =4

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tRPRE tRPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DO DO DO DO DO DO DO DO
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3

RL = 11

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, AL =0, CL = 11, Preamble = 2tCK.

2. DO n (or b) = data-out from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during READ commands at T0. BC4 setting activated by
MR0[1:0] = 01 and A12 = 0 during READ commands at T4.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

Figure 141: READ (BC4) to READ (BL8) OTF with 1tCK Preamble in Different Bank Group
T0 T1 T2 T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21
CK_c
CK_t

Command READ DES DES DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES

tCCD_S =4

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tRPRE tRPST tRPRE tRPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DO DO DO DO DO DO DO DO
n n+1 n+2 n+3 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

RL = 11

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, AL =0, CL = 11, Preamble = 1tCK.

2. DO n (or b) = data-out from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during READ commands at T0. BL8 setting activated by
MR0[1:0] = 01 and A12 = 1 during READ commands at T4.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.

Figure 142: READ (BC4) to READ (BL8) OTF with 2tCK Preamble in Different Bank Group
T0 T1 T2 T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21
CK_c
CK_t

Command READ DES DES DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES

tCCD_S =4

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tRPRE tRPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DO DO DO DO DO DO DO DO
n n+1 n+2 n+3 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

RL = 11

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, AL = 0, CL = 11, Preamble = 2tCK.

2. DO n (or b) = data-out from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during READ commands at T0. BL8 setting activated by
MR0[1:0] = 01 and A12 = 1 during READ commands at T4.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

READ Operation Followed by WRITE Operation

Figure 143: READ (BL8) to WRITE (BL8) with 1tCK Preamble in Same or Different Bank Group
T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 T22
CK_c
CK_t

Command READ DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

READ to WRITE command delay tWTR

= RL +BL/2 - WL + 2 tCK 4 Clocks

Bank Group BGa or

BGa BGb
Address

Address Bank Bank

Col n Col b
tRPRE tRPST tWPRE tWPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DO DO DO DO DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

WL = 9

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK, WL = 9 (CWL = 9, AL = 0), WRITE preamble = 1tCK.
2. DO n = data-out from column n; DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T0 and
WRITE commands at T8.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.

Figure 144: READ (BL8) to WRITE (BL8) with 2tCK Preamble in Same or Different Bank Group
T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 T22
CK_c
CK_t

Command READ DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES
t
WR
READ to WRITE command delay
= RL +BL/2 - WL + 3 tCK 4 Clocks t
WTR

Bank Group BGa or

BGa BGb
Address

Address Bank Bank

Col n Col b
t
t
RPRE t
RPST t
WPRE WPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DO DO DO DO DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

WL = 10

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, RL = 11 (CL = 11, AL = 0), READ preamble = 2tCK, WL = 10 (CWL = 9+1 [see Note 5], AL = 0), WRITE preamble
= 2tCK.
2. DO n = data-out from column n; DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T0 and
WRITE commands at T8.
5. When operating in 2tCK WRITE preamble mode, CWL may need to be programmed to a value at least 1 clock
greater than the lowest CWL setting.
6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

Figure 145: READ (BC4) OTF to WRITE (BC4) OTF with 1tCK Preamble in Same or Different Bank Group
T0 T1 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20
CK_c
CK_t

Command READ DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

READ to WRITE command delay tWTR

= RL +BL/2 - WL + 2 tCK 4 Clocks

Bank Group BGa BGa or

Address BGb

Address Bank Bank

Col n Col b
tRPRE tRPST tWPRE tWPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DI DI DI DI
n n+1 n+2 n+3 b b+1 b+2 b+3

WL = 9

Time Break Transitioning Data Don’t Care

Notes: 1. BC = 4, RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK, WL = 9 (CWL = 9, AL = 0), WRITE preamble = 1tCK.
2. DO n = data-out from column n; DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 (OTF) setting activated by MR0[1:0] = 01 and A12 = 0 during READ commands at T0 and WRITE commands at
T6.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.

Figure 146: READ (BC4) OTF to WRITE (BC4) OTF with 2tCK Preamble in Same or Different Bank Group
T0 T1 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20
CK_c
CK_t

Command READ DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

READ to WRITE command delay tWTR

= RL +BL/2 - WL + 3 tCK 4 Clocks

Bank Group BGa BGa or

Address BGb

Address Bank Bank

Col n Col b
tRPRE tRPST tWPRE tWPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DI DI DI DI
n n+1 n+2 n+3 b b+1 b+2 b+3

WL = 10

Time Break Transitioning Data Don’t Care

Notes: 1. BC = 4, RL = 11 (CL = 11, AL = 0), READ preamble = 2tCK, WL = 10 (CWL = 9 + 1 [see Note 5], AL = 0), WRITE preamble
= 2tCK.
2. DO n = data-out from column n; DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 (OTF) setting activated by MR0[1:0] = 01 and A12 = 0 during READ commands at T0 and WRITE commands at
T6.
5. When operating in 2tCK WRITE preamble mode, CWL may need to be programmed to a value at least 1 clock
greater than the lowest CWL setting.
6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

Figure 147: READ (BC4) Fixed to WRITE (BC4) Fixed with 1tCK Preamble in Same or Different Bank
Group
T0 T1 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20
CK_c
CK_t

Command READ DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

READ to WRITE command delay tWTR

= RL +BL/2 - WL + 2 tCK 2 Clocks

Bank Group BGa BGa or

Address BGb

Address Bank Bank

Col n Col b
tRPRE tRPST tWPRE tWPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DI DI DI DI
n n+1 n+2 n+3 b b+1 b+2 b+3

WL = 9

Time Break Transitioning Data Don’t Care

Notes: 1. BC = 4, RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK, WL = 9 (CWL = 9, AL = 0), WRITE preamble = 1tCK.
2. DO n = data-out from column n; DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 (fixed) setting activated by MR0[1:0] = 01.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.

Figure 148: READ (BC4) Fixed to WRITE (BC4) Fixed with 2tCK Preamble in Same or Different Bank
Group
T0 T1 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20
CK_c
CK_t

Command READ DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

READ to WRITE command delay tWTR

= RL +BL/2 - WL + 3 tCK 2 Clocks

Bank Group BGa BGa or

Address BGb

Address Bank Bank

Col n Col b
tRPRE tRPST tWPRE tWPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DI DI DI DI
n n+1 n+2 n+3 b b+1 b+2 b+3

WL = 10

Time Break Transitioning Data Don’t Care

Notes: 1. BC = 4, RL = 11 (CL = 11, AL = 0), READ preamble = 2tCK, WL = 9 (CWL = 9 + 1 [see Note 5], AL = 0), WRITE preamble
= 2tCK.
2. DO n = data-out from column n; DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 (fixed) setting activated by MR0[1:0] = 10.
5. When operating in 2tCK WRITE preamble mode, CWL may need to be programmed to a value at least 1 clock
greater than the lowest CWL setting.
6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

Figure 149: READ (BC4) to WRITE (BL8) OTF with 1tCK Preamble in Same or Different Bank Group
T0 T1 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20
CK_c
CK_t

Command READ DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

READ to WRITE command delay tWTR

= RL +BL/2 - WL + 2 tCK 4 Clocks

Bank Group BGa BGa or

Address BGb

Address Bank Bank

Col n Col b
tRPST tWPST
tRPRE tWPRE

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 b b+1 b+2 b+3 n+4 n+5 n+6 n+7

WL = 9

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK, WL = 9 (CWL = 9, AL = 0), WRITE preamble = 1tCK.
2. DO n = data-out from column n; DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T0.
BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during READ commands at T6.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.

Figure 150: READ (BC4) to WRITE (BL8) OTF with 2tCK Preamble in Same or Different Bank Group
T0 T1 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20
CK_c
CK_t

Command READ DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

READ to WRITE command delay tWTR

= RL +BL/2 - WL + 3 tCK 4 Clocks

Bank Group BGa BGa or

Address BGb

Address Bank Bank

Col n Col b
tRPST tWPST
tRPRE tWPRE

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 b b+1 b+2 b+3 n+4 n+5 n+6 n+7

WL = 10

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, RL = 11 (CL = 11, AL = 0), READ preamble = 2tCK, WL = 10 (CWL = 9 + 1 [see Note 5], AL = 0), WRITE preamble
= 2tCK.
2. DO n = data-out from column n; DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T0.
BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during READ commands at T6.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

Figure 151: READ (BL8) to WRITE (BC4) OTF with 1tCK Preamble in Same or Different Bank Group
T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 T22
CK_c
CK_t

Command READ DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

READ to WRITE command delay tWTR

= RL +BL/2 - WL + 2 tCK 4 Clocks

Bank Group BGa BGa or

Address BGb

Address Bank Bank

Col n Col b
tRPRE tRPST tWPRE tWPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DO DO DO DO DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3

WL = 9

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK, WL = 9 (CWL = 9, AL = 0), WRITE preamble = 1tCK.
2. DO n = data-out from column n; DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during READ commands at T0.
BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T8.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.

Figure 152: READ (BL8) to WRITE (BC4) OTF with 2tCK Preamble in Same or Different Bank Group
T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 T22
CK_c
CK_t

Command READ DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

READ to WRITE command delay tWTR

= RL +BL/2 - WL + 3 tCK 4 Clocks

Bank Group BGa BGa or

Address BGb

Address Bank Bank

Col n Col b
tRPRE tRPST tWPRE tWPST

DQS_t,
DQS_c
RL = 11

DQ DO DO DO DO DO DO DO DO DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3

WL = 10

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, RL = 11 (CL = 11, AL = 0), READ preamble = 2tCK, WL = 10 (CWL = 9 + 1 [see Note 5], AL = 0), WRITE preamble
= 2tCK.
2. DO n = data-out from column n; DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during READ commands at T0.
BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T8.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.

READ Operation Followed by PRECHARGE Operation

The minimum external READ command to PRECHARGE command spacing to the same bank is equal
to AL + tRTP with tRTP being the internal READ command to PRECHARGE command delay. Note that
the minimum ACT to PRE timing, tRAS, must be satisfied as well. The minimum value for the internal
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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

READ command to PRECHARGE command delay is given by tRTP (MIN) = MAX (4 έ nCK, 7.5ns). A new
bank ACTIVATE command may be issued to the same bank if the following two conditions are satisfied
simultaneously:
s The minimum RAS precharge time (tRP [MIN]) has been satisfied from the clock at which the
precharge begins.
s The minimum RAS cycle time (tRC [MIN]) from the previous bank activation has been satisfied.

Figure 153: READ to PRECHARGE with 1tCK Preamble

T0 T1 T2 T3 T6 T7 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21
CK_c
CK_t

Command DES READ DES DES DES PRE DES DES DES DES DES DES DES DES ACT DES DES DES

Bank Group BGa

BGa or BGb BGa
Address

Address Bank a Bank a Bank a

Col n (or all) Row b
tRTP tRP

RL = AL + CL
BC4 Opertaion
DQS_t,
DQS_c

DQ DO DO DO DO
n n+1 n+2 n+3

BL8 Opertaion
DQS_t,
DQS_c

DQ DO DO DO DO DO DO DO DO
n n+1 n+2 n+3 n+4 n+5 n+6 n+7

Time Break Transitioning Data Don’t Care

Notes: 1. RL = 11 (CL = 11, AL = 0 ), Preamble = 1tCK, tRTP = 6, tRP = 11.

2. DO n = data-out from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. The example assumes that tRAS (MIN) is satisfied at the PRECHARGE command time (T7) and that tRC (MIN) is satis-
fied at the next ACTIVATE command time (T18).
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

Figure 154: READ to PRECHARGE with 2tCK Preamble

T0 T1 T2 T3 T6 T7 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21
CK_c
CK_t

Command DES READ DES DES DES PRE DES DES DES DES DES DES DES DES ACT DES DES DES

Bank Group BGa or

BGa BGb BGa
Address

Address Bank a Bank a Bank a

Col n (or all) Row b
tRTP tRP

RL = AL + CL
BC4 Opertaion
DQS_t,
DQS_c

DQ DO DO DO DO
n n+1 n+2 n+3

BL8 Opertaion
DQS_t,
DQS_c

DQ DO DO DO DO DO DO DO DO
n n+1 n+2 n+3 n+4 n+5 n+6 n+7

Time Break Transitioning Data Don’t Care

Notes: 1. RL = 11 (CL = 11, AL = 0 ), Preamble = 2tCK, tRTP = 6, tRP = 11.

2. DO n = data-out from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. The example assumes that tRAS (MIN) is satisfied at the PRECHARGE command time (T7) and that tRC (MIN) is satis-
fied at the next ACTIVATE command time (T18).
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.

Figure 155: READ to PRECHARGE with Additive Latency and 1tCK Preamble
T0 T1 T2 T3 T10 T11 T12 T13 T16 T19 T20 T21 T22 T23 T24 T25 T26 T27
CK_c
CK_t

Command DES READ DES DES DES DES DES DES PRE DES DES DES DES DES DES DES DES ACT

Bank Group BGa or

BGa BGb BGa
Address

Address Bank a Bank a Bank a

Col n (or all) Row b

AL = CL - 2 = 9 tRTP tRP

CL = 11
BC4 Opertaion
DQS_t,
DQS_c

DQ DO DO DO DO
n n+1 n+2 n+3

BL8 Opertaion
DQS_t,
DQS_c

DQ DO DO DO DO DO DO DO DO
n n+1 n+2 n+3 n+4 n+5 n+6 n+7

Time Break Transitioning Data Don’t Care

Notes: 1. RL =20 (CL = 11, AL = CL - 2), Preamble = 1tCK, tRTP = 6, tRP = 11.
2. DO n = data-out from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. The example assumes that tRAS (MIN) is satisfied at the PRECHARGE command time (T16) and that tRC (MIN) is
satisfied at the next ACTIVATE command time (T27).
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

Figure 156: READ with Auto Precharge and 1tCK Preamble

T0 T1 T2 T3 T6 T7 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21
CK_c
CK_t

Command DES RDA DES DES DES PRE DES DES DES DES DES DES DES DES ACT DES DES DES

Bank Group BGa or

BGa BGb BGa
Address

Address Bank a Bank a Bank a

Col n Col n Row b
tRTP tRP

RL = AL + CL
BC4 Opertaion
DQS_t,
DQS_c

DQ DO DO DO DO
n n+1 n+2 n+3

BL8 Opertaion
DQS_t,
DQS_c

DQ DO DO DO DO DO DO DO DO
n n+1 n+2 n+3 n+4 n+5 n+6 n+7

Time Break Transitioning Data Don’t Care

Notes: 1. RL = 11 (CL = 11, AL = 0 ), Preamble = 1tCK, tRTP = 6, tRP = 11.

2. DO n = data-out from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. t
RTP = 6 setting activated by MR0[A11:9 = 001].
5. The example assumes that tRC (MIN) is satisfied at the next ACTIVATE command time (T18).
6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.

Figure 157: READ with Auto Precharge, Additive Latency, and 1tCK Preamble
T0 T1 T2 T3 T10 T11 T12 T13 T16 T19 T20 T21 T22 T23 T24 T25 T26 T27
CK_c
CK_t

Command DES RDA DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES ACT

Bank Group
BGa BGa
Address

Address Bank a Bank a

Col n Row b

AL = CL - 2 = 9 tRTP tRP

CL = 11
BC4 Opertaion
DQS_t,
DQS_c

DQ DO DO DO DO
n n+1 n+2 n+3

BL8 Opertaion
DQS_t,
DQS_c

DQ DO DO DO DO DO DO DO DO
n n+1 n+2 n+3 n+4 n+5 n+6 n+7

Time Break Transitioning Data Don’t Care

Notes: 1. RL = 20 (CL = 11, AL = CL - 2), Preamble = 1tCK, tRTP = 6, tRP = 11.

2. DO n = data-out from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. t
RTP = 6 setting activated by MR0[11:9] = 001.
5. The example assumes that tRC (MIN) is satisfied at the next ACTIVATE command time (T27).
6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.
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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

READ Operation with Read Data Bus Inversion (DBI)

Figure 158: Consecutive READ (BL8) with 1tCK Preamble and DBI in Different Bank Group
T0 T1 T2 T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21
CK_c
CK_t

Command READ DES DES DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES

tCCD_S =4

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tRPRE tRPST

DQS_t,
DQS_c
RL = 11 + 2 (Read DBI adder)

DQ DO DO DO DO DO DO DO DO DO DO DO DO DO DO DO DO
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b + 3 b +4 _ b + 5 b+6 b+7

RL = 11 + 2 (Read DBI adder)

DBI_n DBI DBI DBI DBI DBI DBI DBI DBI DBI DBI DBI DBI DBI DBI DBI DBI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, AL = 0, CL = 11, Preamble = 1tCK, RL = 11 + 2 (Read DBI adder).

2. DO n (or b) = data-out from column n (or b); DBI n (or b) = data bus inversion from column n (or b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T0 and T4.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Enable.

READ Operation with Command/Address Parity (CA Parity)

Figure 159: Consecutive READ (BL8) with 1tCK Preamble and CA Parity in Different Bank Group
T0 T1 T2 T3 T4 T7 T8 T13 T14 T15 T16 T17 T18 T19 T20 T21 T20 T21
CK_c
CK_t

Command READ DES DES DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES

tCCD_S =4

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
Parity
tRPRE tRPST

DQS_t,
DQS_c
RL = 15

DQ DO DO DO DO DO DO DO DO DO DO DO DO DO DO DO DO
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b + 3 b +4 _ b + 5 b+6 b+7

RL = 15

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, AL = 0, CL = 11, PL = 4, (RL = CL + AL + PL = 15), Preamble = 1tCK.

2. DO n (or b) = data-out from column n (or b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[A1:A0 = 00] or MR0[A1:A0 = 01] and A12 = 1 during READ commands at T0
and T4.
5. CA parity = Enable, CS to CA latency = Disable, Read DBI = Disable.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

Figure 160: READ (BL8) to WRITE (BL8) with 1tCK Preamble and CA Parity in Same or Different Bank
Group
T0 T1 T7 T8 T9 T14 T15 T16 T17 T18 T19 T20 T21 T22 T23 T24 T25 T26
CK_c
CK_t

Command READ DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR
READ to WRITE command delay
= RL +BL/2 - WL + 2 tCK 4 Clocks tWTR

Bank Group BGa BGa or

Address BGb

Address Bank Bank

Col n Col b
Parity
tRPRE tRPST tWPRE tWPST

DQS_t,
DQS_c
RL = 15

DQ DO DO DO DO DO DO DO DO DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

WL = 13

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, AL = 0, CL = 11, PL = 4, (RL = CL + AL + PL = 15), READ preamble = 1tCK, CWL = 9, AL = 0, PL = 4, (WL = CL +

AL + PL = 13), WRITE preamble = 1tCK.
2. DO n = data-out from column n, DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T0 and
WRITE command at T8.
5. CA parity = Enable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.

READ Followed by WRITE with CRC Enabled

Figure 161: READ (BL8) to WRITE (BL8 or BC4: OTF) with 1tCK Preamble and Write CRC in Same or
Different Bank Group
T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 T22
CK_c
CK_t

Command READ DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR
READ to WRITE command delay
= RL +BL/2 - WL + 2 tCK 4 Clocks tWTR

Bank Group BGa BGa or

Address BGb

Address Bank Bank

Col n Col b
tRPRE tRPST tWPRE tWPST

DQS_t,
DQS_c
RL = 11

DQ x4, DO DO DO DO DO DO DO DO DI DI DI DI DI DI DI DI CRC CRC

n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7
BL = 8
WL = 9

DQ x8/X16, DO DO DO DO DO DO DO DO DI DI DI DI DI DI DI DI CRC
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7
BL = 8

DQ x4, DO DO DO DO DO DO DO DO DI DI DI DI
READ: BL = 8, n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 CRC CRC
WRITE: BC = 4 (OTF)

DQ x8/X16,
DO DO DO DO DO DO DO DO DI DI DI DI CRC
READ: BL = 8, n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3
WRITE: BC = 4 (OTF)

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8 (or BC = 4: OTF for Write), RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK, WL = 9 (CWL = 9, AL = 0), WRITE
preamble = 1tCK.
2. DO n = data-out from column n, DI b = data-in from column b.
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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T0 and
WRITE commands at T8.
5. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T8.
6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Enable.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

Figure 162: READ (BC4: Fixed) to WRITE (BC4: Fixed) with 1tCK Preamble and Write CRC in Same or
Different Bank Group
T0 T1 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20
CK_c
CK_t

Command READ DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR
READ to WRITE command delay
2 Clocks tWTR
= RL +BL/2 - WL + 2 tCK

Bank Group BGa BGa or

Address BGb

Address Bank Bank

Col n Col b
tRPRE tRPST tWPRE tWPST

DQS_t,
DQS_c
RL = 11

DQ x4, DO DO DO DO DI DI DI DI CRC CRC

n n+1 n+2 n+3 b b+1 b+2 b+3
BC = 4 (Fixed)
WL = 9

DQ x8/X16, DO DO DO DO DI DI DI DI CRC
n n+1 n+2 n+3 b b+1 b+2 b+3
BC = 4 (Fixed)

Time Break Transitioning Data Don’t Care

Notes: 1. BC = 4 (Fixed), RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK, WL = 9 (CWL = 9, AL = 0), WRITE preamble = 1tCK.
2. DO n = data-out from column n, DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 10.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Enable.

READ Operation with Command/Address Latency (CAL) Enabled

Figure 163: Consecutive READ (BL8) with CAL (3tCK) and 1tCK Preamble in Different Bank Group
T0 T1 T2 T3 T4 T5 T6 T7 T8 T13 T14 T15 T17 T18 T19 T21 T22 T23
CK_c
CK_t

tCAL =3 tCAL =3

Command DES DES READ DES DES DES READ DES DES DES DES DES DES DES DES DES DES
w/o CS_n

CS_n

tCCD_S =4

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tRPRE tRPST

DQS_t,
DQS_c
RL = 11

DQ DI DI DI DI DI DI DI DI DI DI DI DI
n n+1 n+2 n+5 n+6 n+7 b b+1 b+2 b+5 b+6 b+7

RL = 11

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK.

2. DI n (or b) = data-in from column n (or b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T3 and T7.
5. CA parity = Disable, CS to CA latency = Enable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.
6. Enabling CAL mode does not impact ODT control timings. The same timing relationship relative to the
command/address bus as when CAL is disabled should be maintained.

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 8Gb: x4, x8, x16 DDR4 SDRAM
READ Operation

Figure 164: Consecutive READ (BL8) with CAL (4tCK) and 1tCK Preamble in Different Bank Group
T0 T1 T2 T3 T4 T5 T6 T7 T8 T14 T15 T16 T18 T19 T21 T22 T23 T24
CK_c
CK_t

tCAL =4 tCAL =4

Command DES DES READ DES DES DES READ DES DES DES DES DES DES DES DES DES DES
w/o CS_n

CS_n

tCCD_S =4

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tRPRE tRPST

DQS_t,
DQS_c
RL = 11

DQ DI DI DI DI DI DI DI DI DI DI DI DI
n n+1 n+2 n+5 n+6 n+7 b b+1 b+2 b+5 b+6 b+7

RL = 11

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK.

2. DI n (or b) = data-in from column n (or b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T3 and T8.
5. CA parity = Disable, CS to CA latency = Enable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.
6. Enabling CAL mode does not impact ODT control timings. The same timing relationship relative to the
command/address bus as when CAL is disabled should be maintained.

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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

WRITE Operation
Write Timing Definitions
The write timings shown in the following figures are applicable in normal operation mode, that is,
when the DLL is enabled and locked.

7RITE 4IMING n #LOCK TO $ATA 3TROBE 2ELATIONSHIP

The clock-to-data strobe relationship is shown below and is applicable in normal operation mode, that
is, when the DLL is enabled and locked.
Rising data strobe edge parameters:
s tDQSS (MIN) to tDQSS (MAX) describes the allowed range for a rising data strobe edge relative to CK.
s tDQSS is the actual position of a rising strobe edge relative to CK.
s tDQSH describes the data strobe high pulse width.
s tWPST strobe going to HIGH, nondrive level (shown in the postamble section of the graphic below).
Falling data strobe edge parameters:
s tDQSL describes the data strobe low pulse width.
s tWPRE strobe going to LOW, initial drive level (shown in the preamble section of the graphic below).

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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

Figure 165: Write Timing Definition

T0 T1 T2 T7 T8 T9 T10 T11 T12 T13 T14
CK_c
CK_t
Command3 WRITE DES DES DES DES DES DES DES DES DES DES

WL = AL + CWL

Address4 Bank,
Col n

tDQSS tDSH tDSH tDSH tDSH

tDQSS tWPRE(1nCK) tWPSTaa

(MIN)
DQS_t, DQS_c
tDQSL tDQSH tDQSL tDQSH tDQSL tDQSH tDQSL tDQSH
tDQSH (MIN) tDQSL (MIN)
tDSS tDSS tDSS tDSS tDSS

DQ2 DIN
n
DIN
n+ 2
DIN
n+ 3
DIN
n+ 4
DIN
n+ 6
DIN
n+ 7

tDSH tDSH tDSH tDSH

tDQSS tWPRE(1nCK) tWPST (MIN)
(nominal)
DQS_t, DQS_c
tDQSL tDQSH tDQSL tDQSH tDQSL tDQSH tDQSL tDQSH
tDQSH tDQSL (MIN)
(MIN)
tDSS tDSS tDSS tDSS tDSS

DQ2 DIN
n
DIN
n+ 2
DIN
n+ 3
DIN
n+ 4
DIN
n+ 6
DIN
n+ 7

tDQSS

tDSH tDSH tDSH tDSH

tWPRE(1nCK) tWPST (MIN)
tDQSS (MAX)
DQS_t, DQS_c
tDQSL tDQSH tDQSL tDQSH tDQSL tDQSH tDQSL tDQSH

tDQSH tDQSL (MIN)

(MIN)
tDSS tDSS tDSS tDSS tDSS

DIN DIN DIN DIN DIN DIN

DQ2 n n+ 2 n+ 3 n+ 4 n+ 6 n+ 7

DM_n

Time Break Transitioning Data Don’t Care

Notes: 1. BL8, WL = 9 (AL = 0, CWL = 9).

2. DIN n = data-in from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0.
t
5. DQSS must be met at each rising clock edge.

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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

t
WPRE Calculation

Figure 166: tWPRE Method for Calculating Transitions and Endpoints

CK_t

VDD /2

CK_c

Single-ended signal provided as background information

DQS_t

VREFDQ

DQS_c

VREFDQ

DQS_t DQS_t
DQS_c
VREFDQ

DQS_c

Resulting differential signal relevant for t WPRE specification

VIH,DIFF,Peak
VIH,DIFF,DQS
VSW2
VSW1

DQS_t, DQS_c 0V
t WPRE begins ( t 1) t WPRE ends ( t 2)

Notes: 1. Vsw1 = (0.1) έ VIH,diff,DQS.

2. Vsw2 = (0.9) έ VIH,diff,DQS.

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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

t
WPST Calculation

Figure 167: tWPST Method for Calculating Transitions and Endpoints

CK_t

VDD /2

CK_c

Single-ended signal provided as background information

VREFDQ

DQS_t
DQS_c

VREFDQ

DQS_c

VREFDQ

DQS_t

Resulting differential signal relevant for t WPST specification

t WPST begins ( t 1)

0V
VSW2
VSW1
VIL,DIFF,DQS
DQS_t, DQS_c VIL,DIFF,Peak
t WPST ends ( t 2)

Notes: 1. Vsw1 =(0.9) έ VIL,diff,DQS.

2. Vsw2 = (0.1) έ VIL,diff,DQS.

7RITE 4IMING n $ATA 3TROBE TO $ATA 2ELATIONSHIP

The DQ input receiver uses a compliance mask (Rx) for voltage and timing as shown in the figure
below. The receiver mask (Rx mask) defines the area where the input signal must not encroach in order
for the DRAM input receiver to be able to successfully capture a valid input signal. The Rx mask is not
the valid data-eye. TdiVW and VdiVW define the absolute maximum Rx mask.

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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

Figure 168: Rx Compliance Mask

Rx Mask
VDIVW

VCENTDQ,midpoint

TdiVW

VCENTDQ,midpoint is defined as the midpoint between the largest VREFDQ voltage level and the smallest
VREFDQ voltage level across all DQ pins for a given DRAM. Each DQ pin's VREFDQ is defined by the
center (widest opening) of the cumulative data input eye as depicted in the following figure. This
means a DRAM's level variation is accounted for within the DRAM Rx mask. The DRAM VREFDQ level
will be set by the system to account for RON and ODT settings.

Figure 169: VCENT_DQ VREFDQ Voltage Variation

DQx DQy DQz

(smallest VREFDQ Level) (largest VREFDQ Level)

VCENTDQx VCENTDQz

VCENTDQ,midpoint
VCENTDQy

VREF variation
(component)

The following figure shows the Rx mask requirements both from a midpoint-to-midpoint reference
(left side) and from an edge-to-edge reference. The intent is not to add any new requirement or speci-
fication between the two but rather how to convert the relationship between the two methodologies.
The minimum data-eye shown in the composite view is not actually obtainable due to the minimum
pulse width requirement.

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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

Figure 170: Rx Mask DQ-to-DQS Timings

DQS, DQs Data-In at DRAM Ball DQS, DQs Data-In at DRAM Ball
Rx Mask Rx Mask – Alternative View
DQS_c DQS_c

DQS_t DQS_t
0.5 × TdiVW 0.5 × TdiVW 0.5 × TdiVW 0.5 × TdiVW

DRAMa DRAMa

VdiVW

VdiVW
DQx–z Rx Mask DQx–z Rx Mask

TdiVW TdiVW

tDQS2DQ +0.5 × TdiVW

tDQS2DQ

DRAMb DRAMb Rx Mask

VdiVW

VdiVW
DQy
Rx Mask DQy TdiVW

tDQ2DQ tDQ2DQ

DRAMb DRAMb Rx Mask

VdiVW

VdiVW
DQz
Rx Mask DQz TdiVW

tDQ2DQ

tDQS2DQ +0.5 × TdiVW

tDQS2DQ

DRAMc DRAMc Rx Mask

VdiVW

VdiVW
DQz
Rx Mask DQz TdiVW

tDQ2DQ tDQ2DQ

DRAMc DRAMc Rx Mask

VdiVW

VdiVW
DQy
Rx Mask DQy TdiVW

tDQ2DQ

Notes: 1. DQx represents an optimally centered mask.

DQy represents earliest valid mask.
DQz represents latest valid mask.
2. DRAMa represents a DRAM without any DQS/DQ skews.
DRAMb represents a DRAM with early skews (negative tDQS2DQ).
DRAMc represents a DRAM with delayed skews (positive tDQS2DQ).
3. This figure shows the skew allowed between DRAM-to-DRAM and between DQ-to-DQ for a DRAM. Signals assume
data is center-aligned at DRAM latch.
TdiPW is not shown; composite data-eyes shown would violate TdiPW.
VCENTDQ,midpoint is not shown but is assumed to be midpoint of VdiVW.

The previous figure shows the basic Rx mask requirements. Converting the Rx mask requirements to a
classical DQ-to-DQS relationship is shown in the following figure. It should become apparent that
DRAM write training is required to take full advantage of the Rx mask.

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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

Figure 171: Rx Mask DQ-to-DQS DRAM-Based Timings

DQS, DQs Data-In at DRAM Ball DQS, DQs Data-In at DRAM Ball
Rx Mask vs. Composite Data-Eye Rx Mask vs. UI Data-Eye

DQS_c DQS_c

DQS_t DQS_t
TdiPW tDSx tDHx

DRAMa Rx Mask DRAMa Rx Mask

VdiVW

VdiVW
DQx , y, z TdiVW DQx–z TdiVW

TdiPW TdiPW

tDSy tDHy

*Skew

DRAMb Rx Mask

VdiVW
tDQ2DQ
DQy TdiVW

DRAMb

VdiVW
tDQ2DQ Rx Mask
DQz TdiVW

TdiPW

tDSz tDHz

*Skew

DRAMc Rx Mask

VdiVW
tDQ2DQ
DQy TdiVW

DRAMc Rx Mask tDQ2DQ

VdiVW
DQz TdiVW

TdiPW

Notes: 1. DQx represents an optimally centered mask.

DQy represents earliest valid mask.
DQz represents latest valid mask.
2. *Skew = tDQS2DQ + 0.5 έ TdiVW
DRAMa represents a DRAM without any DQS/DQ skews.
DRAMb represents a DRAM with the earliest skews (negative tDQS2DQ, tDQSy > *Skew).
DRAMc represents a DRAM with the latest skews (positive tDQS2DQ, tDQHz > *Skew).
3. DS/tDH are traditional data-eye setup/hold edges at DC levels.
t
t
DS and tDH are not specified; tDH and tDS may be any value provided the pulse width and Rx mask limits are not
violated.
t
DH (MIN) > TdiVW + tDS (MIN) + tDQ2DQ.
The DDR4 SDRAM's input receivers are expected to capture the input data with an Rx mask of TdiVW
provided the minimum pulse width is satisfied. The DRAM controller will have to train the data input
buffer to utilize the Rx mask specifications to this maximum benefit. If the DRAM controller does not

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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

train the data input buffers, then the worst case limits have to be used for the Rx mask (TdiVW + 2 έ
t
DQS2DQ), which will generally be the classical minimum (tDS and tDH) and is required as well.

Figure 172: Example of Data Input Requirements Without Training

TdiVW + 2 × tDQS2DQ
VIH(DC)
0.5 × VdiVW
VdiVW

Rx Mask VCENTDQ,midpoint
0.5 × VdiVW
VIL(DC)

tDS tDH

0.5 × TdiVW + tDQS2DQ 0.5 × TdiVW + tDQS2DQ

DQS_c

DQS_t

WRITE Burst Operation

The following write timing diagrams are intended to help understand each write parameter's meaning
and are only examples. Each parameter will be defined in detail separately. In these write timing
diagrams, CK and DQS are shown aligned, and DQS and DQ are shown center-aligned for the purpose
of illustration.
DDR4 WRITE command supports bursts of BL8 (fixed), BC4 (fixed), and BL8/BC4 on-the-fly (OTF);
OTF uses address A12 to control OTF when OTF is enabled:
s A12 = 0, BC4 (BC4 = burst chop)
s A12 = 1, BL8

WRITE commands can issue precharge automatically with a WRITE with auto precharge (WRA)
command, which is enabled by A10 HIGH.
s WRITE command with A10 = 0 (WR) performs standard write, bank remains active after WRITE burst
s WRITE command with A10 = 1 (WRA) performs write with auto precharge, bank goes into precharge
after WRITE burst

The DATA MASK (DM) function is supported for the x8 and x16 configurations only (the DM function
is not supported on x4 devices). The DM function shares a common pin with the DBI_n and TDQS
functions. The DM function only applies to WRITE operations and cannot be enabled at the same time
the DBI function is enabled.
s If DM_n is sampled LOW on a given byte lane, the DRAM masks the write data received on the DQ
inputs.
s If DM_n is sampled HIGH on a given byte lane, the DRAM does not mask the data and writes this data
into the DRAM core.
s If CRC write is enabled, then DM enabled (via MRS) will be selected between write CRC nonper-
sistent mode (DM disabled) and write CRC persistent mode (DM enabled).

CCMTD-1725822587-9875
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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

Figure 173: WRITE Burst Operation, WL = 9 (AL = 0, CWL = 9, BL8)

T0 T1 T2 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16
CK_c
CK_t

Command WRITE DES DES DES DES DES DES DES DES DES DES DES DES

Bank Group BGa

Address

Address Bank
Col n
tWPST
tWPRE

DQS_t,
DQS_c

DQ DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7

WL = AL + CWL = 9

Time Break Transitioning Data Don’t Care

Notes: 1. BL8, WL = 0, AL = 0, CWL = 9, Preamble = 1tCK.

2. DI n = Data-in from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0.
5. CA parity = Disable, CS to CA Latency = Disable, Read DBI = Disable.

Figure 174: WRITE Burst Operation, WL = 19 (AL = 10, CWL = 9, BL8)

T0 T1 T2 T9 T10 T11 T17 T18 T19 T20 T21 T22 T23
CK_c
CK_t

Command WRITE DES DES DES DES DES DES DES DES DES DES DES DES

Bank Group BGa

Address

Address Bank
Col n
tWPRE tWPST

DQS_t,
DQS_c

DQ DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7
AL = 10 CWL = 9

WL = AL + CWL = 19

Time Break Transitioning Data Don’t Care

Notes: 1. BL8, WL = 19, AL = 10 (CL - 1), CWL = 9, Preamble = 1tCK.

2. DI n = data-in from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable.

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¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

WRITE Operation Followed by Another WRITE Operation

Figure 175: Consecutive WRITE (BL8) with 1tCK Preamble in Different Bank Group
T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19
CK_c
CK_t

Command WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

tCCD_S =4 4 Clocks tWTR

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tWPRE tWPST

DQS_t,
DQS_c
WL = AL + CWL = 9

DQ DI DI DI DI DI DI DI DI DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

WL = AL + CWL = 9

Time Break Transitioning Data Don’t Care

Notes: 1. BL8, AL = 0, CWL = 9, Preamble = 1tCK.

2. DI n (or b) = data-in from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T4.
5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Disable, Write CRC = Disable.
6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge
after the last write data shown at T17.

Figure 176: Consecutive WRITE (BL8) with 2tCK Preamble in Different Bank Group
T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19
CK_c
CK_t

Command WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

tCCD_S =4 4 Clocks tWTR

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tWPRE tWPST

DQS_t,
DQS_c
WL = AL + CWL = 10

DQ DI DI DI DI DI DI DI DI DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

WL = AL + CWL = 10

Time Break Transitioning Data Don’t Care

Notes: 1. BL8, AL = 0, CWL = 9 + 1 = 10 (see Note 7), Preamble = 2tCK.

2. DI n (or b) = data-in from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T4.
5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Disable, Write CRC = Disable.
6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge
after the last write data shown at T17.

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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

7. When operating in 2tCK WRITE preamble mode, CWL may need to be programmed to a value at least 1 clock
greater than the lowest CWL setting supported in the applicable tCK range, which means CWL = 9 is not allowed
when operating in 2tCK WRITE preamble mode.

Figure 177: Nonconsecutive WRITE (BL8) with 1tCK Preamble in Same or Different Bank Group
T0 T1 T2 T3 T4 T5 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19
CK_c
CK_t

Command WRITE DES DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES
tWR

tCCD_S/L =5 4 Clocks tWTR

Bank Group BGa BGa

Address or BGb

Address Bank Bank

Col n Col b
tWPRE tWPST

DQS_t,
DQS_c
WL = AL + CWL = 9

DQ DI DI DI DI DI DI DI DI DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

WL = AL + CWL = 9

Time Break Transitioning Data Don’t Care

Notes: 1. BL8, AL = 0, CWL = 9, Preamble = 1tCK, tCCD_S/L = 5tCK.

2. DI n (or b) = data-in from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T5.
5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Disable, Write CRC = Disable.
6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge
after the last write data shown at T18.

Figure 178: Nonconsecutive WRITE (BL8) with 2tCK Preamble in Same or Different Bank Group
T0 T1 T2 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20
CK_c
CK_t

Command WRITE DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

tCCD_S/L =6 4 Clocks tWTR

Bank Group BGa BGa

Address or BGb

Address Bank Bank

Col n Col b
tWPRE tWPRE tWPST

DQS_t,
DQS_c
WL = AL + CWL = 10

DQ DI DI DI DI DI DI DI DI DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

WL = AL + CWL = 10

Time Break Transitioning Data Don’t Care

Notes: 1. BL8, AL = 0, CWL = 9 + 1 = 10 (see Note 8), Preamble = 2tCK, tCCD_S/L = 6tCK.
2. DI n (or b) = data-in from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T6.
5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Disable, Write CRC = Disable.
6. t##$?3,   ISNT ALLOWED IN tCK preamble mode.

CCMTD-1725822587-9875
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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

7. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge
after the last write data shown at T20.
8. When operating in 2tCK WRITE preamble mode, CWL may need to be programmed to a value at least 1 clock
greater than the lowest CWL setting supported in the applicable tCK range, which means CWL = 9 is not allowed
when operating in 2tCK WRITE preamble mode.

Figure 179: WRITE (BC4) OTF to WRITE (BC4) OTF with 1tCK Preamble in Different Bank Group
T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19
CK_c
CK_t

Command WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

tCCD_S =4 4 Clocks tWTR

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tWPRE tWPST tWPRE tWPST

DQS_t,
DQS_c
WL = AL + CWL = 9

DQ DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 b b+1 b+2 b+3

WL = AL + CWL = 9

Time Break Transitioning Data Don’t Care

Notes: 1. BC4, AL = 0, CWL = 9, Preamble = 1tCK.

2. DI n (or b) = data-in from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T0 and T4.
5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Disable, Write CRC = Disable.
6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge
after the last write data shown at T17.

Figure 180: WRITE (BC4) OTF to WRITE (BC4) OTF with 2tCK Preamble in Different Bank Group
T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19
CK_c
CK_t

Command WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

tCCD_S =4 4 Clocks tWTR

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tWPRE tWPRE tWPST

DQS_t,
DQS_c
WL = AL + CWL = 10

DQ DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 b b+1 b+2 b+3

WL = AL + CWL = 10

Time Break Transitioning Data Don’t Care

Notes: 1. BC4, AL = 0, CWL = 9 + 1 = 10 (see Note 7), Preamble = 2tCK.

2. DI n (or b) = data-in from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T4.
5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Disable, Write CRC = Disable.
CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
229 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge
after the last write data shown at T18.
7. When operating in 2tCK WRITE preamble mode, CWL may need to be programmed to a value at least 1 clock
greater than the lowest CWL setting supported in the applicable tCK range, which means CWL = 9 is not allowed
when operating in 2tCK WRITE preamble mode.

Figure 181: WRITE (BC4) Fixed to WRITE (BC4) Fixed with 1tCK Preamble in Different Bank Group
T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19
CK_c
CK_t

Command WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

tCCD_S =4 2 Clocks tWTR

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tWPRE tWPST tWPRE tWPST

DQS_t,
DQS_c
WL = AL + CWL = 9

DQ DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 b b+1 b+2 b+3

WL = AL + CWL = 9

Time Break Transitioning Data Don’t Care

Notes: 1. BC4, AL = 0, CWL = 9, Preamble = 1tCK.

2. DI n (or b) = data-in from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 (fixed) setting activated by MR0[1:0] = 10.
5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Disable, Write CRC = Disable.
6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge
after the last write data shown at T15.

Figure 182: WRITE (BL8) to WRITE (BC4) OTF with 1tCK Preamble in Different Bank Group
T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19
CK_c
CK_t

Command WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES
t
WR
t
CCD_S = 4 4 Clocks t
WTR

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
t
t
WPRE WPST

DQS_t,
DQS_c
WL = AL + CWL = 9

DQ DI DI DI DI DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3

WL = AL + CWL = 9

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8/BC = 4, AL = 0, CL = 9, Preamble = 1tCK.

2. DI n (or b) = data-in from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during WRITE command at T0.
BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE command at T4.
CCMTD-1725822587-9875
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230 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write CRC = Disable.
6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge
after the last write data shown at T17.

Figure 183: WRITE (BC4) OTF to WRITE (BL8) with 1tCK Preamble in Different Bank Group
T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19
CK_c
CK_t

Command WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

tCCD_S =4 4 Clocks tWTR

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tWPRE tWPST tWPRE tWPST

DQS_t,
DQS_c
WL = AL + CWL = 9

DQ DI DI DI DI DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

WL = AL + CWL = 9

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8/BC = 4, AL = 0, CL = 9, Preamble = 1tCK.

2. DI n (or b) = data-in from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE command at T0.
BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during WRITE command at T4.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write CRC = Disable.
6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge
after the last write data shown at T17.

WRITE Operation Followed by READ Operation

Figure 184: WRITE (BL8) to READ (BL8) with 1tCK Preamble in Different Bank Group
T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T24 T25 T26 T27 T28 T29
CK_c
CK_t

Command WRITE DES DES DES DES DES DES DES DES DES READ DES DES DES DES DES DES DES

4 Clocks tWTR_S =2

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tWPRE tWPST tRPRE

DQS_t,
DQS_c
WL = AL + CWL = 9 RL = AL + CL = 11

DQ DI DI DI DI DI DI DI DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, WL = 9 (CWL = 9, AL = 0), CL = 11, READ preamble = 1tCK, WRITE preamble = 1tCK.
2. DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0 and READ
command at T15.

CCMTD-1725822587-9875
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¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.
6. The write timing parameter (tWTR_S) is referenced from the first rising clock edge after the last write data shown
at T13.

Figure 185: WRITE (BL8) to READ (BL8) with 1tCK Preamble in Same Bank Group
T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T26 T27 T28 T29
CK_c
CK_t

Command WRITE DES DES DES DES DES DES DES DES DES DES DES READ DES DES DES DES DES

4 Clocks tWTR_L =4

Bank Group BGa BGa

Address

Address Bank Bank

Col n Col b
tWPRE tWPST tRPRE

DQS_t,
DQS_c
WL = AL + CWL = 9 RL = AL + CL = 11

DQ DI DI DI DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, WL = 9 (CWL = 9, AL = 0), CL = 11, READ preamble = 1tCK, WRITE preamble = 1tCK.
2. DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0 and READ
command at T17.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.
6. The write timing parameter (tWTR_L) is referenced from the first rising clock edge after the last write data shown
at T13.

Figure 186: WRITE (BC4) OTF to READ (BC4) OTF with 1tCK Preamble in Different Bank Group
T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T24 T25 T26 T27 T28 T29
CK_c
CK_t

Command WRITE DES DES DES DES DES DES DES DES DES READ DES DES DES DES DES DES DES

4 Clocks tWTR_S =2

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tWPRE tWPST tRPRE tRPST

DQS_t,
DQS_c
WL = AL + CWL = 9 RL = AL + CL = 11

DQ DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 b b+1 b+2 b+3

Time Break Transitioning Data Don’t Care

Notes: 1. BC = 4, WL = 9 (CWL = 9, AL = 0), CL = 11, READ preamble = 1tCK, WRITE preamble = 1tCK.
2. DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE command at T0 and READ command at T15.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.
6. The write timing parameter (tWTR_S) is referenced from the first rising clock edge after the last write data shown
at T13.

CCMTD-1725822587-9875
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232 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

Figure 187: WRITE (BC4) OTF to READ (BC4) OTF with 1tCK Preamble in Same Bank Group
T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T26 T27 T28 T29
CK_c
CK_t

Command WRITE DES DES DES DES DES DES DES DES DES DES DES READ DES DES DES DES DES

4 Clocks tWTR_L =4

Bank Group BGa BGa

Address

Address Bank Bank

Col n Col b
tWPRE tWPST tRPRE

DQS_t,
DQS_c
WL = AL + CWL = 9 RL = AL + CL = 11

DQ DI DI DI DI DI DI DI
n n+1 n+2 n+3 b b+1 b+2

Time Break Transitioning Data Don’t Care

Notes: 1. BC = 4, WL = 9 (CWL = 9, AL = 0), CL = 11, READ preamble = 1tCK, WRITE preamble = 1tCK.
2. DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE command at T0 and READ command at T17.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.
6. The write timing parameter (tWTR_L) is referenced from the first rising clock edge after the last write data shown
at T13.

Figure 188: WRITE (BC4) Fixed to READ (BC4) Fixed with 1 tCK Preamble in Different Bank Group
T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T22 T23 T24 T25 T26 T27 T28 T29
CK_c
CK_t

Command WRITE DES DES DES DES DES DES DES DES DES DES DES READ DES DES DES DES DES

2 Clocks tWTR_S =2

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b
tWPRE tWPST tRPRE tRPST

DQS_t,
DQS_c
WL = AL + CWL = 9 RL = AL + CL = 11

DQ DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 b b+1 b+2 b+3

Time Break Transitioning Data Don’t Care

Notes: 1. BC = 4, WL = 9 (CWL = 9, AL = 0), CL = 11, READ preamble = 1 tCK, WRITE preamble = 1tCK.
2. DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 10.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.
6. The write timing parameter (tWTR_S) is referenced from the first rising clock edge after the last write data shown
at T11.

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
233 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

Figure 189: WRITE (BC4) Fixed to READ (BC4) Fixed with 1tCK Preamble in Same Bank Group
T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T24 T25 T26 T27 T28 T29
CK_c
CK_t

Command WRITE DES DES DES DES DES DES DES DES DES READ DES DES DES DES DES DES DES

2 Clocks tWTR_L =4

Bank Group BGa BGa

Address

Address Bank Bank

Col n Col b
tWPRE tWPST tRPRE tRPST

DQS_t,
DQS_c
WL = AL + CWL = 9 RL = AL + CL = 11

DQ DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 b b+1 b+2 b+3

Time Break Transitioning Data Don’t Care

Notes: 1. BC = 4, WL = 9 (CWL = 9, AL = 0), C L = 11, READ preamble = 1tCK, WRITE preamble = 1tCK.
2. DI b = data-in from column b.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 10.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable.
6. The write timing parameter (tWTR_L) is referenced from the first rising clock edge after the last write data shown
at T11.

WRITE Operation Followed by PRECHARGE Operation

The minimum external WRITE command to PRECHARGE command spacing is equal to WL (AL +
CWL) plus either 4tCK (BL8/BC4-OTF) or 2tCK (BC4-fixed) plus tWR. The minimum ACT to PRE timing,
t
RAS, must be satisfied as well.

Figure 190: WRITE (BL8/BC4-OTF) to PRECHARGE with 1tCK Preamble

T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T22 T23 T24 T25 T26
CK_c
CK_t

Command WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES PRE DES

WL = AL + CWL = 9 4 Clocks tWR = 12 tRP

BGa, Bank b BGa, Bank b

Col n (or all)
Address

BC4 (OTF) Opertaion

DQS_t,
DQS_c

DQ DI DI DI DI
n n+1 n+2 n+3

BL8 Opertaion
DQS_t,
DQS_c

DQ DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8 with BC4-OTF, WL = 9 (CWL = 9, AL = 0 ), Preamble = 1tCK, tWR = 12.

2. DI n = data-in from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE command at T0. BL8 setting activated by
MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0.

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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, CRC = Disable.

6. The write recovery time (tWR) is referenced from the first rising clock edge after the last write data shown at T13.
t
WR specifies the last burst WRITE cycle until the PRECHARGE command can be issued to the same bank.

Figure 191: WRITE (BC4-Fixed) to PRECHARGE with 1tCK Preamble

T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T22 T23 T24 T25 T26
CK_c
CK_t

Command WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES PRE DES DES DES

WL = AL + CWL = 9 2 Clocks tWR = 12 tRP

BGa, Bank b BGa, Bank b

Col n (or all)
Address

BC4 (Fixed) Opertaion

DQS_t,
DQS_c

DQ DI DI DI DI
n n+1 n+2 n+3

Time Break Transitioning Data Don’t Care

Notes: 1. BC4 = fixed, WL = 9 (CWL = 9, AL = 0 ), Preamble = 1tCK, tWR = 12.

2. DI n = data-in from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 10.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, CRC = Disable.
6. The write recovery time ( tWR) is referenced from the first rising clock edge after the last write data shown at T11.
t
WR specifies the last burst WRITE cycle until the PRECHARGE command can be issued to the same bank.

Figure 192: WRITE (BL8/BC4-OTF) to Auto PRECHARGE with 1tCK Preamble

T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T22 T23 T24 T25 T26
CK_c
CK_t

Command WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES

WL = AL + CWL = 9 4 Clocks tWR = 12 tRP

BGa, Bank b
Col n
Address

BC4 (OTF) Opertaion

DQS_t,
DQS_c

DQ DI DI DI DI
n n+1 n+2 n+3

BL8 Opertaion
DQS_t,
DQS_c

DQ DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8 with BC4-OTF, WL = 9 (CWL = 9, AL = 0 ), Preamble = 1tCK, tWR = 12.

2. DI n = data-in from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE command at T0.
BL8 setting activated by MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, CRC = Disable.
6. The write recovery time ( tWR) is referenced from the first rising clock edge after the last write data shown at T13.
tWR specifies the last burst WRITE cycle until the PRECHARGE command can be issued to the same bank.

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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

Figure 193: WRITE (BC4-Fixed) to Auto PRECHARGE with 1tCK Preamble

T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T22 T23 T24 T25 T26
CK_c
CK_t

Command WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES

WL = AL + CWL = 9 2 Clocks tWR = 12 tRP

BGa, Bank b
Col n
Address

BC4 (Fixed) Opertaion

DQS_t,
DQS_c

DQ DI DI DI DI
n n+1 n+2 n+3

Time Break Transitioning Data Don’t Care

Notes: 1. BC4 = fixed, WL = 9 (CWL = 9, AL = 0 ), Preamble = 1tCK, tWR = 12.

2. DI n = data-in from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 10.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, CRC = Disable.
6. The write recovery time (tWR) is referenced from the first rising clock edge after the last write data shown at T11.
t
WR specifies the last burst WRITE cycle until the PRECHARGE command can be issued to the same bank.

WRITE Operation with WRITE DBI Enabled

Figure 194: WRITE (BL8/BC4-OTF) with 1tCK Preamble and DBI

T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17
CK_c
CK_t

Command WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES

WL = AL + CWL = 9 4 Clocks tWR

tWTR

Address BGa

Address Bank,
Col n

BC4 (OTF) Opertaion

DQS_t,
DQS_c

DQ DI DI DI DI
n n+1 n+2 n+3

DBI_n DI DI DI DI
n n+1 n+2 n+3

BL8 Opertaion
DQS_t,
DQS_c

DQ DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7

DBI_n DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7

Transitioning Data Don’t Care

Notes: 1. BL = 8 with BC4-OTF, WL = 9 (CWL = 9, AL = 0 ), Preamble = 1tCK.

2. DI n = data-in from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE command at T0.
BL8 setting activated by MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0.
5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Enabled, Write CRC = Disabled.

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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

6. The write recovery time (tWR_DBI) is referenced from the first rising clock edge after the last write data shown at
T13.

Figure 195: WRITE (BC4-Fixed) with 1tCK Preamble and DBI

T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17
CK_c
CK_t

Command WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES

WL = AL + CWL = 9 2 Clocks tWR

tWTR

Address BGa

Address Bank,
Col n

BC4 (Fixed) Opertaion

DQS_t,
DQS_c

DQ DI DI DI DI
n n+1 n+2 n+3

DBI_n DI DI DI DI
n n+1 n+2 n+3

Transitioning Data Don’t Care

Notes: 1. BC4 = fixed, WL = 9 (CWL = 9, AL = 0 ), Preamble = 1tCK.

2. DI n = data-in from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 10.
5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Enabled, Write CRC = Disabled.

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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

WRITE Operation with CA Parity Enabled

Figure 196: Consecutive Write (BL8) with 1tCK Preamble and CA Parity in Different Bank Group
T0 T1 T2 T3 T4 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 T22 T23
CK_c
CK_t

Command WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

tCCD_S =4 4 Clocks tWTR

Bank Group BGa BGb

Address

Address Bank Bank

Col n Col b

Parity Valid Valid

tWPRE tWPST

DQS_t,
DQS_c
WL = PL + AL + CWL = 13

DQ DI DI DI DI DI DI DI DI DI DI DI DI DI DI DI DI
n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7

WL = PL + AL + CWL = 13

Time Break Transitioning Data Don’t Care

Notes: 1. BL = 8, WL = 9 (CWL = 13, AL = 0 ), Preamble = 1tCK.

2. DI n = data-in from column n.
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T4.
5. CA parity = Enable, CS to CA latency = Disable, Write DBI = Enabled, Write CRC = Disable.
6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge
after the last write data shown at T21.

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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

WRITE Operation with Write CRC Enabled

Figure 197: Consecutive WRITE (BL8/BC4-OTF) with 1tCK Preamble and Write CRC in Same or
Different Bank Group
T0 T1 T2 T3 T4 T5 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19
CK_c
CK_t

Command WRITE DES DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES
tWR

tCCD_S/L =5 4 Clocks tWTR

Bank Group BGa BGa or

Address BGb

Address Bank Bank

Col n Col b
tWPRE tWPST

DQS_t,
DQS_c
WL = AL + CWL = 9

DQ x4, DI DI DI DI DI DI DI DI CRC CRC DI DI DI DI DI DI DI DI CRC CRC

n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7
BL = 8
WL = AL + CWL = 9

DQ x8/X16, DI DI DI DI DI DI DI DI CRC DI DI DI DI DI DI DI DI CRC

n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7
BL = 8

DQ x4, DI DI DI DI DI DI DI DI
BC = 4 (OTF) n n+1 n+2 n+3 CRC CRC b b+1 b+2 b+3 CRC CRC

DQ x8/X16,
DI DI DI DI CRC DI DI DI DI CRC
BC = 4 (OTF) n n+1 n+2 n+3 b b+1 b+2 b+3

Time Break Transitioning Data Don’t Care

Notes: 1. BL8/BC4-OTF, AL = 0, CWL = 9, Preamble = 1tCK, tCCD_S/L = 5tCK.

2. DI n (or b) = data-in from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T5.
5. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T0 and T5.
6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write CRC = Enable.
7. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge
after the last write data shown at T18.

Figure 198: Consecutive WRITE (BC4-Fixed) with 1tCK Preamble and Write CRC in Same or Different
Bank Group
T0 T1 T2 T3 T4 T5 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19
CK_c
CK_t

Command WRITE DES DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES
tWR

tCCD_S/L =5 2 Clocks tWTR

Bank Group BGa BGa or

Address BGb

Address Bank Bank

Col n Col b
tWPRE tWPST

DQS_t,
DQS_c
WL = AL + CWL = 9

DQ x4, DI DI DI DI DI DI DI DI
BC = 4 (Fixed) n n+1 n+2 n+3 CRC CRC b b+1 b+2 b+3 CRC CRC

WL = AL + CWL = 9

DQ x8/X16,
DI DI DI DI CRC DI DI DI DI CRC
BC = 4 (Fixed) n n+1 n+2 n+3 b b+1 b+2 b+3

Time Break Transitioning Data Don’t Care

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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

Notes: 1. BC4-fixed, AL = 0, CWL = 9, Preamble = 1tCK, tCCD_S/L = 5tCK.

2. DI n (or b) = data-in from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BC4 setting activated by MR0[1:0] = 10 during WRITE commands at T0 and T5.
5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write CRC = Enable, DM = Disable.
6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge
after the last write data shown at T16.

Figure 199: Nonconsecutive WRITE (BL8/BC4-OTF) with 1tCK Preamble and Write CRC in Same or
Different Bank Group
T0 T1 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20
CK_c
CK_t

Command WRITE DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES
t WR

t CCD_S/L =6 4 Clocks t WTR

Bank Group BGa BGa or

Address BGb

Address Bank Bank

Col n Col b
t WPRE t WPST

DQS_t,
DQS_c
WL = AL + CWL = 9

DQ x4, DI DI DI DI DI DI DI DI CRC CRC DI DI DI DI DI DI DI DI CRC CRC

n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7
BL = 8
WL = AL + CWL = 9

DQ x8/X16, DI DI DI DI DI DI DI DI CRC DI DI DI DI DI DI DI DI CRC

n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7
BL = 8

DQ x4, DI DI DI DI DI DI DI DI
BC = 4 (OTF) n n+1 n+2 n+3 CRC CRC b b+1 b+2 b+3 CRC CRC

DQ x8/X16,
DI DI DI DI CRC DI DI DI DI CRC
BC = 4 (OTF) n n+1 n+2 n+3 b b+1 b+2 b+3

Time Break Transitioning Data Don’t Care

Notes: 1. BL8/BC4-OTF, AL = 0, CWL = 9, Preamble = 1tCK, tCCD_S/L = 6tCK.

2. DI n (or b) = data-in from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T6.
5. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T0 and T6.
6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write CRC = Enable, DM = Disable.
7. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge
after the last write data shown at T19.

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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

Figure 200: Nonconsecutive WRITE (BL8/BC4-OTF) with 2tCK Preamble and Write CRC in Same or
Different Bank Group
T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 T22
CK_c
CK_t

Command WRITE DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR

tCCD_S/L =7 4 Clocks tWTR

Bank Group BGa BGa or

Address BGb

Address Bank Bank

Col n Col b
tWPRE tWPRE tWPST

DQS_t,
DQS_c
WL = AL + CWL = 10

DQ x4, DI DI DI DI DI DI DI DI CRC CRC DI DI DI DI DI DI DI DI CRC CRC

n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7
BL = 8
WL = AL + CWL = 10

DQ x8/X16, DI DI DI DI DI DI DI DI CRC DI DI DI DI DI DI DI DI CRC

n n+1 n+2 n+3 n+4 n+5 n+6 n+7 b b+1 b+2 b+3 b+4 b+5 b+6 b+7
BL = 8

DQ x4, DI DI DI DI DI DI DI DI
BC = 4 (OTF) n n+1 n+2 n+3 CRC CRC b b+1 b+2 b+3 CRC CRC

DQ x8/X16,
DI DI DI DI CRC DI DI DI DI CRC
BC = 4 (OTF) n n+1 n+2 n+3 b b+1 b+2 b+3

Time Break Transitioning Data Don’t Care

Notes: 1. BL8/BC4-OTF, AL = 0, CWL = 9 + 1 = 10 (see Note 9), Preamble = 2tCK, tCCD_S/L = 7tCK (see Note 7).
2. DI n (or b) = data-in from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T7.
5. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T0 and T7.
6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write CRC = Enable, DM = Disable.
7. tCCD_S/L = 6tCK is not allowed in 2tCK preamble mode if minimum tCCD_S/L allowed in 1tCK preamble mode would

have been 6 clocks.

8. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge
after the last write data shown at T21.
9. When operating in 2tCK WRITE preamble mode, CWL may need to be programmed to a value at least 1 clock
greater than the lowest CWL setting supported in the applicable tCK range. That means CWL = 9 is not allowed
when operating in 2tCK WRITE preamble mode.

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 8Gb: x4, x8, x16 DDR4 SDRAM
WRITE Operation

Figure 201: WRITE (BL8/BC4-OTF/Fixed) with 1tCK Preamble and Write CRC in Same or Different Bank
Group
T0 T1 T2 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20
CK_c
CK_t

Command WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES
tWR_CRC_DM

4 Clocks tWTR_S_CRC_DM/tWTR_L_CRC_DM

Bank Group BGa

Address

Address Bank
Col n
tWPRE tWPST

DQS_t,
DQS_c
WL = AL + CWL = 9

DQ x4, DI DI DI DI DI DI DI DI CRC CRC

n n+1 n+2 n+3 n+4 n+5 n+6 n+7
BL = 8

DQ x8/X16, DI DI DI DI DI DI DI DI CRC
n n+1 n+2 n+3 n+4 n+5 n+6 n+7
BL = 8

DMx4/x8/x16 DM DM DM DM DM DM DM DM
n n+1 n+2 n+3 n+4 n+5 n+6 n+7
BL = 8

DQ x4, DI DI DI DI
BC = 4 (OTF/Fixed) n n+1 n+2 n+3 CRC CRC

DQ x8/X16,
DI DI DI DI CRC
BC = 4 (OTF/Fixed) n n+1 n+2 n+3

DM x4/x8/x16
DM DM DM DM
BC = 4 (OTF / Fixed) n n+1 n+2 n+3

Time Break Transitioning Data Don’t Care

Notes: 1. BL8/BC4, AL = 0, CWL = 9, Preamble = 1tCK.

2. DI n (or b) = data-in from column n (or column b).
3. DES commands are shown for ease of illustration; other commands may be valid at these times.
4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0.
5. BC4 setting activated by either MR0[1:0] = 10 or MR0[1:0] = 01 and A12 = 0 during WRITE command at T0.
6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write CRC = Enable, DM = Enable.
7. The write recovery time ( tWR_CRC_DM) and write timing parameter (tWTR_S_CRC_DM/tWTR_L_CRC_DM) are
referenced from the first rising clock edge after the last write data shown at T13.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Write Timing Violations

Write Timing Violations

Motivation
Generally, if timing parameters are violated, a complete reset/initialization procedure has to be initi-
ated to make sure that the device works properly. However, for certain minor violations, it is desirable
that the device is guaranteed not to "hang up" and that errors are limited to that specific operation. A
minor violation does not include a major timing violation (for example, when a DQS strobe misses in
the tDQSCK window).
For the following, it will be assumed that there are no timing violations with regard to the WRITE
command itself (including ODT, and so on) and that it does satisfy all timing requirements not
mentioned below.

Data Setup and Hold Violations

If the data-to-strobe timing requirements (tDS, tDH) are violated, for any of the strobe edges associated
with a WRITE burst, then wrong data might be written to the memory location addressed with this
WRITE command.
In the example, the relevant strobe edges for WRITE Burst A are associated with the clock edges: T5,
T5.5, T6, T6.5, T7, T7.5, T8, and T8.5.
Subsequent reads from that location might result in unpredictable read data; however, the device will
work properly otherwise.

Strobe-to-Strobe and Strobe-to-Clock Violations

If the strobe timing requirements (tDQSH, tDQSL, tWPRE, tWPST) or the strobe to clock timing require-
ments (tDSS, tDSH, tDQSS) are violated, for any of the strobe edges associated with a WRITE burst, then
wrong data might be written to the memory location addressed with the offending WRITE command.
Subsequent reads from that location might result in unpredictable read data; however, the device will
work properly otherwise with the following constraints:
s Both write CRC and data burst OTF are disabled; timing specifications other than tDQSH, tDQSL,
t
WPRE, tWPST, tDSS, tDSH, tDQSS are not violated.
s The offending write strobe (and preamble) arrive no earlier or later than six DQS transition edges
from the WRITE latency position.
s A READ command following an offending WRITE command from any open bank is allowed.
s One or more subsequent WR or a subsequent WRA (to same bank as offending WR) may be issued
tCCD_L later, but incorrect data could be written. Subsequent WR and WRA can be either offending
or non-offending writes. Reads from these writes may provide incorrect data.
s One or more subsequent WR or a subsequent WRA (to a different bank group) may be issued tCCD_S
later, but incorrect data could be written. Subsequent WR and WRA can be either offending or
non-offending writes. Reads from these writes may provide incorrect data.
s After one or more precharge commands (PRE or PREA) are issued to the device after an offending
WRITE command and all banks are in precharged state (idle state), a subsequent, non-offending WR
or WRA to any open bank will be able to write correct data.

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 8Gb: x4, x8, x16 DDR4 SDRAM
ZQ CALIBRATION Commands

ZQ CALIBRATION Commands
A ZQ CALIBRATION command is used to calibrate DRAM RON and ODT values. The device needs a
longer time to calibrate the output driver and on-die termination circuits at initialization and a rela-
tively smaller time to perform periodic calibrations.
The ZQCL command is used to perform the initial calibration during the power-up initialization
sequence. This command may be issued at any time by the controller depending on the system envi-
ronment. The ZQCL command triggers the calibration engine inside the DRAM and, after calibration
is achieved, the calibrated values are transferred from the calibration engine to DRAM I/O, which is
reflected as an updated output driver and ODT values.

The first ZQCL command issued after reset is allowed a timing period of tZQinit to perform the full cali-
bration and the transfer of values. All other ZQCL commands except the first ZQCL command issued
after reset are allowed a timing period of tZQoper.
The ZQCS command is used to perform periodic calibrations to account for voltage and temperature
variations. A shorter timing window is provided to perform the calibration and transfer of values as
defined by timing parameter tZQCS. One ZQCS command can effectively correct a minimum of 0.5%
(ZQ correction) of RON and RTT impedance error within 64 nCK for all speed bins assuming the
maximum sensitivities specified in the Output Driver and ODT Voltage and Temperature Sensitivity
tables. The appropriate interval between ZQCS commands can be determined from these tables and
other application-specific parameters. One method for calculating the interval between ZQCS
commands, given the temperature (Tdrift_rate) and voltage (Vdrift_rate) drift rates that the device is
subjected to in the application, is illustrated. The interval could be defined by the following formula:
ZQcorrection
(Tsense x Tdrift_rate) + (Vsense x Tdrift_rate)
Where Tsense = MAX(dRTTdT, dRONdTM) and Vsense = MAX(dRTTdV, dRONdVM) define the tempera-
ture and voltage sensitivities.
For example, if Tsens = 1.5%/ιC, Vsens = 0.15%/mV, Tdriftrate = 1 ιC/sec and Vdriftrate = 15 mV/sec, then
the interval between ZQCS commands is calculated as:
0.5
= 0.133 §128ms
(1.5 × 1) + (0.15 × 15)
No other activities should be performed on the DRAM channel by the controller for the duration of
t
ZQinit, tZQoper, or tZQCS. The quiet time on the DRAM channel allows accurate calibration of output
driver and on-die termination values. After DRAM calibration is achieved, the device should disable
the ZQ current consumption path to reduce power.

All banks must be precharged andtRP met before ZQCL or ZQCS commands are issued by the
controller.
ZQ CALIBRATION commands can also be issued in parallel to DLL lock time when coming out of self
refresh. Upon self refresh exit, the device will not perform an I/O calibration without an explicit ZQ
CALIBRATION command. The earliest possible time for a ZQ CALIBRATION command (short or long)
after self refresh exit is tXS, tXS_Abort, or tXS_FAST depending on operation mode.
In systems that share the ZQ resistor between devices, the controller must not allow any overlap of
t
ZQoper, tZQinit, or tZQCS between the devices.

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 8Gb: x4, x8, x16 DDR4 SDRAM
ZQ CALIBRATION Commands

Figure 202: ZQ Calibration Timing

T0 T1 Ta0 Ta1 Ta2 Ta3 Tb0 Tb1 Tc0 Tc1 Tc2
CK_c
CK_t

Command ZQCL DES DES DES Valid Valid ZQCS DES DES DES Valid

Address Valid Valid Valid

A10 Valid Valid Valid

CKE Valid Valid Valid

Note 1

Note 2
ODT Valid Valid Valid

DQ Bus High-Z or RTT(Park) Activities High-Z or RTT(Park) Activities

Note 3

tZQinit_tZQoper tZQCS

Time Break Don’t Care

Notes: 1. CKE must be continuously registered HIGH during the calibration procedure.
2. During ZQ calibration, the ODT signal must be held LOW and DRAM continues to provide RTT_PARK.
3. All devices connected to the DQ bus should be High-Z during the calibration procedure.

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 8Gb: x4, x8, x16 DDR4 SDRAM
On-Die Termination

On-Die Termination
The on-die termination (ODT) feature enables the device to change termination resistance for each
DQ, DQS, and DM_n/DBI_n signal for x4 and x8 configurations (and TDQS for the x8 configuration
when enabled via A11 = 1 in MR1) via the ODT control pin, WRITE command, or default parking value
with MR setting. For the x16 configuration, ODT is applied to each UDQ, LDQ, UDQS, LDQS,
UDM_n/UDBI_n, and LDM_n/LDBI_n signal. The ODT feature is designed to improve the signal
integrity of the memory channel by allowing the DRAM controller to independently change termina-
tion resistance for any or all DRAM devices. If DBI read mode is enabled while the DRAM is in standby,
either DM mode or DBI write mode must also be enabled if RTT(NOM) or RTT(Park) is desired. More
details about ODT control modes and ODT timing modes can be found further along in this document.
The ODT feature is turned off and not supported in self refresh mode.

Figure 203: Functional Representation of ODT

ODT VDDQ
To other
circuitry RTT
such as
RCV, Switch
... DQ, DQS, DM, TDQS

The switch is enabled by the internal ODT control logic, which uses the external ODT pin and other
control information. The value of RTT is determined by the settings of mode register bits (see Mode
Register). The ODT pin will be ignored if the mode register MR1 is programmed to disable RTT(NOM)
[MR1[10,9,8] = 0,0,0] and in self refresh mode.

ODT Mode Register and ODT State Table

The ODT mode of the DDR4 device has four states: data termination disable, RTT(NOM), RTT(WR), and
RTT(Park). The ODT mode is enabled if any of MR1[10:8] (RTT(NOM)), MR2[11:9] (RTT(WR)), or MR5[8:6]
(RTT(Park)) are non-zero. When enabled, the value of RTT is determined by the settings of these bits.
RTT control of each RTT condition is possible with a WR or RD command and ODT pin.
s RTT(WR): The DRAM (rank) that is being written to provide termination regardless of ODT pin status
(either HIGH or LOW).
s RTT(NOM): DRAM turns ON RTT(NOM) if it sees ODT asserted HIGH (except when ODT is disabled by
MR1).
s RTT(Park): Default parked value set via MR5 to be enabled and RTT(NOM) is not turned on.
s The Termination State Table that follows shows various interactions.

The RTT values have the following priority:

s Data termination disable
s RTT(WR)
s RTT(NOM)
s RTT(Park)

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 8Gb: x4, x8, x16 DDR4 SDRAM
ODT Mode Register and ODT State Table

Table 72: Termination State Table

ODT
1
Case RTT(Park) RTT(NOM) RTT(WR)2 ODT Pin ODT READS 3
Standby7 ODT WRITES
A4 Disabled Disabled Disabled Don't Care Off (High-Z) Off (High-Z) Off (High-Z)
Enabled Don't Care Off (High-Z) Off (High-Z) RTT(WR)

B5 Enabled Disabled Disabled Don't Care Off (High-Z) RTT(Park) RTT(Park)

Enabled Don't Care Off (High-Z) RTT(Park) RTT(WR)

C6 Disabled Enabled Disabled Low Off (High-Z) Off (High-Z) Off (High-Z)
High Off (High-Z) RTT(NOM) RTT(NOM)
Enabled Low Off (High-Z) Off (High-Z) RTT(WR)
High Off (High-Z) RTT(NOM) RTT(WR)

D6 Enabled Enabled Disabled Low Off (High-Z) RTT(Park) RTT(Park)

High Off (High-Z) RTT(NOM) RTT(NOM)
Enabled Low Off (High-Z) RTT(Park) RTT(WR)
High Off (High-Z) RTT(NOM) RTT(WR)

Notes: 1. If RTT(NOM) MR is disabled, power to the ODT receiver will be turned off to save power.
2. If RTT(WR) is enabled, RTT(WR) will be activated by a WRITE command for a defined period time independent of the
ODT pin and MR setting of RTT(Park)/RTT(NOM). This is described in the Dynamic ODT section.
3. When a READ command is executed, the DRAM termination state will be High-Z for a defined period independent
of the ODT pin and MR setting of RTT(Park)/RTT(NOM). This is described in the ODT During Read section.
4. Case A is generally best for single-rank memories.
5. Case B is generally best for dual-rank, single-slotted memories.
6. Case C and Case D are generally best for multi-slotted memories.
7. The ODT feature is turned off and not supported in self refresh mode.

ODT Read Disable State Table

Upon receiving a READ command, the DRAM driving data disables ODT after RL - (2 or 3) clock cycles,
where 2 = 1tCK preamble mode and 3 = 2tCK preamble mode. ODT stays off for a duration of BL/2 + (2
or 3) + (0 or 1) clock cycles, where 2 = 1tCK preamble mode, 3 = 2tCK preamble mode, 0 = CRC disabled,
and 1 = CRC enabled.

Table 73: Read Termination Disable Window

Start ODT Disable After
Preamble CRC Read Duration of ODT Disable
1t CK Disabled RL - 2 BL/2 + 2
Enabled RL - 2 BL/2 + 3

2tCK Disabled RL - 3 BL/2 + 3

Enabled RL - 3 BL/2 + 4

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 8Gb: x4, x8, x16 DDR4 SDRAM
Synchronous ODT Mode

Synchronous ODT Mode

Synchronous ODT mode is selected whenever the DLL is turned on and locked. Based on the
power-down definition, these modes include the following:
s Any bank active with CKE HIGH
s Refresh with CKE HIGH
s Idle mode with CKE HIGH
s Active power-down mode
s Precharge power-down mode

In synchronous ODT mode, RTT(NOM) will be turned on DODTLon clock cycles after ODT is sampled
HIGH by a rising clock edge and turned off DODTLoff clock cycles after ODT is registered LOW by a
rising clock edge. The ODT latency is determined by the programmed values for: CAS WRITE latency
(CWL), additive latency (AL), and parity latency (PL), as well as the programmed state of the preamble.

ODT Latency and Posted ODT

The ODT latencies for synchronous ODT mode are summarized in the table below. For details, refer to
the latency definitions.

Table 74: ODT Latency at DDR4-1600/-1866/-2133/-2400/-2666/-3200

Applicable when write CRC is disabled

Symbol Parameter 1tCK Preamble 2tCK Preamble Unit

DODTLon Direct ODT turn-on latency CWL + AL + PL - 2 CWL + AL + PL - 3 t
CK
DODTLoff Direct ODT turn-off latency CWL + AL + PL - 2 CWL + AL + PL - 3
RODTLoff READ command to internal ODT turn-off CL + AL + PL - 2 CL + AL + PL - 3
latency
RODTLon4 READ command to RTT(Park) turn-on RODTLoff + 4 RODTLoff + 5
latency in BC4-fixed
RODTLon8 READ command to RTT(Park) turn-on RODTLoff + 6 RODTLoff + 7
latency in BL8/BC4-OTF
ODTH4 ODT Assertion time, BC4 mode 4 5
ODTH8 ODT Assertion time, BL8 mode 6 7

Timing Parameters
In synchronous ODT mode, the following parameters apply:
s DODTLon, DODTLoff, RODTLoff, RODTLon4, RODTLon8, and tADC (MIN)/(MAX).
s tADC (MIN) and tADC (MAX) are minimum and maximum RTT change timing skew between
different termination values. These timing parameters apply to both the synchronous ODT mode
and the data termination disable mode.

When ODT is asserted, it must remain HIGH until minimum ODTH4 (BC = 4) or ODTH8 (BL = 8) is
satisfied. If write CRC mode or 2tCK preamble mode is enabled, ODTH should be adjusted to account
for it. ODTHx is measured from ODT first registered HIGH to ODT first registered LOW or from the
registration of a WRITE command.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Synchronous ODT Mode

Figure 204: Synchronous ODT Timing with BL8

T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T1 8

diff_CK

Command

ODT

DODTLon = WL - 2 DODTLoff = WL - 2

t ADC (MAX) tADC (MAX)

tADC (MIN) tADC (MIN)

DRAM_RTT RTT(Park) RTT(NOM) RTT(Park)

Transitioning

Notes: 1. Example for CWL = 9, AL = 0, PL = 0; DODTLon = AL + PL + CWL - 2 = 7; DODTLoff = AL + PL + CWL - 2 = 7.

2. ODT must be held HIGH for at least ODTH8 after assertion (T1).

Figure 205: Synchronous ODT with BC4

T0 T1 T2 T3 T4 T5 T18 T19 T20 T21 T22 T23 T36 T37 T38 T39 T40 T41 42

diff_CK

WRS4
Command
ODTH4

ODT

DODTLoff = WL - 2

ODTLcnw= WL - 2

DODTLon = CWL - 2 ODTLcwn4 = ODTLcnw + 4

tADC (MAX) tADC (MAX) tADC (MAX) tADC (MAX)

tADC (MIN) tADC (MIN) tADC (MIN) tADC (MIN)

RTT(Park) RTT(NOM) RTT(Park) RTT(WR) RTT(Park)

DRAM_RTT

Transitioning

Notes: 1. Example for CWL = 9, AL = 10, PL = 0; DODTLon/off = AL + PL+ CWL - 2 = 17; ODTcnw = AL + PL+ CWL - 2 = 17.
2. ODT must be held HIGH for at least ODTH4 after assertion (T1).

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 8Gb: x4, x8, x16 DDR4 SDRAM
Synchronous ODT Mode

ODT During Reads

Because the DRAM cannot terminate with RTT and drive with RON at the same time, RTT may nominally
not be enabled until the end of the postamble as shown in the example below. At cycle T26 the device
turns on the termination when it stops driving, which is determined by tHZ. If the DRAM stops driving
early (that is, tHZ is early), thentADC (MIN) timing may apply. If the DRAM stops driving late (that is,
t
HZ is late), then the DRAM complies with tADC (MAX) timing.
Using CL = 11 as an example for the figure below: PL = 0, AL = CL - 1 = 10, RL = PL + AL + CL = 21, CWL=
9; RODTLoff = RL - 2 = 19, DODTLon = PL + AL + CWL - 2 = 17, 1tCK preamble.

Figure 206: ODT During Reads

T0 T1 T2 T3 T4 T8 T9 T10 T18 T19 T20 T21 T22 T23 T24 T25 T26 T27 T28

diff_CK

Command RD

Address A

RL = AL + CL + PL

ODT

RODTLoff = RL- 2

DODTLon = WL - 2

t ADC (MAX) t ADC (MAX)

t ADC (MIN) t ADC (MIN)

DQS_ODT RTT(Park) RTT(NOM)

1t CK Preamble
t ADC (MAX) t ADC (MAX)
t ADC (MIN) t ADC (MIN)

DQS_ODT RTT(Park) RTT(NOM)

2t CK Preamble

DQSdiff

t ADC (MAX) + 1nCK t ADC (MAX)

t ADC (MIN) t ADC (MIN)

DQ_ODT RTT(Park) RTT(NOM)

1t CK Preamble

DQ QA0 QA1 QA2 QA3 QA4 QA5 QA6 QA7

t ADC (MAX) + 2nCK t ADC (MAX)

t ADC (MIN) t ADC (MIN)

DQ_ODT RTT(Park) RTT(NOM)

2t CK Preamble

DQ QA0 QA1 QA2 QA3 QA4 QA5 QA6 QA7

Transitioning

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 8Gb: x4, x8, x16 DDR4 SDRAM
Dynamic ODT

Dynamic ODT
In certain application cases and to further enhance signal integrity on the data bus, it is desirable that
the termination strength of the device can be changed without issuing an MRS command. This
requirement is supported by the dynamic ODT feature.

Functional Description
Dynamic ODT mode is enabled if bit A9 or A10 of MR2 is set to 1.
s Three RTTvalues are available: RTT(NOM), RTT(WR), and RTT(Park).
n The value for RTT(NOM) is preselected via bits MR1[10:8].
n The value for RTT(WR) is preselected via bits MR2[11:9].
n The value for RTT(Park) is preselected via bits MR5[8:6].
s During operation without WRITE commands, the termination is controlled as follows:
n Nominal termination strength RTT(NOM) or RTT(Park) is selected.
n RTT(NOM) on/off timing is controlled via ODT pin and latencies DODTLon and DODTLoff, and
RTT(Park) is on when ODT is LOW.
s When a WRITE command (WR, WRA, WRS4, WRS8, WRAS4, and WRAS8) is registered, and if dynam-
ic ODT is enabled, the termination is controlled as follows:
n Latency ODTLcnw after the WRITE command, termination strength RTT(WR) is selected.
n Latency ODTLcwn8 (for BL8, fixed by MRS or selected OTF) or ODTLcwn4 (for BC4, fixed by MRS
or selected OTF) after the WRITE command, termination strength RTT(WR) is de-selected.

One or two clocks will be added into or subtracted from ODTLcwn8 and ODTLcwn4, depending on
write CRC mode and/or 2tCK preamble enablement.
The following table shows latencies and timing parameters relevant to the on-die termination control
in dynamic ODT mode. The dynamic ODT feature is not supported in DLL-off mode. An MRS
command must be used to set RTT(WR) to disable dynamic ODT externally (MR2[11:9] = 000).

Table 75: Dynamic ODT Latencies and Timing (1tCK Preamble Mode and CRC Disabled)
Name and Abbr. Defined from Defined to 1600/1866/ 2666 2933/3200 Unit
Description 2133/2400
ODT latency for change ODTLc Registering Change RTT ODTLcnw = WL - 2 t
CK
from RTT(Park)/RTT(NOM) nw external strength from
to RTT(WR) WRITE com- RTT(Park)/RTT(NO
mand
M) to RTT(WR)

ODT latency for change ODTL- Registering Change RTT ODTLcwn4 = 4 + ODTLcnw tCK
from RTT(WR) to cwn4 external strength from
RTT(Park)/RTT(NOM) (BC = WRITE com- RTT(WR) to
4) mand RTT(Park)/RTT(NO
M)

ODT latency for change ODTL- Registering Change RTT ODTLcwn8 = 6 + ODTLcnw t
CK
from RTT(WR) to cwn8 external strength from (AVG)
RTT(Park)/RTT(NOM) (BL = WRITE com- RTT(NOM) to
8) mand RTT(WR)
RTT change skew t
ADC ODTLcnw RTT valid t
ADC (MIN) = t
ADC (MIN) = t
ADC (MIN) = t
CK
ODTLcwn 0.30 0.28 0.26 (AVG)
t t t
ADC (MAX) = ADC (MAX) = ADC (MAX)
0.70 0.72 = 0.74

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 8Gb: x4, x8, x16 DDR4 SDRAM
Dynamic ODT

Table 76: Dynamic ODT Latencies and Timing with Preamble Mode and CRC Mode Matrix

1tCK Parameter 2tCK Parameter

Symbol CRC Off CRC On CRC Off CRC On Unit
ODTLcnw1 WL - 2 WL - 2 WL - 3 WL - 3 t
CK
ODTLcwn4 ODTLcnw + 4 ODTLcnw + 7 ODTLcnw + 5 ODTLcnw + 8
ODTLcwn8 ODTLcnw + 6 ODTLcnw + 7 ODTLcnw + 7 ODTLcnw + 8

Notes: 1. ODTLcnw = WL - 2 (1tCK preamble) or WL - 3 (2tCK preamble).

Figure 207: Dynamic ODT (1t CK Preamble; CL = 14, CWL = 11, BL = 8, AL = 0, CRC Disabled)
T0 T1 T2 T5 T6 T7 T8 T9 T10 T11 T14 T15 T16 T17 T18 T19 T20 T21 T22 T23 T24

diff_CK

WR
Command

ODT

DODTLon = WL - 2

DODTLoff = WL - 2

tADC (MAX) tADC (MAX) tADC (MAX) tADC (MAX)

RTT RTT(Park) RTT(WR) RTT(Park) RTT(NOM) RTT(Park)

tADC (MIN) tADC (MIN) tADC (MIN) tADC (MIN)

ODTLcnw

ODTLcwn

Transitioning

Notes: 1. ODTLcnw = WL - 2 (1tCK preamble) or WL - 3 (2tCK preamble).

2. If BC4, then ODTLcwn = WL + 4 if CRC disabled or WL + 5 if CRC enabled; If BL8, then ODTLcwn = WL + 6 if CRC
disabled or WL + 7 if CRC enabled.

Figure 208: Dynamic ODT Overlapped with RTT(NOM) (CL = 14, CWL = 11, BL = 8, AL = 0, CRC Disabled)
T0 T1 T2 T5 T6 T7 T9 T10 T11 T12 T15 T16 T17 T18 T19 T20 T21 T22 T23 T24 T25

diff_CK

WR
Command

ODT

ODTLcnw

ODTLcwn8

tADC (MAX) tADC (MAX) tADC (MAX)

RTT RTT_NOM RTT_WR RTT_NOM RTT_PARK

tADC (MIN) tADC (MIN) tADC (MIN)

DODTLoff = CWL -2

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 8Gb: x4, x8, x16 DDR4 SDRAM
Dynamic ODT

Note: 1. Behavior with WR command issued while ODT is registered HIGH.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Asynchronous ODT Mode

Asynchronous ODT Mode

Asynchronous ODT mode is selected when the DRAM runs in DLL-off mode. In asynchronous ODT
timing mode, the internal ODT command is not delayed by either additive latency (AL) or the parity
latency (PL) relative to the external ODT signal (RTT(NOM)). In asynchronous ODT mode, two timing
parameters apply: tAONAS (MIN/MAX), and tAOFAS (MIN/MAX).
RTT(NOM) Turn-on Time
s Minimum RTT(NOM) turn-on time (tAONAS [MIN]) is when the device termination circuit leaves
RTT(Park) and ODT resistance begins to turn on.
s Maximum RTT(NOM) turn-on time (tAONAS [MAX]) is when the ODT resistance has reached
RTT(NOM).
s tAONAS (MIN) and tAONAS (MAX) are measured from ODT being sampled HIGH.

RTT(NOM) Turn-off Time

s Minimum RTT(NOM) turn-off time (tAOFAS [MIN]) is when the device's termination circuit starts to
leave RTT(NOM).
s Maximum RTT(NOM) turn-off time (tAOFAS [MAX]) is when the on-die termination has reached
RTT(Park).
s tAOFAS (MIN) and tAOFAS (MAX) are measured from ODT being sampled LOW.

Figure 209: Asynchronous ODT Timings with DLL Off

T0 T1 T2 T3 T4 T5 T6 Ti Ti + 1 Ti + 2 Ti + 3 Ti + 4 Ti + 5 Ti + 6 Ta Tb

diff_CK

CKE

tIH tIS tIH tIS

ODT

tAONAS (MAX)
tAONAS (MIN)

RTT RTT(Park) RTT(NOM)

tAONAS (MIN)
tAONAS (MAX)

Transitioning

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 8Gb: x4, x8, x16 DDR4 SDRAM
Electrical Specifications

Electrical Specifications
Absolute Ratings
Stresses greater than those listed may cause permanent damage to the device. This is a stress rating
only, and functional operation of the device at these or any other conditions outside those indicated in
the operational sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may adversely affect reliability. Although "unlimited" row accesses to
the same row is allowed within the refresh period; excessive row accesses to the same row over a long
term can result in degraded operation.

Table 77: Absolute Maximum Ratings

Symbol Parameter Min Max Unit Notes
VDD Voltage on VDD pin relative to VSS n 1.5 V 1
VDDQ Voltage on VDDQ pin relative to VSS n 1.5 V 1
VPP Voltage on VPP pin relative to VSS n 3.0 V 3
VIN, VOUT Voltage on any pin relative to VSS n 1.5 V
TSTG Storage temperature n 150 ιC 2

Notes: 1. VDD and VDDQ must be within 300mV of each other at all times, and VREF must not be greater than 0.6 έ VDDQ.
When VDD and VDDQ are <500mV, VREF can be ζ300mV.
2. Storage temperature is the case surface temperature on the center/top side of the DRAM. For the measurement
conditions, please refer to the JESD51-2 standard.
3. VPP must be equal to or greater than VDD/VDDQ at all times when powered.

DRAM Component Operating Temperature Range

Operating temperature, TOPER, is the case surface temperature on the center/top side of the DRAM. For
measurement conditions, refer to the JEDEC document JESD51-2.

Table 78: Temperature Range

Symbol Parameter Min Max Unit Notes
TOPER Normal operating temperature range -40 85 ιC 1
Extended temperature range (optional) >85 105 ιC 2

Notes: 1. The normal temperature range specifies the temperatures at which all DRAM specifications will be supported.
During operation, the DRAM case temperature must be maintained between 0ιC to 85ιC under all operating
conditions for the commercial offering; The industrial and automotive temperature offerings allow the case
temperature to go below 0ιC to -40ιC.
2. Some applications require operation of the commercial, industrial, and automotive temperature DRAMs in the
extended temperature range (between 85ιC and 105ιC case temperature). Full specifications are supported in this
range, but the following additional conditions apply:
s Refer to tREFI and tRFC parameters table for tREFI requirements when operating above 85ιC
s If SELF REFRESH operation is required in the extended temperature range, it is mandatory to use
either the manual self refresh mode with extended temperature range capability (MR2[6] = 0 and
MR2 [7] = 1) or enable the optional auto self refresh mode (MR2 [6] = 1 and MR2 [7] = 1).

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Supply Operating Conditions

Table 79: Recommended Supply Operating Conditions

Rating
Symbol Parameter Min Typ Max Unit Notes
VDD Supply voltage 1.14 1.2 1.26V 1, 2, 3, 4, 5
VDDQ Supply voltage 1.14 1.2 1.26V 1, 2, 6
for output
VPP Wordline sup- 2.375 2.5 2.750V 7
ply voltage

Notes: 1. Under all conditions VDDQ must be less than or equal to VDD.
2. VDDQ tracks with VDD. AC parameters are measured with VDD and VDDQ tied together.
3. VDD slew rate between 300mV and 80% of VDD,min shall be between 0.004 V/ms and 600 V/ms, 20 MHz
band-limited measurement.
4. VDD ramp time from 300mV to VDD,min shall be no longer than 200ms.
5. A stable valid VDD level is a set DC level (0 Hz to 250 KHz) and must be no less than VDD,min and no greater than
VDD,max. If the set DC level is altered anytime after initialization, the DLL reset and calibrations must be performed
again after the new set DC level is final. AC noise of ά60mV (greater than 250 KHz) is allowed on VDD provided the
noise doesn't alter VDD to less than VDD,min or greater than VDD,max.
6. A stable valid VDDQ level is a set DC level (0 Hz to 250 KHz) and must be no less than VDDQ,min and no greater than
VDDQ,max. If the set DC level is altered anytime after initialization, the DLL reset and calibrations must be
performed again after the new set DC level is final. AC noise of ά60mV (greater than 250 KHz) is allowed on VDDQ
provided the noise doesn't alter VDDQ to less than VDDQ,min or greater than VDDQ,max.
7. A stable valid VPP level is a set DC level (0 Hz to 250 KHz) and must be no less than VPP,min and no greater than
VPP,max. If the set DC level is altered anytime after initialization, the DLL reset and calibrations must be performed
again after the new set DC level is final. AC noise of ά120mV (greater than 250 KHz) is allowed on VPP provided
the noise doesn't alter VPP to less than VPP,min or greater than VPP,max.

Table 80: VDD Slew Rate

Symbol Min Max Unit Notes

VDD_sl 0.004 600 V/ms 1, 2
VDD_on n 200 ms 3

Notes: 1. Measurement made between 300mV and 80% VDD (minimum level).
2. The DC bandwidth is limited to 20 MHz.
3. Maximum time to ramp VDD from 300 mV to VDD minimum.

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Leakages

Table 81: Leakages

Condition Symbol Min Max Unit Notes
Input leakage (excluding ZQ and TEN) IIN n 2 ρA 1
ZQ leakage IZQ n 10 ρA 1
TEN leakage ITEN n 10 ρA 1, 2
VREFCA leakage IVREFCA n 2 ρA 3
Output leakage: VOUT = VDDQ IOZpd n 10 ρA 4
Output leakage: VOUT = VSSQ IOZpu n n ρA 4, 5

Notes: 1. Input under test 0V < VIN < 1.1V.

2. Additional leakage due to weak pull-down.
3. VREFCA = VDD/2, VDD at valid level after initialization.
4. DQs are disabled.
5. ODT is disabled with the ODT input HIGH.

VREFCA Supply
VREFCA is to be supplied to the DRAM and equal to VDD/2. The VREFCA is a reference supply input and
therefore does not draw biasing current.
The DC-tolerance limits and AC-noise limits for the reference voltages VREFCA are illustrated in the
figure below. The figure shows a valid reference voltage VREF(t) as a function of time (VREF stands for
VREFCA). VREF(DC) is the linear average of VREF(t) over a very long period of time (1 second). This average
has to meet the MIN/MAX requirements. Furthermore, VREF(t) may temporarily deviate from VREF(DC)
by no more than ά1% VDD for the AC-noise limit.

Figure 210: VREFDQ Voltage Range

Voltage

VDD

VREF(t)
VREF AC-noise
VREF(DC) MAX
VREF(DC)
VDD/2

VREF(DC) MIN

VSS

Time
The voltage levels for setup and hold time measurements are dependent on VREF. VREF is understood
as VREF(DC), as defined in the above figure. This clarifies that DC-variations of VREF affect the absolute

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voltage a signal has to reach to achieve a valid HIGH or LOW level, and therefore, the time to which
setup and hold is measured. System timing and voltage budgets need to account for VREF(DC) devia-
tions from the optimum position within the data-eye of the input signals. This also clarifies that the
DRAM setup/hold specification and derating values need to include time and voltage associated with
VREF AC-noise. Timing and voltage effects due to AC-noise on VREF up to the specified limit (ά1% of
VDD) are included in DRAM timings and their associated deratings.

VREFDQ Supply and Calibration Ranges

The device internally generates its own VREFDQ. DRAM internal VREFDQ specification parameters:
voltage range, step size, VREF step time, VREF full step time, and VREF valid level are used to help provide
estimated values for the internal VREFDQ and are not pass/fail limits. The voltage operating range spec-
ifies the minimum required range for DDR4 SDRAM devices. The minimum range is defined by
VREFDQ,min and VREFDQ,max. A calibration sequence should be performed by the DRAM controller to
adjust VREFDQ and optimize the timing and voltage margin of the DRAM data input receivers.

Table 82: VREFDQ Specification

Parameter Symbol Min Typ Max Unit Notes

Range 1 VREFDQ operating points VREFDQ R1 60% n 92% VDDQ 1, 2
Range 2 VREFDQ operating points VREFDQ R2 45% n 77% VDDQ 1, 2
VREF step size VREF,step 0.5% 0.65% 0.8% VDDQ 3
VREF set tolerance VREF,set_tol n 0% 1.625% VDDQ 4, 5, 6
n 0% 0.15% VDDQ 4, 7, 8
VREF step time VREF,time n n 150 ns 9, 10, 11
VREF valid tolerance VREF_val_tol n 0% 0.15% VDDQ 12

Notes: 1. VREF(DC) voltage is referenced to VDDQ(DC). VDDQ(DC) is 1.2V.

2. DRAM range 1 or range 2 is set by the MRS6[6]6.
3. VREF step size increment/decrement range. VREF at DC level.
4. VREF,new = VREF,old άn έ VREF,step N  NUMBER OF STEPS )F INCREMENT USE h v IF DECREMENT USE h v
5. For n >4, the minimum value of VREF setting tolerance = VREF,new - 1.625% έ VDDQ. The maximum value of VREF
setting tolerance = VREF,new + 1.625% έ VDDQ.
6. Measured by recording the MIN and MAX values of the VREF output over the range, drawing a straight line
between those points, and comparing all other VREF output settings to that line.
7. For n ζ4, the minimum value of VREF setting tolerance = VREF,new - 0.15% έ VDDQ. The maximum value of VREF
setting tolerance = VREF,new + 0.15% έ VDDQ.
8. Measured by recording the MIN and MAX values of the VREF output across four consecutive steps (n = 4), drawing
a straight line between those points, and comparing all VREF output settings to that line.
9. Time from MRS command to increment or decrement one step size for VREF.
10. Time from MRS command to increment or decrement more than one step size up to the full range of VREF.
11. If the VREF monitor is enabled, VREF must be derated by +10ns if DQ bus load is 0pF and an additional +15 ns/pF of
DQ bus loading.
12. Only applicable for DRAM component-level test/characterization purposes. Not applicable for normal mode of
operation. VREF valid qualifies the step times, which will be characterized at the component level.

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VREFDQ Ranges
MR6[6] selects range 1 (60% to 92.5% of VDDQ) or range 2 (45% to 77.5% of VDDQ), and MR6[5:0] sets the
VREFDQ level, as listed in the following table. The values in MR6[6:0] will update the VDDQ range and
level independent of MR6[7] setting. It is recommended MR6[7] be enabled when changing the settings
in MR6[6:0], and it is highly recommended MR6[7] be enabled when changing the settings in MR6[6:0]
multiple times during a calibration routine.

Table 83: VREFDQ Range and Levels

MR6[6] 0 = MR6[6] 1 = MR6[6] 0 = MR6[6] 1 =

MR6[5:0] Range 1 Range 2 MR6[5:0] Range 1 Range 2
00 0000 60.00% 45.00% 01 1010 76.90% 61.90%
00 0001 60.65% 45.65% 01 1011 77.55% 62.55%
00 0010 61.30% 46.30% 01 1100 78.20% 63.20%
00 0011 61.95% 46.95% 01 1101 78.85% 63.85%
00 0100 62.60% 47.60% 01 1110 79.50% 64.50%
00 0101 63.25% 48.25% 01 1111 80.15% 65.15%
00 0110 63.90% 48.90% 10 0000 80.80% 65.80%
00 0111 64.55% 49.55% 10 0001 81.45% 66.45%
00 1000 65.20% 50.20% 10 0010 82.10% 67.10%
00 1001 65.85% 50.85% 10 0011 82.75% 67.75%
00 1010 66.50% 51.50% 10 0100 83.40% 68.40%
00 1011 67.15% 52.15% 10 0101 84.05% 69.05%
00 1100 67.80% 52.80% 10 0110 84.70% 69.70%
00 1101 68.45% 53.45% 10 0111 85.35% 70.35%
00 1110 69.10% 54.10% 10 1000 86.00% 71.00%
00 1111 69.75% 54.75% 10 1001 86.65% 71.65%
01 0000 70.40% 55.40% 10 1010 87.30% 72.30%
01 0001 71.05% 56.05% 10 1011 87.95% 72.95%
01 0010 71.70% 56.70% 10 1100 88.60% 73.60%
01 0011 72.35% 57.35% 10 1101 89.25% 74.25%
01 0100 73.00% 58.00% 10 1110 89.90% 74.90%
01 0101 73.65% 58.65% 10 1111 90.55% 75.55%
01 0110 74.30% 59.30% 11 0000 91.20% 76.20%
01 0111 74.95% 59.95% 11 0001 91.85% 76.85%
01 1000 75.60% 60.60% 11 0010 92.50% 77.50%
01 1001 76.25% 61.25% 11 0011 to 11 1111 are reserved

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Levels
RESET_n Input Levels

Table 84: RESET_n Input Levels (CMOS)

Parameter Symbol Min Max Unit Note
AC input high voltage VIH(AC)_RESET 0.8 έ VDD VDD V 1
DC input high voltage VIH(DC)_RESET 0.7 έ VDD VDD V 2
DC input low voltage VIL(DC)_RESET VSS 0.3 έ VDD V 3
AC input low voltage VIL(AC)_RESET VSS 0.2 έ VDD V 4
Rising time t
R_RESET n 1 ρs 5

RESET pulse width after power-up t

PW_RESET_S 1 n ρs 6, 7

RESET pulse width during power-up t

PW_RESET_L 200 n ρs 6

Notes: 1. Overshoot should not exceed the VIN shown in the Absolute Maximum Ratings table.
2. After RESET_n is registered HIGH, the RESET_n level must be maintained above VIH(DC)_RESET, otherwise operation
will be uncertain until it is reset by asserting RESET_n signal LOW.
3. After RESET_n is registered LOW, the RESET_n level must be maintained below VIL(DC)_RESET during tPW_RESET,
otherwise the DRAM may not be reset.
4. Undershoot should not exceed the VIN shown in the Absolute Maximum Ratings table.
5. Slope reversal (ring-back) during this level transition from LOW to HIGH should be mitigated as much as possible.
6. RESET is destructive to data contents.
7. See RESET Procedure at Power Stable Condition figure.

Figure 211: RESET_n Input Slew Rate Definition

tPW_RESET

VIH(AC)_RESET,min
VIH(DC)_RESET,min

VIL(DC)_RESET,max
VIL(AC)_RESET,max

tR_RESET

Command/Address Input Levels

Table 85: Command and Address Input Levels: DDR4-1600 Through DDR4-2400
Parameter Symbol Min Max Unit Note
AC input high voltage VIH(AC) VREF + 100 VDD5 mV 1, 2, 3
DC input high voltage VIH(DC) VREF + 75 VDD mV 1, 2
DC input low voltage VIL(DC) VSS VREF - 75 mV 1, 2

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Table 85: Command and Address Input Levels: DDR4-1600 Through DDR4-2400 (Continued)
Parameter Symbol Min Max Unit Note
AC input low voltage VIL(AC) VSS5 VREF - 100 mV 1, 2, 3
Reference voltage for CMD/ADDR inputs VREFFCA(DC) 0.49 έ VDD 0.51 έ VDD V 4

Notes: 1. For input except RESET_n. VREF = VREFCA(DC).

2. VREF = VREFCA(DC).
3. Input signal must meet VIL/VIH(AC) to meet tIS timings and VIL/VIH(DC) to meet tIH timings.
4. The AC peak noise on VREF may not allow VREF to deviate from VREFCA(DC) by more than ά1% VDD (for reference:
approximately ά12mV).
5. 2EFER TO h/VERSHOOT AND 5NDERSHOOT 3PECIFICATIONSv

Table 86: Command and Address Input Levels: DDR4-2666

Parameter Symbol Min Max Unit Note
AC input high voltage VIH(AC) VREF + 90 VDD5 mV 1, 2, 3
DC input high voltage VIH(DC) VREF + 65 VDD mV 1, 2
DC input low voltage VIL(DC) VSS VREF - 65 mV 1, 2
AC input low voltage VIL(AC) VSS5 VREF - 90 mV 1, 2, 3
Reference voltage for CMD/ADDR inputs VREFFCA(DC) 0.49 έ VDD 0.51 έ VDD V 4

Notes: 1. For input except RESET_n. VREF = VREFCA(DC).

2. VREF = VREFCA(DC).
3. Input signal must meet VIL/VIH(AC) to meet tIS timings and VIL/VIH(DC) to meet tIH timings.
4. The AC peak noise on VREF may not allow VREF to deviate from VREFCA(DC) by more than ά1% VDD (for reference:
approximately ά12mV).
5. 2EFER TO h/VERSHOOT AND 5NDERSHOOT 3PECIFICATIONSv

Table 87: Command and Address Input Levels: DDR4-2933 and DDR4-3200
Parameter Symbol Min Max Unit Note
AC input high voltage VIH(AC) VREF + 90 VDD5 mV 1, 2, 3
DC input high voltage VIH(DC) VREF + 65 VDD mV 1, 2
DC input low voltage VIL(DC) VSS VREF - 65 mV 1, 2
AC input low voltage VIL(AC) VSS5 VREF - 90 mV 1, 2, 3
Reference voltage for CMD/ADDR inputs VREFFCA(DC) 0.49 έ VDD 0.51 έ VDD V 4

Notes: 1. For input except RESET_n. VREF = VREFCA(DC).

2. VREF = VREFCA(DC).
3. Input signal must meet VIL/VIH(AC) to meet tIS timings and VIL/VIH(DC) to meet tIH timings.
4. The AC peak noise on VREF may not allow VREF to deviate from VREFCA(DC) by more than ά1% VDD (for reference:
approximately ά12mV).
5. 2EFER TO h/VERSHOOT AND 5NDERSHOOT 3PECIFICATIONSv

Table 88: Single-Ended Input Slew Rates

Parameter Symbol Min Max Unit Note
3INGLE ENDED INPUT SLEW RATE n #! SRCA 1.0 7.0 V/ns 1, 2, 3, 4

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Notes: 1. For input except RESET_n.

2. VREF = VREFCA(DC).
3. tIS/tIH timings assume SRCA = 1V/ns.
4. Measured between VIH(AC) and VIL(AC) for falling edges and between VIL(AC) and VIH(AC) for rising edges

Figure 212: Single-Ended Input Slew Rate Definition

Command, Control, and Address Setup, Hold, and Derating

The total tIS (setup time) and tIH (hold time) required is calculated to account for slew rate variation
by adding the data sheet tIS (base) values, the VIL(AC)/VIH(AC) points, and tIH (base) values, the
VIL(DC)/VIH(DC) points; to the ȟtIS and ȟtIH derating values, respectively. The base values are derived
with single-end signals at 1V/ns and differential clock at 2 V/ns. Example: tIS (total setup time) = tIS
(base) + ȟtIS. For a valid transition, the input signal has to remain above/below VIH(AC)/VIL(AC) for the
time defined by tVAC.
Although the total setup time for slow slew rates might be negative (for example, a valid input signal
will not have reached VIH(AC)/VIL(AC) at the time of the rising clock transition), a valid input signal is still
required to complete the transition and to reach VIH(AC)/VIL(AC). For slew rates that fall between the
values listed in derating tables, the derating values may be obtained by linear interpolation.

Setup (tIS) nominal slew rate for a rising signal is defined as the slew rate between the last crossing of
VIL(DC)max and the first crossing of VIH(AC)min that does not ring back below VIH(DC)min . Setup (tIS)
nominal slew rate for a falling signal is defined as the slew rate between the last crossing of VIH(DC)min
and the first crossing of VIL(AC)max that does not ring back above VIL(DC)max.

Hold (tIH) nominal slew rate for a rising signal is defined as the slew rate between the last crossing of
VIL(DC)max and the first crossing of VIH(AC)min that does not ring back below VIH(DC)min. Hold (tIH)

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nominal slew rate for a falling signal is defined as the slew rate between the last crossing of VIH(DC)min
and the first crossing of VIL(AC)minthat does not ring back above VIL(DC)max.

Table 89: #OMMAND AND !DDRESS 3ETUP AND (OLD 6ALUES 2EFERENCED n !#$# "ASED
Symbol 1600 1866 2133 2400 2666 2933 3200 Unit Reference
t
IS(base, AC100) 115 100 80 62 n n n ps VIH(AC)/VIL(AC)
t
IH(base, DC75) 140 125 105 87 n n n ps VIH(DC)/VIL(DC)
t
IS(base, AC90) n n n n 55 48 40 ps VIH(AC)/VIL(AC)
t
IH(base, DC65) n n n n 80 73 65 ps VIH(DC)/VIL(DC)
tIS/tIH(Vref) 215 200 180 162 145 138 130 ps VIH(DC)/VIL(DC)

Table 90: Derating Values for tIS/t)( n !#$# "ASED

ȟtIS with AC100 Threshold, ȟt)( WITH $# 4HRESHOLD $ERATING PS n !#$# "ASED
CK, CK# Differential Slew Rate
10.0 V/ns 8.0 V/ns 6.0 V/ns 4.0 V/ns 3.0 V/ns 2.0 V/ns 1.5 V/ns 1.0 V/ns
CMD/ADD
R Slew
Rate V/ns ȟtIS ȟtIH ȟtIS ȟtIH ȟtIS ȟtIH ȟtIS ȟtIH ȟtIS ȟtIH ȟtIH ȟtIH ȟtIS ȟtIH ȟtIS ȟtIH
7.0 76 54 76 55 77 56 79 58 82 60 86 64 94 73 111 89
6.0 73 53 74 53 75 54 77 56 79 58 83 63 92 71 108 88
5.0 70 50 71 51 72 52 74 54 76 56 80 60 88 68 105 85
4.0 65 46 66 47 67 48 69 50 71 52 75 56 83 65 100 81
3.0 57 40 57 41 58 42 60 44 63 46 67 50 75 58 92 75
2.0 40 28 41 28 42 29 44 31 46 33 50 38 58 46 75 63
1.5 23 15 24 16 25 17 27 19 29 21 33 25 42 33 58 50
1.0 n n n n n n n n n n 0 0 8 8 25 25
0.9 n n n n n n n n n n n n 1 4 18 21
0.8 n n n n n n n n n n n n n n 9 16
0.7 n n n n n n n n n n n n n n n 9
0.6 n n n n n n n n n n n n n n n 0
0.5 n n n n n n n n n n n n n n n n
0.4 n n n n n n n n n n n n n n n n

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Table 91: Derating Values for tIS/t)( n !#$# "ASED

ȟtIS with AC90 Threshold, ȟt)( WITH $# 4HRESHOLD $ERATING PS n !#$# "ASED
CK, CK# Differential Slew Rate
10.0 V/ns 8.0 V/ns 6.0 V/ns 4.0 V/ns 3.0 V/ns 2.0 V/ns 1.5 V/ns 1.0 V/ns
CMD/ADD
R Slew
Rate V/ns ȟtIS ȟtIH ȟtIS ȟtIH ȟtIS ȟtIH ȟtIS ȟtIH ȟtIS ȟtIH ȟtIH ȟtIH ȟtIS ȟtIH ȟtIS ȟtIH
7.0 68 47 69 47 70 48 72 50 73 52 77 56 85 63 100 78
6.0 66 45 67 46 68 47 69 49 71 50 75 54 83 62 98 77
5.0 63 43 64 44 65 45 66 46 68 48 72 52 80 60 95 75
4.0 59 40 59 40 60 41 62 43 64 45 68 49 75 56 90 71
3.0 51 34 52 35 53 36 54 38 56 40 60 43 68 51 83 66
2.0 36 24 37 24 38 25 39 27 41 29 45 33 53 40 68 55
1.5 21 13 22 13 23 14 24 16 26 18 30 22 38 29 53 44
1.0 n n n n n n n n n n 0 0 8 8 23 23
0.9 n n n n n n n n n n n n 1 4 16 19
0.8 n n n n n n n n n n n n n n 8 14
0.7 n n n n n n n n n n n n n n n 9
0.6 n n n n n n n n n n n n n n n 1
0.5 n n n n n n n n n n n n n n n n
0.4 n n n n n n n n n n n n n n n n

Data Receiver Input Requirements

The following parameters apply to the data receiver Rx MASK operation detailed in the Write Timing
section, Data Strobe-to-Data Relationship.
The rising edge slew rates are defined by srr1 and srr2. The slew rate measurement points for a rising
edge are shown in the figure below. A LOW-to-HIGH transition time, tr1, is measured from 0.5 έ
VdiVW,max below VCENTDQ,midpoint to the last transition through 0.5 έ VdiVW,max above VCENTDQ,midpoint;
tr2 is measured from the last transition through 0.5 έ VdiVW,max above VCENTDQ,midpoint to the first tran-
sition through the 0.5 έ VIHL(AC)min above VCENTDQ,midpoint.
The falling edge slew rates are defined by srf1 and srf2. The slew rate measurement points for a falling
edge are shown in the figure below. A HIGH-to-LOW transition time, tf1, is measured from 0.5 έ
VdiVW,max above VCENTDQ,midpoint to the last transition through 0.5 έ VdiVW,max below VCENTDQ,midpoint;
tf2 is measured from the last transition through 0.5 έ VdiVW,max below VCENTDQ,midpoint to the first tran-
sition through the 0.5 έ VIHL(AC)min below VCENTDQ,midpoint.

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Figure 213: DQ Slew Rate Definitions

tr2
VIHL(AC)min
0.5 ×
VIHL(AC)min

0.5 × VdiVW,max

VdiVW,max
Rx Mask VCENTDQ,midpoint
VIHL(AC)min

0.5 × VdiVW,max
0.5 ×

tr1

tf1
VIHL(AC)min
0.5 ×
VIHL(AC)min

0.5 × VdiVW,max

VdiVW,max
Rx Mask VCENTDQ,midpoint
VIHL(AC)min

0.5 × VdiVW,max
0.5 ×

tf2

Notes: 1. Rising edge slew rate equation srr1 = VdiVW,max/(tr1).

2. Rising edge slew rate equation srr2 = (VIHL(AC)min - VdiVW,max )/(2 έ tr2).
3. Falling edge slew rate equation srf1 = VdiVW,max/(tf1).
4. Falling edge slew rate equation srf2 = (VIHL(AC)min - VdiVW,max )/(2 έ tf2).

Table 92: DQ Input Receiver Specifications

DDR4-1600,
1866, 2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200
Parameter Symbol Min Max Min Max Min Max Min Max Min Max Unit Notes
VIN Rx mask VdiVW n 136 n 130 n 120 n 115 n 110 mV 2, 3
input
peak-to-peak
DQ Rx input TdiVW n 0.2 n 0.2 n 0.22 n 0.23 n 0.23 UI 2, 3
timing window
DQ AC input VIHL(AC) 186 n 160 n 150 n 145 n 140 n mV 4, 5
swing
peak-to-peak
DQ input pulse TdiPW 0.58 n 0.58 n 0.58 n 0.58 n 0.58 n UI 6
width

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Table 92: DQ Input Receiver Specifications (Continued)

DDR4-1600,
1866, 2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200
Parameter Symbol Min Max Min Max Min Max Min Max Min Max Unit Notes
DQS-to-DQ Rx t
DQS2DQ n 0.17 n 0.17 n 0.19 n 0.22 n 0.22 UI 7
mask offset
DQ-to-DQ Rx tDQ2DQ n 0.1 n 0.1 n 0.105 n 0.115 n 0.125 UI 8
mask offset
Input slew rate srr1, srf1 1 9 1 9 1 9 1 9 1 9 V/ns 9
over VdiVW if
t
CK η 0.937ns
Input slew rate srr1, srf1 n n 1.25 9 1.25 9 1.25 9 1.25 9 V/ns 9
over VdiVW if
0.937ns > tCK η
0.625ns
Rising input srr2 0.2 έ 9 0.2 έ 9 0.2 έ 9 0.2 έ 9 0.2 έ 9 V/ns 10
slew rate over srr1 srr1 srr1 srr1 srr1
1/2 VIHL(AC)
Falling input srf2 0.2 έ 9 0.2 έ 9 0.2 έ 9 0.2 έ 9 0.2 έ 9 V/ns 10
slew rate over srf1 srf1 srf1 srf1 srf1
1/2 VIHL(AC)

Notes: 1. All Rx mask specifications must be satisfied for each UI. For example, if the minimum input pulse width is violated
when satisfying TdiVW (MIN), VdiVW,max, and minimum slew rate limits, then either TdiVW (MIN) or minimum slew
rates would have to be increased to the point where the minimum input pulse width would no longer be violated.
2. Data Rx mask voltage and timing total input valid window where VdiVW is centered around VCENTDQ,midpoint after
VREFDQ training is completed. The data Rx mask is applied per bit and should include voltage and temperature drift
terms. The input buffer design specification is to achieve at least a BER =1e- 16 when the Rx mask is not violated.
3. Defined over the DQ internal VREF range 1.
4. Overshoot and undershoot specifications apply.
5. DQ input pulse signal swing into the receiver must meet or exceed VIHL(AC)min. VIHL(AC)min is to be achieved on an
UI basis when a rising and falling edge occur in the same UI (a valid TdiPW).
6. DQ minimum input pulse width defined at the VCENTDQ,midpoint.
7. DQS-to-DQ Rx mask offset is skew between DQS and DQ within a nibble (x4) or word (x8, x16 [for x16, the upper
and lower bytes are treated as separate x8s]) at the SDRAM balls over process, voltage, and temperature.
8. DQ-to-DQ Rx mask offset is skew between DQs within a nibble (x4) or word (x8, x16) at the SDRAM balls for a given
component over process, voltage, and temperature.
9. Input slew rate over VdiVW mask centered at VCENTDQ,midpoint. Slowest DQ slew rate to fastest DQ slew rate per
transition edge must be within 1.7V/ns of each other.
10. Input slew rate between VdiVW mask edge and VIHL(AC)min points.
11. Note 1 applies to the entire table.
The following figure shows the Rx mask relationship to the input timing specifications relative to
system tDS and tDH. The classical definition for tDS/tDH required a DQ rising and falling edges to not
violate tDS and tDH relative to the DQS strobe at any time; however, with the Rx mask tDS and tDH can
shift relative to the DQS strobe provided the input pulse width specification is satisfied and the Rx mask
is not violated.

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Figure 214: Rx Mask Relative to tDS/tDH

TdiPW

VIH(DC)
0.5 × VdiVW
VdiVW

Rx VCENTDQ,pin mean
Mask
0.5 × VdiVW
VIL(DC)

tf1 TdiVW tr1

tDS= Greater of 0.5 × TdiVW tDH= Greater of 0.5 × TdiVW

or or
0.5 × (TdiPW + VdiVW/tf1) 0.5 × (TdiPW + VdiVW/tr1)
DQS_c

DQS_t

The following figure and table show an example of the worst case Rx mask required if the DQS and DQ
pins do not have DRAM controller to DRAM write DQ training. The figure and table show that without
DRAM write DQ training, the Rx mask would increase from 0.2UI to essentially 0.54UI. This would also
be the minimum tDS and tDH required as well.

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Figure 215: Rx Mask Without Write Training

TdiVW + 2 × tDQS2DQ
VIH(DC)
0.5 × VdiVW
VdiVW

Rx Mask VCENTDQ,midpoint
0.5 × VdiVW
VIL(DC)

tDS tDH

0.5 × TdiVW + tDQS2DQ 0.5 × TdiVW + tDQS2DQ

DQS_c

DQS_t

Table 93: Rx Mask and tDS/tDH without Write Training

Rx Mask
with Write
t t t
VIHL(AC) TdiPW VdiVW TdiVW DQS2DQ DQ2DQ Train DS + tDH
DDR4 (mV) (UI) (mV) (UI) (UI) (UI) (ps) (ps)
1600 186 0.58 136 0.2 ά0.17 0.1 125 338
1866 186 0.58 136 0.2 ά0.17 0.1 107.1 289
2133 186 0.58 136 0.2 ά0.17 0.1 94 253
2400 160 0.58 130 0.2 ά0.17 0.1 83.3 225
2666 150 0.58 120 0.22 ά0.19 0.105 82.5 225
2933 145 0.58 115 0.23 ά0.22 0.115 78.4 228
3200 140 0.58 110 0.23 ά0.22 0.125 71.8 209

Notes: 1. VIHL(AC), VdiVW, and VILH(DC) referenced to VCENTDQ,midpoint.

Connectivity Test (CT) Mode Input Levels

Table 94: TEN Input Levels (CMOS)

Parameter Symbol Min Max Unit Note
TEN AC input high voltage VIH(AC)_TEN 0.8 έ VDD VDD V 1
TEN DC input high voltage VIH(DC)_TEN 0.7 έ VDD VDD V
TEN DC input low voltage VIL(DC)_TEN VSS 0.3 έ VDD V
TEN AC input low voltage VIL(AC)_TEN VSS 0.2 έ VDD V 2
TEN falling time t
F_TEN n 10 ns

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Table 94: TEN Input Levels (CMOS) (Continued)

Parameter Symbol Min Max Unit Note
TEN rising time tR_TEN n 10 ns

Notes: 1. Overshoot should not exceed the VIN values in the Absolute Maximum Ratings table.
2. Undershoot should not exceed the VIN values in the Absolute Maximum Ratings table.

Figure 216: TEN Input Slew Rate Definition

VIH(AC)_TENmin
VIH(DC)_TENmin

VIL(DC)_TENmin
VIL(AC)_TENmin

tF_TEN tR_TEN

Table 95: CT Type-A Input Levels

Parameter Symbol Min Max Unit Note
CTipA AC input high voltage VIH(AC) VREF + 200 VDD1 1 V 2, 3

CTipA DC input high voltage VIH(DC) VREF + 150 VDD V 2, 3

CTipA DC input low voltage VIL(DC) VSS VREF - 150 V 2, 3
CTipA AC input low voltage VIL(AC) VSS1 1 VREF - 200 V 2, 3

CTipA falling time t

F_CTipA n 5 ns 2

CTipA rising time tR_CTipA n 5 ns 2

Notes: 1. Refer to Overshoot and Undershoot Specifications.

2. CT Type-A inputs: CS_n, BG[1:0], BA[1:0], A[9:0], A10/AP, A11, A12/BC_n, A13, WE_n/A14, CAS_n/A15, RAS_n/A16,
A17, CKE, ACT_n, ODT, CLK_t, CLK_C, PAR.
3. VREFCA = 0.5 έ VDD.

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Figure 217: CT Type-A Input Slew Rate Definition

VIH(AC)_CTipAmin
VIH(DC)_CTipAmin

VREFCA

VIL(DC)_CTipAmax
VIL(AC)_CTipAmax

tF_CTipA tR_CTipA

Table 96: CT Type-B Input Levels

Parameter Symbol Min Max Unit Note
CTipB AC input high voltage VIH(AC) VREF + 300 VDD1 1 V 2, 3

CTipB DC input high voltage VIH(DC) VREF + 200 VDD V 2, 3

CTipB DC input low voltage VIL(DC) VSS VREF - 200 V 2, 3
CTipB AC input low voltage VIL(AC) VSS11 VREF - 300 V 2, 3

CTipB falling time t

F_CTipB n 5 ns 2

CTipB rising time t

R_CTipB n 5 ns 2

Notes: 1. Refer to Overshoot and Undershoot Specifications.

2. CT Type-B inputs: DML_n/DBIL_n, DMU_n/DBIU_n and DM_n/DBI_n.
3. VREFDQ should be 0.5 έ VDD

Figure 218: CT Type-B Input Slew Rate Definition

VIH(AC)_CTipBmin
VIH(DC)_CTipBmin

VREFDQ

VIL(DC)_CTipBmax
VIL(AC)_CTipBmax

tF_CTipB tR_CTipB

Table 97: CT Type-C Input Levels (CMOS)

Parameter Symbol Min Max Unit Note
CTipC AC input high voltage VIH(AC)_CTipC 0.8 έ VDD VDD1 V 2

CTipC DC input high voltage VIH(DC)_CTipC 0.7 έ VDD VDD V 2

CTipC DC input low voltage VIL(DC)_CTipC VSS 0.3 έ VDD V 2
CTipC AC input low voltage VIL(AC)_CTipC VSS1 0.2 έ VDD V 2

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Table 97: CT Type-C Input Levels (CMOS) (Continued)

Parameter Symbol Min Max Unit Note
CTipC falling time tF_CTipC n 10 ns 2

CTipC rising time t

R_CTipC n 10 ns 2

Notes: 1. Refer to Overshoot and Undershoot Specifications.

2. CT Type-C inputs: Alert_n.

Figure 219: CT Type-C Input Slew Rate Definition

VIH(AC)_TENmin
VIH(DC)_TENmin

VIL(DC)_TENmin
VIL(AC)_TENmin

tF_TEN tR_TEN

Table 98: CT Type-D Input Levels

Parameter Symbol Min Max Unit Note
CTipD AC input high voltage VIH(AC)_CTipD 0.8 έ VDD VDD V 4
CTipD DC input high voltage VIH(DC)_CTipD 0.7 έ VDD VDD V 2
CTipD DC input low voltage VIL(DC)_CTipD VSS 0.3 έ VDD V 1
CTipD AC input low voltage VIL(AC)_CTipD VSS 0.2 έ VDD V 5
Rising time t
R_RESET n 1 ρs 3

RESET pulse width - after power-up t

PW_RESET_S 1 n ρs

RESET pulse width - during power-up t

PW_RESET_L 200 n ρs

Notes: 1. After RESET_n is registered LOW, the RESET_n level must be maintained below VIL(DC)_RESET during tPW_RESET,
otherwise, the DRAM may not be reset.
2. After RESET_n is registered HIGH, the RESET_n level must be maintained above VIH(DC)_RESET, otherwise, operation
will be uncertain until it is reset by asserting RESET_n signal LOW.
3. Slope reversal (ring-back) during this level transition from LOW to HIGH should be mitigated as much as possible.
4. Overshoot should not exceed the VIN values in the Absolute Maximum Ratings table.
5. Undershoot should not exceed the VIN values in the Absolute Maximum Ratings table.
6. CT Type-D inputs: RESET_n; same requirements as in normal mode.

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Figure 220: CT Type-D Input Slew Rate Definition

tPW_RESET

VIH(AC)_RESETmin
VIH(DC)_RESETmin

VIL(DC)_RESETmax
VIL(AC)_RESETmax

tR_RESET

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Levels
Differential Inputs

Figure 221: $IFFERENTIAL !# 3WING AND h4IME %XCEEDING !# ,EVELv tDVAC

tDVAC

VIH,diff(AC)min

VIH,diff,min

CK_t, CK_c
0.0

VIL,diff,max

VIL,diff(AC)max

Half cycle tDVAC

Notes: 1. Differential signal rising edge from VIL,diff,max to VIH,diff(AC)min must be monotonic slope.

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2. Differential signal falling edge from IH,diff,min to VIL,diff(AC)max must be monotonic slope.

Table 99: Differential Input Swing Requirements for CK_t, CK_c

DDR4-1600 / DDR4-2400 /
1866 / 2133 2666 DDR4-2933 DDR4-3200
Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
Differential input high VIHdiff 150 Note 3 135 Note 3 125 Note 3 110 Note 3 mV 1
Differential input low VILdiff Note 3 n Note 3 -135 Note 3 -125 Note 3 -110 mV 1
Differential input high VIH- 2έ Note 3 2έ Note 3 2έ Note 3 2έ Note 3 V 2
(AC) diff(AC)
(VIH(AC) (VIH(AC) (VIH(AC) (VIH(AC)
- VREF) - VREF) - VREF) - VREF)
Differential input low VIL- Note 3 2έ Note 3 2έ Note 3 2έ Note 3 2έ V 2
(AC) diff(AC)
(VIL(AC) (VIL(AC) (VIL(AC) (VIL(AC)
- VREF) - VREF) - VREF) - VREF)

Notes: 1. Used to define a differential signal slew-rate.

2. For CK_t, CK_c use VIH(AC) and VIL(AC) of ADD/CMD and VREFCA.
3. These values are not defined; however, the differential signals (CK_t, CK_c) need to be within the respective limits,
VIH(DC)max and VIL(DC)min for single-ended signals as well as the limitations for overshoot and undershoot.

Table 100: Minimum Time AC Time tDVAC for CK

t
DVAC (ps) at |VIH,diff(AC) to VIL,diff(AC)|
Slew Rate (V/ns) 200mV TBDmV
>4.0 120 TBD
4.0 115 TBD
3.0 110 TBD
2.0 105 TBD
1.9 100 TBD
1.6 95 TBD
1.4 90 TBD
1.2 85 TBD
1.0 80 TBD
<1.0 80 TBD

Notes: 1. Below VIL(AC).

Single-Ended Requirements for CK Differential Signals

Each individual component of a differential signal (CK_t, CK_c) has to comply with certain require-
ments for single-ended signals. CK_t and CK_c have to reach approximately VSEHmin/VSEL,max, which
are approximately equal to the AC levels VIH(AC) and VIL(AC) for ADD/CMD signals in every half-cycle.
The applicable AC levels for ADD/CMD might differ per speed-bin, and so on. For example, if a value
other than 100mV is used for ADD/CMD VIH(AC) and VIL(AC) signals, then these AC levels also apply for
the single-ended signals CK_t and CK_c.

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While ADD/CMD signal requirements are with respect to VREFCA, the single-ended components of
differential signals have a requirement with respect to VDD/2; this is nominally the same. The transi-
tion of single-ended signals through the AC levels is used to measure setup time. For single-ended
components of differential signals the requirement to reach VSEL,max/VSEH,min has no bearing on
timing, but adds a restriction on the common mode characteristics of these signals.

Figure 222: Single-Ended Requirements for CK

VDD or VDDQ

VSEH,min

VDD/2 or VDDQ/2
VSEH
CK
VSEL,max

VSEL
VSS or VSSQ

Table 101: Single-Ended Requirements for CK

DDR4-1600 / 1866 /
2133 DDR4-2400 / 2666 DDR4-2933 / 3200
Parameter Symbol Min Max Min Max Min Max Unit Notes
Single-ended high level for VSEH VDD/2 + Note 3 VDD/2 + Note 3 VDD/2 + Note 3 V 1, 2
CK_t, CK_c 0.100 0.095 0.085
Single-ended low level for VSEL Note 3 VDD/2 - Note 3 VDD/2 - Note 3 VDD/2 - V 1, 2
CK_t, CK_c 0.100 0.095 0.085

Notes: 1. For CK_t, CK_c use VIH(AC) and VIL(AC) of ADD/CMD and VREFCA.
2. ADDR/CMD VIH(AC) and VIL(AC) based on VREFCA.
3. These values are not defined; however, the differential signal (CK_t, CK_c) need to be within the respective limits,
VIH(DC)max and VIL(DC)min for single-ended signals as well as the limitations for overshoot and undershoot.

Slew Rate Definitions for CK Differential Input Signals

Table 102: CK Differential Input Slew Rate Definition

Measured
Description From To Defined by
Differential input slew rate for rising edge VIL,diff,max VIH,diff,min |VIH,diff,min - VIL,diff,max|/ȟTRdiff
Differential input slew rate for falling edge VIH,diff,min VIL,diff,max |VIH,diff,min - VIL,diff,max|/ȟTFdiff

Notes: 1. The differential signal CK_t, CK_c must be monotonic between these thresholds.

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Figure 223: Differential Input Slew Rate Definition for CK_t, CK_c

CK Differential Input Cross Point Voltage

To guarantee tight setup and hold times as well as output skew parameters with respect to clock and
strobe, each cross point voltage of differential input signal CK_t, CK_c must meet the requirements
shown below. The differential input cross point voltage VIX(CK) is measured from the actual cross point
of true and complement signals to the midlevel between VDD and VSS.

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Figure 224: VIX(CK) Definition

VDD

CK_c

VIX(CK)
VDD/2
VIX(CK) VIX(CK)

CK_t
VSEH VSEL
VSS

Table 103: Cross Point Voltage For CK Differential Input Signals at DDR4-1600 through DDR4-2400
DDR4-1600, 1866, 2133, 2400
Parameter Sym Input Level Min Max
Differential input VIX(CK) VSEH > VDD/2 + 145mV N/A 120mV
cross point volt-
age relative to VDD/2 + 100mV ζ VSEH ζ VDD/2 + 145mV N/A (VSEH - VDD/2) - 25mV
VDD/2 for CK_t, VDD/2 - 145mV ζ VSEL ζ VDD/2 - 100mV n6DD/2 - VSEL) + 25mV N/A
CK_c
VSEL < VDD/2 - 145mV nM6 N/A

Table 104: Cross Point Voltage For CK Differential Input Signals at DDR4-2666 through DDR4-3200
DDR4-2666, 2933, 3200
Parameter Sym Input Level Min Max
Differential input VIX(CK) VSEH > VDD/2 + 145mV N/A 110mV
cross point volt-
age relative to VDD/2 + 90mV ζ VSEH ζ VDD/2 + 145mV N/A (VSEH - VDD/2) - 30mV
VDD/2 for CK_t, VDD/2 - 145mV ζ VSEL ζ VDD/2 - 90mV n6DD/2 - VSEL) + 30mV N/A
CK_c
VSEL < VDD/2 - 145mV nM6 N/A

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DQS Differential Input Signal Definition and Swing Requirements

Figure 225: Differential Input Signal Definition for DQS_t, DQS_c
DQS_t, DQS_c: Differential Input Voltage

VIH,diff,peak

Half cycle

0.0V

Half cycle

VIL,diff,peak

Table 105: DDR4-1600 through DDR4-2400 Differential Input Swing Requirements for DQS_t, DQS_c
DDR4-1600, 1866,
2133 DDR4-2400
Parameter Symbol Min Max Min Max Unit Notes
Peak differential input high voltage VIH,diff,peak 186 VDDQ 160 VDDQ mV 1, 2
Peak differential input low voltage VIL,diff,peak VSSQ n VSSQ n mV 1, 2

Notes: 1. Minimum and maximum limits are relative to single-ended portion and can be exceeded within allowed overshoot
and undershoot limits.
2. Minimum value point is used to determine differential signal slew-rate.

Table 106: DDR4-2633 through DDR4-3200 Differential Input Swing Requirements for DQS_t, DQS_c
DDR4-2666 DDR4-2933 DDR4-3200
Parameter Symbol Min Max Min Max Min Max Unit Notes
Peak differential input high volt- VIH,diff,peak 150 VDDQ 145 VDDQ 140 VDDQ mV 1, 2
age
Peak differential input low volt- VIL,diff,peak VSSQ n VSSQ n VSSQ n mV 1, 2
age

Notes: 1. Minimum and maximum limits are relative to single-ended portion and can be exceeded within allowed overshoot
and undershoot limits.
2. Minimum value point is used to determine differential signal slew-rate.
The peak voltage of the DQS signals are calculated using the following equations: VIH,dif,Peak voltage =
MAX(ft)
VIL,dif,Peak voltage = MIN(ft)
(ft) = DQS_t, DQS_c.
The MAX(f(t)) or MIN(f(t)) used to determine the midpoint from which to reference the ά35% window
of the exempt non-monotonic signaling shall be the smallest peak voltage observed in all UIs.

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Figure 226: DQS_t, DQS_c Input Peak Voltage Calculation and Range of Exempt non-Monotonic
Signaling

DQS_t, DQS_c: Single-Ended Input Voltages

DQS_t

+50%
+35%

MIN(ft) MAX(ft)

–35%
–50%

DQS_c

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Measurement Levels

DQS Differential Input Cross Point Voltage

To achieve tight RxMask input requirements as well as output skew parameters with respect to strobe,
the cross point voltage of differential input signals (DQS_t, DQS_c) must meet VIX_DQS,ratio in the table
below. The differential input cross point voltage VIX_DQS (VIX_DQS_FR and VIX_DQS_RF) is measured from
the actual cross point of DQS_t, DQS_c relative to the VDQS,mid of the DQS_t and DQS_c signals.
VDQS,mid is the midpoint of the minimum levels achieved by the transitioning DQS_t and DQS_c
signals, and noted by VDQS_trans. VDQS_trans is the difference between the lowest horizontal tangent
above VDQS,mid of the transitioning DQS signals and the highest horizontal tangent below VDQS,mid of
THE TRANSITIONING $13 SIGNALS ! NON MONOTONIC TRANSITIONING SIGNALS LEDGE IS EXEMPT OR NOT USED IN
determination of a horizontal tangent provided the said ledge occurs within ά35% of the midpoint of
either VIH.DIFF.Peak voltage (DQS_t rising) or VIL.DIFF.Peak voltage (DQS_c rising), as shown in the figure
below.
A secondary horizontal tangent resulting from a ring-back transition is also exempt in determination
OF A HORIZONTAL TANGENT 4HAT IS A FALLING TRANSITIONS HORIZONTAL TANGENT IS DERIVED FROM ITS NEGATIVE
SLOPE TO ZERO SLOPE TRANSITION POINT ! IN THE FIGURE BELOW AND A RING BACKS HORIZONTAL TANGENT IS
derived from its positive slope to zero slope transition (point B in the figure below) and is not a valid
HORIZONTAL TANGENT A RISING TRANSITIONS HORIZONTAL TANGENT IS DERIVED FROM ITS POSITIVE SLOPE TO ZERO
SLOPE TRANSITION POINT # IN THE FIGURE BELOW AND A RING BACKS HORIZONTAL TANGENT DERIVED FROM ITS
negative slope to zero slope transition (point D in the figure below) and is not a valid horizontal
tangent.

Figure 227: VIXDQS Definition

Lowest horizontal tanget above VDQS,mid
of the transitioning signals

C
DQS_t
DQS_t, DQS_c: Single-Ended Input Voltages

VDQS_trans
VIX_DQS,FR VIX_DQS,RF
VDQS,mid
VIX_DQS,RF VIX_DQS,FR VDQS_trans/2

DQS_c

Highest horizontal tanget below VDQS,mid

of the transitioning signals
VSSQ

Table 107: Cross Point Voltage For Differential Input Signals DQS
DDR4-1600, 1866, 2133, 2400,
2666, 2933, 3200
Parameter Symbol Min Max Unit Notes
DQS_t and DQS_c crossing relative to the VIX_DQS,ratio n 25 % 1, 2
midpoint of the DQS_t and DQS_c signal
swings
VDQS,mid to Vcent(midpoint) offset VDQS,mid_to_V- n Note 3 mV 2
cent

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Measurement Levels

Notes: 1. VIX_DQS,ratio is DQS VIX crossing (VIX_DQS,FR or VIX_DQS,RF) divided by VDQS_trans. VDQS_trans is the difference between
the lowest horizontal tangent above VDQS,midd of the transitioning DQS signals and the highest horizontal tangent
below VDQS,mid of the transitioning DQS signals.
2. VDQS,mid will be similar to the VREFDQ internal setting value (Vcent(midpoint) offset) obtained during VREF Training if
the DQS and DQs drivers and paths are matched.
3. The maximum limit shall not exceed the smaller of V IH,diff,DQS minimum limit or 50mV.

Slew Rate Definitions for DQS Differential Input Signals

Table 108: DQS Differential Input Slew Rate Definition

Measured
Description From To Defined by
Differential input slew rate for rising edge VIL,diff,DQS VIH,diff,DQS |VIH,diff,DQS - VIL,diff,DQS|/ȟTRdiff
Differential input slew rate for falling edge VIH,diff,DQS VIL,diff,DQS |VIHdiffDQS - VIL,diff,DQS|/ȟTFdiff

Notes: 1. The differential signal DQS_t, DQS_c must be monotonic between these thresholds.

Figure 228: Differential Input Slew Rate and Input Level Definition for DQS_t, DQS_c

Table 109: DDR4-1600 through DDR4-2400 Differential Input Slew Rate and Input Levels for DQS_t,
DQS_c
DDR4-1600, 1866, 2133 DDR4-2400
Parameter Symbol Min Max Min Max Unit Notes
Peak differential input high voltage VIH,diff,peak 186 VDDQ 160 VDDQ mV 1
Differential input high voltage VIH,diff,DQS 136 n 130 n mV 2, 3
Differential input low voltage VIL,diff,DQS n n n n mV 2, 3
Peak differential input low voltage VIL,diff,peak -VDDQ n -VDDQ n mV 1
DQS differential input slew rate SRIdiff 3.0 18 3.0 18 V/ns 4, 5

Notes: 1. Minimum and maximum limits are relative to single-ended portion and can be exceeded within allowed overshoot
and undershoot limits.
2. Differential signal rising edge from VIL,diff,DQS to VIH,diff,DQS must be monotonic slope.
3. Differential signal falling edge from VIH,diff,DQS to VIL,diff,DQS must be monotonic slope.
4. Differential input slew rate for rising edge from VIL,diff,DQS to VIH,diff,DQS is defined by |VIL,diff,min -
VIH,diff,max|/ȟTRdiff.

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Measurement Levels

5. Differential input slew rate for falling edge from VIH,diff,DQS to VIL,diff,DQS is defined by |VIL,diff,min -
VIH,diff,max|/ȟTFdiff.

Table 110: DDR4-2666 through DDR4-3200 Differential Input Slew Rate and Input Levels for DQS_t,
DQS_c
DDR4-2666 DDR4-2933 DDR4-3200
Parameter Symbol Min Max Min Max Min Max Unit Notes
Peak differential input VIH,diff,peak 150 VDDQ 145 VDDQ 140 VDDQ mV 1
high voltage
Differential input high VIH,diff,DQS 130 n 115 n 110 n mV 2, 3
voltage
Differential input low VIL,diff,DQS n n n n n n mV 2, 3
voltage
Peak differential input VIL,diff,peak VSSQ n VSSQ n VSSQ n mV 1
low voltage
DQS differential input SRIdiff 2.5 18 2.5 18 2.5 18 V/ns 4, 5
slew rate

Notes: 1. Minimum and maximum limits are relative to single-ended portion and can be exceeded within allowed overshoot
and undershoot limits.
2. Differential signal rising edge from VIL,diff,DQS to VIH,diff,DQS must be monotonic slope.
3. Differential signal falling edge from VIH,diff,DQS to VIL,diff,DQS must be monotonic slope.
4. Differential input slew rate for rising edge from VIL,diff,DQS to VIH,diff,DQS is defined by |VIL,diff,min -
VIH,diff,max|/ȟTRdiff.
5. Differential input slew rate for falling edge from VIH,diff,DQS to VIL,diff,DQS is defined by |VIL,diff,min -
VIH,diff,max|/ȟTFdiff.

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%LECTRICAL #HARACTERISTICS n /VERSHOOT AND 5NDERSHOOT
Specifications

%LECTRICAL #HARACTERISTICS n /VERSHOOT AND 5NDERSHOOT 3PECIFICATIONS

Address, Command, and Control Overshoot and Undershoot Specifications

Table 111: ADDR, CMD, CNTL Overshoot and Undershoot/Specifications

DDR4- DDR4- DDR4- DDR4- DDR4- DDR4- DDR4-
Description 1600 1866 2133 2400 2666 2933 3200 Unit
Address and control pins (A[17:0], BG[1:0], BA[1:0], CS_n, RAS_n, CAS_n, WE_n, CKE, ODT, C2-0)
Area A: Maximum peak amplitude above VDD 0.06 0.06 0.06 0.06 0.06 0.06 0.06 V
absolute MAX
Area B: Amplitude allowed between VDD and VDD 0.24 0.24 0.24 0.24 0.24 0.24 0.24 V
absolute MAX
Area C: Maximum peak amplitude allowed for 0.30 0.30 0.30 0.30 0.30 0.30 0.30 V
undershoot below VSS

Area A maximum overshoot area per 1tCK 0.0083 0.0071 0.0062 0.0055 0.0055 0.0055 0.0055 V/ns

Area B maximum overshoot area per 1tCK 0.2550 0.2185 0.1914 0.1699 0.1699 0.1699 0.1699 V/ns

Area C maximum undershoot area per 1tCK 0.2644 0.2265 0.1984 0.1762 0.1762 0.1762 0.1762 V/ns

Figure 229: ADDR, CMD, CNTL Overshoot and Undershoot Definition

Absolute MAX overshoot
A Overshoot area above VDD absolute MAX
VDD absolute MAX

B Overshoot area below VDD absolute MAX

and above VDD MAX
Volts (V)

VDD
1tCK
VSS

C Undershoot area below VSS

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Specifications

Clock Overshoot and Undershoot Specifications

Table 112: CK Overshoot and Undershoot/ Specifications

DDR4- DDR4- DDR4- DDR4- DDR4- DDR4- DDR4-
Description 1600 1866 2133 2400 2666 2933 3200 Unit
CLK_t, CLK_n
Area A: Maximum peak amplitude above VDD 0.06 0.06 0.06 0.06 0.06 0.06 0.06 V
absolute MAX
Area B: Amplitude allowed between VDD and 0.24 0.24 0.24 0.24 0.24 0.24 0.24 V
VDD absolute MAX
Area C: Maximum peak amplitude allowed for 0.30 0.30 0.30 0.30 0.30 0.30 0.30 V
undershoot below VSS
Area A maximum overshoot area per 1UI 0.0038 0.0032 0.0028 0.0025 0.0025 0.0025 0.0025 V/ns
Area B maximum overshoot area per 1UI 0.1125 0.0964 0.0844 0.0750 0.0750 0.0750 0.0750 V/ns
Area C maximum undershoot area per 1UI 0.1144 0.0980 0.0858 0.0762 0.0762 0.0762 0.0762 V/ns

Figure 230: CK Overshoot and Undershoot Definition

Absolute MAX overshoot
A Overshoot area above VDD absolute MAX
VDD absolute MAX

B Overshoot area below VDD absolute MAX

and above VDD MAX
Volts (V)

VDD
1UI
VSS

C Undershoot area below VSS

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Specifications

Data, Strobe, and Mask Overshoot and Undershoot Specifications

Table 113: Data, Strobe, and Mask Overshoot and Undershoot/ Specifications
DDR4- DDR4- DDR4- DDR4- DDR4- DDR4- DDR4-
Description 1600 1866 2133 2400 2666 2933 3200 Unit
DQS_t, DQS_n, LDQS_t, LDQS_n, UDQS_t, UDQS_n, DQ[0:15], DM/DBI, UDM/UDBI, LDM/LDBI,
Area A: Maximum peak amplitude above 0.16 0.16 0.16 0.16 0.16 0.16 0.16 V
VDDQ absolute MAX
Area B: Amplitude allowed between VDDQ and 0.24 0.24 0.24 0.24 0.24 0.24 0.24 V
VDDQ absolute MAX
Area C: Maximum peak amplitude allowed for 0.30 0.30 0.30 0.30 0.30 0.30 0.30 V
undershoot below VSSQ
Area D: Maximum peak amplitude below VSSQ 0.10 0.10 0.10 0.10 0.10 0.10 0.10 V
absolute MIN
Area A maximum overshoot area per 1UI 0.0150 0.0129 0.0113 0.0100 0.0100 0.0100 0.0100 V/ns
Area B maximum overshoot area per 1UI 0.1050 0.0900 0.0788 0.0700 0.0700 0.0700 0.0700 V/ns
Area C maximum undershoot area per 1UI 0.1050 0.0900 0.0788 0.0700 0.0700 0.0700 0.0700 V/ns
Area D maximum undershoot area per 1UI 0.0150 0.0129 0.0113 0.0100 0.0100 0.0100 0.0100 V/ns

Figure 231: Data, Strobe, and Mask Overshoot and Undershoot Definition
Absolute MAX overshoot
A Overshoot area above VDDQ absolute MAX
VDDQ absolute MAX

B Overshoot area below VDDQ absolute MAX

and above VDDQ MAX
Volts (V)

VDDQ
1UI
VSSQ

C Undershoot area below VSSQ MIN and

above VSSQ absolute MIN
VSSQ absolute MIN
D Undershoot area below VSSQ absolute MIN
Absolute MAX undershoot

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Levels

%LECTRICAL #HARACTERISTICS n !# AND $# /UTPUT -EASUREMENT ,EVELS

Single-Ended Outputs

Table 114: Single-Ended Output Levels

Parameter Symbol DDR4-1600 to DDR4-3200 Unit
DC output high measurement level (for IV curve linearity) VOH(DC) 1.1 έ VDDQ V
DC output mid measurement level (for IV curve linearity) VOM(DC) 0.8 έ VDDQ V
DC output low measurement level (for IV curve linearity) VOL(DC) 0.5 έ VDDQ V
AC output high measurement level (for output slew rate) VOH(AC) (0.7 + 0.15) έ VDDQ V
AC output low measurement level (for output slew rate) VOL(AC) (0.7 - 0.15) έ VDDQ V

Notes: 1. The swing of ά0.15 έ VDDQ is based on approximately 50% of the static single-ended output peak-to-peak swing
with a driver impedance of RZQ/7 and an effective test load of 50ȳ to VTT = VDDQ.

Using the same reference load used for timing measurements, output slew rate for falling and rising
edges is defined and measured between VOL(AC) and VOH(AC) for single-ended signals.

Table 115: Single-Ended Output Slew Rate Definition

Measured
Description From To Defined by
Single-ended output slew rate for rising edge VOL(AC) VOH(AC) [VOH(AC) - VOL(AC)]/ȟTRse
Single-ended output slew rate for falling edge VOH(AC) VOL(AC) [VOH(AC) - VOL(AC)]/ȟTFse

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Figure 232: Single-ended Output Slew Rate Definition

TRse

VOH(AC)
Single-Ended Output Voltage (DQ)

VOL(AC)

TFse

Table 116: Single-Ended Output Slew Rate

DDR4-1600/ 1866 / 2133 /
2400 DDR4-2666 DDR4-2933 / 3200
Parameter Symbol Min Max Min Max Min Max Unit
Single-ended output SRQse 4 9 4 9 4 9 V/ns
slew rate

Notes: 1. SR = slew rate; Q = query output; se = single-ended signals.

2. In two cases a maximum slew rate of 12V/ns applies for a single DQ signal within a byte lane:
s Case 1 is defined for a single DQ signal within a byte lane that is switching into a certain direction
(either from HIGH-to-LOW or LOW-to-HIGH) while all remaining DQ signals in the same byte lane
are static (they stay at either HIGH or LOW).
s Case 2 is defined for a single DQ signal within a byte lane that is switching into a certain direction
(either from HIGH-to-LOW or LOW-to-HIGH) while all remaining DQ signals in the same byte lane
are switching into the opposite direction (from LOW-to-HIGH or HIGH-to-LOW, respectively). For
the remaining DQ signal switching into the opposite direction, the standard maximum limit of 9
V/ns applies.
3. For RON = RZQ/7.

Differential Outputs

Table 117: Differential Output Levels

Parameter Symbol DDR4-1600 to DDR4-3200 Unit
AC differential output high measurement level (for output slew VOH,diff(AC) 0.3 έ VDDQ V
rate)
AC differential output low measurement level (for output slew VOL,diff(AC) n έ VDDQ V
rate)

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Notes: 1. The swing of ά0.3 έ VDDQ is based on approximately 50% of the static single-ended output peak-to-peak swing
with a driver impedance of RZQ/7 and an effective test load of 50ȳ to VTT = VDDQ at each differential output.

Using the same reference load used for timing measurements, output slew rate for falling and rising
edges is defined and measured between VOL,diff(AC) and VOH,diff(AC) for differential signals.

Table 118: Differential Output Slew Rate Definition

Measured
Description From To Defined by
Differential output slew rate for rising edge VOL,diff(AC) VOH,diff(AC) [VOH,diff(AC) - VOL,diff(AC)]/ȟTRdiff
Differential output slew rate for falling edge VOH,diff(AC) VOL,diff(AC) [VOH,diff(AC) - VOL,diff(AC)]/ȟTFdiff

Figure 233: Differential Output Slew Rate Definition

TRdiff
Differential Input Voltage (DQS_t, DQS_c)

VOH,diff(AC)

VOL,diff(AC)

TFdiff

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Table 119: Differential Output Slew Rate

DDR4-1600 / 1866 / 2133 /
2400 DDR4-2666 DDR4-2933 / 3200
Parameter Symbol Min Max Min Max Min Max Unit
Differential output slew SRQdiff 8 18 8 18 8 18 V/ns
rate

Notes: 1. SR = slew rate; Q = query output; diff = differential signals.

2. For RON = RZQ/7.

Reference Load for AC Timing and Output Slew Rate

The effective reference load of 50ȳ to VTT = VDDQ and driver impedance of RZQ/7 for each output was
used in defining the relevant AC timing parameters of the device as well as output slew rate measure-
ments.
RON nominal of DQ, DQS_t and DQS_c drivers uses 34 ohms to specify the relevant AC timing param-
eter values of the device. The maximum DC high level of output signal = 1.0 έ VDDQ, the minimum DC
low level of output signal = { 34 /( 34 + 50 ) } έ VDDQ = 0.4 έ VDDQ.
The nominal reference level of an output signal can be approximated by the following: The center of
maximum DC high and minimum DC low = { ( 1 + 0.4 ) / 2 } έ VDDQ = 0.7 έ VDDQ. The actual reference
level of output signal might vary with driver RON and reference load tolerances. Thus, the actual refer-
ENCE LEVEL OR MIDPOINT OF AN OUTPUT SIGNAL IS AT THE WIDEST PART OF THE OUTPUT SIGNALS EYE

Figure 234: Reference Load For AC Timing and Output Slew Rate

VDDQ VTT = VDDQ

DQ, DQS_t, DQS_c,

DM, TDQS_t, TDQS_c
CK_t, CK_c
DUT
RTT = 50ȍ

VSSQ

Timing reference point

Connectivity Test Mode Output Levels

Table 120: Connectivity Test Mode Output Levels

Parameter Symbol DDR4-1600 to DDR4-3200 Unit
DC output high measurement level (for IV curve linearity) VOH(DC) 1.1 έ VDDQ V
DC output mid measurement level (for IV curve linearity) VOM(DC) 0.8 έ VDDQ V
DC output low measurement level (for IV curve linearity) VOL(DC) 0.5 έ VDDQ V
DC output below measurement level (for IV curve linearity) VOB(DC) 0.2 έ VDDQ V
AC output high measurement level (for output slew rate) VOH(AC) VTT + (0.1 έ VDDQ) V

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Levels

Table 120: Connectivity Test Mode Output Levels (Continued)

Parameter Symbol DDR4-1600 to DDR4-3200 Unit
AC output low measurement level (for output slew rate) VOL(AC) VTT - (0.1 έ VDDQ) V

Notes: 1. Driver impedance of RZQ/7 and an effective test load of 50ȳ to VTT = VDDQ.

Figure 235: Connectivity Test Mode Reference Test Load

VDDQ
DQ, DQS_t, DQS_c,
LDQS_t, LDQS_c, UDQS_t, UDQS_c,
DM, LDM, HDM, TDQS_t, TDQS_c
CT_Inputs
DUT 0.5 × VDDQ
RTT = 50 ȍ

VSSQ

Timing reference point

Figure 236: Connectivity Test Mode Output Slew Rate Definition

VOH(AC)

VTT
0.5 x VDD

VOL(AC)

TFoutput_CT TRoutput_CT

Table 121: Connectivity Test Mode Output Slew Rate

DDR4-1600 / 1866 / DDR4-2933 /
2133 / 2400 DDR4-2666 3200
Parameter Symbol Min Max Min Max Min Max Unit
Output signal falling TF_output_CT n 10 n 10 n 10 ns/V
time
Output signal rising time TR_output_CT n 10 n 10 n 10 ns/V

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%LECTRICAL #HARACTERISTICS n !# AND $# /UTPUT $RIVER
Characteristics

%LECTRICAL #HARACTERISTICS n !# AND $# /UTPUT $RIVER #HARACTERISTICS

Connectivity Test Mode Output Driver Electrical Characteristics
The DDR4 driver supports special values during connectivity test mode. These RON values are refer-
enced in this section. A functional representation of the output buffer is shown in the figure below.

Figure 237: Output Driver During Connectivity Test Mode

Chip in drive mode

Output driver
VDDQ

IPU_CT

To
RONPU_CT
other
circuitry
DQ
like
RCV, IOUT
RONPD_CT
...
VOUT
IPD_CT

VSSQ

The output driver impedance, RON, is determined by the value of the external reference resistor RZQ as
follows: RON = RZQ/7. This targets 34ȳ with nominal RZQ = 240ȳ; however, connectivity test mode uses
uncalibrated drivers and only a maximum target is defined. Mismatch between pull up and pull down
is undefined.
The individual pull-up and pull-down resistors (RONPu_CT and RONPd_CT) are defined as follows:
RONPu_CT when RONPd_CT is off:
VDDQ - VOUT
RONPU_CT =
IOUT

RONPD_CT when RONPU_CT is off:

VOUT
RONPD_CT =
IOUT

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Characteristics

Table 122: Output Driver Electrical Characteristics During Connectivity Test Mode
RON,nom_CT Resistor VOUT Min Nom Max Unit
VOB(DC) = 0.2 έ VDDQ N/A N/A 1.9 RZQ/7
VOL(DC) = 0.5 έ VDDQ N/A N/A 2.0 RZQ/7
RONPD_CT
VOM(DC) = 0.8 έ VDDQ N/A N/A 2.2 RZQ/7
VOH(DC) = 1.1 έ VDDQ N/A N/A 2.5 RZQ/7
34ȳ
VOB(DC) = 0.2 έ VDDQ N/A N/A 1.9 RZQ/7
VOL(DC) = 0.5 έ VDDQ N/A N/A 2.0 RZQ/7
RONPU_CT
VOM(DC) = 0.8 έ VDDQ N/A N/A 2.2 RZQ/7
VOH(DC) = 1.1 έ VDDQ N/A N/A 2.5 RZQ/7

Notes: 1. Assumes RZQ = 240ȳ; ZQ calibration not required.

Output Driver Electrical Characteristics

The DDR4 driver supports two RON values. These RON values are referred to as strong mode (low RON:
34ȳ) and weak mode (high RON: 48ȳ). A functional representation of the output buffer is shown in the
figure below.

Figure 238: Output Driver: Definition of Voltages and Currents

Chip in drive mode

Output driver
VDDQ

IPU

To
RONPU
other
circuitry
DQ
like
RCV, IOUT
RONPD
...
VOUT
IPD

VSSQ

The output driver impedance, RON, is determined by the value of the external reference resistor RZQ as
follows: RON(34) = RZQ/7, or RON(48) = RZQ/5. This provides either a nominal 34.3ȳ ά10% or 48ȳ ά10%
with nominal RZQ = 240ȳ.
The individual pull-up and pull-down resistors (RONPu and RONPd) are defined as follows:
RONPu when RONPd is off:

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Characteristics

VDDQ - VOUT
RONPU =
IOUT

RONPD when RONPU is off:

VOUT
RONPD =
IOUT

Table 123: Strong Mode (34ȳ) Output Driver Electrical Characteristics

RON,nom Resistor VOUT Min Nom Max Unit Notes
VOL(DC) = 0.5 έ VDDQ 0.73 1.00 1.10 RZQ/7 1, 2, 3
RON34PD VOM(DC) = 0.8 έ VDDQ 0.83 1.00 1.10 RZQ/7 1, 2, 3
VOH(DC) = 1.1 έ VDDQ 0.83 1.00 1.25 RZQ/7 1, 2, 3
34ȳ
VOL(DC) = 0.5 έ VDDQ 0.90 1.00 1.25 RZQ/7 1, 2, 3
RON34PU VOM(DC) = 0.8 έ VDDQ 0.90 1.00 1.10 RZQ/7 1, 2, 3
VOH(DC) = 1.1 έ VDDQ 0.80 1.00 1.10 RZQ/7 1, 2, 3
Mismatch between pull-up and VOM(DC) = 0.8 έ VDDQ 10 n 23 % 1, 2, 3,
pull-down, MMPUPD 4, 6, 7
Mismatch between DQ to DQ within VOM(DC) = 0.8 έ VDDQ n n 10 % 1, 2, 3,
byte variation pull-up, MMPUdd 4, 5
Mismatch between DQ to DQ within VOM(DC) = 0.8 έ VDDQ - n 10 % 1, 2, 3,
byte variation pull-down, MMPDdd 4, 6, 7

Notes: 1. The tolerance limits are specified after calibration with stable voltage and temperature. For the behavior of the
tolerance limits if temperature or voltage changes after calibration, see following section on voltage and tempera-
ture sensitivity.
2. The tolerance limits are specified under the condition that VDDQ = VDD and that VSSQ = VSS.
3. Micron recommends calibrating pull-down and pull-up output driver impedances at 0.8 έ VDDQ. Other calibration
schemes may be used to achieve the linearity specification shown above; for example, calibration at 0.5 έ VDDQ
and 1.1 VDDQ.
4. DQ-to-DQ mismatch within byte variation for a given component including DQS_t and DQS_c (characterized).
5. Measurement definition for mismatch between pull-up and pull-down, MMPUPD:
Measure both RONPU and RONPD at 0.8 έ VDDQ separately; RON,nom is the nominal RON value:
RONPU - RONPD
MMPUPD = × 100
RON,nom
6. RON variance range ratio to RON nominal value in a given component, including DQS_t and DQS_c:
RONPU,max - RONPU,min
MMPUDD = × 100
RON,nom

RONPD,max - RONPD,min
MMPDDD = × 100
RON,nom
7. The lower and upper bytes of a x16 are each treated on a per byte basis.
8. 4HE MINIMUM VALUES ARE DERATED BY  WHEN THE DEVICE OPERATES BETWEEN nιC and 0ιC (TC).

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Characteristics

9. Assumes RZQ = 240ȳ; entire operating temperature range after proper ZQ calibration.

Table 124: Weak Mode (48ȳ) Output Driver Electrical Characteristics

RON,nom Resistor VOUT Min Nom Max Unit Notes
48ȳ RON48PD VOL(DC) = 0.5 έ VDDQ 0.73 1.00 1.10 RZQ/5 1, 2, 3
VOM(DC) = 0.8 έ VDDQ 0.83 1.00 1.10 RZQ/5 1, 2, 3
VOH(DC) = 1.1 έ VDDQ 0.83 1.00 1.25 RZQ/5 1, 2, 3
RON48PU VOL(DC) = 0.5 έ VDDQ 0.90 1.00 1.25 RZQ/5 1, 2, 3
VOM(DC) = 0.8 έ VDDQ 0.90 1.00 1.10 RZQ/5 1, 2, 3
VOH(DC) = 1.1 έ VDDQ 0.80 1.00 1.10 RZQ/5 1, 2, 3
Mismatch between pull-up and VOM(DC) = 0.8 έ VDDQ 10 n 23 % 1, 2, 3, 4,
pull-down, MMPUPD 6, 7
Mismatch between DQ to DQ VOM(DC) = 0.8 έ VDDQ n n 10 % 1, 2, 3, 4, 5
within byte variation pull-up,
MMPUdd
Mismatch between DQ to DQ VOM(DC) = 0.8 έ VDDQ n n 10 % 1, 2, 3, 4,
within byte variation pull-down, 6, 7
MMPDdd

Notes: 1. The tolerance limits are specified after calibration with stable voltage and temperature. For the behavior of the
tolerance limits if temperature or voltage changes after calibration, see following section on voltage and tempera-
ture sensitivity.
2. The tolerance limits are specified under the condition that VDDQ = VDD and that VSSQ = VSS.
3. Micron recommends calibrating pull-down and pull-up output driver impedances at 0.8 έ VDDQ. Other calibration
schemes may be used to achieve the linearity specification shown above; for example, calibration at 0.5 έ VDDQ
and 1.1 VDDQ.
4. DQ-to-DQ mismatch within byte variation for a given component including DQS_t and DQS_c (characterized).
5. Measurement definition for mismatch between pull-up and pull-down, MMPUPD:
Measure both RONPU and RONPD at 0.8 έ VDDQ separately; RON,nom is the nominal RON value:

RONPU - RONPD
MMPUPD = × 100
RON,nom
6. RON variance range ratio to RON nominal value in a given component, including DQS_t and DQS_c:

RONPU,max - RONPU,min
MMPUDD = × 100
RON,nom

RONPD,max - RONPD,min
MMPDDD = × 100
RON,nom
7. The lower and upper bytes of a x16 are each treated on a per byte basis.
8. 4HE MINIMUM VALUES ARE DERATED BY  WHEN THE DEVICE OPERATES BETWEEN nιC and 0ιC (TC).
9. Assumes RZQ = 240ȳ; entire operating temperature range after proper ZQ calibration

Output Driver Temperature and Voltage Sensitivity

If temperature and/or voltage change after calibration, the tolerance limits widen according to the
equations and tables below.

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Characteristics

ȟT = T - T(@calibration); ȟV = VDDQ - VDDQ(@ calibration); VDD = VDDQ

Table 125: Output Driver Sensitivity Definitions

Symbol Min Max Unit
RONPU@ VOH(DC) 0.6 - dRONdTH έ |ȟT| - dRONdVH έ |ȟV| 1.1 _ dRONdTH έ |ȟT| + dRONdVH έ |ȟV| RZQ/6
RON@ VOM(DC) 0.9 - dRONdTM έ |ȟT| - dRONdVM έ |ȟV| 1.1 + dRONdTM έ |ȟT| + dRONdVM έ |ȟV| RZQ/6
RONPD@ VOL(DC) 0.6 - dRONdTL έ |ȟT| - dRONdVL έ |ȟV| 1.1 + dRONdTL έ |ȟT| + dRONdVL έ |ȟV| RZQ/6

Table 126: Output Driver Voltage and Temperature Sensitivity

Voltage and Temperature Range
Symbol Min Max Unit
dRONdTM 0 1.5 %/ιC
dRONdVM 0 0.15 %/mV
dRONdTL 0 1.5 %/ιC
dRONdVL 0 0.15 %/mV
dRONdTH 0 1.5 %/ιC
dRONdVM 0 0.15 %/mV

Alert Driver
A functional representation of the alert output buffer is shown in the figure below. Output driver
impedance, RON, is defined as follows.

Figure 239: Alert Driver

Alert driver

DRAM
Alert
IOUT
RONPD VOUT

IPD
VSSQ

RONPD when RONPU is off:

VOUT
RONPD =
IOUT

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Characteristics

Table 127: Alert Driver Voltage

RON,nom Register VOUT Min Nom Max Unit
N/A RONPD VOL(DC) = 0.1 έ VDDQ 0.3 N/A 1.2 RZQ/7
VOM(DC) = 0.8 έ VDDQ 0.4 N/A 1.2 RZQ/7
VOH(DC) = 1.1 έ VDDQ 0.4 N/A 1.4 RZQ/7

Notes: 1. VDDQ voltage is at VDDQ(DC).

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%LECTRICAL #HARACTERISTICS n /N $IE 4ERMINATION #HARACTERISTICS

ODT Levels and I-V Characteristics
On-die termination (ODT) effective resistance settings are defined and can be selected by any or all of
the following options:
s MR1[10:8] (RTT(NOM)): Disable, 240 ohms, 120 ohms, 80 ohms, 60 ohms, 48 ohms, 40 ohms, and 34
ohms.
s MR2[11:9] (RTT(WR)): Disable, 240 ohms,120 ohms, and 80 ohms.
s MR5[8:6] (RTT(Park)): Disable, 240 ohms, 120 ohms, 80 ohms, 60 ohms, 48 ohms, 40 ohms, and 34
ohms.

ODT is applied to the following inputs:

s x4: DQ, DM_n, DQS_t, and DQS_c inputs.
s x8: DQ, DM_n, DQS_t, DQS_c, TDQS_t, and TDQS_c inputs.
s x16: DQ, LDM_n, UDM_n, LDQS_t, LDQS_c, UDQS_t, and UDQS_c inputs.

A functional representation of ODT is shown in the figure below.

Figure 240: ODT Definition of Voltages and Currents

Chip in termination mode

ODT
VDDQ

RTT
To other
circuitry
like RCV,
DQ
...
IOUT

VOUT

VSSQ

Table 128: ODT DC Characteristics

RTT VOUT Min Nom Max Unit Notes
240 ohm VOL(DC) = 0.5 έ VDDQ 0.9 1 1.25 RZQ 1, 2, 3
VOM(DC) = 0.8 έ VDDQ 0.9 1 1.1 RZQ 1, 2, 3
VOH(DC) = 1.1 έ VDDQ 0.8 1 1.1 RZQ 1, 2, 3
120 ohm VOL(DC) = 0.5 έ VDDQ 0.9 1 1.25 RZQ/2 1, 2, 3
VOM(DC) = 0.8 έ VDDQ 0.9 1 1.1 RZQ/2 1, 2, 3
VOH(DC) = 1.1 έ VDDQ 0.8 1 1.1 RZQ/2 1, 2, 3
80 ohm VOL(DC) = 0.5 έ VDDQ 0.9 1 1.25 RZQ/3 1, 2, 3
VOM(DC) = 0.8 έ VDDQ 0.9 1 1.1 RZQ/3 1, 2, 3
VOH(DC) = 1.1 έ VDDQ 0.8 1 1.1 RZQ/3 1, 2, 3

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Table 128: ODT DC Characteristics (Continued)

RTT VOUT Min Nom Max Unit Notes
60 ohm VOL(DC) = 0.5 έ VDDQ 0.9 1 1.25 RZQ/4 1, 2, 3
VOM(DC) = 0.8 έ VDDQ 0.9 1 1.1 RZQ/4 1, 2, 3
VOH(DC) = 1.1 έ VDDQ 0.8 1 1.1 RZQ/4 1, 2, 3
48 ohm VOL(DC) = 0.5 έ VDDQ 0.9 1 1.25 RZQ/5 1, 2, 3
VOM(DC) = 0.8 έ VDDQ 0.9 1 1.1 RZQ/5 1, 2, 3
VOH(DC) = 1.1 έ VDDQ 0.8 1 1.1 RZQ/5 1, 2, 3
40 ohm VOL(DC) = 0.5 έ VDDQ 0.9 1 1.25 RZQ/6 1, 2, 3
VOM(DC) = 0.8 έ VDDQ 0.9 1 1.1 RZQ/6 1, 2, 3
VOH(DC) = 1.1 έ VDDQ 0.8 1 1.1 RZQ/6 1, 2, 3
34 ohm VOL(DC) = 0.5 έ VDDQ 0.9 1 1.25 RZQ/7 1, 2, 3
VOM(DC) = 0.8 έ VDDQ 0.9 1 1.1 RZQ/7 1, 2, 3
VOH(DC) = 1.1 έ VDDQ 0.8 1 1.1 RZQ/7 1, 2, 3
DQ-to-DQ mismatch VOM(DC) = 0.8 έ VDDQ 0 n 10 % 1, 2, 4, 5, 6
within byte

Notes: 1. The tolerance limits are specified after calibration to 240 ohm ά1% resistor with stable voltage and temperature.
For the behavior of the tolerance limits if temperature or voltage changes after calibration, see ODT Temperature
and Voltage Sensitivity.
2. Micron recommends calibrating pull-up ODT resistors at 0.8 έ VDDQ. Other calibration schemes may be used to
achieve the linearity specification shown here.
3. The tolerance limits are specified under the condition that VDDQ = VDD and VSSQ = VSS.
4. The DQ-to-DQ mismatch within byte variation for a given component including DQS_t and DQS_c.
5. RTT variance range ratio to RTT nominal value in a given component, including DQS_t and DQS_c.

RTT(MAX) - RTT(MIN)
DQ-to-DQ mismatch = × 100
RTT(NOM)
6. DQ-to-DQ mismatch for a x16 device is treated as two separate bytes.
7. &OR )4 !4 AND 54 DEVICES THE MINIMUM VALUES ARE DERATED BY  WHEN THE DEVICE OPERATES BETWEEN nιC and
0ιC (TC).

ODT Temperature and Voltage Sensitivity

If temperature and/or voltage change after calibration, the tolerance limits widen according to the
following equations and tables.
ȟT = T - T(@ calibration); ȟV = VDDQ - VDDQ(@ calibration); VDD = VDDQ

Table 129: ODT Sensitivity Definitions

Parameter Min Max Unit
RTT@ 0.9 - dRTTdT έ |ȟT| - dRTTdV έ |ȟV| 1.6 + dRTTdTH έ |ȟT| + dRTTdVH έ |ȟV| RZQ/n

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Table 130: ODT Voltage and Temperature Sensitivity

Parameter Min Max Unit
dRTTdT 0 1.5 %/ιC
dRTTdV 0 0.15 %/mV

ODT Timing Definitions

The reference load for ODT timings is different than the reference load used for timing measurements.

Figure 241: ODT Timing Reference Load

VDDQ

DQ, DQS_t, DQS_c,

DM, TDQS_t, TDQS_c
CK_t, CK_c
DUT
RTT = 50ȍ

VSSQ VTT = VSSQ

Timing reference point

ODT Timing Definitions and Waveforms

Definitions fortADC, tAONAS, and tAOFAS are provided in the 4 and shown in 3 and 5. Measurement
reference settings are provided in the subsequent 5.

The tADC for the dynamic ODT case and read disable ODT cases are represented by tADC of Direct
ODT Control case.

Table 131: ODT Timing Definitions

Parameter Begin Point Definition End Point Definition Figure
tADC Rising edge of CK_t, CK_c defined by the end point of DOD- Extrapolated point at VRTT,nom 3
TLoff
Rising edge of CK_t, CK_c defined by the end point of DOD- Extrapolated point at VSSQ 3
TLon
Rising edge of CK_t, CK_c defined by the end point of Extrapolated point at VRTT,nom 4
ODTLcnw
Rising edge of CK_t, CK_c defined by the end point of Extrapolated point at VSSQ 4
ODTLcwn4 or ODTLcwn8
t
AONAS Rising edge of CK_t, CK_c with ODT being first registered Extrapolated point at VSSQ 5
HIGH
t
AOFAS Rising edge of CK_t, CK_c with ODT being first registered Extrapolated point at VRTT,nom 5
LOW

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Table 132: Reference Settings for ODT Timing Measurements

Measure RTT(Park) RTT(NOM) RTT(WR) VSW1 VSW2 Note
Parameter
t
ADC Disable RZQ/7 (34ȳ) n 0.20V 0.40V 1, 2, 4
n RZQ/7 (34ȳ) High-Z 0.20V 0.40V 1, 3, 5
tAONAS Disable RZQ/7 (34ȳ) n 0.20V 0.40V 1, 2, 6
tAOFAS Disable RZQ/7 (34ȳ) n 0.20V 0.40V 1, 2, 6

Notes: 1. MR settings are as follows: MR1 has A10 = 1, A9 = 1, A8 = 1 for RTT(NOM) setting; MR5 has A8 = 0, A7 = 0, A6 = 0 for
RTT(Park) setting; and MR2 has A11 = 0, A10 = 1, A9 = 1 for RTT(WR) setting.
2. ODT state change is controlled by ODT pin.
3. ODT state change is controlled by a WRITE command.
4. Refer to Figure 3.
5. Refer to Figure 4.
6. Refer to Figure 5.

Figure 242: tADC Definition with Direct ODT Control

DODTLoff Begin point: Rising edge DODTLon Begin point: Rising edge
of CK_t, CK_c defined of CK_t, CK_c defined
by the end point of by the end point of
DODTLoff DODTLon
CK_c

CK_t

tADC tADC

End point: Extrapolated

VRTT,nom point at VRTT,nom VRTT,nom

Vsw2
DQ, DM
DQS_t, DQS_c Vsw1
TDQS_t, TDQS_c End point: Extrapolated
VSSQ VSSQ point at VSSQ

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Figure 243: tADC Definition with Dynamic ODT Control

ODTLcnw Begin point: Rising edge ODTLcnw4/8 Begin point: Rising edge
of CK_t, CK_c defined of CK_t, CK_c defined
by the end point of by the end point of
ODTLcnw ODTLcnw4 or ODTLcnw8
CK_c

CK_t

tADC tADC

End point: Extrapolated

VRTT,nom point at VRTT,nom VRTT,nom

Vsw2
DQ, DM
DQS_t, DQS_c Vsw1
TDQS_t, TDQS_c End point: Extrapolated
VSSQ VSSQ point at VSSQ

Figure 244: tAOFAS and tAONAS Definitions

Rising edge of CK_t, CK_c Rising edge of CK_t, CK_c
with ODT being first with ODT being first
registered LOW registered HIGH

CK_c

CK_t

tAOFAS tAONAS

End point: Extrapolated

VRTT,nom point at VRTT_NOM VRTT,nom

Vsw2
DQ, DM
DQS_t, DQS_c Vsw1
TDQS_t, TDQS_c End point: Extrapolated
VSSQ VSSQ point at VSSQ

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DRAM Package Electrical Specifications

DRAM Package Electrical Specifications

Table 133: DRAM Package Electrical Specifications for x4 and x8 Devices

1600/1866/2133/ 2933 3200
2400/2666
Parameter Symbol Min Max Min Max Min Max Unit Notes
Input/out- Zpkg ZIO 45 85 48 85 48 85 ohm 1, 2, 4
put
Package delay TdIO 14 42 14 40 14 40 ps 1, 3, 4
Lpkg LIO n 3.3 n 3.3 n 3.3 nH 10
Cpkg CIO n 0.78 n 0.78 n 0.78 pF 11
DQS_t, Zpkg ZIO DQS 45 85 48 85 48 85 ohm 1, 2
DQS_c
Package delay TdIO DQS 14 42 14 40 14 40 ps 1, 3
Delta Zpkg DZIO DQS n 10 n 10 n 10 ohm 1, 2, 6
Delta delay DTdIO DQS n 5 n 5 n 5 ps 1, 3, 6
Lpkg LIO DQS n 3.3 n 3.3 n 3.3 nH 10
Cpkg CIO DQS n 0.78 n 0.78 n 0.78 pF 11
Input CTRL Zpkg ZI CTRL 50 90 50 90 50 90 ohm 1, 2, 8
pins
Package delay TdI CTRL 14 42 14 40 14 40 ps 1, 3, 8
Lpkg LI CTRL n 3.4 n 3.4 n 3.4 nH 10
Cpkg CI CTRL n 0.7 n 0.7 n 0.7 pF 11
Input CMD Zpkg ZI ADD CMD 50 90 50 90 50 90 ohm 1, 2, 7
ADD pins
Package delay TdI ADD CMD 14 45 14 40 14 40 ps 1, 3, 7
Lpkg LI ADD CMD n 3.6 n 3.6 n 3.6 nH 10
Cpkg CI ADD CMD n 0.74 n 0.74 n 0.74 pF 11
CK_t, CK_c Zpkg ZCK 50 90 50 90 50 90 ohm 1, 2
Package delay TdCK 14 42 14 42 14 42 ps 1, 3
Delta Zpkg DZDCK n 10 n 10 n 10 ohm 1, 2, 5
Delta delay DTdDCK n 5 n 5 n 5 ps 1, 3, 5
Lpkg LI CLK n 3.4 n 3.4 n 3.4 nH 10
Cpkg CI CLK n 0.7 n 0.7 n 0.7 pF 11
ZQ Zpkg ZO ZQ n 100 n 100 n 100 ohm 1, 2
ZQ delay TdO ZQ 20 90 20 90 20 90 ps 1, 3
ALERT Zpkg ZO ALERT 40 100 40 100 40 100 ohm 1, 2
ALERT delay TdO ALERT 20 55 20 55 20 55 ps 1, 3

Notes: 1. This parameter is not subject to a production test; it is verified by design and characterization and are provided
for reference; system signal simulations should not use these values but use the Micron package model. The
package parasitic (L and C) are validated using package only samples. The capacitance is measured with VDD, VDDQ,

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 8Gb: x4, x8, x16 DDR4 SDRAM
DRAM Package Electrical Specifications

VSS, and VSSQ shorted with all other signal pins floating. The inductance is measured with VDD, VDDQ, VSS, and VSSQ
shorted and all other signal pins shorted at the die, not pin, side.
2. Package-only impedance (Zpkg) is calculated based on the Lpkg and Cpkg total for a given pin where: Zpkg (total
per pin) = SQRT (Lpkg/Cpkg).
3. Package-only delay (Tpkg) is calculated based on Lpkg and Cpkg total for a given pin where: Tdpkg (total per pin)
= SQRT (Lpkg έ Cpkg).
4. ZIO and TdIO apply to DQ, DM, TDQS_t and TDQS_c.
5. Absolute value of ZCK_t, ZCK_c for impedance (Z) or absolute value of TdCK_t, TdCK_c for delay (Td).
6. Absolute value of ZIO (DQS_t), ZIO (DQS_c) for impedance (Z) or absolute value of TdIO (DQS_t), TdIO (DQS_c) for
delay (Td).
7. ZI ADD CMD and TdI ADD CMD apply to A[17:0], BA[1:0], BG[1:0], RAS_n CAS_n, WE_n, ACT_n, and PAR.
8. ZI CTRL and TdI CTRL apply to ODT, CS_n, and CKE.
9. Package implementations will meet specification if the Zpkg and package delay fall within the ranges shown, and
the maximum Lpkg and Cpkg do not exceed the maximum values shown.
10. It is assumed that Lpkg can be approximated as Lpkg = ZO έ Td.
11. It is assumed that Cpkg can be approximated as Cpkg = Td/ZO.

Table 134: DRAM Package Electrical Specifications for x16 Devices

1600/1866/2133/
2400/2666 2933 3200
Parameter Symbol Min Max Min Max Min Max Unit Notes
Input/out- Zpkg ZIO 45 85 45 85 45 85 ohm 1, 2, 4
put
Package delay TdIO 14 45 14 45 14 45 ps 1, 3, 4
Lpkg LIO n 3.4 n 3.4 n 3.4 nH 11
Cpkg CIO n 0.82 n 0.82 n 0.82 pF 11
LDQS_t/LDQ Zpkg ZIO DQS 45 85 45 85 45 85 ohm 1, 2
S_c/UDQS_t/
UDQS_c Package delay TdIO DQS 14 45 14 45 14 45 ps 1, 3
Lpkg LIO DQS n 3.4 n 3.4 n 3.4 nH 11
Cpkg CIO DQS n 0.82 n 0.82 n 0.82 pF 11
LDQS_t/LDQ Delta Zpkg DZIO DQS n 10.5 n 10.5 n 10.5 ohm 1, 2, 6
S_c,
UDQS_t/UD Delta delay DTdIO DQS n 5 n 5 n 5 ps 1, 3, 6
QS_c,
Input CTRL Zpkg ZI CTRL 50 90 50 90 50 90 ohm 1, 2, 8
pins
Package delay TdI CTRL 14 42 14 42 14 42 ps 1, 3, 8
Lpkg LI CTRL n 3.4 n 3.4 n 3.4 nH 11
Cpkg CI CTRL n 0.7 n 0.7 n 0.7 pF 11
Input CMD Zpkg ZI ADD CMD 50 90 50 90 50 90 ohm 1, 2, 7
ADD pins
Package delay TdI ADD CMD 14 52 14 52 14 52 ps 1, 3, 7
Lpkg LI ADD CMD n 3.9 n 3.9 n 3.9 nH 11
Cpkg CI ADD CMD n 0.86 n 0.86 n 0.86 pF 11

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DRAM Package Electrical Specifications

Table 134: DRAM Package Electrical Specifications for x16 Devices (Continued)
1600/1866/2133/
2400/2666 2933 3200
Parameter Symbol Min Max Min Max Min Max Unit Notes
CK_t, CK_c Zpkg ZCK 50 90 50 90 50 90 ohm 1, 2
Package delay TdCK 14 42 14 42 14 42 ps 1, 3
Delta Zpkg DZDCK n 10.5 n 10.5 n 10.5 ohm 1, 2, 5
Delta delay DTdDCK n 5 n 5 n 5 ps 1, 3, 5
Input CLK Lpkg LI CLK n 3.4 n 3.4 n 3.4 nH 11
Cpkg CI CLK n 0.7 n 0.7 n 0.7 pF 11
ZQ Zpkg ZO ZQ n 100 n 100 n 100 ohm 1, 2
ZQ delay TdO ZQ 20 90 20 90 20 90 ps 1, 3
ALERT Zpkg ZO ALERT 40 100 40 100 40 100 ohm 1, 2
ALERT delay TdO ALERT 20 55 20 55 20 55 ps 1, 3

Notes: 1. This parameter is not subject to a production test; it is verified by design and characterization and are provided
for reference; system signal simulations should not use these values but use the Micron package model. The
package parasitic (L and C) are validated using package only samples. The capacitance is measured with VDD, VDDQ,
VSS, and VSSQ shorted with all other signal pins floating. The inductance is measured with VDD, VDDQ, VSS, and VSSQ
shorted and all other signal pins shorted at the die, not pin, side.
2. Package-only impedance (Zpkg) is calculated based on the Lpkg and Cpkg total for a given pin where: Zpkg (total
per pin) = SQRT (Lpkg/Cpkg).
3. Package-only delay (Tpkg) is calculated based on Lpkg and Cpkg total for a given pin where: Tdpkg (total per pin)
= SQRT (Lpkg έ Cpkg).
4. ZIO and TdIO apply to DQ, DM, TDQS_t and TDQS_c.
5. Absolute value of ZCK_t, ZCK_c for impedance (Z) or absolute value of TdCK_t, TdCK_c for delay (Td).
6. Absolute value of ZIO (DQS_t), ZIO (DQS_c) for impedance (Z) or absolute value of TdIO (DQS_t), TdIO (DQS_c) for
delay (Td).
7. ZI ADD CMD and TdI ADD CMD apply to A[17:0], BA[1:0], BG[1:0], RAS_n CAS_n, WE_n, ACT_n, and PAR.
8. ZI CTRL and TdI CTRL apply to ODT, CS_n, and CKE.
9. Package implementations will meet specification if the Zpkg and package delay fall within the ranges shown, and
the maximum Lpkg and Cpkg do not exceed the maximum values shown.
10. It is assumed that Lpkg can be approximated as Lpkg = ZO έ Td.
11. It is assumed that Cpkg can be approximated as Cpkg = Td/ZO.

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DRAM Package Electrical Specifications

Table 135: Pad Input/Output Capacitance

DDR4-1600, DDR4-2400,
1866, 2133 2666 DDR4-2933 DDR4-3200
Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
Input/output capacitance: CIO 0.55 1.4 0.55 1.15 0.55 1.00 0.55 1.00 pF 1, 2, 3
DQ, DM, DQS_t, DQS_c,
TDQS_t, TDQS_c
Input capacitance: CK_t CCK 0.2 0.8 0.2 0.7 0.2 0.7 0.15 0.7 pF 2, 3
and CK_c
Input capacitance delta: CDCK - 0.05 - 0.05 - 0.05 - 0.05 pF 2, 3, 6
CK_t and CK_c
Input/output capacitance CDDQS - 0.05 - 0.05 - 0.05 - 0.05 pF 2, 3, 5
delta: DQS_t and DQS_c
Input capacitance: CTRL, CI 0.2 0.8 0.2 0.7 0.2 0.6 0.15 0.55 pF 2, 3, 4
ADD, CMD input-only pins
Input capacitance delta: All CDI_CTRL n 0.1 n 0.1 n 0.1 n 0.1 pF 2, 3,
CTRL input-only pins 8, 9
Input capacitance delta: All CDI_AD- n 0.1 n 0.1 n 0.1 n 0.1 pF 1, 2,
ADD/CMD input-only pins D_CMD
10, 11

Input/output capacitance CDIO n 0.1 n 0.1 n 0.1 n 0.1 pF 1, 2, 3,
delta: DQ, DM, DQS_t, 4
DQS_c, TDQS_t, TDQS_c
Input/output capacitance: CALERT 0.5 1.5 0.5 1.5 0.5 1.5 0.5 1.5 pF 2, 3
ALERT pin
Input/output capacitance: CZQ n 2.3 n 2.3 n 2.3 n 2.3 pF 2, 3,
ZQ pin 12
Input/output capacitance: CTEN 0.2 2.3 0.2 2.3 0.2 2.3 0.15 2.3 pF 2, 3,
TEN pin 13

Notes: 1. Although the DM, TDQS_t, and TDQS_c pins have different functions, the loading matches DQ and DQS.
2. This parameter is not subject to a production test; it is verified by design and characterization and are provided
for reference; system signal simulations should not use these values but use the Micron package model. The capac-
ITANCE IF AND WHEN IS MEASURED ACCORDING TO THE *%0 SPECIFICATION h0ROCEDURE FOR -EASURING )NPUT #APACI-
TANCE 5SING A 6ECTOR .ETWORK !NALYZER 6.! v WITH 6DD, VDDQ, VSS, and VSSQ applied and all other pins floating
(except the pin under test, CKE, RESET_n and ODT, as necessary). VDD = VDDQ = 1.2V, VBIAS = VDD/2 and on-die
termination off. Measured data is rounded using industry standard half-rounded up methodology to the nearest
hundredth of the MSB.
3. This parameter applies to monolithic die, obtained by de-embedding the package L and C parasitics.
4. CDIO = CIO(DQ, DM) - 0.5 έ (CIO(DQS_t) + CIO(DQS_c)).
5. Absolute value of CIO (DQS_t), CIO (DQS_c)
6. Absolute value of CCK_t, CCK_c
7. CI applies to ODT, CS_n, CKE, A[17:0], BA[1:0], BG[1:0], RAS_n, CAS_n, ACT_n, PAR and WE_n.
8. CDI_CTRL applies to ODT, CS_n, and CKE.
9. CDI_CTRL = CI(CTRL) - 0.5 έ (CI(CLK_t) + CI(CLK_c)).
10. CDI_ADD_CMD applies to A[17:0], BA1:0], BG[1:0], RAS_n, CAS_n, ACT_n, PAR and WE_n.
11. CDI_ADD_CMD = CI(ADD_CMD) - 0.5 έ (CI(CLK_t) + CI(CLK_c)).
12. Maximum external load capacitance on ZQ pin: 5pF.
13. Only applicable if TEN pin does not have an internal pull-up.

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Thermal Characteristics

Thermal Characteristics

Table 136: Thermal Characteristics

Parameter/Condition Value Units Symbol Notes
Operating case temperature: 0 to +85 ιC TC 1, 2, 3
Commercial
0 to +95 ιC TC 1, 2, 3, 4
Operating case temperature: n TO  ιC TC 1, 2, 3
Industrial
n TO  ιC TC 1, 2, 3, 4
Operating case temperature: n TO  ιC TC 1, 2, 3
Automotive
n TO  ιC TC 1, 2, 3, 4

78-ball Junction-to-case (TOP) 3.1 ιC/W ȣJC 5

h0-v Junction-to-board 10.6 ιC/W ȣJB
REV A
96-ball Junction-to-case (TOP) 3.0 ιC/W ȣJC 5
h(!v Junction-to-board 9.9 ιC/W ȣJB

78-ball Junction-to-case (TOP) 3.5 ιC/W ȣJC 5

h7%v Junction-to-board 21 ιC/W ȣJB
REV B
Junction-to-case (TOP) 4.1 ιC/W ȣJC 5
 BALL h*9v
Junction-to-board 16.2 ιC/W ȣJB

78-ball Junction-to-case (TOP) 3.2 ιC/W ȣJC 5

h7%v Junction-to-board 20.2 ιC/W ȣJB
REV D
Junction-to-case (TOP) TBD ιC/W ȣJC 5
 BALL h,9v
Junction-to-board TBD ιC/W ȣJB
Junction-to-case (TOP) 4.9 ιC/W ȣJC 5
 BALL h3!v
Junction-to-board 14.2 ιC/W ȣJB
REV E
Junction-to-case (TOP) 4.8 ιC/W ȣJC 5
 BALL h,9v
Junction-to-board 15.2 ιC/W ȣJB

78-ball Junction-to-case (TOP) 2.8 ιC/W ȣJC 5

h7%v Junction-to-board 13.1 ιC/W ȣJB
REV G
Junction-to-case (TOP) N/A ιC/W ȣJC 5
N/A
Junction-to-board N/A ιC/W ȣJB
Junction-to-case (TOP) 4.4 ιC/W ȣJC 5
 BALL h3!v
Junction-to-board 13.2 ιC/W ȣJB
REV H
Junction-to-case (TOP) 3.4 ιC/W ȣJC 5
 BALL h,9v
Junction-to-board 14.7 ιC/W ȣJB
Junction-to-case (TOP) 6.0 ιC/W ȣJC 5
 BALL h3!v
Junction-to-board 17.9 ιC/W ȣJB
REV J
Junction-to-case (TOP) 5.9 ιC/W ȣJC 5
 BALL h4"v
Junction-to-board 17.4 ιC/W ȣJB

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#URRENT 3PECIFICATIONS n -EASUREMENT #ONDITIONS

Table 136: Thermal Characteristics (Continued)

Parameter/Condition Value Units Symbol Notes
Junction-to-case (TOP) 8.2 ιC/W ȣJC 5
78-ball "SA"
Junction-to-board 19.8 ιC/W ȣJB
REV R
Junction-to-case (TOP) 8.1 ιC/W ȣJC 5
96-ball "TB"
Junction-to-board 19.2 ιC/W ȣJB

Notes: 1. MAX operating case temperature. TCis measured in the center of the package.
2. A thermal solution must be designed to ensure the DRAM device does not exceed the maximum TC during opera-
tion.
3. Device functionality is not guaranteed if the DRAM device exceeds the maximum TC during operation.
4. If TC exceeds 85ιC, the DRAM must be refreshed externally at 2x refresh, which is a 3.9ρs interval refresh rate.
5. The thermal resistance data is based off of a typical number.

Figure 245: Thermal Measurement Point

TC test point
(L/2)

(W/2)

#URRENT 3PECIFICATIONS n -EASUREMENT #ONDITIONS

IDD, IPP, and IDDQ Measurement Conditions
IDD, IPP, and IDDQ measurement conditions, such as test load and patterns, are defined in this section.
s IDD currents (IDD0, IDD1, IDD2N, IDD2NT, IDD2P, IDD2Q, IDD3N, IDD3P, IDD4R, IDD4W, IDD5R, IDD6N, IDD6E,
IDD6R, IDD6A, IDD7, DD8 and IDD9) are measured as time-averaged currents with all VDD balls of the
device under test grouped together.
s IPP currents are IPP3N for standby cases (IDD2N, IDD2NT, IDD2P, IDD2Q, IDD3N, IDD3P, IDD8), IPP0 for
active cases (IDD0,IDD1, IDD4R, IDD4W), IPP5R for the distributed refresh case (IDD5R), IPP6x for self
refresh cases (IDD6N, IDD6E, IDD6R, IDD6A), IPP7 for the operating bank interleave read case (IDD7) and
IPP9 for the MBIST-PPR operation case. These have the same definitions as the IDD currents refer-
enced but are measured on the VPP supply.
s IDDQ currents are measured as time-averaged currents with VDDQ balls of the device under test
grouped together. Micron does not specify IDDQ currents.

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#URRENT 3PECIFICATIONS n -EASUREMENT #ONDITIONS

s IPP and IDDQ currents are not included in IDD currents, IDD and IDDQ currents are not included in IPP
currents, and IDD and IPP currents are not included in IDDQ currents.

NOTE: IDDQ values cannot be directly used to calculate theI/O power of the device. They can be used to
support correlation of simulated I/O power to actual I/O power. In DRAM module application, IDDQ
cannot be measured separately because VDD and VDDQ are using a merged-power layer in the module
PCB.
The following definitions apply for IDD, IPP and IDDQ measurements.
s hv AND h,/7v ARE DEFINED AS 6IN ζVIL(AC)max
s hv AND h()'(v ARE DEFINED AS 6IN ηVIH(AC)min
s h-IDLEVELv IS DEFINED AS INPUTS 6REF = VDD/2
s Timings used for IDD, IPP and IDDQ measurement-loop patterns are provided in the Current Test
Definition and Patterns section.
s Basic IDD, IPP, and IDDQ measurement conditions are described in the Current Test Definition and
Patterns section.
s Detailed IDD, IPP, and IDDQ measurement-loop patterns are described in the Current Test Definition
and Patterns section.
s Current measurements are done after properly initializing the device. This includes, but is not
limited to, setting:
RON = RZQ/7 (34 ohm in MR1);
Qoff = 0B (output buffer enabled in MR1);
RTT(NOM) = RZQ/6 (40 ohm in MR1);
RTT(WR) = RZQ/2 (120 ohm in MR2);
RTT(Park) = disabled;
TDQS feature disabled in MR1; CRC disabled in MR2; CA parity feature disabled in MR3; Gear-down
mode disabled in MR3; Read/Write DBI disabled in MR5; DM disabled in MR5
s Define D = {CS_n, RAS_n, CAS_n, WE_n}: = {HIGH, LOW, LOW, LOW}; apply BG/BA changes when
directed.
s Define D_n = {CS_n, RAS_n, CAS_n, WE_n}: = {HIGH, HIGH, HIGH, HIGH}; apply invert of BG/BA
changes when directed above.

NOTE: The measurement-loop patterns must be executed at least once before actual current measure-
ments can be taken, with the exception of IDD9 which may be measured any time after MBIST-PPR entry.

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#URRENT 3PECIFICATIONS n -EASUREMENT #ONDITIONS

Figure 246: Measurement Setup and Test Load for IDDx, IPPx, and IDDQx

IDD IPP IDDQ

VDD VPP VDDQ

RESET_n
CK_t/CK_c
DDR4
DQS_t, DQS_c
CKE SDRAM
CS_n DQ
C DM_n
ACT_n, RAS_n, CAS_n, WE_n
A, BG, BA
ODT
ZQ V VSSQ
SS

Figure 247: Correlation: Simulated Channel I/O Power to Actual Channel I/O Power
Applic ation-s pe c ific
memory c ha nne l I DD Q
env ironmen t tes t loa d

C hanne l I/O I DD Q IDD Q

pow er simulation simulation meas ure ment

C or relation

C orre c tion

C hanne l I/O
pow er n umber

Note: 1. Supported by IDDQ measurement.

IDD Definitions

Table 137: Basic IDD, IPP, and IDDQ Measurement Conditions

Symbol Description
IDD0 Operating One Bank Active-Precharge Current (AL = 0)
CKE: HIGH; External clock: On; tCK, nRC, nRAS, CL: see the previous table; BL: 8;1 AL: 0; CS_n: HIGH between
ACT and PRE; Command, address, bank group address, bank address inputs: partially toggling according to the
next table; Data I/O: VDDQ; DM_n: stable at 0; Bank activity: cycling with one bank active at a time: 0, 0, 1, 1, 2,
2, ... (see the IDD0 Measurement-Loop Pattern table); Output buffer and RTT: enabled in mode registers;2 ODT
signal: stable at 0; Pattern details: see the IDD0 Measurement-Loop Pattern table

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#URRENT 3PECIFICATIONS n -EASUREMENT #ONDITIONS

Table 137: Basic IDD, IPP, and IDDQ Measurement Conditions

Symbol Description
IPP0 Operating One Bank Active-Precharge IPP Current (AL = 0)
Same conditions as IDD0 above
IDD1 Operating One Bank Active-Read-Precharge Current (AL = 0)
CKE: HIGH; External clock: on; tCK, nRC, nRAS, nRCD, CL: see the previous table; BL: 8;,, 5 AL: 0; CS_n: HIGH
between ACT, RD, and PRE; Command, address, bank group address, bank address inputs, Data I/O: partially
toggling according to the IDD1 Measurement-Loop Pattern table; DM_n: stable at 0; Bank activity: cycling with
one bank active at a time: 0, 0, 1, 1, 2, 2, ... (see the following table); Output buffer and RTT: enabled in mode
registers;2 ODT Signal: stable at 0; Pattern details: see the IDD1 Measurement-Loop Pattern table
IDD2N Precharge Standby Current (AL = 0)
CKE: HIGH; External clock: On; tCK, CL: see the previous table; BL: 8;1 AL: 0; CS_n: stable at 1; Command,
address, bank group address, bank address Inputs: partially toggling according to the IDD2N and IDD3N Measure-
ment-Loop Pattern table; Data I/O: VDDQ; DM_n: stable at 1; Bank activity: all banks closed; Output buffer and
RTT: enabled in mode registers;2 ODT signal: stable at 0; Pattern details: see the IDD2N and IDD3N Measure-
ment-Loop Pattern table
IDD2NT Precharge Standby ODT Current
CKE: HIGH; External clock: on; tCK, CL: see the previous table; BL: 8;1 AL: 0; CS_n: stable at 1; Command,
address, bank gropup address, bank address inputs: partially toggling according to the IDD2NT Measure-
ment-Loop Pattern table; Data I/O: VSSQ; DM_n: stable at 1; Bank activity: all banks closed; Output buffer and
RTT: enabled in mode registers;2 ODT signal: toggling according to the IDD2NT Measurement-Loop Pattern
table; Pattern details: see the IDD2NT Measurement-Loop Pattern table
IDD2P Precharge Power-Down Current
CKE: LOW; External clock: on; tCK, CL: see the previous table; BL: 8;1 AL: 0; CS_n: stable at 1; Command,
address, bank group address, bank address inputs: stable at 0; Data I/O: VDDQ; DM_n: stable at 1; Bank activity:
all banks closed; Output buffer and RTT: Enabled in mode registers;2 ODT signal: stable at 0
IDD2Q Precharge Quiet Standby Current
CKE: HIGH; External clock: on; tCK, CL: see the previous table; BL: 8;1 AL: 0; CS_n: stable at 1; Command,
address, bank group address, bank address inputs: stable at 0; Data I/O: VDDQ; DM_n: stable at 1; Bank activity:
all banks closed; Output buffer and RTT: Enabled in mode registers;2 ODT signal: stable at 0
IDD3N Active Standby Current (AL = 0)
CKE: HIGH; External clock: on; tCK, CL: see the previous table; BL: 8;1 AL: 0; CS_n: stable at 1; Command,
address, bank group address, bank address inputs: partially toggling according to the IDD2N and IDD3N Measure-
ment-Loop Pattern table; Data I/O: VDDQ; DM_n: stable at 1; Bank activity: all banks open; Output buffer and
RTT: Enabled in mode registers;2 ODT signal: stable at 0; Pattern details: see the IDD2N and IDD3N Measure-
ment-Loop Pattern table
IPP3N Active Standby IPP3N Current (AL = 0)
Same conditions as IDD3N above
IDD3P Active Power-Down Current (AL = 0)
CKE: LOW; External clock: on; tCK, CL: see the previous table; BL: 8;1 AL: 0; CS_n: stable at 1; Command,
address, bank group address, bank address inputs: stable at 1; Data I/O: VDDQ; DM_n: stable at 1; Bank activity:
all banks open; Output buffer and RTT: Enabled in mode registers;2 ODT signal: stable at 0

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#URRENT 3PECIFICATIONS n -EASUREMENT #ONDITIONS

Table 137: Basic IDD, IPP, and IDDQ Measurement Conditions

Symbol Description
IDD4R Operating Burst Read Current (AL = 0)
CKE: HIGH; External clock: on; tCK, CL: see the previous table; BL: 8;, 5 AL: 0; CS_n: HIGH between RD; Com-
mand, address, bank group address, bank address inputs: partially toggling according to the IDD4R Measure-
ment-Loop Pattern table; Data I/O: seamless read data burst with different data between one burst and the
next one according to the IDD4R Measurement-Loop Pattern table; DM_n: stable at 1; Bank activity: all banks
open, RD commands cycling through banks: 0, 0, 1, 1, 2, 2, ... (see the IDD4R Measurement-Loop Pattern table);
Output buffer and RTT: Enabled in mode registers;2 ODT signal: stable at 0; Pattern details: see the IDD4R Mea-
surement-Loop Pattern table
IDD4W Operating Burst Write Current (AL = 0)
CKE: HIGH; External clock: on; tCK, CL: see the previous table; BL: 8;1 AL: 0; CS_n: HIGH between WR; Com-
mand, address, bank group address, bank address inputs: partially toggling according to the IDD4W Measure-
ment-Loop Pattern table; Data I/O: seamless write data burst with different data between one burst and the
next one according to the IDD4W Measurement-Loop Pattern table; DM: stable at 0; Bank activity: all banks
open, WR commands cycling through banks: 0, 0, 1, 1, 2, 2, ... (see IDD4W Measurement-Loop Pattern table);
Output buffer and RTT: enabled in mode registers (see note2); ODT signal: stable at HIGH; Pattern details: see
the IDD4W Measurement-Loop Pattern table
IDD5R Distributed Refresh Current (1X REF)
CKE: HIGH; External clock: on; tCK, CL, nREFI: see the previous table; BL: 8;1 AL: 0; CS_n: HIGH between REF;
Command, address, bank group address, bank address inputs: partially toggling according to the IDD5R Mea-
surement-Loop Pattern table; Data I/O: VDDQ; DM_n: stable at 1; Bank activity: REF command every nREFI (see
the IDD5R Measurement-Loop Pattern table); Output buffer and RTT: enabled in mode registers2; ODT signal:
stable at 0; Pattern details: see the IDD5R Measurement-Loop Pattern table
IPP5R Distributed Refresh Current (1X REF)
Same conditions as IDD5R above
IDD6N Self Refresh Current: Normal Temperature Range
TC nιC; Auto self refresh (ASR): disabled;3 Self refresh temperature range (SRT): normal;4 CKE: LOW; Exter-
nal clock: off; CK_t and CK_c: LOW; CL: see the table above; BL: 8;1 AL: 0; CS_n, command, address, bank group
address, bank address, data I/O: VDDQ; DM_n: stable at 1; Bank activity: SELF REFRESH operation; Output buffer
and RTT: enabled in mode registers;2 ODT signal: midlevel
IDD6E Self Refresh Current: Extended Temperature Range 4
TC nιC; Auto self refresh (ASR): disabled4; Self refresh temperature range (SRT): extended;4 CKE: LOW;
External clock: off; CK_t and CK_c: LOW; CL: see the previous table; BL: 8;1 AL: 0; CS_n, command, address,
group bank address, bank address, data I/O: VDDQ; DM_n: stable at 1; Bank activity: EXTENDED TEMPERATURE
SELF REFRESH operation; Output buffer and RTT: enabled in mode registers;2 ODT signal: midlevel
IPP6x Self Refresh IPP Current
Same conditions as IDD6E above
IDD6R Self Refresh Current: Reduced Temperature Range
TC nιC; Auto self refresh (ASR): disabled; Self refresh temperature range (SRT): reduced;4 CKE: LOW; Exter-
nal clock: off; CK_t and CK_c: LOW; CL: see the previous table; BL: 8;1 AL: 0; CS_n, command, address, bank
group address, bank address, data I/O: VDDQ; DM_n: stable at 1; Bank activity: EXTENDED TEMPERATURE SELF
REFRESH operation; Output buffer and RTT: enabled in mode registers;2 ODT signal: midlevel

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#URRENT 3PECIFICATIONS n -EASUREMENT #ONDITIONS

Table 137: Basic IDD, IPP, and IDDQ Measurement Conditions

Symbol Description
IDD7 Operating Bank Interleave Read Current
CKE: HIGH; External clock: on; tCK, nRC, nRAS, nRCD, nRRD, nFAW, CL: see the previous table; BL: 8;, 5 AL: CL -
1; CS_n: HIGH between ACT and RDA; Command, address, group bank adress, bank address inputs: partially
toggling according to the IDD7 Measurement-Loop Pattern table; Data I/O: read data bursts with different data
between one burst and the next one according to the IDD7 Measurement-Loop Pattern table; DM: stable at 1;
Bank activity: two times interleaved cycling through banks (0, 1, ...7) with different addressing, see the IDD7
Measurement-Loop Pattern table; Output buffer and RTT: enabled in mode registers;2 ODT signal: stable at 0;
Pattern details: see the IDD7 Measurement-Loop Pattern table
IPP7 Operating Bank Interleave Read IPP Current
Same conditions as IDD7 above
IDD8 Maximum Power Down Current
Place DRAM in MPSM then CKE: HIGH; External clock: on; tCK, CL: see the previous table; BL: 8;1 AL: 0; CS_n:
stable at 1; Command, address, bank group address, bank address inputs: stable at 0; Data I/O: VDDQ; DM_n:
stable at 1; Bank activity: all banks closed; Output buffer and RTT: Enabled in mode registers;2 ODT signal: sta-
ble at 0
IDD9 MBIST-PPR Current 7
Device in MBIST-PPR mode; External clock: on; CS_n: stable at 1 after MBIST-PPR entry; Command, address,
bank group address, bank address inputs: stable at 1; Data I/O: VDDQ; DM_n: stable at 1; Bank activity: all banks
closed; Output buffer and RTT: Enabled in mode registers;2 ODT signal: stable at 0
IPP9 MBIST-PPR IPP Current
Same condition with IDD9 above

Notes: 1. Burst length: BL8 fixed by MRS: set MR0[1:0] 00.

2. Output buffer enable: set MR1[12] 0 (output buffer enabled); set MR1[2:1] 00 (RON = RZQ/7); RTT(NOM) enable: set
MR1[10:8] 011 (RZQ/6); RTT(WR) enable: set MR2[11:9] 001 (RZQ/2), and RTT(Park) enable: set MR5[8:6] 000 (disabled).
3. Auto self refresh (ASR): set MR2[6] 0 to disable or MR2[6] 1 to enable feature.
4. Self refresh temperature range (SRT): set MR2[7] 0 for normal or MR2[7] 1 for extended temperature range.
5. READ burst type: Nibble sequential, set MR0[3] 0.
6. In the dual-rank DDP case, note the following IDD measurement considerations:
s For all IDD measurements except IDD6, the unselected rank should be in an IDD2P condition.
s For all IPP measurements except IPP6, the unselected rank should be in an IDD3N condition.
s For all IDD6/IPP6 measurements, both ranks should be in the same IDD6 condition.

7. When measuring IDD9/IPP9 after entering MBIST-PPR mode and ALERT_N driving LOW, there is a chance that the
DRAM may perform an internal hPPR if fails are found after internal self-test is completed and before ALERT_N
fires HIGH.

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n 0ATTERNS AND 4EST #ONDITIONS

#URRENT 3PECIFICATIONS n 0ATTERNS AND 4EST #ONDITIONS

Current Test Definitions and Patterns

Table 138: IDD0 and IPP0 Measurement-Loop Pattern1

A[17,13,11]]
RAS_n/A16

CAS_n/A15
CK_t, CK_c

Command

WE_n/A14
Sub-Loop

A12/BC_n
Number

A[10]/AP
BG[1:0]2
Data3

BA[1:0]
ACT_n

A[9:7]

A[6:3]

A[2:0]
Cycle

CS_n

ODT
CKE

0 0 ACT 0 0 0 0 0 0 0 0 0 0 0 0 0 0 n
1, 2 D, D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 n
3, 4 D_n, 1 1 1 1 1 0 3 3 0 0 0 7 F 0 n
D_n
... Repeat pattern 1...4 until nRAS - 1; truncate if necessary
nRAS PRE 0 1 0 1 0 0 0 0 0 0 0 0 0 0 n
... Repeat pattern 1...4 until nRC - 1; truncate if necessary
1 1 έ nRC Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 1 instead
2 2 έ nRC Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 2 instead
3 3 έ nRC Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 3 instead
4 4 έ nRC Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 1 instead
Static High
Toggling

5 5 έ nRC Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 2 instead

6 6 έ nRC Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 3 instead
7 7 έ nRC Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 0 instead
8 8 έ nRC Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 0 instead4
9 9 έ nRC Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 1 instead4
10 10 έ nRC Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 2 instead4
11 11 έ nRC Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 3 instead4
12 12 έ nRC Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 1 instead4
13 13 έ nRC Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 2 instead4
14 14 έ nRC Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 3 instead4
15 15 έ nRC Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 0 instead4

Notes: 1. DQS_t, DQS_c are VDDQ.

2. BG1 is a "Don't Care" for x16 devices.
3. DQ signals are VDDQ.
4. For x4 and x8 only.

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n 0ATTERNS AND 4EST #ONDITIONS

Table 139: IDD1 -EASUREMENT n ,OOP 0ATTERN1

A[17,13,11]]
CK_c, CK_t,

RAS_n/A16

CAS_n/A15
Command

WE_n/A14
Sub-Loop

A12/BC_n

A[10]/AP
BG[1:0]2
Number
Data3

BA[1:0]
ACT_n

A[9:7]

A[6:3]

A[2:0]
Cycle

CS_n

ODT
CKE

0 0 ACT 0 0 0 0 0 0 0 0 0 0 0 0 0 0 n
1, 2 D, D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 n
3, 4 D_n, 1 1 1 1 1 0 3 3 0 0 0 7 F 0 n
D_n
... Repeat pattern 1...4 until nRCD - AL - 1; truncate if necessary
nRCD - AL RD 0 1 1 0 1 0 0 0 0 0 0 0 0 0 D0 = 00, D1 =
FF,
... Repeat pattern 1...4 until nRAS - 1; truncate if necessary
D2 = FF, D3 =
nRAS PRE 0 1 0 1 0 0 0 0 0 0 0 0 0 0 00,
... Repeat pattern 1...4 until nRC - 1; truncate if necessary D4 = FF, D5 =
00,
D5 = 00, D7 =
FF
1 1 έ nRC + 0 ACT 0 0 0 1 1 0 1 1 0 0 0 0 0 0 n
1 έ nRC + 1, 2 D, D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 n
1 έ nRC + 3, 4 D_n, 1 1 1 1 1 0 3 3 0 0 0 7 F 0 n
D_n
... Repeat pattern nRC + 1...4 until 1 έ nRC + nRAS - 1; truncate if necessary
Static High

1έ
Toggling

RD 0 1 1 0 1 0 1 1 0 0 0 0 0 0 D0 = FF, D1 =
nRC+nRCD - 00,
AL D2 = 00, D3 =
FF,
... Repeat pattern 1...4 until nRAS - 1; truncate if necessary
D4 = 00, D5 =
1 έ nRC + PRE 0 1 0 1 0 0 1 1 0 0 0 0 0 0 FF,
nRAS D5 = FF, D7 =
... Repeat pattern nRC + 1...4 until 2 έ nRC - 1; truncate if necessary 00

2 2 έ nRC Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 2 instead

3 3 έ nRC Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 3 instead
4 4 έ nRC Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 1 instead
5 5 έ nRC Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 2 instead
6 6 έ nRC Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 3 instead
7 7 έ nRC Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 0 instead
8 9 έ nRC Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 0 instead4
9 10 έ nRC Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 1 instead4
10 11 έ nRC Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 2 instead4
11 12 έ nRC Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 3 instead4
12 13 έ nRC Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 1 instead4

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n 0ATTERNS AND 4EST #ONDITIONS

Table 139: IDD1 -EASUREMENT n ,OOP 0ATTERN1

A[17,13,11]]
CK_c, CK_t,

RAS_n/A16

CAS_n/A15
Command

WE_n/A14
Sub-Loop

A12/BC_n

A[10]/AP
BG[1:0]2
Number Data3

BA[1:0]
ACT_n

A[9:7]

A[6:3]

A[2:0]
Cycle

CS_n

ODT
Static High CKE

13 14 έ nRC Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 2 instead4

Toggling

14 15 έ nRC Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 3 instead4

15 16 έ nRC Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 0 instead4

Notes: 1. DQS_t, DQS_c are VDDQ when not toggling.

2. BG1 is a "Don't Care" for x16 devices.
3. DQ signals are VDDQ except when burst sequence drives each DQ signal by a READ command.
4. For x4 and x8 only.

Table 140: IDD2N, IDD3N, and IPP3P -EASUREMENT n ,OOP 0ATTERN1

A[17,13,11]]
CK_c, CK_t,

RAS_n/A16

CAS_n/A15
Command

WE_n/A14
Sub-Loop

A12/BC_n
Number

A[10]/AP
BG[1:0]2

BA[1:0] Data3
ACT_n

A[9:7]

A[6:3]

A[2:0]
Cycle

CS_n

ODT
CKE

0 0 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 n
1 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 n
2 D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 n
3 D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 n
1 n Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 1 instead
2 n Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 2 instead
3 n Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 3 instead
4 n Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 1 instead
5 n Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 2 instead
Static High
Toggling

6 n Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 3 instead

7 n Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 0 instead
8 n Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 0 instead4
9 n Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 1 instead4
10 n Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 2 instead4
11 n Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 3 instead4
12 n Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 1 instead4
13 n Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 2 instead4
14 n Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 3 instead4
15 n Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 0 instead4

Notes: 1. DQS_t, DQS_c are VDDQ.

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n 0ATTERNS AND 4EST #ONDITIONS

2. BG1 is a "Don't Care" for x16 devices.

3. DQ signals are VDDQ.
4. For x4 and x8 only.

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n 0ATTERNS AND 4EST #ONDITIONS

Table 141: IDD2NT -EASUREMENT n ,OOP 0ATTERN1

A[17,13,11]]
CK_c, CK_t,

RAS_n/A16

CAS_n/A15
Command

WE_n/A14
Sub-Loop

A12/BC_n
Number

A[10]/AP
BG[1:0]2
Data3

BA[1:0]
ACT_n

A[9:7]

A[6:3]

A[2:0]
Cycle

CS_n

ODT
CKE

0 0 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 n
1 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 n
2 D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 n
3 D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 n
1 n Repeat sub-loop 0 with ODT = 1, use BG[1:0] = 1, use BA[1:0] = 1 instead
2 n Repeat sub-loop 0 with ODT = 0, use BG[1:0] = 0, use BA[1:0] = 2 instead
3 n Repeat sub-loop 0 with ODT = 1, use BG[1:0] = 1, use BA[1:0] = 3 instead
4 n Repeat sub-loop 0 with ODT = 0, use BG[1:0] = 0, use BA[1:0] = 1 instead
5 n Repeat sub-loop 0 with ODT = 1, use BG[1:0] = 1, use BA[1:0] = 2 instead
Static High
Toggling

6 n Repeat sub-loop 0 with ODT = 0, use BG[1:0] = 0, use BA[1:0] = 3 instead
7 n Repeat sub-loop 0 with ODT = 1, use BG[1:0] = 1, use BA[1:0] = 0 instead
8 n Repeat sub-loop 0 with ODT = 0, use BG[1:0] = 2, use BA[1:0] = 0 instead4
9 n Repeat sub-loop 0 with ODT = 1, use BG[1:0] = 3, use BA[1:0] = 1 instead4
10 n Repeat sub-loop 0 with ODT = 0, use BG[1:0] = 2, use BA[1:0] = 2 instead4
11 n Repeat sub-loop 0 with ODT = 1, use BG[1:0] = 3, use BA[1:0] = 3 instead4
12 n Repeat sub-loop 0 with ODT = 0, use BG[1:0] = 2, use BA[1:0] = 1 instead4
13 n Repeat sub-loop 0 with ODT = 1, use BG[1:0] = 3, use BA[1:0] = 2 instead4
14 n Repeat sub-loop 0 with ODT = 0, use BG[1:0] = 2, use BA[1:0] = 3 instead4
15 n Repeat sub-loop 0 with ODT = 1, use BG[1:0] = 3, use BA[1:0] = 0 instead4

Notes: 1. DQS_t, DQS_c are VSSQ.

2. BG1 is a "Don't Care" for x16 devices.
3. DQ signals are VSSQ.
4. For x4 and x8 only.

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n 0ATTERNS AND 4EST #ONDITIONS

Table 142: IDD4R -EASUREMENT n ,OOP 0ATTERN1

A[17,13,11]]
CK_c, CK_t,

RAS_n/A16

CAS_n/A15
Command

WE_n/A14
Sub-Loop

A12/BC_n

A[10]/AP
BG[1:0]2
Number
Data3

BA[1:0]
ACT_n

A[9:7]

A[6:3]

A[2:0]
Cycle

CS_n

ODT
CKE

0 0 RD 0 1 1 0 1 0 0 0 0 0 0 0 0 0 D0 = 00, D1 = FF,
D2 = FF, D3 = 00,
1 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0
D4 = FF, D5 = 00,
2, 3 D_n, 1 1 1 1 1 0 3 3 0 0 0 7 F 0 D5 = 00, D7 = FF
D_n
1 4 RD 0 1 1 0 1 0 1 1 0 0 0 7 F 0 D0 = FF, D1 = 00
D2 = 00, D3 = FF
5 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0
D4 = 00, D5 = FF
6, 7 D_n, 1 1 1 1 1 0 3 3 0 0 0 7 F 0 D5 = FF, D7 = 00
D_n
2 n Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 2 instead
3 n Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 3 instead
4 n Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 1 instead
Static High
Toggling

5 n Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 2 instead

6 n Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 3 instead
7 n Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 0 instead
8 n Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 0 instead4
9 n Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 1 instead4
10 n Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 2 instead4
11 n Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 3 instead4
12 n Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 1 instead4
13 n Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 2 instead4
14 n Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 3 instead4
15 n Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 0 instead4

Notes: 1. DQS_t, DQS_c are VDDQ when not toggling.

2. BG1 is a "Don't Care" for x16 devices.
3. Burst sequence driven on each DQ signal by a READ command. Outside burst operation, DQ signals are VDDQ.
4. For x4 and x8 only.

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n 0ATTERNS AND 4EST #ONDITIONS

Table 143: IDD4W -EASUREMENT n ,OOP 0ATTERN1

A[17,13,11]]
CK_c, CK_t,

RAS_n/A16

CAS_n/A15
Command

WE_n/A14
Sub-Loop

A12/BC_n
Number

A[10]/AP
BG[1:0]2
Data3

BA[1:0]
ACT_n

A[9:7]

A[6:3]

A[2:0]
Cycle

CS_n

ODT
CKE

0 0 WR 0 1 1 0 0 1 0 0 0 0 0 0 0 0 D0 = 00, D1 = FF,
D2 = FF, D3 = 00,
1 D 1 0 0 0 0 1 0 0 0 0 0 0 0 0
D4 = FF, D5 = 00,
2, 3 D_n, 1 1 1 1 0 1 3 3 0 0 0 7 F 0 D5 = 00, D7 = FF
D_n
1 4 WR 0 1 1 0 0 1 1 1 0 0 0 7 F 0 D0 = FF, D1 = 00
D2 = 00, D3 = FF
5 D 1 0 0 0 0 1 0 0 0 0 0 0 0 0
D4 = 00, D5 = FF
6, 7 D_n, 1 1 1 1 0 1 3 3 0 0 0 7 F 0 D5 = FF, D7 = 00
D_n
2 n Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 2 instead
3 n Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 3 instead
4 n Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 1 instead
Static High
Toggling

5 n Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 2 instead

6 n Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 3 instead
7 n Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 0 instead
8 n Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 0 instead4
9 n Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 1 instead4
10 n Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 2 instead4
11 n Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 3 instead4
12 n Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 1 instead4
13 n Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 2 instead4
14 n Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 3 instead4
15 n Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 0 instead4

Notes: 1. DQS_t, DQS_c are VDDQ when not toggling.

2. BG1 is a "Don't Care" for x16 devices.
3. Burst sequence driven on each DQ signal by WRITE command. Outside burst operation, DQ signals are VDDQ.
4. For x4 and x8 only.

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n 0ATTERNS AND 4EST #ONDITIONS

Table 144: IDD4Wc -EASUREMENT n ,OOP 0ATTERN1

A[17,13,11]]
CK_c, CK_t,

RAS_n/A16

CAS_n/A15
Command

WE_n/A14
Sub-Loop

A12/BC_n

A[10]/AP
BG[1:0]3
Number

Data4

BA[1:0]
ACT_n

A[9:7]

A[6:3]

A[2:0]
Cycle

CS_n

ODT
CKE

0 0 WR 0 1 1 0 0 1 0 0 0 0 0 0 0 0 D0 = 00, D1 = FF,
D2 = FF, D3 = 00,
1, 2 D, D 1 0 0 0 0 1 0 0 0 0 0 0 0 0
D4 = FF, D5 = 00,
3, 4 D_n, 1 1 1 1 0 1 3 3 0 0 0 7 F 0 D8 = CRC
D_n
1 5 WR 0 1 1 0 0 1 1 1 0 0 0 7 F 0 D0 = FF, D1 = 00,
D2 = 00, D3 = FF,
6, 7 D, D 1 0 0 0 0 1 0 0 0 0 0 0 0 0
D4 = 00, D5 = FF,
8, 9 D_n, 1 1 1 1 0 1 3 3 0 0 0 7 F 0 D5 = FF, D7 = 00
D_n D8 = CRC
2 n Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 2 instead
3 n Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 3 instead
4 n Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 1 instead
Static High
Toggling

5 n Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 2 instead

6 n Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 3 instead
7 n Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 0 instead
8 n Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 0 instead4
9 n Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 1 instead4
10 n Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 2 instead4
11 n Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 3 instead4
12 n Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 1 instead4
13 n Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 2 instead4
14 n Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 3 instead4
15 n Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 0 instead4

Notes: 1. Pattern provided for reference only.

2. DQS_t, DQS_c are VDDQ when not toggling.
3. BG1 is a "Don't Care" for x16 devices.
4. Burst sequence driven on each DQ signal by WRITE command. Outside burst operation, DQ signals are VDDQ.
5. For x4 and x8 only.

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8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
319 Micron Technology, Inc. reserves the right to change products or specifications without notice.
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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n 0ATTERNS AND 4EST #ONDITIONS

Table 145: IDD5R -EASUREMENT n ,OOP 0ATTERN1

A[17,13,11]]
CK_c, CK_t,

RAS_n/A16

CAS_n/A15
Command

WE_n/A14
Sub-Loop

A12/BC_n

A[10]/AP
BG[1:0]2
Number
Data3

BA[1:0]
ACT_n

A[9:7]

A[6:3]

A[2:0]
Cycle

CS_n

ODT
CKE

0 0 REF 0 1 0 0 1 0 0 0 0 0 0 0 0 0 n
1 1 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 n
2 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 n
3 D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 n
4 D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 n
n Repeat pattern 1...4, use BG[1:0] = 1, use BA[1:0] = 1 instead
n Repeat pattern 1...4, use BG[1:0] = 0, use BA[1:0] = 2 instead
n Repeat pattern 1...4, use BG[1:0] = 1, use BA[1:0] = 3 instead
n Repeat pattern 1...4, use BG[1:0] = 0, use BA[1:0] = 1 instead
n Repeat pattern 1...4, use BG[1:0] = 1, use BA[1:0] = 2 instead
Static High
Toggling

n Repeat pattern 1...4, use BG[1:0] = 0, use BA[1:0] = 3 instead

n Repeat pattern 1...4, use BG[1:0] = 1, use BA[1:0] = 0 instead
n Repeat pattern 1...4, use BG[1:0] = 2, use BA[1:0] = 0 instead4
n Repeat pattern 1...4, use BG[1:0] = 3, use BA[1:0] = 1 instead4
n Repeat pattern 1...4, use BG[1:0] = 2, use BA[1:0] = 2 instead4
n Repeat pattern 1...4, use BG[1:0] = 3, use BA[1:0] = 3 instead4
n Repeat pattern 1...4, use BG[1:0] = 2, use BA[1:0] = 1 instead4
n Repeat pattern 1...4, use BG[1:0] = 3, use BA[1:0] = 2 instead4
n Repeat pattern 1...4, use BG[1:0] = 2, use BA[1:0] = 3 instead4
n Repeat pattern 1...4, use BG[1:0] = 3, use BA[1:0] = 0 instead4
2 65...nREFI - 1 Repeat sub-loop 1; truncate if necessary

Notes: 1. DQS_t, DQS_c are VDDQ.

2. BG1 is a "Don't Care" for x16 devices.
3. DQ signals are VDDQ.
4. For x4 and x8 only.

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n 0ATTERNS AND 4EST #ONDITIONS

Table 146: IDD7 -EASUREMENT n ,OOP 0ATTERN1

A[17,13,11]]
RAS_n/A16

CAS_n/A15
CK_t, CK_c

Command

WE_n/A14
Sub-Loop

A12/BC_n
Number

A[10]/AP
BG[1:0]2
Data3

BA[1:0]
ACT_n

A[9:7]

A[6:3]

A[2:0]
Cycle

CS_n

ODT
CKE

0 0 ACT 0 0 0 0 0 0 0 0 0 0 0 0 0 0 n
1 RDA 0 1 1 0 1 0 0 0 0 0 1 0 0 0
2 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 n
3 D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 n
... Repeat pattern 2...3 until nRRD - 1, if nRRD > 4. Truncate if necessary
1 nRRD ACT 0 0 0 0 0 0 1 1 0 0 0 0 0 0 n
nRRD+1 RDA 0 1 1 0 1 0 1 1 0 0 1 0 0 0
... Repeat pattern 2...3 until 2 έ nRRD - 1, if nRRD > 4. Truncate if necessary
2 2 έ nRRD Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 2 instead
3 3 έ nRRD Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 3 instead
4 4 έ nRRD Repeat pattern 2...3 until nFAW - 1, if nFAW > 4 έ nRRD. Truncate if necessary
5 nFAW Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 1 instead
Static High

6 nFAW + nRRD Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 2 instead

Toggling

7 nFAW + 2 έ nRRD Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 3 instead

8 nFAW + 3 έ nRRD Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 0 instead
9 nFAW + 4 έ nRRD Repeat sub-loop 4
10 2 έ nFAW Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 0 instead
11 2 έ nFAW + nRRD Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 1 instead
12 2 έ nFAW + 2 έ nRRD Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 2 instead
13 2 έ nFAW + 3 έ nRRD Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 3 instead
14 2 έ nFAW + 4 έ nRRD Repeat sub-loop 4
15 3 έ nFAW Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 1 instead
16 3 έ nFAW + nRRD Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 2 instead
17 3 έ nFAW + 2 έ nRRD Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 3 instead
18 3 έ nFAW + 3 έ nRRD Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 0 instead
19 3 έ nFAW + 4 έ nRRD Repeat sub-loop 4
20 4 έ nFAW Repeat pattern 2...3 until nRC - 1, if nRC > 4 έ nFAW. Truncate if necessary

Notes: 1. DQS_t, DQS_c are VDDQ.

2. BG1 is a "Don't Care" for x16 devices.
3. DQ signals are VDDQ except when burst sequence drives each DQ signal by a READ command.
4. For x4 and x8 only.

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n 0ATTERNS AND 4EST #ONDITIONS

IDD Specifications

Table 147: Timings used for IDD, IPP, and IDDQ -EASUREMENT n ,OOP 0ATTERNS

DDR4-1600 DDR4-1866 DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200

10-10-10

11-11-11

12-12-12

12-12-12

13-13-13

14-14-14

14-14-14

15-15-15

16-16-16

16-16-16

17-17-17

18-18-18

18-18-18

19-19-19

20-20-20

20-20-20

21-21-21

22-22-22

20-20-20

22-22-22

24-24-24
Symbol Unit
tCK 1.25 1.071 0.937 0.833 0.75 0.682 0.625 ns

CL 10 11 12 12 13 14 14 15 16 16 17 18 18 19 20 20 21 22 20 22 24 CK
CWL 9 11 11 10 12 12 11 14 14 16 16 16 18 18 18 14 18 18 16 20 20 CK
nRCD 10 11 12 12 13 14 14 15 16 16 17 18 18 19 20 19 20 21 20 22 24 CK
nRC 38 39 40 44 45 46 50 51 52 55 56 57 61 62 63 66 67 68 72 74 76 CK
nRP 10 11 12 12 13 14 14 15 16 16 17 18 18 19 20 19 20 21 20 22 24 CK
nRAS 28 32 36 39 43 47 52 CK
nFAW x41 16 16 16 16 16 16 16 CK

x8 20 22 23 26 28 31 34 CK
x1 28 28 32 36 40 44 48 CK
6
nRRD_ x4 4 4 4 4 4 4 4 CK
S
x8 4 4 4 4 4 4 4 CK
x1 5 6 6 7 8 8 9 CK
6
nRRD_ x4 5 5 6 6 7 8 8 CK
L
x8 5 5 6 6 7 8 8 CK
x1 6 6 7 8 9 10 11 CK
6
nCCD_S 4 4 4 4 4 4 4 CK
nCCD_L 5 5 6 6 7 8 8 CK
nWTR_S 2 3 3 3 4 4 4 CK
nWTR_L 6 7 8 9 10 11 12 CK
nREFI 6,240 7,283 8,325 9,364 10,400 11,437 12,480 CK
nRFC 2Gb 128 150 171 193 214 235 256 CK
nRFC 4Gb 208 243 278 313 347 382 416 CK
nRFC 8Gb 280 327 374 421 467 514 560 CK
nRFC 16Gb 280 327 374 421 467 514 560 CK

Notes: 1. 1KB based x4 use same numbers of clocks for nFAW as the x8.

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n ,IMITS

#URRENT 3PECIFICATIONS n ,IMITS

Table 148: IDD, IPP, and IDDQ Current Limits; Die Rev. A (0ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 Unit

IDD0: One bank ACTIVATE-to-PRE- x4, x8 55 60 65 TBD mA
CHARGE current x16 85 90 95 TBD mA
IPP0: One bank ACTIVATE-to-PRE- x4, x8 3 3 3 TBD mA
CHARGE IPP current x16 4 4 4 TBD mA
IDD1: One bank ACTIVATE-to-READ-to- x4, x8 70 75 80 TBD mA
PRECHARGE current x16 105 110 115 TBD mA
IDD2N: Precharge standby current x4, x8 45 50 55 TBD mA
x16 65 70 75 TBD mA
IDD2NT: Precharge standby ODT current x4, x8 55 60 65 TBD mA
x16 75 80 90 TBD mA
IDD2P: Precharge power-down current x4, x8 25 30 35 TBD mA
x16 45 50 55 TBD mA
IDD2Q: Precharge quiet standby current x4, x8 45 45 50 TBD mA
x16 65 65 70 TBD mA
IDD3N: Active standby current x4, x8 55 55 60 TBD mA
x16 75 75 85 TBD mA
IPP3N: Active standby IPP current ALL 3 3 3 TBD mA
IDD3P: Active power-down current x4, x8 35 40 40 TBD mA
x16 55 60 65 TBD mA
IDD4R: Burst read current x4 135 145 160 TBD mA
x8 150 150 175 TBD mA
x16 210 230 250 TBD mA
IDD4W: Burst write current x4 135 145 160 TBD mA
x8 150 160 175 TBD mA
x16 210 230 250 TBD mA
IDD5R: Distributed refresh current (1X x4, x8 64 64 68 TBD mA
REF) x16 84 84 94 TBD mA
IPP5R: Distributed refresh IPP current (1X ALL 5 5 5 TBD mA
REF)

IDD6N 3ELF REFRESH CURRENT nιC 1 ALL 30 30 30 TBD mA

IDD6E 3ELF REFRESH CURRENT nιC 2, 4 x4, x8 35 35 35 TBD mA

x16 50 50 50 mA

IDD6R 3ELF REFRESH CURRENT n# 3, 4 ALL 25 25 25 TBD mA

IDD6A: Auto self refresh current (25ιC)4 ALL 20 20 20 TBD mA

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n ,IMITS

Table 148: IDD, IPP, and IDDQ Current Limits; Die Rev. A (0ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 Unit

IDD6A: Auto self refresh current (45ιC)4 ALL 25 25 25 TBD mA

IDD6A: Auto self refresh current (75ιC)4 x4, x8 35 35 35 TBD mA

x16 50 50 50 TBD mA
IPP6x: Auto self refresh IPP current; ALL 5 5 5 mA
nιC25
IDD7: Bank interleave read current x4 250 255 265 TBD mA
x8 200 205 215 TBD mA
x16 265 270 280 TBD mA
IPP7: Bank interleave read IPP current x4 25 25 25 TBD mA
x8 15 15 15 TBD
x16 20 20 20 TBD mA
IDD8: Maximum power-down current ALL 20 20 20 TBD mA

Notes: 1. Applicable for MR2 settings A7 = 0 and A6 = 0; manual mode with normal temperature range of operation
nιC).
2. Applicable for MR2 settings A7 = 1 and A6 = 0; manual mode with extended temperature range of operation
nιC).
3. Applicable for MR2 settings A7 = 0 and A6 = 1; manual mode with reduced temperature range of operation
nιC).
4. IDD6E, IDD6R, IDD6A values are verified by design and characterization, and may not be subject to production test.
5. When additive latency is enabled for IDD0, current changes by approximately 0%.
6. When additive latency is enabled for IDD1, current changes by approximately +5%(x4/x8), +4%(x16).
7. When additive latency is enabled for IDD2N, current changes by approximately +0%.
8. When DLL is disabled for IDD2N CURRENT CHANGES BY APPROXIMATELY n
9. When CAL is enabled for IDD2N CURRENT CHANGES BY APPROXIMATELY n
10. When gear-down is enabled for IDD2N, current changes by approximately 0%.
11. When CA parity is enabled for IDD2N, current changes by approximately +7%.
12. When additive latency is enabled for IDD3N, current changes by approximately +1%.
13. When additive latency is enabled for IDD4R, current changes by approximately +5%.
14. When read DBI is enabled for IDD4R, current changes by approximately 0%.
15. When additive latency is enabled for IDD4W, current changes by approximately +3%(x4/x8), +4%(x16).
16. When write DBI is enabled for IDD4W, current changes by approximately 0%.
17. When write CRC is enabled for IDD4W, current changes by approximately +10%(x4/x8), +10%(x16).
18. When CA parity is enabled for IDD4W, current changes by approximately +12% (x8), +12% (x16).
19. When 2X REF is enabled for IDD5R CURRENT CHANGES BY APPROXIMATELY n
20. When 4X REF is enabled for IDD5R CURRENT CHANGES BY APPROXIMATELY n
21. IPP0 test and limit is applicable for IDD0 and IDD1 conditions.
22. IPP3N test and limit is applicable for all IDD2x, IDD3x, IDD4x and IDD8 conditions; that is, testing IPP3N should satisfy the
IPPs for the noted IDD tests.
23. DDR4-1600 and DDR4-1866 use the same IDD limits as DDR4-2133.
24. The IDD values must be derated (increased) when operated outside of the range 0ιC ζ TC ζ 85ιC:
When TC < 0ιC: IDD2P, and IDD3P must be derated by 6%; IDD4R and IDD4W must be derated by 4%; IDD6, IDD6ET, and
IDD7 must be derated by 11%.

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n ,IMITS

When TC > 85ιC: IDD0, IDD1, IDD2N, IDD2NT, IDD2Q, IDD3N, IDD3P, IDD4R, IDD4W, and IDD5R must be derated by 3%; IDD2P
must be derated by 40%. These values are verified by design and characterization, and may not be subject to
production test.
25. IPP6x is applicable to IDD6N, IDD6E, IDD6R and IDD6A conditions.

Table 149: IDD, IPP, and IDDQ Current Limits; Die Rev. B (0ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IDD0: One bank ACTI- x4 40 43 46 49 52 mA
VATE-to-PRECHARGE cur- x8 45 48 51 54 57 mA
rent
x16 75 80 85 90 95 mA
IPP0: One bank ACTI- x4, x8 3 3 3 3 3 mA
VATE-to-PRECHARGE IPP x16 4 4 4 4 4 mA
current
IDD1: One bank ACTI- x4 52 55 58 61 64 mA
VATE-to-READ-to- PRE- x8 57 60 63 66 69 mA
CHARGE current
x16 95 100 105 110 115 mA
IDD2N: Precharge standby ALL 33 34 35 36 37 mA
current
IDD2NT: Precharge standby x4, x8 45 50 50 55 60 mA
ODT current x16 67 75 75 78 81 mA
IDD2P: Precharge ALL 25 25 25 25 25 mA
power-down current
IDD2Q: Precharge quiet ALL 30 30 30 30 30 mA
standby current
IDD3N: Active standby cur- x4 35 38 41 44 47 mA
rent x8 40 43 46 49 52 mA
x16 44 47 50 53 56 mA
IPP3N: Active standby IPP ALL 3 3 3 3 3 mA
current
IDD3P: Active power-down x4 30 32 34 36 38 mA
current x8 35 37 39 41 43 mA
x16 39 41 43 45 47 mA
IDD4R: Burst read current x4 100 110 121 132 143 mA
x8 125 135 146 157 168 mA
x16 225 243 263 283 302 mA
IDD4W: Burst write current x4 95 103 112 121 130 mA
x8 115 123 132 141 150 mA
x16 213 228 244 261 278 mA
IDD5R: Distributed refresh x4, x8 50 53 56 59 62 mA
current (1X REF) x16 56 59 61 64 67 mA
IPP5R: Distributed refresh ALL 5 5 5 5 5 mA
IPP current (1X REF)

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n ,IMITS

Table 149: IDD, IPP, and IDDQ Current Limits; Die Rev. B (0ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IDD6N: Self refresh current; ALL 30 30 30 30 30 mA
nιC 1

IDD6E: Self refresh current; ALL 35 35 35 35 35 mA

nιC 2, 4

IDD6R: Self refresh current; ALL 20 20 20 20 20 mA

n# 3, 4
IDD6A: Auto self refresh cur- ALL 8.6 8.6 8.6 8.6 8.6 mA
rent (25ιC)4
IDD6A: Auto self refresh cur- ALL 20 20 20 20 20 mA
rent (45ιC)4
IDD6A: Auto self refresh cur- ALL 30 30 30 30 30 mA
rent (75ιC)4
IPP6x: Auto self refresh IPP ALL 5 5 5 5 5 mA
CURRENT nιC25
IDD7: Bank interleave read x4 175 185 200 215 230 mA
current x8 170 175 180 185 190 mA
x16 239 249 259 269 279 mA
IPP7: Bank interleave read x4 16 17 18 19 20 mA
IPP current x8 15 15 15 15 15 mA
x16 20 20 20 20 20 mA
IDD8: Maximum ALL 25 25 25 25 25 mA
power-down current

Notes: 1. Applicable for MR2 settings A7 = 0 and A6 = 0; manual mode with normal temperature range of operation
nιC).
2. Applicable for MR2 settings A7 = 1 and A6 = 0; manual mode with extended temperature range of operation
nιC).
3. Applicable for MR2 settings A7 = 0 and A6 = 1; manual mode with reduced temperature range of operation
nιC).
4. IDD6E, IDD6R, IDD6A values are verified by design and characterization, and may not be subject to production test.
5. When additive latency is enabled for IDD0, current changes by approximately 0%.
6. When additive latency is enabled for IDD1, current changes by approximately +5%(x4/x8), +4%(x16).
7. When additive latency is enabled for IDD2N, current changes by approximately 0%.
8. When DLL is disabled for IDD2N CURRENT CHANGES BY APPROXIMATELY n
9. When CAL is enabled for IDD2N CURRENT CHANGES BY APPROXIMATELY n
10. When gear-down is enabled for IDD2N, current changes by approximately 0%.
11. When CA parity is enabled for IDD2N, current changes by approximately +7%.
12. When additive latency is enabled for IDD3N, current changes by approximately +1%.
13. When additive latency is enabled for IDD4R, current changes by approximately +5%.
14. When read DBI is enabled for IDD4R, current changes by approximately 0%.
15. When additive latency is enabled for IDD4W, current changes by approximately +3%(x4/x8), +4%(x16).
16. When write DBI is enabled for IDD4W, current changes by approximately 0%.
17. When write CRC is enabled for IDD4W, current changes by approximately +10%(x4/x8), +10%(x16).

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#URRENT 3PECIFICATIONS n ,IMITS

18. When CA parity is enabled for IDD4W, current changes by approximately +12% (x8), +12% (x16).
19. When 2X REF is enabled for IDD5R CURRENT CHANGES BY APPROXIMATELY n
20. When 4X REF is enabled for IDD5R CURRENT CHANGES BY APPROXIMATELY n
21. IPP0 test and limit is applicable for IDD0 and IDD1 conditions.
22. IPP3N test and limit is applicable for all IDD2x, IDD3x, IDD4x and IDD8 conditions; that is, testing IPP3N should satisfy the
IPPs for the noted IDD tests.
23. DDR4-1600 and DDR4-1866 use the same IDD limits as DDR4-2133.
24. The IDD values must be derated (increased) when operated outside of the range 0ιC ζ TC ζ 85ιC:
When TC < 0ιC: IDD2P, and IDD3P must be derated by 6%; IDD4R and IDD4W must be derated by 4%; IDD6, IDD6ET, and
IDD7 must be derated by 11%.
When TC > 85ιC: IDD0, IDD1, IDD2N, IDD2NT, IDD2Q, IDD3N, IDD3P, IDD4R, IDD4W, and IDD5R must be derated by 3%; IDD2P
must be derated by 40%. These values are verified by design and characterization, and may not be subject to
production test.
25. IPP6x is applicable to IDD6N, IDD6E, IDD6R and IDD6A conditions.

Table 150: IDD, IPP, and IDDQ Current Limits; Die Rev. D (0ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IDD0: One bank ACTI- x4 40 43 46 49 52 mA
VATE-to-PRECHARGE cur- x8 45 48 51 54 57 mA
rent
x16 75 80 85 90 95 mA
IPP0: One bank ACTI- x4, x8 3 3 3 3 3 mA
VATE-to-PRECHARGE IPP x16 4 4 4 4 4 mA
current
IDD1: One bank ACTI- x4 52 55 58 61 64 mA
VATE-to-READ-to- PRE- x8 57 60 63 66 69 mA
CHARGE current
x16 95 100 105 110 115 mA
IDD2N: Precharge standby ALL 33 34 35 36 37 mA
current
IDD2NT: Precharge standby x4, x8 45 50 50 55 60 mA
ODT current x16 67 75 75 78 81 mA
IDD2P: Precharge ALL 25 25 25 25 25 mA
power-down current
IDD2Q: Precharge quiet ALL 30 30 30 30 30 mA
standby current
IDD3N: Active standby cur- x4 40 43 46 49 52 mA
rent x8 45 48 51 54 56 mA
x16 49 52 55 58 61 mA
IPP3N: Active standby IPP ALL 3 3 3 3 3 mA
current
IDD3P: Active power-down x4 30 32 34 36 38 mA
current x8 35 37 39 41 43 mA
x16 39 41 43 45 47 mA

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n ,IMITS

Table 150: IDD, IPP, and IDDQ Current Limits; Die Rev. D (0ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IDD4R: Burst read current x4 100 110 121 132 143 mA
x8 125 135 146 157 168 mA
x16 225 243 263 283 302 mA
IDD4W: Burst write current x4 105 113 122 130 140 mA
x8 125 132 142 150 160 mA
x16 225 240 255 270 290 mA
IDD5R: Distributed refresh x4, x8 56 58 61 64 66 mA
current (1X REF) x16 61 64 67 69 72 mA
IPP5R: Distributed refresh ALL 5 5 5 5 5 mA
IPP current (1X REF)
IDD6N: Self refresh current; ALL 31 31 31 31 31 mA
nιC 1
IDD6E: Self refresh current; ALL 36 36 36 36 36 mA
nιC 2, 4

IDD6R: Self refresh current; ALL 21 21 21 21 21 mA

n# 3, 4

IDD6A: Auto self refresh cur- ALL 8.6 8.6 8.6 8.6 8.6 mA
rent (25ιC)4
IDD6A: Auto self refresh cur- ALL 21 21 21 21 21 mA
rent (45ιC)4
IDD6A: Auto self refresh cur- ALL 31 31 31 31 31 mA
rent (75ιC)4
IPP6x: Auto self refresh IPP ALL 5 5 5 5 5 mA
CURRENT nιC25
IDD7: Bank interleave read x4 175 185 200 215 230 mA
current x8 170 175 180 185 190 mA
x16 239 249 259 269 279 mA
IPP7: Bank interleave read x4 16 17 18 19 20 mA
IPP current x8 15 15 15 15 15 mA
x16 20 20 20 20 20 mA
IDD8: Maximum ALL 25 25 25 25 25 mA
power-down current

Notes: 1. Applicable for MR2 settings A7 = 0 and A6 = 0; manual mode with normal temperature range of operation
nιC).
2. Applicable for MR2 settings A7 = 1 and A6 = 0; manual mode with extended temperature range of operation
nιC).
3. Applicable for MR2 settings A7 = 0 and A6 = 1; manual mode with reduced temperature range of operation
nιC).
4. IDD6E, IDD6R, IDD6A values are verified by design and characterization, and may not be subject to production test.
5. When additive latency is enabled for IDD0, current changes by approximately 0%.

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6. When additive latency is enabled for IDD1, current changes by approximately +5%(x4/x8), +4%(x16).
7. When additive latency is enabled for IDD2N, current changes by approximately 0%.
8. When DLL is disabled for IDD2N CURRENT CHANGES BY APPROXIMATELY n
9. When CAL is enabled for IDD2N CURRENT CHANGES BY APPROXIMATELY n
10. When gear-down is enabled for IDD2N, current changes by approximately 0%.
11. When CA parity is enabled for IDD2N, current changes by approximately +7%.
12. When additive latency is enabled for IDD3N, current changes by approximately +1%.
13. When additive latency is enabled for IDD4R, current changes by approximately +5%.
14. When read DBI is enabled for IDD4R, current changes by approximately 0%.
15. When additive latency is enabled for IDD4W, current changes by approximately +3%(x4/x8), +4%(x16).
16. When write DBI is enabled for IDD4W, current changes by approximately 0%.
17. When write CRC is enabled for IDD4W, current changes by approximately +10%(x4/x8), +10%(x16).
18. When CA parity is enabled for IDD4W, current changes by approximately +12% (x8), +12% (x16).
19. When 2X REF is enabled for IDD5R CURRENT CHANGES BY APPROXIMATELY n
20. When 4X REF is enabled for IDD5R CURRENT CHANGES BY APPROXIMATELY n
21. IPP0 test and limit is applicable for IDD0 and IDD1 conditions.
22. IPP3N test and limit is applicable for all IDD2x, IDD3x, IDD4x and IDD8 conditions; that is, testing IPP3N should satisfy the
IPPs for the noted IDD tests.
23. DDR4-1600 and DDR4-1866 use the same IDD limits as DDR4-2133.
24. The IDD values must be derated (increased) when operated outside of the range 0ιC ζ TC ζ 85ιC:
When TC < 0ιC: IDD2P, and IDD3P must be derated by +6%; IDD4R and IDD4W must be derated by +4%; IDD6, IDD6ET,
and IDD7 must be derated by +11%.
When TC > 85ιC: IDD0, IDD1, IDD2N, IDD2NT, IDD2Q, IDD3N, IDD3P, IDD4R, and IDD4W must be derated by +3%; IDD2P must
be derated by +40%; and IDD5R and IPP5R must be derated by +40%. These values are verified by design and char-
acterization, and may not be subject to production test.
25. IPP6x is applicable to IDD6N, IDD6E, IDD6R and IDD6A conditions.

Table 151: IDD, IPP, and IDDQ Current Limits; Die Rev. E (-40ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IDD0: One bank ACTI- x4 37 39 41 43 45 mA
VATE-to-PRECHARGE cur- x8 39 41 43 45 47 mA
rent
x16 46 48 50 52 54 mA
IPP0: One bank ACTI- x4, x8 3 3 3 3 3 mA
VATE-to-PRECHARGE IPP x16 4 4 4 4 4 mA
current
IDD1: One bank ACTI- x4 50 52 54 56 58 mA
VATE-to-READ-to- PRE- x8 55 57 59 61 63 mA
CHARGE current
x16 72 74 76 78 80 mA
IDD2N: Precharge standby ALL 29 30 31 32 33 mA
current
IDD2NT: Precharge standby x4, x8 36 38 40 42 44 mA
ODT current x16 43 46 49 52 55 mA
IDD2P: Precharge ALL 22 22 22 22 22 mA
power-down current
IDD2Q: Precharge quiet ALL 26 26 26 26 26 mA
standby current

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#URRENT 3PECIFICATIONS n ,IMITS

Table 151: IDD, IPP, and IDDQ Current Limits; Die Rev. E (-40ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IDD3N: Active standby cur- x4 34 36 38 40 42 mA
rent x8 35 37 39 41 43 mA
x16 36 38 40 42 44 mA
IPP3N: Active standby IPP ALL 3 3 3 3 3 mA
current
IDD3P: Active power-down x4 28 29 30 31 32 mA
current x8 29 30 31 32 33 mA
x16 30 31 32 33 34 mA
IDD4R: Burst read current x4 110 120 131 142 153 mA
x8 135 145 156 167 178 mA
x16 235 253 273 293 312 mA
IDD4W: Burst write current x4 96 105 114 123 132 mA
x8 114 123 132 141 150 mA
x16 182 199 216 233 250 mA
IDD5R: Distributed refresh ALL 46 47 48 49 50 mA
current (1X REF)
IPP5R: Distributed refresh ALL 5 5 5 5 5 mA
IPP current (1X REF)
IDD6N: Self refresh current; ALL 34 34 34 34 34 mA
nιC 1

IDD6E: Self refresh current; ALL 58 58 58 58 58 mA

nιC 2, 4
IDD6R: Self refresh current; ALL 21 21 21 21 21 mA
nιC 3, 4

IDD6A: Auto self refresh cur- ALL 8.6 8.6 8.6 8.6 8.6 mA
rent (25ιC)4
IDD6A: Auto self refresh cur- ALL 21 21 21 21 21 mA
rent (45ιC)4
IDD6A: Auto self refresh cur- ALL 31 31 31 31 31 mA
rent (75ιC)4
IDD6A: Auto self refresh cur- ALL 58 58 58 58 58 mA
rent (95ιC)4
IPP6x: Auto self refresh IPP ALL 5 5 5 5 5 mA
CURRENT nιC26
IDD7: Bank interleave read x4 175 185 200 215 230 mA
current x8 170 175 180 185 190 mA
x16 234 243 252 261 270 mA

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#URRENT 3PECIFICATIONS n ,IMITS

Table 151: IDD, IPP, and IDDQ Current Limits; Die Rev. E (-40ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IPP7: Bank interleave read x4 14 14 14 14 14 mA
IPP current x8 13 13 13 13 13 mA
x16 18 18 18 18 18 mA
IDD8: Maximum ALL 18 18 18 18 18 mA
power-down current

Notes: 1. Applicable for MR2 settings A7 = 0 and A6 = 0; manual mode with normal temperature range of operation
 nιC).
2. Applicable for MR2 settings A7 = 1 and A6 = 0; manual mode with extended temperature range of operation
 nιC).
3. Applicable for MR2 settings A7 = 0 and A6 = 1; manual mode with reduced temperature range of operation
 nιC).
4. IDD6E, IDD6R, IDD6A values are verified by design and characterization, and may not be subject to production test.
5. When additive latency is enabled for IDD0, current changes by approximately +1%.
6. When additive latency is enabled for IDD1, current changes by approximately +8%(x4/x8), +7%(x16).
7. When additive latency is enabled for IDD2N, current changes by approximately +1%.
8. When DLL is disabled for IDD2N CURRENT CHANGES BY APPROXIMATELY n
9. When CAL is enabled for IDD2N CURRENT CHANGES BY APPROXIMATELY n
10. When gear-down is enabled for IDD2N, current changes by approximately 0%.
11. When CA parity is enabled for IDD2N, current changes by approximately +10%.
12. When additive latency is enabled for IDD3N, current changes by approximately +1%.
13. When additive latency is enabled for IDD4R, current changes by approximately +4%.
14. When read DBI is enabled for IDD4R, current changes by approximately -14%.
15. When additive latency is enabled for IDD4W, current changes by approximately +3%(x4/x8), +4%(x16).
16. When write DBI is enabled for IDD4W, current changes by approximately 0%.
17. When write CRC is enabled for IDD4W, current changes by approximately -5%.
18. When CA parity is enabled for IDD4W, current changes by approximately +12%.
19. When 2X REF is enabled for IDD5R, current changes by approximately +0%.
20. When 4X REF is enabled for IDD5R, current changes by approximately +0%.
21. When 2X REF is enabled for IPP5R, current changes by approximately +0%.
22. When 4X REF is enabled for IPP5R, current changes by approximately +0%.
23. IPP0 test and limit is applicable for IDD0 and IDD1 conditions.
24. IPP3N test and limit is applicable for all IDD2x, IDD3x, IDD4x and IDD8 conditions; that is, testing IPP3N should satisfy the
IPPs for the noted IDD tests.
25. DDR4-1600 and DDR4-1866 use the same IDD limits as DDR4-2133.
26. The IDD values must be derated (increased) when operating between 85ιC < TC ζ 95ιC: IDD0, IDD1, IDD2N, IDD2NT,
IDD2Q, IDD3N, IDD3P, IDD4R, and IDD4W must be derated by +3%; IDD2P must be derated by +10%; and IDD5R and IPP5R
must be derated by +43%; All IPP currents except IPP6x and IPP5R must be derated by +0%. These values are verified
by design and characterization, and may not be subject to production test.
27. IPP6x is applicable to IDD6N, IDD6E, IDD6R and IDD6A conditions.

Table 152: IDD, IPP, and IDDQ Current Limits; Die Rev. E (-40ι ζ TC ζ 105ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IDD0: One bank ACTI- x8 43 45 47 49 51 mA
VATE-to-PRECHARGE cur- x16 50 52 54 56 58 mA
rent

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n ,IMITS

Table 152: IDD, IPP, and IDDQ Current Limits; Die Rev. E (-40ι ζ TC ζ 105ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IPP0: One bank ACTI- x8 3 3 3 3 3 mA
VATE-to-PRECHARGE IPP x16 4 4 4 4 4 mA
current
IDD1: One bank ACTI- x8 59 61 63 65 67 mA
VATE-to-READ-to- PRE- x16 77 79 81 83 85 mA
CHARGE current
IDD2N: Precharge standby ALL 32 33 34 35 36 mA
current
IDD2NT: Precharge standby x8 40 42 44 46 48 mA
ODT current x16 47 49 53 56 59 mA
IDD2P: Precharge ALL 26 26 26 26 26 mA
power-down current
IDD2Q: Precharge quiet ALL 29 29 29 29 29 mA
standby current
IDD3N: Active standby cur- x8 39 41 43 45 47 mA
rent x16 40 42 44 46 48 mA
IPP3N: Active standby IPP ALL 3 3 3 3 3 mA
current
IDD3P: Active power-down x8 33 34 35 36 37 mA
current x16 34 35 36 37 38 mA
IDD4R: Burst read current x8 145 155 166 178 189 mA
x16 247 265 292 306 326 mA
IDD4W: Burst write current x8 123 132 141 151 160 mA
x16 193 210 228 245 263 mA
IDD5R: Distributed refresh ALL 96 97 98 99 100 mA
current (1X REF)
IPP5R: Distributed refresh ALL 5 5 5 5 5 mA
IPP current (1X REF)
IDD6N: Self refresh current; ALL 34 34 34 34 34 mA
nιC 1
IDD6E: Self refresh current; ALL 95 95 95 95 95 mA
nιC 2, 4

IDD6R: Self refresh current; ALL 21 21 21 21 21 mA

nιC 3, 4

IDD6A: Auto self refresh cur- ALL 8.6 8.6 8.6 8.6 8.6 mA
rent (25ιC)4
IDD6A: Auto self refresh cur- ALL 21 21 21 21 21 mA
rent (45ιC)4
IDD6A: Auto self refresh cur- ALL 31 31 31 31 31 mA
rent (75ιC)4

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n ,IMITS

Table 152: IDD, IPP, and IDDQ Current Limits; Die Rev. E (-40ι ζ TC ζ 105ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IDD6A: Auto self refresh cur- ALL 95 95 95 95 95 mA
rent (105ιC)4
IPP6x: Auto self refresh IPP ALL 6 6 6 6 6 mA
CURRENT nιC26
IDD7: Bank interleave read x8 175 180 185 190 195 mA
current x16 239 248 257 266 275 mA
IPP7: Bank interleave read x8 13 13 13 13 13 mA
IPP current x16 18 18 18 18 18 mA
IDD8: Maximum ALL 20 20 20 20 20 mA
power-down current

Notes: 1. Applicable for MR2 settings A7 = 0 and A6 = 0; manual mode with normal temperature range of operation
 nιC).
2. Applicable for MR2 settings A7 = 1 and A6 = 0; manual mode with extended temperature range of operation
 nιC).
3. Applicable for MR2 settings A7 = 0 and A6 = 1; manual mode with reduced temperature range of operation
 nιC).
4. IDD6E, IDD6R, IDD6A values are verified by design and characterization, and may not be subject to production test.
5. When additive latency is enabled for IDD0, current changes by approximately +1%.
6. When additive latency is enabled for IDD1, current changes by approximately +8%(x4/x8), +7%(x16).
7. When additive latency is enabled for IDD2N, current changes by approximately +1%.
8. When DLL is disabled for IDD2N CURRENT CHANGES BY APPROXIMATELY n
9. When CAL is enabled for IDD2N CURRENT CHANGES BY APPROXIMATELY n
10. When gear-down is enabled for IDD2N, current changes by approximately 0%.
11. When CA parity is enabled for IDD2N, current changes by approximately +10%.
12. When additive latency is enabled for IDD3N, current changes by approximately +1%.
13. When additive latency is enabled for IDD4R, current changes by approximately +4%.
14. When read DBI is enabled for IDD4R, current changes by approximately -14%.
15. When additive latency is enabled for IDD4W, current changes by approximately +3%(x4/x8), +4%(x16).
16. When write DBI is enabled for IDD4W, current changes by approximately 0%.
17. When write CRC is enabled for IDD4W, current changes by approximately -5%.
18. When CA parity is enabled for IDD4W, current changes by approximately +12%.
19. When 2X REF is enabled for IDD5R, current changes by approximately +0%.
20. When 4X REF is enabled for IDD5R, current changes by approximately +0%.
21. When 2X REF is enabled for IPP5R, current changes by approximately +0%.
22. When 4X REF is enabled for IPP5R, current changes by approximately +0%.
23. IPP0 test and limit is applicable for IDD0 and IDD1 conditions.
24. IPP3N test and limit is applicable for all IDD2x, IDD3x, IDD4x and IDD8 conditions; that is, testing IPP3N should satisfy the
IPPs for the noted IDD tests.
25. DDR4-1600 and DDR4-1866 use the same IDD limits as DDR4-2133.

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#URRENT 3PECIFICATIONS n ,IMITS

26. IPP6x is applicable to IDD6N, IDD6E, IDD6R and IDD6A conditions.

Table 153: IDD, IPP, and IDDQ Current Limits; Die Rev. G (0ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IDD0: One bank ACTI- x4 40 43 46 49 52 mA
VATE-to-PRECHARGE cur- x8 45 48 51 54 57 mA
rent
x16 75 80 85 90 95 mA
IPP0: One bank ACTI- x4, x8 3 3 3 3 3 mA
VATE-to-PRECHARGE IPP x16 4 4 4 4 4 mA
current
IDD1: One bank ACTI- x4 52 55 58 61 64 mA
VATE-to-READ-to- PRE- x8 57 60 63 66 69 mA
CHARGE current
x16 95 100 105 110 115 mA
IDD2N: Precharge standby ALL 33 34 35 36 37 mA
current
IDD2NT: Precharge standby x4, x8 45 50 50 55 60 mA
ODT current x16 67 75 75 78 81 mA
IDD2P: Precharge ALL 25 25 25 25 25 mA
power-down current
IDD2Q: Precharge quiet ALL 30 30 30 30 30 mA
standby current
IDD3N: Active standby cur- x4 40 43 46 49 52 mA
rent x8 45 48 51 54 56 mA
x16 49 52 55 58 61 mA
IPP3N: Active standby IPP ALL 3 3 3 3 3 mA
current
IDD3P: Active power-down x4 30 32 34 36 38 mA
current x8 35 37 39 41 43 mA
x16 39 41 43 45 47 mA
IDD4R: Burst read current x4 100 110 121 132 143 mA
x8 125 135 146 157 168 mA
x16 225 243 263 283 302 mA
IDD4W: Burst write current x4 100 108 117 126 135 mA
x8 120 128 137 146 155 mA
x16 218 233 249 266 283 mA
IDD5R: Distributed refresh x4, x8 56 58 61 64 66 mA
current (1X REF) x16 61 64 67 69 72 mA
IPP5R: Distributed refresh ALL 5 5 5 5 5 mA
IPP current (1X REF)
IDD6N: Self refresh current; ALL 31 31 31 31 31 mA
nιC 1

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n ,IMITS

Table 153: IDD, IPP, and IDDQ Current Limits; Die Rev. G (0ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IDD6E: Self refresh current; ALL 36 36 36 36 36 mA
nιC 2, 4

IDD6R: Self refresh current; ALL 21 21 21 21 21 mA

n# 3, 4

IDD6A: Auto self refresh cur- ALL 8.6 8.6 8.6 8.6 8.6 mA
rent (25ιC)4
IDD6A: Auto self refresh cur- ALL 21 21 21 21 21 mA
rent (45ιC)4
IDD6A: Auto self refresh cur- ALL 31 31 31 31 31 mA
rent (75ιC)4
IPP6x: Auto self refresh IPP ALL 5 5 5 5 5 mA
CURRENT nιC25
IDD7: Bank interleave read x4 175 185 200 215 230 mA
current x8 170 175 180 185 190 mA
x16 239 249 259 269 279 mA
IPP7: Bank interleave read x4 16 17 18 19 20 mA
IPP current x8 15 15 15 15 15 mA
x16 20 20 20 20 20 mA
IDD8: Maximum ALL 25 25 25 25 25 mA
power-down current

Notes: 1. Applicable for MR2 settings A7 = 0 and A6 = 0; manual mode with normal temperature range of operation
nιC).
2. Applicable for MR2 settings A7 = 1 and A6 = 0; manual mode with extended temperature range of operation
nιC).
3. Applicable for MR2 settings A7 = 0 and A6 = 1; manual mode with reduced temperature range of operation
nιC).
4. IDD6E, IDD6R, IDD6A values are verified by design and characterization, and may not be subject to production test.
5. When additive latency is enabled for IDD0, current changes by approximately 0%.
6. When additive latency is enabled for IDD1, current changes by approximately +5%(x4/x8), +4%(x16).
7. When additive latency is enabled for IDD2N, current changes by approximately 0%.
8. When DLL is disabled for IDD2N CURRENT CHANGES BY APPROXIMATELY n
9. When CAL is enabled for IDD2N CURRENT CHANGES BY APPROXIMATELY n
10. When gear-down is enabled for IDD2N, current changes by approximately 0%.
11. When CA parity is enabled for IDD2N, current changes by approximately +7%.
12. When additive latency is enabled for IDD3N, current changes by approximately +1%.
13. When additive latency is enabled for IDD4R, current changes by approximately +5%.
14. When read DBI is enabled for IDD4R, current changes by approximately 0%.
15. When additive latency is enabled for IDD4W, current changes by approximately +3%(x4/x8), +4%(x16).
16. When write DBI is enabled for IDD4W, current changes by approximately 0%.
17. When write CRC is enabled for IDD4W, current changes by approximately +10%(x4/x8), +10%(x16).
18. When CA parity is enabled for IDD4W, current changes by approximately +12% (x8), +12% (x16).
19. When 2X REF is enabled for IDD5R CURRENT CHANGES BY APPROXIMATELY n
20. When 4X REF is enabled for IDD5R CURRENT CHANGES BY APPROXIMATELY n

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#URRENT 3PECIFICATIONS n ,IMITS

21. IPP0 test and limit is applicable for IDD0 and IDD1 conditions.
22. IPP3N test and limit is applicable for all IDD2x, IDD3x, IDD4x and IDD8 conditions; that is, testing IPP3N should satisfy the
IPPs for the noted IDD tests.
23. DDR4-1600 and DDR4-1866 use the same IDD limits as DDR4-2133.
24. The IDD values must be derated (increased) when operated outside of the range 0ιC ζ TC ζ 85ιC:
When TC < 0ιC: IDD2P, and IDD3P must be derated by 6%; IDD4R and IDD4W must be derated by 4%; IDD6, IDD6ET, and
IDD7 must be derated by 11%.
When TC > 85ιC: IDD0, IDD1, IDD2N, IDD2NT, IDD2Q, IDD3N, IDD3P, IDD4R, IDD4W, and IDD5R must be derated by 3%; IDD2P
must be derated by 40%. These values are verified by design and characterization, and may not be subject to
production test.
25. IPP6x is applicable to IDD6N, IDD6E, IDD6R and IDD6A conditions.

Table 154: IDD, IPP, and IDDQ Current Limits; Die Rev. H (0ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IDD0: One bank ACTI- x4 55 55 57 60 na mA
VATE-to-PRECHARGE cur- x8 55 55 60 61 na mA
rent
x16 75 75 80 83 na mA
IPP0: One bank ACTI- x4, x8 3 3 3 3 na mA
VATE-to-PRECHARGE IPP x16 5 5 5 5 na mA
current
IDD1: One bank ACTI- x4 68 68 71 75 na mA
VATE-to-READ-to- PRE- x8 68 68 73 75 na mA
CHARGE current
x16 100 100 107 111 na mA
IDD2N: Precharge standby ALL 39 39 42 43 na mA
current
IDD2NT: Precharge standby x4, x8 43 43 48 50 na mA
ODT current x16 47 47 50 54 na mA
IDD2P: Precharge ALL 27 27 27 27 na mA
power-down current
IDD2Q: Precharge quiet ALL 34 34 36 36 na mA
standby current
IDD3N: Active standby cur- x4 46 47 49 52 na mA
rent x8 46 47 49 52 na mA
x16 46 47 50 53 na mA
IPP3N: Active standby IPP ALL 4.5 4.5 4.5 4.5 na mA
current
IDD3P: Active power-down x4 34 34 34 37 na mA
current x8 36 36 39 40 na mA
x16 37 37 40 42 na mA
IDD4R: Burst read current x4 135 135 157 173 na mA
x8 147 147 174 188 na mA
x16 259 259 312 341 na mA

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#URRENT 3PECIFICATIONS n ,IMITS

Table 154: IDD, IPP, and IDDQ Current Limits; Die Rev. H (0ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IDD4W: Burst write current x4 163 163 192 210 na mA
x8 181 181 217 234 na mA
x16 298 298 359 392 na mA
IDD5R: Distributed refresh x4 49 49 51 53 na mA
current (1X REF) x8 49 49 51 53 na mA
x16 49 49 52 54 na mA
IPP5R: Distributed refresh ALL 5.5 5.5 5.5 5.5 na mA
IPP current (1X REF)
IDD6N: Self refresh current; ALL 36 36 36 36 na mA
nιC 1
IDD6E: Self refresh current; x4, x8 48 48 49 49 na mA
nιC 2, 4
x16 50 50 50 51 na mA
IDD6R: Self refresh current; ALL 26 26 26 26 na mA
n# 3, 4

IDD6A: Auto self refresh cur- ALL 15 15 15 15 na mA

rent (25ιC)4
IDD6A: Auto self refresh cur- ALL 26 26 26 26 na mA
rent (45ιC)4
IDD6A: Auto self refresh cur- ALL 36 36 36 36 na mA
rent (75ιC)4
IPP6x: Auto self refresh IPP ALL 5 5 5 5 na mA
CURRENT nιC25
IDD7: Bank interleave read x4 278 278 388 369 na mA
current x8 228 228 240 244 na mA
x16 311 311 321 331 na mA
IPP7: Bank interleave read x4 21 21 26 28 na mA
IPP current x8 16 16 16 16 na mA
x16 22 22 22 22 na mA
IDD8: Maximum ALL 21 21 21 21 na mA
power-down current

Notes: 1. Applicable for MR2 settings A7 = 0 and A6 = 0; manual mode with normal temperature range of operation
nιC).
2. Applicable for MR2 settings A7 = 1 and A6 = 0; manual mode with extended temperature range of operation
nιC).
3. Applicable for MR2 settings A7 = 0 and A6 = 1; manual mode with reduced temperature range of operation
nιC).
4. IDD6E, IDD6R, IDD6A values are verified by design and characterization, and may not be subject to production test.
5. When additive latency is enabled for IDD0, current changes by approximately 0%.
6. When additive latency is enabled for IDD1, current changes by approximately +5%(x4/x8), +4%(x16).
7. When additive latency is enabled for IDD2N, current changes by approximately 0%.

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#URRENT 3PECIFICATIONS n ,IMITS

8. When DLL is disabled for IDD2N CURRENT CHANGES BY APPROXIMATELY n

9. When CAL is enabled for IDD2N CURRENT CHANGES BY APPROXIMATELY n
10. When gear-down is enabled for IDD2N, current changes by approximately 0%.
11. When CA parity is enabled for IDD2N, current changes by approximately +7%.
12. When additive latency is enabled for IDD3N, current changes by approximately +1%.
13. When additive latency is enabled for IDD4R, current changes by approximately +5%.
14. When read DBI is enabled for IDD4R, current changes by approximately 0%.
15. When additive latency is enabled for IDD4W, current changes by approximately +3%(x4/x8), +4%(x16).
16. When write DBI is enabled for IDD4W, current changes by approximately 0%.
17. When write CRC is enabled for IDD4W, current changes by approximately +10%(x4/x8), +10%(x16).
18. When CA parity is enabled for IDD4W, current changes by approximately +12% (x8), +12% (x16).
19. When 2X REF is enabled for IDD5R CURRENT CHANGES BY APPROXIMATELY n
20. When 4X REF is enabled for IDD5R CURRENT CHANGES BY APPROXIMATELY n
21. IPP0 test and limit is applicable for IDD0 and IDD1 conditions.
22. IPP3N test and limit is applicable for all IDD2x, IDD3x, IDD4x and IDD8 conditions; that is, testing IPP3N should satisfy the
IPPs for the noted IDD tests.
23. DDR4-1600 and DDR4-1866 use the same IDD limits as DDR4-2133.
24. The IDD values must be derated (increased) when operated outside of the range 0ιC ζ TC ζ 85ιC:
When TC < 0ιC: IDD2P, and IDD3P must be derated by 6%; IDD4R and IDD4W must be derated by 4%; IDD6, IDD6ET, and
IDD7 must be derated by 11%.
When TC > 85ιC: IDD0, IDD1, IDD2N, IDD2NT, IDD2Q, IDD3N, IDD3P, IDD4R, IDD4W, and IDD5R must be derated by 3%; IDD2P
must be derated by 40%. These values are verified by design and characterization, and may not be subject to
production test.
25. IPP6x is applicable to IDD6N, IDD6E, IDD6R and IDD6A conditions.

Table 155: IDD, IPP, and IDDQ Current Limits; Die Rev. J (-40ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IDD0: One bank ACTI- x4 35 37 39 41 43 mA
VATE-to-PRECHARGE cur- x8 37 39 41 43 44 mA
rent
x16 44 46 48 50 52 mA
IPP0: One bank ACTI- x4, x8 3 3 3 3 3 mA
VATE-to-PRECHARGE IPP x16 4 4 4 4 4 mA
current
IDD1: One bank ACTI- x4 48 50 51 53 55 mA
VATE-to-READ-to- PRE- x8 52 54 56 58 60 mA
CHARGE current
x16 68 70 72 74 76 mA
IDD2N: Precharge standby ALL 28 29 30 30 31 mA
current
IDD2NT: Precharge standby x4, x8 34 36 38 40 42 mA
ODT current x16 41 44 47 50 53 mA
IDD2P: Precharge ALL 22 22 22 22 22 mA
power-down current
IDD2Q: Precharge quiet ALL 26 26 26 26 26 mA
standby current

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n ,IMITS

Table 155: IDD, IPP, and IDDQ Current Limits; Die Rev. J (-40ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IDD3N: Active standby cur- x4 34 36 38 40 42 mA
rent x8 35 37 39 41 43 mA
x16 36 38 40 42 44 mA
IPP3N: Active standby IPP ALL 3 3 3 3 3 mA
current
IDD3P: Active power-down x4 28 29 30 31 32 mA
current x8 29 30 31 32 33 mA
x16 30 31 32 33 34 mA
IDD4R: Burst read current x4 105 114 125 135 145 mA
x8 128 138 148 158 169 mA
x16 223 240 260 278 296 mA
IDD4W: Burst write current x4 91 100 108 117 126 mA
x8 108 116 125 134 142 mA
x16 173 189 205 221 238 mA
IDD5R: Distributed refresh ALL 44 45 45 46 47 mA
current (1X REF)
IPP5R: Distributed refresh ALL 5 5 5 5 5 mA
IPP current (1X REF)
IDD6N: Self refresh current; ALL 32 32 32 32 32 mA
nιC 1

IDD6E: Self refresh current; ALL 55 55 55 55 55 mA

nιC 2, 4
IDD6R: Self refresh current; ALL 20 20 20 20 20 mA
nιC 3, 4

IDD6A: Auto self refresh cur- ALL 8.2 8.2 8.2 8.2 8.2 mA
rent (25ιC)4
IDD6A: Auto self refresh cur- ALL 20 20 20 20 20 mA
rent (45ιC)4
IDD6A: Auto self refresh cur- ALL 30 30 30 30 30 mA
rent (75ιC)4
IDD6A: Auto self refresh cur- ALL 55 55 55 55 55 mA
rent (95ιC)4
IPP6x: Auto self refresh IPP ALL 5 5 5 5 5 mA
CURRENT nιC27
IDD7: Bank interleave read x4 166 176 190 205 219 mA
current x8 161 166 171 175 180 mA
x16 222 231 240 248 257 mA

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n ,IMITS

Table 155: IDD, IPP, and IDDQ Current Limits; Die Rev. J (-40ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IPP7: Bank interleave read x4 11 11 11 11 11 mA
IPP current x8 10 10 10 10 13 mA
x16 15 15 15 15 15 mA
IDD8: Maximum ALL 18 18 18 18 18 mA
power-down current

Notes: 1. Applicable for MR2 settings A7 = 0 and A6 = 0; manual mode with normal temperature range of operation
 nιC).
2. Applicable for MR2 settings A7 = 1 and A6 = 0; manual mode with extended temperature range of operation
 nιC).
3. Applicable for MR2 settings A7 = 0 and A6 = 1; manual mode with reduced temperature range of operation
 nιC).
4. IDD6E, IDD6R, IDD6A values are verified by design and characterization, and may not be subject to production test.
5. When additive latency is enabled for IDD0, current changes by approximately +1%.
6. When additive latency is enabled for IDD1, current changes by approximately +8%(x4/x8), +7%(x16).
7. When additive latency is enabled for IDD2N, current changes by approximately +1%.
8. When DLL is disabled for IDD2N CURRENT CHANGES BY APPROXIMATELY n
9. When CAL is enabled for IDD2N CURRENT CHANGES BY APPROXIMATELY n
10. When gear-down is enabled for IDD2N, current changes by approximately 0%.
11. When CA parity is enabled for IDD2N, current changes by approximately +13%.
12. When additive latency is enabled for IDD3N, current changes by approximately +2%.
13. When additive latency is enabled for IDD4R, current changes by approximately +4(x4/x8), +3%(x16).
14. When read DBI is enabled for IDD4R, current changes by approximately -14%(x4/x8), -20%(x16).
15. When additive latency is enabled for IDD4W, current changes by approximately +4%(x4/x8), +3%(x16).
16. When write DBI is enabled for IDD4W, current changes by approximately 0%.
17. When write CRC is enabled for IDD4W, current changes by approximately -5%.
18. When CA parity is enabled for IDD4W, current changes by approximately +12%.
19. When 2X REF is enabled for IDD5R, current changes by approximately +0%.
20. When 4X REF is enabled for IDD5R, current changes by approximately +0%.
21. When 2X REF is enabled for IPP5R, current changes by approximately +0%.
22. When 4X REF is enabled for IPP5R, current changes by approximately +0%.
23. IPP0 test and limit is applicable for IDD0 and IDD1 conditions.
24. IPP3N test and limit is applicable for all IDD2x, IDD3x, IDD4x and IDD8 conditions; that is, testing IPP3N should satisfy the
IPPs for the noted IDD tests.
25. DDR4-1600 and DDR4-1866 use the same IDD limits as DDR4-2133.
26. The IDD values must be derated (increased) when operating between 85ιC < TC ζ 95ιC: IDD0, IDD1, IDD2N, IDD2NT,
IDD2Q, IDD3N, IDD3P, IDD4R, and IDD4W, must be derated by +3%; IDD2P must be derated by +13%; IDD5R and IPP5R must
be derated by +43%; All IPP currents except IPP6x and IPP5R must be derated by +0%. These values are verified by
design and characterization, and may not be subject to production test.
27. IPP6x is applicable to IDD6N, IDD6E, IDD6R and IDD6A conditions.

Table 156: IDD, IPP, and IDDQ Current Limits; Die Rev. R (-40ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IDD0: One bank ACTI- x4 38 40 42 44 46 mA
VATE-to-PRECHARGE cur- x8 40 42 44 46 48 mA
rent
x16 51 53 55 57 59 mA

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n ,IMITS

Table 156: IDD, IPP, and IDDQ Current Limits; Die Rev. R (-40ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IPP0: One bank ACTI- x4, x8 4 4 4 4 4 mA
VATE-to-PRECHARGE IPP x16 5 5 5 5 5 mA
current
IDD1: One bank ACTI- x4 43 45 47 49 51 mA
VATE-to-READ-to- PRE- x8 47 49 51 53 55 mA
CHARGE current
x16 61 63 65 67 69 mA
IDD2N: Precharge standby ALL 34 35 36 37 38 mA
current
IDD2NT: Precharge standby x4, x8 33 35 37 39 41 mA
ODT current x16 38 40 42 44 46 mA
IDD2P: Precharge ALL 30 30 30 30 30 mA
power-down current
IDD2Q: Precharge quiet ALL 34 34 34 34 34 mA
standby current
IDD3N: Active standby cur- x4 34 36 38 40 42 mA
rent x8 35 37 39 41 43 mA
x16 36 38 40 42 44 mA
IPP3N: Active standby IPP ALL 3 3 3 3 3 mA
current
IDD3P: Active power-down x4 28 29 30 31 32 mA
current x8 29 30 31 32 33 mA
x16 30 31 32 33 34 mA
IDD4R: Burst read current x4 74 80 88 95 103 mA
x8 92 98 105 113 123 mA
x16 130 139 151 164 176 mA
IDD4W: Burst write current x4 62 66 70 76 82 mA
x8 79 85 91 98 106 mA
x16 102 109 119 127 138 mA
IDD5R: Distributed refresh ALL 44 45 45 46 47 mA
current (1X REF)
IPP5R: Distributed refresh ALL 5 5 5 5 5 mA
IPP current (1X REF)
IDD6N: Self refresh current; ALL 32 32 32 32 32 mA
nιC 1

IDD6E: Self refresh current; ALL 52 52 52 52 52 mA

nιC 2, 4
IDD6R: Self refresh current; ALL 19 19 19 19 19 mA
nιC 3, 4

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n ,IMITS

Table 156: IDD, IPP, and IDDQ Current Limits; Die Rev. R (-40ι ζ TC ζ 85ιC)

Symbol Width DDR4-2133 DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Unit

IDD6A: Auto self refresh cur- ALL 8 8 8 8 8 mA
rent (25ιC)4
IDD6A: Auto self refresh cur- ALL 19 19 19 19 19 mA
rent (45ιC)4
IDD6A: Auto self refresh cur- ALL 29 29 29 29 29 mA
rent (75ιC)4
IDD6A: Auto self refresh cur- ALL 52 52 52 52 52 mA
rent (95ιC)4
IPP6x: Auto self refresh IPP ALL 5 5 5 5 5 mA
CURRENT nιC27
IDD7: Bank interleave read x4 154 169 186 200 215 mA
current x8 135 140 145 150 155 mA
x16 165 179 196 210 225 mA
IPP7: Bank interleave read x4 13 13 13 13 13 mA
IPP current x8 8 8 8 8 8 mA
x16 13 13 13 13 13 mA
IDD8: Maximum ALL 24 24 24 24 24 mA
power-down current
IDD9: MBIST-PPR current ALL 170 170 170 170 170 mA
IPP9: MBIST-PPR IPP current ALL 13 13 13 13 13 mA

Notes: 1. Applicable for MR2 settings A7 = 0 and A6 = 0; manual mode with normal temperature range of operation
 nιC).
2. Applicable for MR2 settings A7 = 1 and A6 = 0; manual mode with extended temperature range of operation
 nιC).
3. Applicable for MR2 settings A7 = 0 and A6 = 1; manual mode with reduced temperature range of operation
 nιC).
4. IDD6E, IDD6R, IDD6A values are verified by design and characterization, and may not be subject to production test.
5. When additive latency is enabled for IDD0, current changes by approximately +1%.
6. When additive latency is enabled for IDD1, current changes by approximately +5%.
7. When additive latency is enabled for IDD2N, current changes by approximately 2%.
8. When DLL is disabled for IDD2N, current changes by approximately +19%.
9. When CAL is enabled for IDD2N, current changes by approximately -20%.
10. When gear-down is enabled for IDD2N, current changes by approximately +2%.
11. When CA parity is enabled for IDD2N, current changes by approximately +10%.
12. When additive latency is enabled for IDD3N, current changes by approximately -2%.
13. When additive latency is enabled for IDD4R, current changes by approximately +4%.
14. When read DBI is enabled for IDD4R, current changes by approximately -14%
15. When additive latency is enabled for IDD4W, current changes by approximately +6%.
16. When write DBI is enabled for IDD4W, current changes by approximately +1%.
17. When write CRC is enabled for IDD4W, current changes by approximately -5%.
18. When CA parity is enabled for IDD4W, current changes by approximately +14%.
19. When 2X REF is enabled for IDD5R, current changes by approximately 0%.

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 8Gb: x4, x8, x16 DDR4 SDRAM
#URRENT 3PECIFICATIONS n ,IMITS

20. When 4X REF is enabled for IDD5R, current changes by approximately 0%.
21. When 2X REF is enabled for IPP5R, current changes by approximately 0%.
22. When 4X REF is enabled for IPP5R, current changes by approximately 0%.
23. IPP0 test and limit is applicable for IDD0 and IDD1 conditions.
24. IPP3N test and limit is applicable for all IDD2x, IDD3x, IDD4x and IDD8 conditions; that is, testing IPP3N should satisfy the
IPPs for the noted IDD tests.
25. DDR4-1600 and DDR4-1866 use the same IDD limits as DDR4-2133.
26. The IDD values must be derated (increased) when operating between 85ιC < TC ζ 95ιC: IDD0, IDD1, IDD2N ,IDD2P
,IDD2NT ,IDD2Q, IDD3N, IDD3P, IDD4R, and IDD4W, must be derated by +10%. IDD5R and IPP5R must be derated by +43%;
IPP0 must be derated by +13%. IPP3N must be derated by +22%. IPP7 must be derated by +3%. These values are veri-
fied by design and characterization, and may not be subject to production test.
27. IPP6x is applicable to IDD6N, IDD6E, IDD6R and IDD6A conditions.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Speed Bin Tables

Speed Bin Tables

DDR4 DRAM timing is primarily covered by two types of tables: the Speed Bin tables in this section and
the tables found in the Electrical Characteristics and AC Timing Parameters section. The timing
parameter tables define the applicable timing specifications based on the speed rating. The Speed Bin
tables on the following pages list the tAA, tRCD, tRP, tRAS, and tRC limits of a given speed mark and are
applicable to the CL settings in the lower half of the table provided they are applied in the correct clock
range, which is noted.

Backward Compatibility
Although the speed bin tables list the slower data rates, tAA, CL, and CWL, it is difficult to determine
whether a faster speed bin supports all of the tAA, CL, and CWL combinations across all the data rates
of a slower speed bin. To assist in this process, please refer to the Backward Compatibility table.

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 Table 157: Backward Compatibility
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Note 1 applies to the entire table.

Speed Bin Supported

Component
Speed Bin

-125 -125E -107 -107E -093 -093E -083D -083 -083E -075D -075 -075E -068D -068 -068E -062 -062E -062Y
-125 yes
-125E yes2 yes

-107 yes yes

-107E yes2 yes yes2 yes

-093 yes yes yes

-093E yes2 yes yes2 yes yes2 yes

-083D yes yes yes yes

-083 yes yes yes yes yes
-083E yes 2 yes yes 2 yes yes 2 yes yes 2
yes2 yes
345

-075D yes yes yes yes yes

-075 yes yes yes yes yes yes yes
-075E yes yes yes yes yes yes yes yes yes yes yes
Micron Technology, Inc. reserves the right to change products or specifications without notice.

-068D yes yes yes yes yes yes

-068 yes yes yes yes yes yes yes yes yes

8Gb: x4, x8, x16 DDR4 SDRAM

-068E yes yes yes yes yes yes yes yes yes yes
-062 yes yes yes yes yes yes yes
-062E yes yes yes yes yes yes yes yes yes yes yes
-062Y yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes
¥ 2015 Micron Technology, Inc. All rights reserved.

Speed Bin Tables

Notes: 1. The backward compatibility table is not meant to guarantee that any new device will be a drop in replacement for an existing part number.
Customers should review the operating conditions for any device to determine its suitability for use in their design.
2. This condition exceeds the JEDEC requirement in order to allow additional flexibility for components. However, JEDEC SPD compliance may
force modules to only support the JEDEC-defined value. Refer to the SPD documentation for further clarification.
 Table 158: DDR4-1600 Speed Bins and Operating Conditions
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Notes 1n3 apply to the entire table

DDR4-1600 Speed Bin -125E -125

CL-nRCD-nRP 11-11-11 12-12-12
Parameter Symbol Min Max Min Max Unit
Internal READ command to first data t
AA 13.75 19.00 6 15.00 19.00 6 ns
(13.50)4
Internal READ command to first data with read DBI enabled t
AA_DBI t
AA t
AA t
AA t
AA ns
(MIN) + (MAX) + (MIN) + (MAX) +
2nCK 2nCK 2nCK 2nCK
ACTIVATE-to-internal READ or WRITE delay time t
RCD 13.75 n 15.00 n ns
(13.50)4
PRECHARGE command period t
RP 13.75 n 15.00 n ns
(13.50)4
ACTIVATE-to-PRECHARGE command period t
RAS 35 9 έ tREFI 35 9 έ tREFI ns

ACTIVATE-to-ACTIVATE or REFRESH command period t

RC5 t
RAS + n t
RAS + n ns
t t
RP RP
346

Data Rate Equivalent t

AAmin(ns): READ CL: READ WRITE
Speed Bin nonDBI CL: DBI CWL Symbol Min Max Min Max Unit
Max (MT/s) non-DB
1333 - 13.50 9 11 9 t
CK 1.500 1.9006 Reserved ns
Micron Technology, Inc. reserves the right to change products or specifications without notice.

(AVG)
- 15.00 10 12 t
CK 1.5006 1.9006 1.500 1.9006 ns

8Gb: x4, x8, x16 DDR4 SDRAM

(AVG)
1600 -125E 13.75 11 13 9, 11 t
CK 1.250 <1.500 Reserved ns
(AVG)
-125 15.00 12 14 t
CK 1.250 <1.500 ns
(AVG)
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Supported CL settings 9, 106, 11-12 10, 12 nCK

Speed Bin Tables

Supported CL settings with read DBI 11, 126, 13-14 12, 14 nCK

Supported CWL settings 9, 11 9, 11 nCK

Notes: 1. Speed Bin table is only valid with DLL enabled.

2. When operating in 2tCK WRITE preamble mode, CWL must be programmed to a value at least 1 clock greater than the lowest CWL setting
supported in the applicable tCK range.
 3. The programmed value of CWL must be less than or equal to the programmed value of CL.
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4. This value applies to non-native tCK-CL-nRCD-nRP combinations.

5. When calculating tRC in clocks, values may not be used in a combination that violate tRAS or tRP.
6. This value exceeds the JEDEC requirement in order to allow additional flexibility, especially for components. However, JEDEC SPD compliance
may force modules to only support the JEDEC defined value, please refer to the SPD documentation.
347
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Speed Bin Tables

 Table 159: DDR4-1866 Speed Bins and Operating Conditions
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Notes 1n3 apply to the entire table

DDR4-1866 Speed Bin -107E -107

CL-nRCD-nRP 13-13-13 14-14-14
Parameter Symbol Min Max Min Max Unit
Internal READ command to first data t
AA 13.92 19.00 6 15.00 19.00 6 ns
(13.50)4
Internal READ command to first data with read DBI enabled t
AA_DBI t
AA (MIN) t
AA t
AA (MIN) t
AA ns
+ 2nCK (MAX) + + 2nCK (MAX) +
2nCK 2nCK
ACTIVATE to internal READ or WRITE delay time t
RCD 13.92 n 15.00 n ns
(13.50)4
PRECHARGE command period t
RP 13.92 n 15.00 n ns
(13.50)4
ACTIVATE-to-PRECHARGE command period t
RAS 34 9 έ tREFI 34 9 έ tREFI ns

ACTIVATE-to-ACTIVATE or REFRESH command period t

RC5 t
RAS + n t
RAS + n ns
t t
RP RP
348

Data Rate Equivalent t

AAmin: READ CL: READ CL: WRITE
Speed Bin nonDBI DBI CWL Symbol Min Max Min Max Unit
Max (MT/s) nonDBI
1333 n 13.50 9 11 9 t
CK 1.500 1.9006 Reserved ns
Micron Technology, Inc. reserves the right to change products or specifications without notice.

(AVG)
n 15.00 10 12 t
CK (AVG) 1.5006 1.9006 1.500 1.9006 ns

8Gb: x4, x8, x16 DDR4 SDRAM

1600 -125E 13.75 11 13 9, 11 t
CK (AVG) 1.250 <1.500 Reserved ns

-125 15.00 12 14 t
CK (AVG) 1.250 <1.500 ns

1866 -107E 13.92 13 15 10, 12 t

CK (AVG) 1.071 <1.250 Reserved ns

-107 15.00 14 16 t
CK (AVG) 1.071 <1.250 ns
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Speed Bin Tables

Supported CL settings 9, 106, 11n14 10, 12, 14 nCK

Supported CL settings with read DBI 11, 126, 13n16 12, 14, 16 nCK

Supported CWL settings 9n12 9n12 nCK

Notes: 1. Speed Bin table is only valid with DLL enabled.

2. When operating in 2tCK WRITE preamble mode, CWL must be programmed to a value at least 1 clock greater than the lowest CWL setting
supported in the applicable tCK range.
 3. The programmed value of CWL must be less than or equal to the programmed value of CL.
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4. This value applies to non-native tCK-CL-nRCD-nRP combinations.

5. When calculating tRC in clocks, values may not be used in a combination that violate tRAS or tRP.
6. This value exceeds the JEDEC requirement in order to allow additional flexibility, especially for components. However, JEDEC SPD compliance
may force modules to only support the JEDEC defined value, please refer to the SPD documentation.
349
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Speed Bin Tables

 Table 160: DDR4-2133 Speed Bins and Operating Conditions
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Notes 1n3 apply to the entire table

DDR4-2133 Speed Bin -093E -093

CL-nRCD-nRP 15-15-15 16-16-16
Parameter Symbol Min Max Min Max Unit
Internal READ command to first data t
AA 14.06 19.00 6 15.00 19.00 6 ns
(13.50)4
Internal READ command to first data with read DBI enabled t
AA_DBI t
AA (MIN) t
AA t
AA (MIN) t
AA ns
+ 3nCK (MAX) + + 3nCK (MAX) +
3nCK 3nCK
ACTIVATE to internal READ or WRITE delay time t
RCD 14.06 n 15.00 n ns
(13.50)4
PRECHARGE command period t
RP 14.06 n 15.00 n ns
(13.50)4
ACTIVATE-to-PRECHARGE command period t
RAS 33 9 έ tREFI 33 9 έ tREFI ns

ACTIVATE-to-ACTIVATE or REFRESH command period t

RC5 t
RAS + n t
RAS + n ns
t t
RP RP
350

Data Rate Equivalent t

AAmin (ns): READ CL: READ CL: WRITE
Speed Bin non-DBI DBI CWL Symbol Min Max Min Max Unit
Max (MT/s) non-DBI
1333 n 13.50 9 11 9 t
CK (AVG) 1.500 1.9006 Reserved ns
Micron Technology, Inc. reserves the right to change products or specifications without notice.

n 15.00 10 12 t
CK (AVG) 1.5006 1.9006 1.500 1.9006 ns

1600 -125E 13.75 11 13 9, 11 t

CK (AVG) 1.250 <1.500 Reserved ns

8Gb: x4, x8, x16 DDR4 SDRAM

-125 15.00 12 14 t
CK (AVG) 1.250 <1.500 ns

1866 -107E 13.92 13 15 10, 12 t

CK (AVG) 1.071 <1.250 Reserved ns

-107 15.00 14 16 t
CK (AVG) 1.071 <1.250 ns
¥ 2015 Micron Technology, Inc. All rights reserved.

2133 -093E 14.06 15 18 11, 14 t

CK (AVG) 0.937 <1.071 Reserved ns

Speed Bin Tables

-093 15.00 16 19 t
CK (AVG) 0.937 <1.071 ns

Supported CL settings 9, 106, 11n16 10, 12, 14, 16 nCK

Supported CL settings with read DBI 11, 126, 13n16, 18-19 12, 14, 16, 19 nCK

Supported CWL settings 9, 10, 11, 12, 14 9, 10, 11, 12, 14 nCK

Notes: 1. Speed Bin table is only valid with DLL enabled.

 2. When operating in 2tCK WRITE preamble mode, CWL must be programmed to a value at least 1 clock greater than the lowest CWL setting
CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

supported in the applicable tCK range.

3. The programmed value of CWL must be less than or equal to the programmed value of CL.
4. This value applies to non-native tCK-CL-nRCD-nRP combinations.
5. When calculating tRC in clocks, values may not be used in a combination that violate tRAS or tRP.
6. This value exceeds the JEDEC requirement in order to allow additional flexibility, especially for components. However, JEDEC SPD compliance
may force modules to only support the JEDEC defined value, please refer to the SPD documentation.
351
Micron Technology, Inc. reserves the right to change products or specifications without notice.

8Gb: x4, x8, x16 DDR4 SDRAM

¥ 2015 Micron Technology, Inc. All rights reserved.

Speed Bin Tables

 Table 161: DDR4-2400 Speed Bins and Operating Conditions
CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

Notes 1n3 apply to the entire table

DDR4-2400 Speed Bin -083E -083 -083D

CL-nRCD-nRP 16-16-16 17-17-17 18-18-18
Parameter Symbol Min Max Min Max Min Max Unit
Internal READ command to first data t
AA 13.32 19.00 6 14.16 19.00 6 15.00 19.00 6 ns
(13.75)4
Internal READ command to first data with read DBI enabled t
AA_DBI t
AA t
AA t
AA t
AA t
AA t
AA ns
(MIN) + (MAX) + (MIN) + (MAX) + (MIN) + (MAX) +
3nCK 3nCK 3nCK 3nCK 3nCK 3nCK
ACTIVATE to internal READ or WRITE delay time t
RCD 13.32 n 14.16 n 15.00 19.00 ns
(13.75)4
PRECHARGE command period t
RP 13.32 n 14.16 n 15.00 19.00 ns
(13.75)4
ACTIVATE-to-PRECHARGE command period t
RAS 32 9 έ tREFI 32 9 έ tREFI 32 9 έ tREFI ns

ACTIVATE-to-ACTIVATE or REFRESH command period t

RC5 t
RAS + n t
RAS + n t
RAS + n ns
t t t
RP RP RP
352

Equivalent t
AAmin READ READ WRITE
Data Rate Speed Bin CL: CL: CWL
(ns): Symbol Min Max Min Max Min Max Unit
Max (MT/s) non-DBI DBI
non-DBI
Micron Technology, Inc. reserves the right to change products or specifications without notice.

1333 n 13.50 9 11 9 t
CK (AVG) 1.500 1.9006 Reserved Reserved ns

n 15.00 10 12 t
CK (AVG) 1.5006 1.9006 1.500 1.9006 1.500 1.9006 ns

8Gb: x4, x8, x16 DDR4 SDRAM

1600 -125E 13.75 11 13 9, 11 t
CK (AVG) 1.250 <1.500 1.250 <1.500 Reserved ns

-125 15.00 12 14 t
CK (AVG) 1.250 <1.500 ns

1866 -107E 13.92 13 15 10, 12 t

CK (AVG) 1.071 <1.250 1.071 <1.250 Reserved ns

-107 15.00 14 16 t
CK (AVG) 1.071 <1.250 ns
¥ 2015 Micron Technology, Inc. All rights reserved.

Speed Bin Tables

2133 -093E 14.06 15 18 11, 14 t
CK (AVG) 0.937 <1.071 0.937 <1.071 Reserved ns

-093 15.00 16 19 t
CK (AVG) 0.937 <1.071 ns

2400 -083E 13.32 16 19 12, 16 t

CK (AVG) 0.833 <0.937 Reserved Reserved ns

-083 14.16 17 20 t
CK (AVG) 0.833 <0.937 ns

-083D 15.00 18 21 t
CK (AVG) 0.833 <0.937 ns
 CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

DDR4-2400 Speed Bin -083E -083 -083D

CL-nRCD-nRP 16-16-16 17-17-17 18-18-18
Parameter Symbol Min Max Min Max Min Max Unit
Supported CL settings 9, 10 6, 11n18 10n18 10, 12, 14, 16, 18 nCK

Supported CL settings with read DBI 11, 126, 13n16, 12n16, 18n21 12, 14, 16, 19, 21 nCK
18n21
Supported CWL settings 9n12, 14, 16 9-12, 14, 16 9n12, 14, 16 nCK

Notes: 1. Speed Bin table is only valid with DLL enabled.

2. When operating in 2tCK WRITE preamble mode, CWL must be programmed to a value at least 1 clock greater than the lowest CWL setting
supported in the applicable tCK range.
3. The programmed value of CWL must be less than or equal to the programmed value of CL.
4. This value applies to non-native tCK-CL-nRCD-nRP combinations.
5. When calculating tRC in clocks, values may not be used in a combination that violate tRAS or tRP.
6. This value exceeds the JEDEC requirement in order to allow additional flexibility, especially for components. However, JEDEC SPD compliance
may force modules to only support the JEDEC defined value, please refer to the SPD documentation.
353
Micron Technology, Inc. reserves the right to change products or specifications without notice.

8Gb: x4, x8, x16 DDR4 SDRAM

¥ 2015 Micron Technology, Inc. All rights reserved.

Speed Bin Tables

 Table 162: DDR4-2666 Speed Bins and Operating Conditions
CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

Notes 1n3 apply to the entire table

DDR4-2666 Speed Bin -075E -075 -075D

CL-nRCD-nRP 18-18-18 19-19-19 20-20-20
Parameter Symbol Min Max Min Max Min Max Unit
Internal READ command to first data t
14.25
AA 13.50 19.006 19.006 15.00 19.006 ns
(13.75)4
Internal READ command to first data with read DBI enabled t
AA t
AA t
AA t
AA t
AA t
AA
t ns
AA_DBI (MIN) + (MAX) + (MIN) + (MAX) + (MIN) + (MAX) +
3nCK 3nCK 3nCK 3nCK 3nCK 3nCK
ACTIVATE to internal READ or WRITE delay time t
14.25
RCD 13.50 n n 15.00 n ns
(13.75)4
PRECHARGE command period t
14.25
RP 13.50 n n 15.00 n ns
(13.75)4
ACTIVATE-to-PRECHARGE command period t
RAS 32 9 έ tREFI 32 9 έ tREFI 32 9 έ tREFI ns
ACTIVATE-to-ACTIVATE or REFRESH command period t
RAS + t
RAS + t
RAS +
t
RC5 t
n t
n t
n ns
RP RP RP
354

Equivalent t
AAmin READ READ WRITE
Data Rate Speed Bin CL: CL: CWL
(ns): Symbol Min Max Min Max Min Max Unit
Max (MT/s) non-DBI DBI
non-DBI
Micron Technology, Inc. reserves the right to change products or specifications without notice.

1333 - 13.50 9 11 t
CK (AVG) Reserved Reserved ns
9 1.500 1.9006
- 15.00 10 12 t
CK (AVG) 1.500 1.9006 1.500 1.9006 ns

8Gb: x4, x8, x16 DDR4 SDRAM

1600 -125E 13.75 11 13 t
CK (AVG) Reserved ns
9, 11 1.250 <1.500 1.250 <1.500
-125 15.00 12 14 t
CK (AVG) 1.250 <1.500 ns

1866 -107E 13.92 13 15 t

CK (AVG) Reserved ns
10, 12 1.071 <1.250 1.071 <1.250
-107 15.00 14 16 t
CK (AVG) 1.071 <1.250 ns
¥ 2015 Micron Technology, Inc. All rights reserved.

Speed Bin Tables

2133 -093E 14.06 15 18 t
CK (AVG) Reserved ns
11, 14 0.937 <1.071 0.937 <1.071
-093 15.00 16 19 t
CK (AVG) 0.937 <1.071 ns

2400 -083E 13.32 16 19 t

CK (AVG) Reserved Reserved ns
Reserved
-083 14.16 17 20 12, 16 t
CK (AVG) ns
0.833 <0.937 0.833 <0.937
-083D 15.00 18 21 t
CK (AVG) 0.833 <0.937 ns
 CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

DDR4-2666 Speed Bin -075E -075 -075D

CL-nRCD-nRP 18-18-18 19-19-19 20-20-20
Parameter Symbol Min Max Min Max Min Max Unit
2666 -075E 13.50 18 21 tCK (AVG) Reserved ns
Reserved
-075 14.25 19 22 14, 18 t
CK (AVG) 0.750 <0.833 ns
0.750 <0.833
-075D 15.00 20 23 t
CK (AVG) 0.750 <0.833 ns

Supported CL settings 9n20 10-20 10, 12, 14, 16, 18, nCK
20
Supported CL settings with read DBI 11n16, 18n23 12n16, 18n23 12, 14, 16, 19, 21, nCK
23
Supported CWL settings 9n12, 14, 16, 18 9n12, 14, 16, 18 9n12, 14, 16, 18 nCK

Notes: 1. Speed Bin table is only valid with DLL enabled.

2. When operating in 2tCK WRITE preamble mode, CWL must be programmed to a value at least 1 clock greater than the lowest CWL setting
supported in the applicable tCK range.
3. The programmed value of CWL must be less than or equal to the programmed value of CL.
4. This value applies to non-native tCK-CL-nRCD-nRP combinations.
5. When calculating tRC in clocks, values may not be used in a combination that violate tRAS or tRP.
355

6. This value exceeds the JEDEC requirement in order to allow additional flexibility, especially for components. However, JEDEC SPD compliance
may force modules to only support the JEDEC defined value, please refer to the SPD documentation.
Micron Technology, Inc. reserves the right to change products or specifications without notice.

8Gb: x4, x8, x16 DDR4 SDRAM

¥ 2015 Micron Technology, Inc. All rights reserved.

Speed Bin Tables

 Table 163: DDR4-2933 Speed Bins and Operating Conditions
CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

Notes 1n3 apply to the entire table

DDR4-2933 Speed Bin -068E -068 -068D

CL-nRCD-nRP 20-20-20 21-21-21 22-22-22
Parameter Symbol Min Max Min Max Min Max Unit
Internal READ command to first data t
AA 13.64 19.00 6 14.32 19.00 6 15.00 19.00 6 ns
(13.75)4
Internal READ command to first data with read DBI enabled t
AA_DBI t
AA t
AA t
AA t
AA t
AA t
AA ns
(MIN) + (MAX) + (MIN) + (MAX) + (MIN) + (MAX) +
4nCK 4nCK 4nCK 4nCK 4nCK 4nCK
ACTIVATE-to-internal READ or WRITE delay time t
RCD 13.64 n 14.32 n 15.00 n ns
(13.75)4
PRECHARGE command period t
RP 13.64 n 14.32 n 15.00 n ns
(13.75)4
ACTIVATE-to-PRECHARGE command period t
RAS 32 9 έ tREFI 32 9 έ tREFI 32 9 έ tREFI ns

ACTIVATE-to-ACTIVATE or REFRESH command period t

RC5 t
RAS + n t
RAS + n t
RAS + n ns
t t t
RP RP RP
356

Equivalent t READ READ WRITE

Data Rate AAmin(ns): CL:
Speed Bin CL: CWL Symbol Min Max Min Max Min Max Unit
Max (MT/s) non-DBI non-DBI DBI
Micron Technology, Inc. reserves the right to change products or specifications without notice.

1333 n 13.50 9 11 9 tCK (AVG) Reserved Reserved Reserved ns

n 15.00 10 12 t
CK (AVG) 1.500 1.9006 1.500 1.9006 1.500 1.9006 ns

8Gb: x4, x8, x16 DDR4 SDRAM

1600 -125E 13.75 11 13 9, 11 tCK (AVG) 1.250 <1.500 1.250 <1.500 Reserved ns

-125 15.00 12 14 t
CK (AVG) 1.250 <1.500 ns

1866 -107E 13.92 13 15 10, 12 t

CK (AVG) 1.071 <1.250 1.071 <1.250 Reserved ns

-107 15.00 14 16 t
CK (AVG) 1.071 <1.250 ns
¥ 2015 Micron Technology, Inc. All rights reserved.

2133 -093E 14.06 15 18 11, 14 t

CK (AVG) 0.937 <1.071 0.937 <1.071 Reserved ns

Speed Bin Tables

-093 15.00 16 19 t
CK (AVG) 0.937 <1.071 ns

2400 -083E 13.32 16 19 12, 16 t

CK (AVG) Reserved Reserved Reserved ns

-083 14.16 17 20 t
CK (AVG) 0.833 <0.937 0.833 <0.937 ns

083D 15.00 18 21 t
CK (AVG) 0.833 <0.937 ns
 CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

DDR4-2933 Speed Bin -068E -068 -068D

CL-nRCD-nRP 20-20-20 21-21-21 22-22-22
Parameter Symbol Min Max Min Max Min Max Unit
2666 -075E 13.50 18 21 14, 18 tCK (AVG) Reserved Reserved Reserved ns

-075 14.25 19 22 t
CK (AVG) 0.750 <0.833 0.750 <0.833 ns

-075D 15.00 20 23 t
CK (AVG) 0.750 <0.833 ns

2933 -068E 13.64 20 24 16, 20 tCK (AVG) 0.682 <0.750 Reserved Reserved ns

-068 14.32 21 25 t
CK (AVG) 0.682 <0.750 ns

-068D 15.00 22 26 t
CK (AVG) 0.682 <0.750 ns

n 16.37 24 28 t
CK (AVG) Reserved Reserved Reserved ns

Supported CL settings 10n22 10n22 10, 12, 14, 16, 18, nCK
20, 22
Supported CL settings with read DBI 12n16, 18n26 12n16,18n23, 12, 14, 16, 19, 21, nCK
25-26 23, 26
Supported CWL settings 9n12, 14, 16, 18, 9n12, 14, 16, 18, 9n12, 14, 16, 18, nCK
20 20 20
357

Notes: 1. Speed Bin table is only valid with DLL enabled.

2. When operating in 2tCK WRITE preamble mode, CWL must be programmed to a value at least 1 clock greater than the lowest CWL setting
supported in the applicable tCK range.
Micron Technology, Inc. reserves the right to change products or specifications without notice.

3. The programmed value of CWL must be less than or equal to the programmed value of CL.
4. This value applies to non-native tCK-CL-nRCD-nRP combinations.
5. When calculating tRC in clocks, values may not be used in a combination that violate tRAS or tRP.

8Gb: x4, x8, x16 DDR4 SDRAM

6. This value exceeds the JEDEC requirement in order to allow additional flexibility, especially for components. However, JEDEC SPD compliance
may force modules to only support the JEDEC defined value, please refer to the SPD documentation.
¥ 2015 Micron Technology, Inc. All rights reserved.

Speed Bin Tables

 Table 164: DDR4-3200 Speed Bins and Operating Conditions
CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

Notes 1n3 apply to the entire table

DDR4-3200 Speed Bin -062Y6 -062E -062

CL-nRCD-nRP 22-22-22 22-22-22 24-24-24
Parameter Symbol Min Max Min Max Min Max Unit
Internal READ command to first data t
AA 13.75 19.00 6 13.75 19.00 6 15.00 19.00 6 ns
(13.32)
4

Internal READ command to first data with read DBI enabled tAA_DBI tAA tAA tAA tAA tAA tAA ns
(MIN) + (MAX) + (MIN) + (MAX) + (MIN) + (MAX) +
4nCK 4nCK 4nCK 4nCK 4nCK 4nCK
ACTIVATE-to-internal READ or WRITE delay time t
RCD 13.75 n 13.75 n 15.00 n ns
(13.32)
4

PRECHARGE command period t

RP 13.75 n 13.75 n 15.00 n ns
(13.32)
4
358

ACTIVATE-to-PRECHARGE command period t

RAS 32 9 έ tREFI 32 9 έ tREFI 32 9 έ tREFI ns

ACTIVATE-to-ACTIVATE or REFRESH command period t

RC5 t
RAS + n t
RAS + n t
RAS + n ns
tRP tRP tRP
Micron Technology, Inc. reserves the right to change products or specifications without notice.

Equivalent t
AAmin READ READ WRITE
Data Rate Speed Bin CL: CL: CWL
(ns): Symbol Min Max Min Max Min Max Unit
Max (MT/s) non-DBI DBI
non-DBI

8Gb: x4, x8, x16 DDR4 SDRAM

1333 - 13.50 9 11 9 t
CK (AVG) 1.500 1.9006 Reserved Reserved ns

- 15.00 10 12 t
CK (AVG) 1.500 1.9006 1.500 1.9006 ns

1600 -125E 13.75 11 13 9, 11 t

CK (AVG) 1.250 <1.500 1.250 <1.500 Reserved ns
¥ 2015 Micron Technology, Inc. All rights reserved.

-125 15.00 12 14 t
CK (AVG) 1.250 <1.500 ns

Speed Bin Tables

1866 -107E 13.92 13 15 10, 12 t
CK (AVG) 1.071 <1.250 1.071 <1.250 Reserved ns

-107 15.00 14 16 t
CK (AVG) 1.071 <1.250 ns

2133 -093E 14.06 15 18 11, 14 t

CK (AVG) 0.937 <1.071 0.937 <1.071 Reserved ns

-093 15.00 16 19 t
CK (AVG) 0.937 <1.071 ns
 CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

DDR4-3200 Speed Bin -062Y6 -062E -062

CL-nRCD-nRP 22-22-22 22-22-22 24-24-24
Parameter Symbol Min Max Min Max Min Max Unit
2400 -083E 13.32 16 19 12, 16 t
CK (AVG) 0.833 <0.937 Reserved Reserved ns

-083 14.16 17 20 t
CK (AVG) 0.833 <0.937 ns

-083D 15.00 18 21 tCK (AVG) 0.833 <0.937 ns

2666 -075E 13.50 18 21 14, 18 t

CK (AVG) 0.750 <0.833 Reserved Reserved ns

-075 14.25 19 22 t
CK (AVG) 0.750 <0.833 ns

-075D 15.00 20 23 t
CK (AVG) 0.750 <0.833 ns

2933 -068E 13.64 20 24 16, 20 t

CK (AVG) Reserved Reserved Reserved ns

-068 14.32 21 25 t
CK (AVG) 0.682 <0.750 0.682 <0.750 ns

-068D 15.00 22 26 t
CK (AVG) 0.682 <0.750 0.682 <0.750 ns

n 16.37 24 28 t
CK (AVG) 0.682 <0.750 ns

3200 -062E 13.75 22 26 16, 20 t

CK (AVG) 0.625 <0.682 0.625 <0.682 Reserved ns
359

-062 15.00 24 28 t
CK (AVG) 0.625 <0.682 ns

Supported CL settings 9n22, 24 10n22, 24 10, 12, 14, 16, 18, nCK
20, 22, 24
Supported CL settings with read DBI 11n16, 18n23, 12n16, 18n23, 12, 14, 16, 19, 21, nCK
Micron Technology, Inc. reserves the right to change products or specifications without notice.

25-26, 28 25-26, 28 23, 26, 28

Supported CWL settings 9n12, 14, 16, 18, 9n12, 14, 16, 18, 9n12, 14, 16, 18, nCK

8Gb: x4, x8, x16 DDR4 SDRAM

20 20 20

Notes: 1. Speed Bin table is only valid with DLL enabled.

2. When operating in 2tCK WRITE preamble mode, CWL must be programmed to a value at least 1 clock greater than the lowest CWL setting
supported in the applicable tCK range.
3. The programmed value of CWL must be less than or equal to the programmed value of CL.
¥ 2015 Micron Technology, Inc. All rights reserved.

4. This value applies to non-native tCK-CL-nRCD-nRP combinations.

Speed Bin Tables

5. When calculating tRC in clocks, values may not be used in a combination that violate tRAS or tRP.
6. This value exceeds the JEDEC requirement in order to allow additional flexibility, especially for components. However, JEDEC SPD compliance
may force modules to only support the JEDEC defined value, please refer to the SPD documentation.
 8Gb: x4, x8, x16 DDR4 SDRAM
Refresh Parameters By Device Density

Refresh Parameters By Device Density

Table 165: Refresh Parameters by Device Density

Parameter Symbol 2Gb 4Gb 8Gb 16Gb Unit Notes
REF command to ACT or REF com- tRFC (All bank groups) 160 260 350 350 ns
mand time
Average periodic refresh interval tREFI -40ιC ζ TC ζ 85ιC 7.8 7.8 7.8 7.8 ρs
85ιC < TC ζ 95ιC 3.9 3.9 3.9 3.9 ρs 1
95ιC < TC ζ 105ιC 1.95 1.95 1.95 1.95 ρs 1

Notes: 1. Users should refer to the DRAM supplier data sheet and/or the DIMM SPD to determine if the devices support these
options or requirements.

CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN
360 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 AC Electrical Characteristics and AC Timing Parameters

Table 166: Electrical Characteristics and AC Timing Parameters: DDR4-1600 through DDR4-2400
DDR4-1600 DDR4-1866 DDR4-2133 DDR4-2400

CCMTD-1725822587-9875
Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
Clock Timing

8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

Clock period average (DLL off mode) t 8 20 8 20 8 20 8 20 ns
CK (AVG,
DLL_OFF)
Clock period average t 1.25 1.9 1.071 1.9 0.937 1.9 0.833 1.9 ns 3 , 13
CK (AVG,
DLL_ON)
High pulse width average t 0.48 0.52 0.48 0.52 0.48 0.52 0.48 0.52 t
CH (AVG) CK
(AVG)
Low pulse width average t 0.48 0.52 0.48 0.52 0.48 0.52 0.48 0.52 t
CL (AVG) CK
(AVG)
Clock period jitter Total t n63 63 n54 54 n47 47 n42 42 ps 17 , 18
JITper_tot
Deterministic t n31 31 n27 27 n23 23 n21 21 ps 17
JITper_dj
DLL locking t n50 50 n43 43 n38 38 -33 33 ps
JITper,lck

361
Clock absolute period t ps
CK (ABS) MIN = tCK (AVG) MIN + tJITper_tot MIN; MAX = tCK (AVG) MAX +
tJITper_tot MAX

Clock absolute high pulse width t 0.45 n 0.45 n 0.45 n 0.45 n t

CH (ABS) CK
(includes duty cycle jitter) (AVG)
Clock absolute low pulse width t 0.45 n 0.45 n 0.45 n 0.45 n t
CL (ABS) CK
(includes duty cycle jitter) (AVG)
Cycle-to-cycle jitter Total t n 125 n 107 n 94 n 83 ps
JITcc _tot
DLL locking t n 100 n 86 n 75 n 67 ps
JITcc,lck

Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
8Gb: x4, x8, x16 DDR4 SDRAM
Refresh Parameters By Device Density
 Table 166: Electrical Characteristics and AC Timing Parameters: DDR4-1600 through DDR4-2400 (Continued)
CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

DDR4-1600 DDR4-1866 DDR4-2133 DDR4-2400

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
Cumulative error across 2 cycles t
ERR2per n92 92 n79 79 n69 69 n61 61 ps

3 cycles t
ERR3per n109 109 n94 94 n82 82 n73 73 ps

4 cycles t
ERR4per n121 121 n104 104 n91 91 n81 81 ps

5 cycles tERR5per n131 131 n112 112 n98 98 n87 87 ps

6 cycles t
ERR6per n139 139 n119 119 n104 104 n92 92 ps

7 cycles t
ERR7per n145 145 n124 124 n109 109 n97 97 ps

8 cycles t
ERR8per n151 151 n129 129 n113 113 n101 101 ps

9 cycles t
ERR9per n156 156 n134 134 n117 117 n104 104 ps

10 cycles t
ERR10per n160 160 n137 137 n120 120 n107 107 ps

11 cycles t
ERR11per n164 164 n141 141 n123 123 n110 110 ps

12 cycles t
ERR12per n168 168 n144 144 n126 126 n112 112 ps
362

n = 13, 14 . . . t
ERRnper t
ERRnper MIN = (1 + 0.68ln[n]) έ tJITper_tot MIN ps
49, 50 cycles t
ERRnper MAX = (1 + 0.68ln[n]) έ tJITper_tot MAX

Refresh Parameters By Device Density

DQ Input Timing
Micron Technology, Inc. reserves the right to change products or specifications without notice.

Data setup time to DQS_t, Base (cali- t

DS Refer to DQ Input Receiver Specification section n
DQS_c brated VREF) (approximately 0.15tCK to 0.28tCK )

8Gb: x4, x8, x16 DDR4 SDRAM

Noncalibrated t
PDA_S minimum of 0.5UI UI 22
VREF
Data hold time from DQS_t, Base (cali- t
DH Refer to DQ Input Receiver Specification section n
DQS_c brated VREF) (approximately 0.15tCK to 0.28tCK )
Noncalibrated t minimum of 0.5UI UI 22
¥ 2015 Micron Technology, Inc. All rights reserved.

PDA_H
VREF
DQ and DM minimum data pulse width for t
DIPW 0.58 n 0.58 n 0.58 n 0.58 n UI
each input
DQ Output Timing (DLL enabled)
DQS_t, DQS_c to DQ skew, per group, per t
DQSQ n 0.16 n 0.16 n 0.16 n 0.17 UI
access
DQ output hold time from DQS_t, DQS_c tQH 0.76 n 0.76 n 0.76 n 0.74 n UI
 Table 166: Electrical Characteristics and AC Timing Parameters: DDR4-1600 through DDR4-2400 (Continued)
CCMTD-1725822587-9875
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DDR4-1600 DDR4-1866 DDR4-2133 DDR4-2400

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
Data Valid Window per device: tQH - tDQSQ t
DVWd 0.63 0.63 0.64 0.64 UI
each devices output per UI

Data Valid Window per device, per pin: tQH - t

DVWp 0.66 n 0.66 n 0.69 n 0.72 n UI
t
DQSQ each devices output per UI
DQ Low-Z time from CK_t, CK_c tLZDQ n450 225 n390 195 n360 180 n330 175 ps

DQ High-Z time from CK_t, CK_c t

HZDQ n 225 n 195 n 180 n 175 ps

DQ Strobe Input Timing

DQS_t, DQS_c rising edge to CK_t, CK_c rising t
DQSS1ck n0.27 0.27 n0.27 0.27 n0.27 0.27 n0.27 0.27 CK
edge for 1tCK preamble
DQS_t, DQS_c rising edge to CK_t, CK_c rising t
DQSS2ck NA NA NA n0.50 0.50 CK
edge for 2tCK preamble
DQS_t, DQS_c differential input low pulse t
DQSL 0.46 0.54 0.46 0.54 0.46 0.54 0.46 0.54 CK
width
DQS_t, DQS_c differential input high pulse t
DQSH 0.46 0.54 0.46 0.54 0.46 0.54 0.46 0.54 CK
363

width
DQS_t, DQS_c differential input high pulse t
DQSH2PRE NA NA NA 1.46 - CK

Refresh Parameters By Device Density

width for 2tCK preamble
Micron Technology, Inc. reserves the right to change products or specifications without notice.

DQS_t, DQS_c falling edge setup to CK_t, t

DSS1ck 0.18 n 0.18 n 0.18 n 0.18 n CK
CK_c rising edge for 1tCK preamble

8Gb: x4, x8, x16 DDR4 SDRAM

DQS_t, DQS_c falling edge setup to CK_t, tDSS NA NA NA 0 - CK
2ck
CK_c rising edge for 2tCK preamble
DQS_t, DQS_c falling edge hold from CK_t, t
DSH1ck 0.18 n 0.18 n 0.18 n 0.18 n CK
CK_c rising edge for 1tCK preamble
DQS_t, DQS_c falling edge hold from CK_t, t
DSH2ck NA NA NA 0 - CK
¥ 2015 Micron Technology, Inc. All rights reserved.

CK_c rising edge for 2tCK preamble

DQS_t, DQS_c differential WRITE preamble t
WPRE1ck 0.9 n 0.9 n 0.9 n 0.9 n CK
for 1tCK preamble
DQS_t, DQS_c differential WRITE preamble t
WPRE2ck NA NA NA 1.8 n CK
for 2tCK preamble
DQS_t, DQS_c differential WRITE postamble t
WPST 0.33 n 0.33 n 0.33 n 0.33 n CK

DQS Strobe Output Timing (DLL enabled)

 Table 166: Electrical Characteristics and AC Timing Parameters: DDR4-1600 through DDR4-2400 (Continued)
CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

DDR4-1600 DDR4-1866 DDR4-2133 DDR4-2400

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
DQS_t, DQS_c rising edge output access time t
DQSCK n225 225 n195 195 n180 180 n175 175 ps
from rising CK_t, CK_c
DQS_t, DQS_c rising edge output variance t
DQSCKi n 370 n 330 n 310 n 290 ps
window per DRAM
DQS_t, DQS_c differential output high time t
QSH 0.4 n 0.4 n 0.4 n 0.4 n CK

DQS_t, DQS_c differential output low time t

QSL 0.4 n 0.4 n 0.4 n 0.4 n CK

DQS_t, DQS_c Low-Z time (RL - 1) t

LZDQS n450 225 n390 195 n360 180 n330 175 ps

DQS_t, DQS_c High-Z time (RL + BL/2) t

HZDQS n 225 n 195 n 180 n 175 ps

DQS_t, DQS_c differential READ preamble for t

RPRE1ck 0.9 n 0.9 n 0.9 n 0.9 n CK 20
1tCK preamble
DQS_t, DQS_c differential READ preamble for t
RPRE2ck NA NA NA 1.8 n CK 20
2tCK preamble
DQS_t, DQS_c differential READ postamble t
RPST 0.33 n 0.33 n 0.33 n 0.33 n CK 21
364

Command and Address Timing

DLL locking time t
DLLK 597 n 597 n 768 n 768 n CK 2, 4

Refresh Parameters By Device Density

CMD, ADDR setup time to Base tIS 115 n 100 n 80 n 62 n ps
Micron Technology, Inc. reserves the right to change products or specifications without notice.

CK_t, CK_c Base referenced

to VIH(AC) and VIL(AC) levels VREFCA tIS 215 n 200 n 180 n 162 n ps
VREF

CMD, ADDR hold time to Base t

IH 140 n 125 n 105 n 87 n ps

8Gb: x4, x8, x16 DDR4 SDRAM

CK_t, CK_c Base referenced
to VIH(DC) and VIL(DC) levels VREFCA tIH 215 n 200 n 180 n 162 n ps
VREF

CTRL, ADDR pulse width for each input t

IPW 600 n 525 n 460 n 410 n ps

ACTIVATE to internal READ or WRITE delay t

RCD See Speed Bin Tables for tRCD ns
¥ 2015 Micron Technology, Inc. All rights reserved.

PRECHARGE command period t

RP See Speed Bin Tables for tRP ns

ACTIVATE-to-PRECHARGE command period t

RAS See Speed Bin Tables for tRAS ns 12

ACTIVATE-to-ACTIVATE or REF command t

RC See Speed Bin Tables for tRC ns 12
period
ACTIVATE-to-ACTIVATE command period to t
RRD_S MIN = greater MIN = greater MIN = greater MIN = greater CK 1
different bank groups for 1/2KB page size (1/2KB) of 4CK or 5ns of 4CK or 4.2ns of 4CK or 3.7ns of 4CK or 3.3ns
 Table 166: Electrical Characteristics and AC Timing Parameters: DDR4-1600 through DDR4-2400 (Continued)
CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

DDR4-1600 DDR4-1866 DDR4-2133 DDR4-2400

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
ACTIVATE-to-ACTIVATE command period to t
RRD_S MIN = greater MIN = greater MIN = greater MIN = greater CK 1
different bank groups for 1KB page size (1KB) of 4CK or 5ns of 4CK or 4.2ns of 4CK or 3.7ns of 4CK or 3.3ns

ACTIVATE-to-ACTIVATE command period to t

RRD_S MIN = greater MIN = greater MIN = greater MIN = greater CK 1
different bank groups for 2KB page size (2KB) of 4CK or 6ns of 4CK or 5.3ns of 4CK or 5.3ns of 4CK or 5.3ns

ACTIVATE-to-ACTIVATE command period to t

RRD_L MIN = greater MIN = greater MIN = greater MIN = greater CK 1
same bank groups for 1/2KB page size (1/2KB) of 4CK or 6ns of 4CK or 5.3ns of 4CK or 5.3ns of 4CK or 4.9ns

ACTIVATE-to-ACTIVATE command period to t

RRD_L MIN = greater MIN = greater MIN = greater MIN = greater CK 1
same bank groups for 1KB page size (1KB) of 4CK or 6ns of 4CK or 5.3ns of 4CK or 5.3ns of 4CK or 4.9ns

ACTIVATE-to-ACTIVATE command period to t

RRD_L MIN = greater MIN = greater MIN = greater MIN = greater CK 1
same bank groups for 2KB page size (2KB) of 4CK or 7.5ns of 4CK or 6.4ns of 4CK or 6.4ns of 4CK or 6.4ns

Four ACTIVATE windows for 1/2KB page size t

FAW MIN = greater MIN = greater MIN = greater MIN = greater ns
(1/2KB) of 16CK or 20ns of 16CK or 17ns of 16CK or 15ns of 16CK or 13ns

Four ACTIVATE windows for 1KB page size t

FAW MIN = greater MIN = greater MIN = greater MIN = greater ns
(1KB) of 20CK or 25ns of 20CK or 23ns of 20CK or 21ns of 20CK or 21ns
365

Four ACTIVATE windows for 2KB page size t

FAW MIN = greater MIN = greater MIN = greater MIN = greater ns
(2KB) of 28CK or 35ns of 28CK or 30ns of 28CK or 30ns of 28CK or 30ns

Refresh Parameters By Device Density

WRITE recovery time tWR MIN = 15ns ns 1, 5, 9
1ck
Micron Technology, Inc. reserves the right to change products or specifications without notice.

t
WR2ck MIN = 1CK + tWR1ck CK 1, 5, 10

WRITE recovery time when CRC and DM are t

WR_CRC_DM1ck MIN = tWR1ck + MIN = tWR1ck + greater of (5CK or 3.75ns) CK 1, 6, 9

8Gb: x4, x8, x16 DDR4 SDRAM

both enabled greater of (4CK
or 3.75ns)
t
WR_CRC_DM2ck MIN = 1CK + tWR_CRC_DM1ck CK 1, 6, 10

Delay from start of internal WRITE transac- t

WTR_L1ck MIN = greater of 4CK or 7.5ns CK 1, 5, 9
tion to internal READ command n Same bank
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group t
WTR_L2ck MIN = 1CK + tWTR_L1ck CK 1, 5, 10

Delay from start of internal WRITE transac- t

WTR_L_CRC_DM MIN = MIN = tWTR_L1ck + greater of (5CK or 3.75ns) CK 1, 6, 9
tion to internal READ command n Same bank t
WTR_L1ck +
1ck
group when CRC and DM are both enabled greater of (4CK
or 3.75ns)
t
WTR_L_CRC_DM MIN = 1CK + tWTR_L_CRC_DM1ck CK 1, 6, 10
2ck
 Table 166: Electrical Characteristics and AC Timing Parameters: DDR4-1600 through DDR4-2400 (Continued)
CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

DDR4-1600 DDR4-1866 DDR4-2133 DDR4-2400

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
Delay from start of internal WRITE transac- t
WTR_S1ck MIN = greater of (2CK or 2.5ns) CK 1, 5, 7,
tion to internal READ command n Different 8, 9
bank group t
WTR_S2ck MIN = 1CK + tWTR_S1ck CK 1, 5, 7,
8, 10
Delay from start of internal WRITE transac- MIN = MIN = tWTR_S1ck + greater of (5CK or 3.75ns) CK 1, 6, 7,
tion to internal READ command n Different t
WTR_S_CRC_DM WTR_S1ck + t 8, 9
bank group when CRC and DM are both greater of (4CK
1ck
enabled or 3.75ns)
t
WTR_S_CRC_DM MIN = 1CK + tWTR_S_CRC_DM1ck CK 1, 6, 7,
8, 10
2ck

READ-to-PRECHARGE time t
RTP MIN = greater of 4CK or 7.5ns CK 1

CAS_n-to-CAS_n command delay to different t

CCD_S 4 n 4 n 4 n 4 n CK
bank group
CAS_n-to-CAS_n command delay to same t
CCD_L MIN = n MIN = n MIN = n MIN = n CK 14
bank group greate greate greate greate
366

r of r of r of r of
4CK or 4CK or 4CK or 4CK or
6.25ns 5.355n 5.355n 5ns

Refresh Parameters By Device Density

s s
Micron Technology, Inc. reserves the right to change products or specifications without notice.

Auto precharge write recovery + precharge t

DAL (MIN) MIN = WR + ROUNDtRP/tCK (AVG); MAX = N/A CK 8
time
MRS Command Timing

8Gb: x4, x8, x16 DDR4 SDRAM

MRS command cycle time t
MRD 8 n 8 n 8 n 8 n CK

MRS command cycle time in PDA mode tMRD_PDA MIN = greater of (16nCK, 10ns) CK 1

MRS command cycle time in CAL mode t

MRD_CAL MIN = tMOD + tCAL CK
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MRS command update delay tMOD MIN = greater of (24nCK, 15ns) CK 1

MRS command update delay in PDA mode t

MOD_PDA MIN = tMOD CK

MRS command update delay in CAL mode t

MOD_CAL MIN = tMOD + tCAL CK

MRS command to DQS drive in preamble t

SDO MIN = tMOD + 9ns
training
MPR Command Timing
Multipurpose register recovery time t
MPRR MIN = 1CK CK
 Table 166: Electrical Characteristics and AC Timing Parameters: DDR4-1600 through DDR4-2400 (Continued)
CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

DDR4-1600 DDR4-1866 DDR4-2133 DDR4-2400

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
Multipurpose register write recovery time t
WR_MPR MIN = tMOD + AL + PL
CRC Error Reporting Timing
CRC error to ALERT_n latency t
CRC_ALERT 3 13 3 13 3 13 3 13 ns

CRC ALERT_n pulse width t

CRC_ALERT_PW 6 10 6 10 6 10 6 10 CK

CA Parity Timing
Parity latency PL 4 n 4 n 4 n 5 n CK
Commands uncertain to be executed during t
PAR_UNKNOWN n PL n PL n PL n PL CK
this time
Delay from errant command to ALERT_n t
PAR_ALERT_ON n PL + n PL+ n PL + n PL + CK
assertion 6ns 6ns 6ns 6ns
Pulse width of ALERT_n signal when asserted t
PAR_ALERT_PW 48 96 56 112 64 128 72 144 CK

Time from alert asserted until DES commands t

PAR_ALERT_RSP n 43 n 50 n 57 n 64 CK
required in persistent CA parity mode
367

CAL Timing
CS_n to command address latency t
CAL 3 n 4 n 4 n 5 n CK 19

Refresh Parameters By Device Density

CS_n to command address latency in t
CALg N/A n N/A n N/A n N/A n CK
gear-down mode
Micron Technology, Inc. reserves the right to change products or specifications without notice.

MPSM Timing
Command path disable delay upopn MPSM tMPED MIN = tMOD (MIN) + tCPDED (MIN) CK 1

8Gb: x4, x8, x16 DDR4 SDRAM

entry
Valid clock requirement after MPSM t
CKMPE MIN = tMOD (MIN) + tCPDED (MIN) CK 1
entry
Valid clock requirement before MPSM tCKMPX MIN = tCKSRX (MIN) CK 1
exit
¥ 2015 Micron Technology, Inc. All rights reserved.

Exit MPSM to commands not requiring a t

XMP t
XS (MIN) CK
locked DLL
Exit MPSM to commands requiring a locked t
XMPDLL MIN = tXMP (MIN) + tXSDLL (MIN) CK 1
DLL
CS setup time to CKE t
MPX_S MIN = tIS (MIN) + tIH (MIN) ns

CS_n HIGH hold time to CKE rising edge tMPX_HH MIN = tXP ns
 Table 166: Electrical Characteristics and AC Timing Parameters: DDR4-1600 through DDR4-2400 (Continued)
CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

DDR4-1600 DDR4-1866 DDR4-2133 DDR4-2400

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
CS_n LOW hold time to CKE rising edge t
MPX_LH 12 t
XMP- 12 t
XMP- 12 t
XMP- 12 t
XMP- ns
10ns 10ns 10ns 10ns
Connectivity Test Timing
TEN pin HIGH to CS_n LOW n Enter CT mode t
CT_Enable 200 n 200 n 200 n 200 n ns

CS_n LOW and valid input to valid output t

CT_Valid n 200 n 200 n 200 n 200 ns

CK_t, CK_c valid and CKE HIGH after TEN goes t

CTCKE_Valid 10 n 10 n 10 n 10 n ns
HIGH
Calibration and VREFDQ Train Timing
ZQCL command: Long cali- POWER-UP t
ZQinit 1024 n 1024 n 1024 n 1024 n CK
bration time and RESET
operation
Normal opera- t
ZQoper 512 n 512 n 512 n 512 n CK
tion
ZQCS command: Short calibration time tZQCS 128 n 128 n 128 n 128 n CK
368

The VREF increment/decrement step time VREF_time MIN = 150ns

Enter VREFDQ training mode to the first write t
VREFDQE MIN = 150ns ns 1

Refresh Parameters By Device Density

or VREFDQ MRS command delay
Micron Technology, Inc. reserves the right to change products or specifications without notice.

Exit VREFDQ training mode to the first WRITE t

VREFDQX MIN = 150ns ns 1
command delay

8Gb: x4, x8, x16 DDR4 SDRAM

Initialization and Reset Timing
Exit reset from CKE HIGH to a valid command t
XPR MIN = tRFC1 + 10ns ns 1

RESET_L pulse low after power stable t

PW_RESET_S 1.0 n 1.0 n 1.0 n 1.0 n ρs

RESET_L pulse low at power-up t

PW_RESET_L 200 n 200 n 200 n 200 n ρs
¥ 2015 Micron Technology, Inc. All rights reserved.

Begin power supply ramp to power supplies t

VDDPR MIN = N/A; MAX = 200 ms
stable
RESET_n LOW to power supplies stable t
RPS MIN = 0; MAX = 0 ns

Refresh Timing
 Table 166: Electrical Characteristics and AC Timing Parameters: DDR4-1600 through DDR4-2400 (Continued)
CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

DDR4-1600 DDR4-1866 DDR4-2133 DDR4-2400

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
REFRESH-to-ACTIVATE or t
RFC1 MIN = 260 ns 1, 11
REFRESH command period
(all bank groups) 4Gb t
RFC2 MIN = 160 ns 1, 11
t
RFC4 MIN = 110 ns 1, 11
tRFC1 MIN = 350 ns 1, 11

8Gb t
RFC2 MIN = 260 ns 1, 11
t
RFC4 MIN = 160 ns 1, 11
t
RFC1 MIN = 350 ns 1, 11

16Gb t
RFC2 MIN = 260 ns 1, 11
t
RFC4 MIN = 160 ns 1, 11

Average periodic refresh -40ιC ζ TC ζ t

REFI MIN = N/A; MAX = 7.8 ρs 11
interval 85ιC
85ιC < TC ζ t
REFI MIN = N/A; MAX = 3.9 ρs 11
369

95ιC
95ιC < TC ζ t
REFI MIN = N/A; MAX = 1.95 ρs 11

Refresh Parameters By Device Density

105ιC
Micron Technology, Inc. reserves the right to change products or specifications without notice.

Self Refresh Timing

Exit self refresh to commands not requiring a
t
locked DLL XS MIN = tRFC1 + 10ns ns 1

8Gb: x4, x8, x16 DDR4 SDRAM

Exit self refresh to commands not requiring a t
XS_ABORT t
MIN = RFC4 + 10ns
locked DLL in self refresh abort ns 1
Exit self refresh to ZQCL, ZQCS and MRS (CL, t
XS_FAST MIN = tRFC4 + 10ns 1
CWL, WR, RTP and gear-down) ns
Exit self refresh to commands requiring a t
MIN = tDLLK (MIN) CK 1
¥ 2015 Micron Technology, Inc. All rights reserved.

XSDLL
locked DLL
Minimum CKE low pulse width for self t
CKESR MIN = tCKE (MIN) + 1nCK CK 1
refresh entry to self refresh exit timing
Minimum CKE low pulse width for self t
CKESR_PAR MIN = tCKE (MIN) + 1nCK + PL CK 1
refresh entry to self refresh exit timing when
CA parity is enabled
Valid clocks after self refresh entry (SRE) or tCKSRE MIN = greater of (5CK, 10ns) CK 1
power-down entry (PDE)
 Table 166: Electrical Characteristics and AC Timing Parameters: DDR4-1600 through DDR4-2400 (Continued)
CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

DDR4-1600 DDR4-1866 DDR4-2133 DDR4-2400

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
Valid clock requirement after self refresh t
CKSRE_PAR MIN = greater of (5CK, 10ns) + PL CK 1
entry or power-down when CA parity is
enabled
Valid clocks before self refresh exit (SRX) or t
CKSRX MIN = greater of (5CK, 10ns) CK 1
power-down exit (PDX), or reset exit
Power-Down Timing
Exit power-down with DLL on to any valid t
XP MIN = greater of 4CK or 6ns CK 1
command
Exit power-down with DLL on to any valid t
XP _PAR MIN = (greater of 4CK or 6ns) + PL CK 1
command when CA Parity is enabled.
CKE MIN pulse width tCKE (MIN) MIN = greater of 3CK or 5ns CK 1

Command pass disable delay tCPDED 4 n 4 n 4 n 4 n CK

Power-down entry to power-down exit tim- t

PD MIN = tCKE (MIN); MAX = 9 έ tREFI CK
ing
Begin power-down period prior to CKE regis- t
ANPD WL - 1CK CK
370

tered HIGH
Power-down entry period: ODT either syn- PDE Greater of tANPD or tRFC - REFRESH command to CKE LOW time CK

Refresh Parameters By Device Density

chronous or asynchronous
Micron Technology, Inc. reserves the right to change products or specifications without notice.

Power-down exit period: ODT either synchro- PDX t

ANPD + tXSDLL CK
nous or asynchronous
Power-Down Entry Minimum Timing

8Gb: x4, x8, x16 DDR4 SDRAM

ACTIVATE command to power-down entry t
ACTPDEN 1 n 1 n 2 n 2 n CK

PRECHARGE/PRECHARGE ALL command to t

PRPDEN 1 n 1 n 2 n 2 n CK
power-down entry
REFRESH command to power-down entry t
REFPDEN 1 n 1 n 2 n 2 n CK
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MRS command to power-down entry t

MRSPDEN MIN = tMOD (MIN) CK 1

READ/READ with auto precharge command t

RDPDEN MIN = RL + 4 + 1 CK 1
to power-down entry
WRITE command to power-down entry t
WRPDEN MIN = WL + 4 + tWR/tCK (AVG) CK 1
(BL8OTF, BL8MRS, BC4OTF)
WRITE command to power-down entry t
WRPBC4DEN MIN = WL + 2 + tWR/tCK (AVG) CK 1
(BC4MRS)
 Table 166: Electrical Characteristics and AC Timing Parameters: DDR4-1600 through DDR4-2400 (Continued)
CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

DDR4-1600 DDR4-1866 DDR4-2133 DDR4-2400

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
WRITE with auto precharge command to t
WRAPDEN MIN = WL + 4 + WR + 1 CK 1
power-down entry (BL8OTF, BL8MRS,BC4OTF)
WRITE with auto precharge command to t
WRAPBC4DEN MIN = WL + 2 + WR + 1 CK 1
power-down entry (BC4MRS)
ODT Timing
Direct ODT turn-on latency DODTLon WL - 2 = CWL + AL + PL - 2 CK
Direct ODT turn-off latency DODTLoff WL - 2 = CWL + AL + PL - 2 CK
RTT dynamic change skew t
ADC 0.3 0.7 0.3 0.7 0.3 0.7 0.3 0.7 CK

Asynchronous RTT(NOM) turn-on delay (DLL tAONAS 1 9 1 9 1 9 1 9 ns

off)
Asynchronous RTT(NOM) turn-off delay (DLL t
AOFAS 1 9 1 9 1 9 1 9 ns
off)
ODT HIGH time with WRITE command and ODTH8 1tCK 6 n 6 n 6 n 6 n CK
BL8
ODTH8 2tCK NA NA NA 7 n
371

ODT HIGH time without WRITE command or ODTH4 1tCK 4 n 4 n 4 n 4 n CK

with WRITE command and BC4

Refresh Parameters By Device Density

ODTH4 2tCK NA NA NA 5 n
Micron Technology, Inc. reserves the right to change products or specifications without notice.

Write Leveling Timing

First DQS_t, DQS_c rising edge after write lev- t
WLMRD 40 n 40 n 40 n 40 n CK
eling mode is programmed

8Gb: x4, x8, x16 DDR4 SDRAM

DQS_t, DQS_c delay after write leveling t
WLDQSEN 25 n 25 n 25 n 25 n CK
mode is programmed
Write leveling setup from rising CK_t, CK_c t
WLS 0.13 n 0.13 n 0.13 n 0.13 n t
CK
crossing to rising DQS_t, DQS_c crossing (AVG)
¥ 2015 Micron Technology, Inc. All rights reserved.

Write leveling hold from rising DQS_t, DQS_c tWLH 0.13 n 0.13 n 0.13 n 0.13 n tCK
crossing to rising CK_t, CK_c crossing (AVG)
Write leveling output delay tWLO 0 9.5 0 9.5 0 9.5 0 9.5 ns

Write leveling output error t

WLOE 0 2 0 2 0 2 0 2 ns

Gear-Down Timing (Not Supported Below DDR4-2666)

Exit reset from CKE HIGH to a valid MRS t
XPR_GEAR N/A N/A N/A N/A CK
gear-down
 Table 166: Electrical Characteristics and AC Timing Parameters: DDR4-1600 through DDR4-2400 (Continued)
CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

DDR4-1600 DDR4-1866 DDR4-2133 DDR4-2400

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
CKE HIGH assert to gear-down enable time) t
XS_GEAR N/A N/A N/A N/A CK

MRS command to sync pulse time t

SYNC_GEAR N/A N/A N/A N/A CK

Sync pulse to first valid command t

CMD_GEAR N/A N/A N/A N/A CK

Gear-down setup time tGEAR_setup N/A n N/A n N/A n N/A n CK

Gear-down hold time t

GEAR_hold N/A n N/A n N/A n N/A n CK

Notes: 1. Maximum limit not applicable.

2. Micron tDLLK values support the legacy JEDEC tDLLK specifications.
3. DDR4-1600 AC timing parameters apply if DRAM operates at lower than 1600 MT/s data rate.
4. Data rate is greater than or equal to 1066 Mb/s.
5. WRITE-to-READ when CRC and DM are both not enabled.
6. WRITE-to-READ delay when CRC and DM are both enabled.
7. The start of internal write transactions is defined as follows:
s For BL8 (fixed by MRS and on-the-fly): rising clock edge four clock cycles after WL
s For BC4 (on-the-fly): rising clock edge four clock cycles after WL
372

s For BC4 (fixed by MRS): rising clock edge two clock cycles after WL

8. For these parameters, the device supports tnPARAM [nCK] = ROUND{tPARAM [ns]/tCK (AVG) [ns]} according to the rounding algorithms found

Refresh Parameters By Device Density

in the Converting Time-Based Specifications to Clock-Based Requirements section, in clock cycles, assuming all input clock jitter specifications
Micron Technology, Inc. reserves the right to change products or specifications without notice.

are satisfied.
9. When operating in 1tCK WRITE preamble mode.
10. When operating in 2tCK WRITE preamble mode.

8Gb: x4, x8, x16 DDR4 SDRAM

11. When CA parity mode is selected and the DLLoff mode is used, each REF command requires an additional "PL" added to tRFC refresh time.
12. DRAM devices should be evenly addressed when being accessed. Disproportionate accesses to a particular row address may result in reduction
of the product lifetime and/or reduction in data retention ability.
13. Applicable from tCK (AVG) MIN to tCK (AVG) MAX as stated in the Speed Bin tables.
14. JEDEC specifies a minimum of five clocks.
15. The maximum read postamble is bound by tDQSCK (MIN) plus tQSH (MIN) on the left side and tHZ(DQS) MAX on the right side.
¥ 2015 Micron Technology, Inc. All rights reserved.

16. The reference level of DQ output signal is specified with a midpoint as a widest part of output signal eye, which should be approximately 0.7
έ VDDQ as a center level of the static single-ended output peak-to-peak swing with a driver impedance of 34 ohms and an effective test load
of 50 ohms to VTT = VDDQ.
17. JEDEC hasn't agreed upon the definition of the deterministic jitter; the user should focus on meeting the total limit.
18. Spread spectrum is not included in the jitter specification values. However, the input clock can accommodate spread-spectrum at a sweep rate
in the range of 20n60 kHz with an additional 1% of tCK (AVG) as a long-term jitter component; however, the spread spectrum may not use a
clock rate below tCK (AVG) MIN.
19. The actual tCAL minimum is the larger of 3 clocks or 3.748ns/tCK; the table lists the applicable clocks required at targeted speed bin.
 20. The maximum READ preamble is bounded by tLZ(DQS) MIN on the left side and tDQSCK (MAX) on the right side. See figure in the Clock to Data
CCMTD-1725822587-9875
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Strobe Relationship section. Boundary of DQS Low-Z occurs one cycle earlier in 2tCK toggle mode, as illustrated in the READ Preamble section.
21. DQ falling signal middle-point of transferring from HIGH to LOW to first rising edge of DQS differential signal cross-point.
22. The tPDA_S/tPDA_H parameters may use the tDS/tDH limits, respectively, if the signal is LOW the entire BL8.
373

Refresh Parameters By Device Density

Micron Technology, Inc. reserves the right to change products or specifications without notice.

8Gb: x4, x8, x16 DDR4 SDRAM

¥ 2015 Micron Technology, Inc. All rights reserved.
 Electrical Characteristics and AC Timing Parameters: 2666 Through 3200
CCMTD-1725822587-9875
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Table 167: Electrical Characteristics and AC Timing Parameters

DDR4-2666 DDR4-2933 DDR4-3200 Reserved
Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
Clock Timing
Clock period average (DLL off mode) t
CK (AVG, 8 20 8 20 8 20 ns
DLL_OFF)
Clock period average t
CK (AVG, 0.75 1.9 0.682 1.9 0.625 1.9 ns 3, 13
DLL_ON)
High pulse width average t
CH (AVG) 0.48 0.52 0.48 0.52 0.48 0.52 t
CK
(AVG)
Low pulse width average t
CL (AVG) 0.48 0.52 0.48 0.52 0.48 0.52 t
CK
(AVG)
Clock period jitter Total t
JITper_tot n38 38 -34 34 n32 32 ps 17 , 18

Deterministic t
JITper_dj n19 19 -17 17 n16 16 ps 17

DLL locking t n30 30 -27 27 n25 25 ps

374

JITper,lck
Clock absolute period t
CK (ABS) MIN = tCK (AVG) MIN + tJITper_tot MIN; MAX = tCK (AVG) MAX + tJIT- ps

Refresh Parameters By Device Density

per_tot MAX
Micron Technology, Inc. reserves the right to change products or specifications without notice.

Clock absolute high pulse width t

CH (ABS) 0.45 n 0.45 n 0.45 n t
CK
(includes duty cycle jitter) (AVG)
Clock absolute low pulse width t
CL (ABS) 0.45 n 0.45 n 0.45 n t
CK

8Gb: x4, x8, x16 DDR4 SDRAM

(includes duty cycle jitter) (AVG)
Cycle-to-cycle jitter Total t
JITcc _tot n 75 n 68 n 62 ps

DLL locking t
JITcc,lck n 60 n 55 n 62 ps
¥ 2015 Micron Technology, Inc. All rights reserved.
 Table 167: Electrical Characteristics and AC Timing Parameters (Continued)
CCMTD-1725822587-9875
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DDR4-2666 DDR4-2933 DDR4-3200 Reserved

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
Cumulative error across 2 cycles t
ERR2per n55 55 -50 50 n46 46 ps

3 cycles t
ERR3per n66 66 -60 60 n55 55 ps

4 cycles t
ERR4per n73 73 -66 66 n61 61 ps

5 cycles tERR5per n78 78 -71 71 n65 65 ps

6 cycles t
ERR6per n83 83 -75 75 n69 69 ps

7 cycles t
ERR7per n87 87 -79 79 n73 73 ps

8 cycles t
ERR8per n91 91 -83 83 n76 76 ps

9 cycles t
ERR9per n94 94 -85 85 n78 78 ps

10 cycles t
ERR10per n96 96 -88 88 n80 80 ps

11 cycles t
ERR11per n99 99 -90 90 n83 83 ps

12 cycles t
ERR12per n101 101 -92 92 n84 84 ps
375

n = 13, 14 . . . t
ERRnper t
ERRnper MIN = (1 + 0.68ln[n]) έ tJITper_tot MIN ps
49, 50 cycles t
ERRnper MAX = (1 + 0.68ln[n]) έ tJITper_tot MAX

Refresh Parameters By Device Density

DQ Input Timing
Micron Technology, Inc. reserves the right to change products or specifications without notice.

Data setup time to DQS_t, Base (cali- t

DS Refer to DQ Input Receiver Specification section n
DQS_c brated VREF) (approximately 0.15tCK to 0.28tCK )

8Gb: x4, x8, x16 DDR4 SDRAM

Non-cali- t
PDA_S minimum of 0.5ui UI 22
brated VREF
Data hold time from Base (cali- t
DH Refer to DQ Input Receiver Specification section n
DQS_t, DQS_c brated VREF) (approximately 0.15tCK to 0.28tCK )
Non-cali- t minimum of 0.5UI UI 22
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PDA_H
brated VREF
DQ and DM minimum data pulse width for t
DIPW 0.58 n 0.58 n 0.58 n UI
each input
DQ Output Timing (DLL enabled)
DQS_t, DQS_c to DQ skew, per group, per t
DQSQ n 0.18 n 0.19 n 0.20 UI
access
DQ output hold time from DQS_t, DQS_c tQH 0.74 n 0.72 n 0.70 n UI
 Table 167: Electrical Characteristics and AC Timing Parameters (Continued)
CCMTD-1725822587-9875
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DDR4-2666 DDR4-2933 DDR4-3200 Reserved

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
Data Valid Window per device: tQH - t
DVWd 0.64 n 0.64 n 0.64 n UI
t
DQSQ each devices output per UI

Data Valid Window per device, per pin: tQH t

DVWp 0.72 n 0.72 n 0.72 n UI
- tDQSQ each devices output per UI
DQ Low-Z time from CK_t, CK_c t
LZDQ n310 170 n280 165 n250 160 ps

DQ High-Z time from CK_t, CK_c tHZDQ n 170 n 165 n 160 ps

DQ Strobe Input Timing

DQS_t, DQS_c rising edge to CK_t, CK_c ris- t
DQSS1ck n0.27 0.27 n0.27 0.27 n0.27 0.27 CK
ing edge for 1tCK preamble
DQS_t, DQS_c rising edge to CK_t, CK_c ris- t
DQSS2ck n0.50 0.50 n0.50 0.50 n0.50 0.50 CK
ing edge for 2tCK preamble
DQS_t, DQS_c differential input low pulse t
DQSL 0.46 0.54 0.46 0.54 0.46 0.54 CK
width
DQS_t, DQS_c differential input high pulse t 0.46 0.54 0.46 0.54 0.46 0.54 CK
376

DQSH
width
DQS_t, DQS_c differential input high pulse tDQSH2PRE 1.46 - 1.46 - 1.46 - CK

Refresh Parameters By Device Density

width for 2tCK preamble
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DQS_t, DQS_c falling edge setup to CK_t, t

DSS1ck 0.18 n 0.18 n 0.18 n CK
CK_c rising edge for 1tCK preamble

8Gb: x4, x8, x16 DDR4 SDRAM

DQS_t, DQS_c falling edge setup to CK_t, t
DSS2ck 0 n 0 n 0 n CK
CK_c rising edge for 2tCK preamble
DQS_t, DQS_c falling edge hold from CK_t, t
DSH1ck 0.18 n 0.18 n 0.18 n CK
CK_c rising edge for 1tCK preamble
DQS_t, DQS_c falling edge hold from CK_t, t
DSH2ck 0 n 0 n 0 n CK
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CK_c rising edge for 2tCK preamble

DQS_t, DQS_c differential WRITE preamble t
WPRE1ck 0.9 n 0.9 n 0.9 n CK
for 1tCK preamble
DQS_t, DQS_c differential WRITE preamble t
WPRE2ck 1.8 n 1.8 n 1.8 n CK
for 2tCK preamble
DQS_t, DQS_c differential WRITE postam- t
WPST 0.33 n 0.33 n 0.33 n CK
ble
 Table 167: Electrical Characteristics and AC Timing Parameters (Continued)
CCMTD-1725822587-9875
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DDR4-2666 DDR4-2933 DDR4-3200 Reserved

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
DQS Strobe Output Timing (DLL enabled)
DQS_t, DQS_c rising edge output access t
DQSCK n170 170 n165 165 n160 160 ps
time from rising CK_t, CK_c
DQS_t, DQS_c rising edge output variance t
DQSCKi n 270 n 265 n 260 ps
window per DRAM
DQS_t, DQS_c differential output high t
QSH 0.40 n 0.40 n 0.40 n CK
time
DQS_t, DQS_c differential output low time t
QSL 0.40 n 0.40 n 0.40 n CK

DQS_t, DQS_c Low-Z time (RL - 1) tLZDQS n310 170 n280 165 n250 160 ps

DQS_t, DQS_c High-Z time (RL + BL/2) t

HZDQS n 170 n 165 n 160 ps

DQS_t, DQS_c differential READ preamble t

RPRE1ck 0.9 n 0.9 n 0.9 n CK 20
for 1tCK preamble
DQS_t, DQS_c differential READ preamble t
RPRE2ck 1.8 n 1.8 n 1.8 n CK 20
for 2tCK preamble
377

DQS_t, DQS_c differential READ postamble t

RPST 0.33 n 0.33 n 0.33 n CK 21

Command and Address Timing

Refresh Parameters By Device Density

DLL locking time tDLLK 854 n 940 n 1024 n CK 2, 4
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CMD, ADDR setup time to Base t

IS 55 n 48 n 40 n ps
CK_t, CK_c referenced to
VREFCA tIS 145 n 138 n 130 n ps

8Gb: x4, x8, x16 DDR4 SDRAM

VIH(AC) and VIL(AC) levels VREF

CMD, ADDR hold time to Base tIH 80 n 73 n 65 n ps

CK_t, CK_c referenced to
VIH(DC) and VIL(DC) levels VREFCA tIH 145 n 138 n 130 n ps
VREF

CTRL, ADDR pulse width for each input t

IPW 385 n 365 n 340 n ps
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ACTIVATE to internal READ or WRITE delay t

RCD See Speed Bin Tables for tRCD ns

PRECHARGE command period t

RP See Speed Bin Tables for tRP ns

ACTIVATE-to-PRECHARGE command tRAS See Speed Bin Tables for tRAS ns 12

period
ACTIVATE-to-ACTIVATE or REF command t
RC See Speed Bin Tables for tRC ns 12
period
 Table 167: Electrical Characteristics and AC Timing Parameters (Continued)
CCMTD-1725822587-9875
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DDR4-2666 DDR4-2933 DDR4-3200 Reserved

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
ACTIVATE-to-ACTIVATE command period t
RRD_S MIN = greater MIN = greater MIN = greater CK 1
to different bank groups for 1/2KB page (1/2KB) of 4CK or 3.0ns of 4CK or 2.7ns of 4CK or 2.5ns
size
ACTIVATE-to-ACTIVATE command period to t
RRD_S MIN = greater MIN = greater MIN = greater CK 1
different bank groups for 1KB page size (1KB) of 4CK or 3.0ns of 4CK or 2.7ns of 4CK or 2.5ns

ACTIVATE-to-ACTIVATE command period to t

RRD_S MIN = greater MIN = greater MIN = greater CK 1
different bank groups for 2KB page size (2KB) of 4CK or 5.3ns of 4CK or 5.3ns of 4CK or 5.3ns

ACTIVATE-to-ACTIVATE command period to t

RRD_L MIN = greater MIN = greater MIN = greater CK 1
same bank groups for 1/2KB page size (1/2KB) of 4CK or 4.9ns of 4CK or 4.9ns of 4CK or 4.9ns

ACTIVATE-to-ACTIVATE command period to t

RRD_L MIN = greater MIN = greater MIN = greater CK 1
same bank groups for 1KB page size (1KB) of 4CK or 4.9ns of 4CK or 4.9ns of 4CK or 4.9ns

ACTIVATE-to-ACTIVATE command period to t

RRD_L MIN = greater MIN = greater MIN = greater CK 1
same bank groups for 2KB page size (2KB) of 4CK or 6.4ns of 4CK or 6.4ns of 4CK or 6.4ns

Four ACTIVATE windows for 1/2KB page t

FAW MIN = greater MIN = greater MIN = greater ns
size (1/2KB) of 16CK or 12ns of 16CK or of 16CK or 10ns
378

10.875ns
Four ACTIVATE windows for 1KB page size t
FAW MIN = greater MIN = greater MIN = greater ns

Refresh Parameters By Device Density

(1KB) of 20CK or 21ns of 20CK or 21ns of 20CK or 21ns
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Four ACTIVATE windows for 2KB page size tFAW MIN = greater MIN = greater MIN = greater ns
(2KB) of 28CK or 30ns of 28CK or 30ns of 28CK or 30ns

WRITE recovery time t MIN = 15ns ns 1, 5, 9

8Gb: x4, x8, x16 DDR4 SDRAM

WR1ck
t
WR2ck MIN = 1CK + tWR1ck CK 1, 5, 10

WRITE recovery time when CRC and DM MIN = tWR1ck + greater of (5CK or 3.75ns) CK 1, 6, 9
are both enabled t
WR_CRC_DM1ck
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WRITE recovery time when CRC and DM are t

WR_CRC_DM2ck MIN = 1CK + tWR_CRC_DM1ck CK 1, 6, 10
both enabled
Delay from start of internal WRITE transac- tWTR_L MIN = greater of 4CK or 7.5ns CK 1, 5, 9
1ck
tion to internal READ command n Same
bank group t
WTR_L2ck MIN = 1CK + tWTR_L1ck CK 1, 5, 10
 Table 167: Electrical Characteristics and AC Timing Parameters (Continued)
CCMTD-1725822587-9875
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DDR4-2666 DDR4-2933 DDR4-3200 Reserved

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
Delay from start of internal WRITE transac- t
WTR_L_CRC_D MIN = tWTR_L1ck + greater of (5CK or 3.75ns) CK 1, 6, 9
tion to internal READ command n Same M1ck
bank group when CRC and DM are both
enabled t
WTR_L_CRC_D MIN = 1CK + tWTR_L_CRC_DM1ck CK 1, 6, 10
M2ck
Delay from start of internal WRITE transac- t
WTR_S1ck MIN = greater of (2CK or 2.5ns) CK 1, 5, 7,
tion to internal READ command n Different 8, 9
bank group tWTR_S MIN = 1CK + tWTR_S1ck CK 1, 5, 7,
2ck
8, 10
Delay from start of internal WRITE transac- MIN = tWTR_S1ck + greater of (5CK or 3.75ns) CK 1, 6, 7,
tion to internal READ command n Different t
WTR_S_CRC_D 8, 9
bank group when CRC and DM are both M1ck
enabled
t
WTR_S_CRC_D MIN = 1CK + tWTR_S_CRC_DM1ck CK 1, 6, 7,
M2ck 8, 10

READ-to-PRECHARGE time t
RTP MIN = greater of 4CK or 7.5ns CK 1
379

CAS_n-to-CAS_n command delay to differ- t

CCD_S 4 n 4 n 4 n CK
ent bank group

Refresh Parameters By Device Density

CAS_n-to-CAS_n command delay to same tCCD_L MIN = n MIN = n MIN = n CK 14
bank group greater greater greater
Micron Technology, Inc. reserves the right to change products or specifications without notice.

of 4CK of 4CK of 4CK

or 5ns or 5ns or 5ns

8Gb: x4, x8, x16 DDR4 SDRAM

Auto precharge write recovery + pre- tDAL (MIN) MIN = WR + ROUNDtRP/tCK (AVG); MAX = N/A CK 8
charge time
MRS Command Timing
MRS command cycle time t
MRD 8 n 8 n 8 n CK

MRS command cycle time in PDA mode t

MRD_PDA MIN = greater of (16nCK, 10ns) 1
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MRS command cycle time in CAL mode t

MRD_CAL MIN = tMOD + tCAL CK

MRS command update delay t

MOD MIN = greater of (24nCK, 15ns) CK 1

MRS command update delay in PDA mode t

MOD_PDA MIN = tMOD CK

MRS command update delay in CAL mode t

MOD_CAL MIN = tMOD + tCAL CK

MRS command to DQS drive in preamble tSDO MIN = tMOD + 9ns

training
 Table 167: Electrical Characteristics and AC Timing Parameters (Continued)
CCMTD-1725822587-9875
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DDR4-2666 DDR4-2933 DDR4-3200 Reserved

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
MPR Command Timing
Multipurpose register recovery time t
MPRR MIN = 1nCK CK

Multipurpose register write recovery time t

WR_MPR MIN = tMOD + AL + PL
CRC Error Reporting Timing
CRC error to ALERT_n latency t
CRC_ALERT 3 13 3 13 3 13 ns

CRC ALERT_n pulse width t

CRC_ALERT_PW 6 10 6 10 6 10 CK

CA Parity Timing
Parity latency PL 5 n 6 n 6 n CK
Commands uncertain to be executed t
PAR_UN- n PL n PL n PL CK
during this time KNOWN
Delay from errant command to ALERT_n t
PAR_ALERT_ON n PL + n PL + n PL + CK
assertion 6ns 6ns 6ns
Pulse width of ALERT_n signal when t
PAR_ALERT_PW 80 160 88 176 96 192 CK
380

asserted
Time from alert asserted until DES com- t
PAR_ALERT_RS n 71 n 78 n 85 CK
mands required in persistent CA parity

Refresh Parameters By Device Density

P
mode
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CAL Timing
CS_n to command address latency t
CAL 5 n 6 n 6 n CK 19

8Gb: x4, x8, x16 DDR4 SDRAM

CS_n to command address latency in tCALg 6 n 8 n 8 n CK
gear-down mode
MPSM Timing
Command path disable delay upopn MPSM t
MPED MIN = tMOD (MIN) + tCPDED (MIN) CK 1
entry
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Valid clock requirement after MPSM t

CKMPE MIN = tMOD (MIN) + tCPDED (MIN) CK 1
entry
Valid clock requirement before MPSM t
CKMPX MIN = tCKSRX (MIN) CK 1
exit
Exit MPSM to commands not requiring a tXMP tXS (MIN) CK
locked DLL
Exit MPSM to commands requiring a locked tXMPDLL MIN = tXMP (MIN) + tXSDLL (MIN) CK 1
DLL
 Table 167: Electrical Characteristics and AC Timing Parameters (Continued)
CCMTD-1725822587-9875
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DDR4-2666 DDR4-2933 DDR4-3200 Reserved

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
CS setup time to CKE t
MPX_S MIN = tIS (MIN) + tIH (MIN) ns

CS_n HIGH hold time to CKE rising edge t

MPX_HH MIN = tXP ns

CS_n LOW hold time to CKE rising edge t

MPX_LH 12 t
XMP-1 12 t
XMP-1 12 t
XMP-1 ns
0ns 0ns 0ns
Connectivity Test Timing
TEN pin HIGH to CS_n LOW n Enter CT t
CT_Enable 200 n 200 n 200 n ns
mode
CS_n LOW and valid input to valid output t
CT_Valid n 200 n 200 n 200 ns

CK_t, CK_c valid and CKE HIGH after TEN t

CTCKE_Valid 10 n 10 n 10 n ns
goes HIGH
Calibration and VREFDQ Train Timing
ZQCL command: Long cal- POWER-UP t
ZQinit 1024 n 1024 n 1024 n CK
ibration time and RESET
operation
381

Normal oper- t
ZQoper 512 n 512 n 512 n CK
ation

Refresh Parameters By Device Density

ZQCS command: Short calibration time t
ZQCS 128 n 128 n 128 n CK
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The VREF increment/decrement step time VREF_time MIN = 150ns

Enter VREFDQ training mode to the first t
VREFDQE MIN = 150ns ns 1

8Gb: x4, x8, x16 DDR4 SDRAM

write or VREFDQ MRS command delay
Exit VREFDQ training mode to the first t
VREFDQX MIN = 150ns ns 1
WRITE command delay
Initialization and Reset Timing
Exit reset from CKE HIGH to a valid com- t
MIN = tRFC1 + 10ns ns 1
¥ 2015 Micron Technology, Inc. All rights reserved.

XPR
mand
RESET_L pulse low after power stable t
PW_RESET_S 1.0 n 1.0 n 1.0 n ρs

RESET_L pulse low at power-up t

PW_RESET_L 200 n 200 n 200 n ρs

Begin power supply ramp to power sup- t

VDDPR MIN = N/A; MAX = 200 ms
plies stable
RESET_n LOW to power supplies stable t
RPS MIN = 0; MAX = 0 ns
 Table 167: Electrical Characteristics and AC Timing Parameters (Continued)
CCMTD-1725822587-9875
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DDR4-2666 DDR4-2933 DDR4-3200 Reserved

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
Refresh Timing
REFRESH-to-ACTIVATE or t
RFC1 MIN = 260 ns 1, 11
REFRESH command period
(all bank groups) 4Gb t
RFC2 MIN = 160 ns 1, 11
t
RFC4 MIN = 110 ns 1, 11
tRFC1 MIN = 350 ns 1, 11

8Gb t
RFC2 MIN = 260 ns 1, 11
t
RFC4 MIN = 160 ns 1, 11
t
RFC1 MIN = 350 ns 1, 11

16Gb t
RFC2 MIN = 260 ns 1, 11
t
RFC4 MIN = 160 ns 1, 11

Average periodic refresh -40ιC ζ TC ζ t

REFI MIN = N/A; MAX = 7.8 ρs 11
interval 85ιC
382

85ιC < TC ζ t
REFI MIN = N/A; MAX = 3.9 ρs 11
95ιC

Refresh Parameters By Device Density

95ιC < TC ζ t
REFI MIN = N/A; MAX = 1.95 ρs 11
Micron Technology, Inc. reserves the right to change products or specifications without notice.

105ιC
Self Refresh Timing

8Gb: x4, x8, x16 DDR4 SDRAM

Exit self refresh to commands not requiring tXS
a locked DLL MIN = tRFC1 + 10ns ns 1
Exit self refresh to commands not requiring t
a locked DLL in self refresh abort XS_ABORT MIN = tRFC4 + 10ns ns 1
Exit self refresh to ZQCL, ZQCS and MRS t
XS_FAST MIN = tRFC4 + 10ns 1
(CL, CWL, WR, RTP and gear-down) ns
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Exit self refresh to commands requiring a t

XSDLL MIN = tDLLK (MIN) CK 1
locked DLL
Minimum CKE low pulse width for self tCKESR MIN = tCKE (MIN) + 1nCK CK 1
refresh entry to self refresh exit timing
Minimum CKE low pulse width for self t
CKESR_par MIN = tCKE (MIN) + 1nCK + PL CK 1
refresh entry to self refresh exit timing
when CA parity is enabled
 Table 167: Electrical Characteristics and AC Timing Parameters (Continued)
CCMTD-1725822587-9875
8gb_ddr4_dram.pdf - Rev. T 09/2021 EN

DDR4-2666 DDR4-2933 DDR4-3200 Reserved

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
Valid clocks after self refresh entry (SRE) or t
CKSRE MIN = greater of (5CK, 10ns) CK 1
power-down entry (PDE)
Valid clock requirement after self refresh t
CKSRE_par MIN = greater of (5CK, 10ns) + PL CK 1
entry or power-down when CA parity is
enabled
Valid clocks before self refresh exit (SRX) t
CKSRX MIN = greater of (5CK, 10ns) CK 1
or power-down exit (PDX), or reset exit
Power-Down Timing
Exit power-down with DLL on to any valid t
XP MIN = greater of 4CK or 6ns CK 1
command
Exit precharge power-down with DLL fro- tXP _PAR MIN = (greater of 4CK or 6ns) + PL CK 1
zen to commands not requiring a locked
DLL when CA Parity is enabled.
CKE MIN pulse width t
CKE (MIN) MIN = greater of 3CK or 5ns CK 1

Command pass disable delay t

CPDED 4 n 4 n 4 n CK
383

Power-down entry to power-down exit t

PD MIN = tCKE (MIN); MAX = 9 έ tREFI CK
timing

Refresh Parameters By Device Density

Begin power-down period prior to CKE t
ANPD WL - 1CK CK
registered HIGH
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Power-down entry period: ODT either syn- PDE Greater of tANPD or tRFC - REFRESH command to CKE LOW time CK
chronous or asynchronous

8Gb: x4, x8, x16 DDR4 SDRAM

Power-down exit period: ODT either syn- PDX tANPD + tXSDLL CK
chronous or asynchronous
Power-Down Entry Minimum Timing
ACTIVATE command to power-down entry t
ACTPDEN 2 n 2 n 2 n CK
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PRECHARGE/PRECHARGE ALL command to t

PRPDEN 2 n 2 n 2 n CK
power-down entry
REFRESH command to power-down entry t
REFPDEN 2 n 2 n 2 n CK

MRS command to power-down entry t

MRSPDEN MIN = tMOD (MIN) CK 1

READ/READ with auto precharge com- t

RDPDEN MIN = RL + 4 + 1 CK 1
mand to power-down entry
WRITE command to power-down entry tWRPDEN MIN = WL + 4 + tWR/tCK (AVG) CK 1
(BL8OTF, BL8MRS, BC4OTF)
 Table 167: Electrical Characteristics and AC Timing Parameters (Continued)
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DDR4-2666 DDR4-2933 DDR4-3200 Reserved

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
WRITE command to power-down entry t
WRPBC4DEN MIN = WL + 2 + tWR/tCK (AVG) CK 1
(BC4MRS)
WRITE with auto precharge command to t
WRAPDEN MIN = WL + 4 + WR + 1 CK 1
power-down entry (BL8OTF,
BL8MRS,BC4OTF)
WRITE with auto precharge command to t
WRAPBC4DEN MIN = WL + 2 + WR + 1 CK 1
power-down entry (BC4MRS)
ODT Timing
Direct ODT turn-on latency DODTLon WL - 2 = CWL + AL + PL - 2 CK
Direct ODT turn-off latency DODTLoff WL - 2 = CWL + AL + PL - 2 CK
RTT dynamic change skew t
ADC 0.28 0.72 0.26 0.74 0.26 0.74 CK

Asynchronous RTT(NOM) turn-on delay (DLL t

AONAS 1 9 1 9 1 9 ns
off)
Asynchronous RTT(NOM) turn-off delay (DLL t
AOFAS 1 9 1 9 1 9 ns
off)
384

ODT HIGH time with WRITE command and ODTH8 1tCK 6 n 6 n 6 n CK

BL8

Refresh Parameters By Device Density

ODTH8 2tCK 7 n 7 n 7 n
Micron Technology, Inc. reserves the right to change products or specifications without notice.

ODT HIGH time without WRITE command ODTH4 1tCK 4 n 4 n 4 n CK

or with WRITE command and BC4
ODTH4 2tCK 5 n 5 n 5 n

8Gb: x4, x8, x16 DDR4 SDRAM

Write Leveling Timing
First DQS_t, DQS_c rising edge after write tWLMRD 40 n 40 n 40 n CK
leveling mode is programmed
DQS_t, DQS_c delay after write leveling t
WLDQSEN 25 n 25 n 25 n CK
mode is programmed
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Write leveling setup from rising CK_t, CK_c t

WLS 0.13 n 0.13 n 0.13 n CK
crossing to rising DQS_t, DQS_c crossing
Write leveling hold from rising DQS_t, t
WLH 0.13 n 0.13 n 0.13 n CK
DQS_c crossing to rising CK_t, CK_c crossing
Write leveling output delay t
WLO 0 9.5 0 9.5 0 9.5 ns

Write leveling output error t

WLOE 0 2 0 2 0 2 ns

Gear-Down Timing
 Table 167: Electrical Characteristics and AC Timing Parameters (Continued)
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DDR4-2666 DDR4-2933 DDR4-3200 Reserved

Parameter Symbol Min Max Min Max Min Max Min Max Unit Notes
Exit reset from CKE HIGH to a valid MRS t
XPR_GEAR t
XPR t
XPR t
XPR CK
gear-down
CKE HIGH assert to gear-down enable time) t
XS_GEAR t
XS t
XS t
XS CK

MRS command to sync pulse time t

SYNC_GEAR t
MOD + 4CK t
MOD + 4CK t
MOD + 4CK CK

Sync pulse to first valid command t

CMD_GEAR t
MOD t
MOD t
MOD CK

Gear-down setup time t

GEAR_setup 2CK n 2CK n 2CK n CK

Gear-down hold time t

GEAR_hold 2CK n 2CK n 2CK n CK

Notes: 1. Maximum limit not applicable.

2. Micron tDLLK values support the legacy JEDEC tDLLK specifications.
3. DDR4-1600 AC timing parameters apply if DRAM operates at lower than 1600 MT/s data rate.
4. Data rate is greater than or equal to 1066 Mb/s.
5. WRITE-to-READ when CRC and DM are both not enabled.
6. WRITE-to-READ delay when CRC and DM are both enabled.
7. The start of internal write transactions is defined as follows:
385

s For BL8 (fixed by MRS and on-the-fly): rising clock edge four clock cycles after WL
s For BC4 (on-the-fly): rising clock edge four clock cycles after WL
s For BC4 (fixed by MRS): rising clock edge two clock cycles after WL

Refresh Parameters By Device Density

Micron Technology, Inc. reserves the right to change products or specifications without notice.

8. For these parameters, the device supports tnPARAM [nCK] = ROUND{tPARAM [ns]/tCK (AVG) [ns]} according to the rounding algorithms found
in the Converting Time-Based Specifications to Clock-Based Requirements section, in clock cycles, assuming all input clock jitter specifications
are satisfied.

8Gb: x4, x8, x16 DDR4 SDRAM

9. When operating in 1tCK WRITE preamble mode.
10. When operating in 2tCK WRITE preamble mode.
11. When CA parity mode is selected and the DLLoff mode is used, each REF command requires an additional "PL" added to tRFC refresh time.
12. DRAM devices should be evenly addressed when being accessed. Disproportionate accesses to a particular row address may result in reduction
of the product lifetime and/or reduction in data retention ability.
13. Applicable from tCK (AVG) MIN to tCK (AVG) MAX as stated in the Speed Bin tables.
¥ 2015 Micron Technology, Inc. All rights reserved.

14. JEDEC specifies a minimum of five clocks.

15. The maximum read postamble is bound by tDQSCK (MIN) plus tQSH (MIN) on the left side and tHZ(DQS) MAX on the right side.
16. The reference level of DQ output signal is specified with a midpoint as a widest part of output signal eye, which should be approximately 0.7
έ VDDQ as a center level of the static single-ended output peak-to-peak swing with a driver impedance of 34 ohms and an effective test load
of 50 ohms to VTT = VDDQ.
17. JEDEC hasn't agreed upon the definition of the deterministic jitter; the user should focus on meeting the total limit.
 18. Spread spectrum is not included in the jitter specification values. However, the input clock can accommodate spread-spectrum at a sweep rate
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in the range of 20n60 kHz with an additional 1% of tCK (AVG) as a long-term jitter component; however, the spread spectrum may not use a
clock rate below tCK (AVG) MIN.
19. The actual tCAL minimum is the larger of 3 clocks or 3.748ns/tCK; the table lists the applicable clocks required at targeted speed bin.
20. The maximum READ preamble is bounded by tLZ(DQS) MIN on the left side and tDQSCK (MAX) on the right side. See figure in the Clock to Data
Strobe Relationship section. Boundary of DQS Low-Z occurs one cycle earlier in 2tCK toggle mode, as illustrated in the READ Preamble section.
21. DQ falling signal middle-point of transferring from HIGH to LOW to first rising edge of DQS differential signal cross-point.
22. The tPDA_S/tPDA_H parameters may use the tDS/tDH limits, respectively, if the signal is LOW the entire BL8.
386

Refresh Parameters By Device Density

Micron Technology, Inc. reserves the right to change products or specifications without notice.

8Gb: x4, x8, x16 DDR4 SDRAM

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 8Gb: x4, x8, x16 DDR4 SDRAM
Clock Specification

Clock Specification
The jitter specified is a random jitter meeting a Gaussian distribution. Input clocks violating the
MIN/MAX values may result in malfunction of the DDR4 SDRAM device.

Definition for tCK(AVG)

t
CK(AVG) is calculated as the average clock period across any consecutive 200-cycle window, where
each clock period is calculated from rising edge to rising edge.
N
tCK(avg) = Ȉ tCKj /N
j=1

Where N = 200

Definition for tCK(ABS)

t
CK(ABS) is defined as the absolute clock period as measured from one rising edge to the next consec-
utive rising edge. tCK(ABS) is not subject to a production test.

Definition for tCH(AVG) and tCL(AVG)

t
CH(AVG) is defined as the average high pulse width as calculated across any consecutive 200 high
pulses.
N
tCH(AVG) = tCH /(N × tCK(AVG))
j
j=1

Where N = 200

t
CL(AVG) is defined as the average low pulse width as calculated across any consecutive 200 low pulses.
N
tCL(AVG) = tCL /(N × tCK(AVG))
j
j=1

Where N = 200

Definition for tJIT(per) and tJIT(per,lck)

t
JIT(per) is defined as the largest deviation of any signal tCK from tCK(AVG).
t
JIT(per) = MIN/MAX of {tCKi - tCK(AVG) where i = 1 to 200}.
t
JIT(per) defines the single period jitter when the DLL is already locked.
t
JIT(per,lck) uses the same definition for single period jitter, but only during the DLL locking period.
t
JIT(per) and tJIT(per,lck) are not subject to production test.

Definition for tJIT(cc) and tJIT(cc,lck)

t
JIT(cc) is defined as the absolute difference in clock period between two consecutive clock cycles.
tJIT(cc) = MAX of |{tCKi +1 - tCKi}|.

t
JIT(cc) defines the cycle to cycle jitter when the DLL is already locked.
t
JIT(cc,lck) uses the same definition for cycle to cycle jitter, during the DLL locking period only.

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 8Gb: x4, x8, x16 DDR4 SDRAM
Jitter Notes

t
JIT(cc) and tJIT(cc,lck) are not subject to production test.

Definition for tERR(nper)

t
ERR is defined as the cumulative error across n multiple consecutive cycles from tCK(AVG). tERR is not
subject to a production test.

Jitter Notes
Note a: Unit tCK(AVG) represents the actual tCK(AVG) of the input clock under operation. Unit nCK
represents one clock cycle of the input clock, including the actual clock edges. Example: tMRD = 4
[nCK] means that if one MODE REGISTER SET command is registered at Tm, another MODE
REGISTER SET command may be registered at Tm + 4, even if (Tm + 4 - Tm) is (4 έ tCK(AVG) + tERR (4
per) MIN).
Note b: These parameters are measured from a command/address signal (such as CKE, CS_n, RAS_n,
CAS_n, WE_n, ODT, BA0, A0, or A1) transition edge to its respective clock signal (CK_t/CK_c) crossing.
The specification values are not affected by the amount of clock jitter applied (for example, tJITper,
t
JITcc) because the setup and hold are relative to the clock signal crossing that latches the
command/address. That is, these parameters should be met whether clock jitter is present or not.
Note c: These parameters are measured from a data strobe signal (DQS_t[L/U], DQS_c[L/U]) crossing
to its respective clock signal (CK_t, CK_c) crossing. The specification values are not affected by the
amount of clock jitter applied (for example, tJITper, tJITcc) because these are relative to the clock signal
crossing. That is, these parameters should be met whether clock jitter is present or not.
Note d: These parameters are measured from a data signal (such as DM[L/U], DQ[L/U]0, or DQ[L/U]1)
transition edge to its respective data strobe signal (DQS_t[L/U], DQS_c[L/U]) crossing.

Note e: For these parameters, the DDR4 SDRAM device supports tnPARAM [nCK] = RU[tPARAM
[ns]/tCK(AVG) [ns]], which is in clock cycles, assuming all input clock jitter specifications are satisfied.
For example, the device will support tnRP = RU [tRP/tCK(AVG)], which is in clock cycles, if all input
clock jitter specifications are met. This means that for DDR4-800 6-6-6, tRP = 15ns, the device will
support tnRP = RU[tRP/tCK(AVG)] = 6, as long as the input clock jitter specifications are met. For
example, the PRECHARGE command at Tm and ACTIVE command at Tm + 6 is valid even if (Tm + 6 -
Tm) is less than 15ns due to input clock jitter.
Note f: When the device is operated with input clock jitter, this parameter needs to be derated by the
actual tERR(mper), act of the input clock, where 2 ζ m ζ 12 (output deratings are relative to the SDRAM
input clock). For example, if the measured jitter into a DDR4-800 SDRAM has tERR(mper), act, MIN =
nPS AND tERR(mper), act, MAX = +193ps, then tDQSCK, MIN(derated) = tDQSCK, MIN - tERR(mper),
ACT -!8  nPS PS  nPS AND tDQSCK, MAX(derated) = tDQSCK, MAX - tERR(mper), act, MIN
= 400ps + 172ps = 572ps. Similarly, tLZ(DQ) for DDR4-800 derates to t,:$1 -).DERATED  nPS
PS  nPS AND tLZ(DQ), MAX(derated) = 400ps + 172ps = 572ps. Note that tERR(mper), act, MIN
is the minimum measured value of tERR(nper) where 2 ζ n ζ 12, and tERR(mper), act, MAX is the
maximum measured value of tERR(nper) where 2 ζ n ζ 12.
Note g: When the device is operated with input clock jitter, this parameter needs to be derated by the
actual tJIT(per), act of the input clock (output deratings are relative to the SDRAM input clock). For
example, if the measured jitter into a DDR4-800 SDRAM has tCK(AVG), act = 2500ps, tJIT(per), act, MIN

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388 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
Converting Time-Based Specifications to Clock-Based
Requirements

 nPS AND tJIT(per), act, MAX = +93ps, then tRPRE, MIN(derated) = tRPRE, MIN + tJIT(per), act, MIN
= 0.9 έ tCK(AVG), act + tJIT(per), act, MIN = 0.9 έ 2500ps - 72ps = 2178ps. Similarly, tQH, MIN(derated)
= tQH, MIN + tJIT(per), act, MIN = 0.38 έ tCK(AVG), act + tJIT(per), act, MIN = 0.38 έ 2500ps - 72ps =
878ps.

Converting Time-Based Specifications to Clock-Based Requirements

Software algorithms for calculation of timing parameters are subject to potential rounding errors when
converting DRAM timing requirements to system clocks; for example, a memory clock with a nominal
frequency of 933.33...3 MHz which yields a clock period of 1.071428571429...ns. It is unrealistic to
represent all digits after the decimal point exactly and some sort of rounding needs to be done.
DDR4 SDRAM SPD-based specifications use a minimum granularity for SPD-associated timing
parameters of 1ps. Clock periods such as tCK (AVG) MIN are defined to the nearest picosecond. For
example, 1.071428571429...ns is stated as 1071ps. Parameters such as tAA MIN are specified in units of
time (nanoseconds) and require mathematical computation to convert to system clocks (nCK). Rules
for rounding allow optimization of device performance without violating device parameters. These
SPD algorithms rely on results that are within nCK adjustment factors on device testing and specifica-
tion to avoid losing performance due to rounding errors when using SPD-based parameters. Note that
JEDEC also defines an nCK adjustment factor, but mandates the inverse nCK adjustment factor be
used in case of conflicting results, so only the inverse nCK adjustment factor is discussed here.
Guidance converting SPD associated timing parameters to system clock requirements:
s Round the application clock period up to the nearest picosecond.
s Express the timing specification and application clock period in picoseconds; scaling a nano-
second-based parameter value by 1000 allows programmers to use integer math instead of real math
by expressing timing in ps.
s Divide the picosecond-based parameter by the picoseconds based application clock period.
s Add an inverse nCK adjustment factor of 97.4%.
s Truncate down to the next lower integer value.
s nCK = Truncate[(parameter in ps)/(application tCK in ps) + (974/1000)].
Guidance converting nonSPD associated timing parameters to system clock requirements:
s Divide the time base specification (in ns) and divided by the clock period (in ns).
s The resultant is set to the next higher integer number of clocks.
s nCK = Ceiling[(parameter in ns/application tCK in ns)].

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389 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
Options Tables

Options Tables

Table 168: /PTIONS n 3PEED "ASED

Function Acronym Data Rate
1600 1866 2133 2400 2666 2933 3200
Write leveling WL Yes Yes Yes Yes Yes Yes Yes
Temperature controlled TCR Yes Yes Yes Yes Yes Yes Yes
refresh
Low-power auto self refresh LPASR Yes Yes Yes Yes Yes Yes Yes
Fine granularity refresh FGR Yes Yes Yes Yes Yes Yes Yes
Multipurpose register MR Yes Yes Yes Yes Yes Yes Yes
Data mask DM Yes Yes Yes Yes Yes Yes Yes
Data bus inversion DBI Yes Yes Yes Yes Yes Yes Yes
TDQS n Yes Yes Yes Yes Yes Yes Yes
ZQ calibration ZQ CAL Yes Yes Yes Yes Yes Yes Yes
VREFDQ calibration n Yes Yes Yes Yes Yes Yes Yes
Per-DRAM addressability Per DRAM Yes Yes Yes Yes Yes Yes Yes
Mode register readout n Yes Yes Yes Yes Yes Yes Yes
Command/Address latency CAL Yes Yes Yes Yes Yes Yes Yes
Write CRC CRC Yes Yes Yes Yes Yes Yes Yes
CA parity n Yes Yes Yes Yes Yes Yes Yes
Gear-down mode n No No No No Yes Yes Yes
Programmable preamble n No No No Yes Yes Yes Yes
Maximum power saving mode MPSM Yes Yes Yes Yes Yes Yes Yes
Additive latency AL Yes Yes Yes Yes Yes Yes Yes
Connectivity test mode CT Yes Yes Yes Yes Yes Yes Yes
Hard post package repair hPPR Yes Yes Yes Yes Yes Yes Yes
mode
Soft post package repair mode sPPR Yes Yes Yes Yes Yes Yes Yes
MBIST-PPR MBIST-PPR Yes Yes Yes Yes Yes Yes Yes

CCMTD-1725822587-9875
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390 Micron Technology, Inc. reserves the right to change products or specifications without notice.
¥ 2015 Micron Technology, Inc. All rights reserved.
 8Gb: x4, x8, x16 DDR4 SDRAM
Options Tables

Table 169: /PTIONS n 7IDTH "ASED

Function Acronym Width
x4 x8 x16
Write leveling WL Yes Yes Yes
Temperature controlled refresh TCR Yes Yes Yes
Low-power auto self refresh LPASR Yes Yes Yes
Fine granularity refresh FGR Yes Yes Yes
Multipurpose register MR Yes Yes Yes
Data mask DM No Yes Yes
Data bus inversion DBI No Yes Yes
TDQS n No Yes No
ZQ calibration ZQ CAL Yes Yes Yes
VREFDQ calibration n Yes Yes Yes
Per-DRAM addressability Per DRAM Yes Yes Yes
Mode regsiter readout n Yes Yes Yes
Command/Address latency CAL Yes Yes Yes
Write CRC CRC Yes Yes Yes
CA parity n Yes Yes Yes
Gear-down mode n Yes Yes Yes
Programmable preamble n Yes Yes Yes
Maximum power-down mode MPSM Yes Yes Yes
Additive latency AL Yes Yes Yes
Connectivity test mode CT JEDEC optional on 8Gb and larger densities Yes
Micron supports on all densities
Hard post package repair mode hPPR JEDEC optional on 4Gb
Micron supports on all densities
Soft post package repair mode sPPR JEDEC optional on 4Gb and 8Gb
Micron supports on all densities
MBIST-PPR MBIST-PPR JEDEC optional
Micron supports only on 8Gb Die Rev R and 16Gb Die Rev F

8000 S. Federal Way, P.O. Box 6, Boise, ID 83707-0006

208-368-4000, micron.com/support
Micron and the Micron logo are trademarks of Micron Technology, Inc.
All other trademarks are the property of their respective owners.
This data sheet contains minimum and maximum limits specified over the power supply and temperature range set forth herein.
Although considered final, these specifications are subject to change, as further product development and data characterization sometimes
occur.
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