PIC16F7X7

Data Sheet
28/40/44-Pin, 8-Bit CMOS Flash
Microcontrollers with 10-Bit A/D
and nanoWatt Technology

 2003 Microchip Technology Inc. Preliminary DS30498B

Note the following details of the code protection feature on Microchip devices:
• Microchip products meet the specification contained in their particular Microchip Data Sheet.

• Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.

• There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip's Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.

• Microchip is willing to work with the customer who is concerned about the integrity of their code.

• Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”

Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.

Information contained in this publication regarding device Trademarks

applications and the like is intended through suggestion only The Microchip name and logo, the Microchip logo, Accuron,
and may be superseded by updates. It is your responsibility to dsPIC, KEELOQ, MPLAB, PIC, PICmicro, PICSTART,
ensure that your application meets with your specifications.
PRO MATE and PowerSmart are registered trademarks of
No representation or warranty is given and no liability is
Microchip Technology Incorporated in the U.S.A. and other
assumed by Microchip Technology Incorporated with respect
countries.
to the accuracy or use of such information, or infringement of
patents or other intellectual property rights arising from such AmpLab, FilterLab, microID, MXDEV, MXLAB, PICMASTER,
use or otherwise. Use of Microchip’s products as critical SEEVAL and The Embedded Control Solutions Company are
components in life support systems is not authorized except registered trademarks of Microchip Technology Incorporated
with express written approval by Microchip. No licenses are in the U.S.A.
conveyed, implicitly or otherwise, under any intellectual Application Maestro, dsPICDEM, dsPICDEM.net, ECAN,
property rights. ECONOMONITOR, FanSense, FlexROM, fuzzyLAB,
In-Circuit Serial Programming, ICSP, ICEPIC, microPort,
Migratable Memory, MPASM, MPLIB, MPLINK, MPSIM,
PICkit, PICDEM, PICDEM.net, PowerCal, PowerInfo,
PowerMate, PowerTool, rfLAB, rfPIC, Select Mode,
SmartSensor, SmartShunt, SmartTel and Total Endurance are
trademarks of Microchip Technology Incorporated in the
U.S.A. and other countries.
Serialized Quick Turn Programming (SQTP) is a service mark
of Microchip Technology Incorporated in the U.S.A.
All other trademarks mentioned herein are property of their
respective companies.
© 2003, Microchip Technology Incorporated, Printed in the
U.S.A., All Rights Reserved.
Printed on recycled paper.

Microchip received QS-9000 quality system

certification for its worldwide headquarters,
design and wafer fabrication facilities in
Chandler and Tempe, Arizona in July 1999
and Mountain View, California in March 2002.
The Company’s quality system processes and
procedures are QS-9000 compliant for its
PICmicro® 8-bit MCUs, KEELOQ® code hopping
devices, Serial EEPROMs, microperipherals,
non-volatile memory and analog products. In
addition, Microchip’s quality system for the
design and manufacture of development
systems is ISO 9001 certified.

DS30498B-page ii Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
28/40/44-Pin, 8-Bit CMOS Flash Microcontrollers with
10-Bit A/D and nanoWatt Technology
Low-Power Features: Peripheral Features:
• Power Managed modes: • High Sink/Source Current: 25 mA
- Primary Run (XT, RC oscillator, 76 µA, • Two 8-bit Timers with Prescaler
1 MHz, 2V) • Timer1/RTC module:
- RC_RUN (7 µA, 31.25 kHz, 2V) - 16-bit timer/counter with prescaler
- SEC_RUN (9 µA, 32 kHz, 2V) - Can be incremented during Sleep via
- Sleep (0.1 µA, 2V) external 32 kHz watch crystal
• Timer1 Oscillator (1.8 µA, 32 kHz, 2V) • Master Synchronous Serial Port (MSSP) with
• Watchdog Timer (0.7 µA, 2V) 3-wire SPITM and I2CTM (Master and Slave) modes
• Two-Speed Oscillator Start-up • Addressable Universal Synchronous
Asynchronous Receiver Transmitter (AUSART)
Oscillators: • Three Capture, Compare, PWM modules:
- Capture is 16-bit, max. resolution is 12.5 ns
• Three Crystal modes:
- Compare is 16-bit, max. resolution is 200 ns
- LP, XT, HS (up to 20 MHz)
- PWM max. resolution is 10 bits
• Two External RC modes
• Parallel Slave Port (PSP) – 40/44-pin devices only
• One External Clock mode:
- ECIO (up to 20 MHz) Special Microcontroller Features:
• Internal Oscillator Block:
- 8 user-selectable frequencies (31 kHz, • Fail-Safe Clock Monitor for protecting critical
125 kHz, 250 kHz, 500 kHz, 1 MHz, 2 MHz, applications against crystal failure
4 MHz, 8 MHz) • Two-Speed Start-up mode for immediate code
execution
Analog Features: • Power-on Reset (POR), Power-up Timer (PWRT)
and Oscillator Start-up Timer (OST)
• 10-bit, up to 14-channel Analog-to-Digital Converter: • Programmable Code Protection
- Programmable Acquisition Time • Processor Read Access to Program Memory
- Conversion available during Sleep mode • Power Saving Sleep mode
• Dual Analog Comparators • In-Circuit Serial Programming (ICSP) via
• Programmable Low Current Brown-out Reset two pins
(BOR) Circuitry and Programmable Low-Voltage • MPLAB® In-Circuit Debug (ICD) via two pins
Detect (LVD)
• MCLR pin function replaceable with input only pin
Comparators

MSSP
Interrupts

Program
Data
Memory 10-bit CCP Timers
Device SRAM I/O I2C AUSART
(# Single-Word A/D (ch) (PWM) SPI 8/16-bit
(Bytes) (Master)
Instructions)

PIC16F737 4096 368 25 16 11 2 3 Yes Yes Yes 2/1

PIC16F747 4096 368 36 17 14 2 3 Yes Yes Yes 2/1
PIC16F767 8192 368 25 16 11 2 3 Yes Yes Yes 2/1
PIC16F777 8192 368 36 17 14 2 3 Yes Yes Yes 2/1

 2003 Microchip Technology Inc. Preliminary DS30498B-page 1

PIC16F7X7
Pin Diagrams
PDIP, SOIC, SSOP (28-pin)

MCLR/VPP/RE3 1 28 RB7/PGD
RA0/AN0 2 27 RB6/PGC
RA1/AN1 3 26 RB5/AN13/CCP3
4 25 RB4/AN11

PIC16F737/767
RA2/AN2/VREF-/CVREF
RA3/AN3/VREF+ 5 24 RB3/CCP2(1)/AN9
RA4/T0CKI/C1OUT 6 23 RB2/AN8
RA5/AN4/LVDIN/SS/C2OUT 7 22 RB1/AN10
VSS 8 21 RB0/INT/AN12
OSC1/CLKI/RA7 9 20 VDD
OSC2/CLKO/RA6 10 19 VSS
RC0/T1OSO/T1CKI 11 18 RC7/RX/DT
RC1/T1OSI/CCP2 12 17 RC6/TX/CK
RC2/CCP1 13 16 RC5/SDO
RC3/SCK/SCL 14 15 RC4/SDI/SDA

RB5/AN13/CCP3
MCLR/VPP/RE3

RB4/AN11
RB7/PGD
RB6/PGC
RA1/AN1
RA0/AN0
QFN (28-pin)

28 27 26 25 24 23 22
RA2/AN2/VREF-/CVREF 1 21 RB3/CCP2(1)/AN9
RA3/AN3/VREF+ 2 20 RB2/AN8
RA4/T0CKI/C1OUT 3 PIC16F737 19 RB1/AN10
RA5/AN4/LVDIN/SS/C2OUT 4 18 RB0/INT/AN12
VSS 5 PIC16F767 17 VDD
OSC2/CLKO/RA6 6 16 VSS
OSC1/CLKI/RA7 7 15 RC7/RX/DT
8 9 10 11 12 13 14
RC0/T1OSO/T1CKI

QFN (44-pin)
RC1/T1OSI/CCP2

RC2/CCP1
RC1/T1OSI/CCP2

RC3/SCK/SCL

RC5/SDO
RC0/T1OSO/T1CKI

RC4/SDI/SDA

RC6/TX/CK
RC3/SCK/SCL
RC4/SDI/SDA
RC6/TX/CK

RC2/CCP1
RD3/PSP3
RD2/PSP2
RD1/PSP1
RD0/PSP0
RC5/SDO
44
43
42
41
40
39
38
37
36
35
34

RC7/RX/DT 1 33 OSC2/CLKO/RA6
RD4/PSP4 2 32 OSC1/CLKI/RA7
RD5/PSP5 3 31 VSS
RD6/PSP6 4 30 VSS
RD7/PSP7 5
PIC16F747 29 NC
VSS 6 28 VDD
VDD 7 PIC16F777 27 RE2/CS/AN7
VDD 8 26 RE1/WR/AN6
RB0/INT/AN12 9 25 RE0/RD/AN5
RB1/AN10 10 24 RA5/AN4/LVDIN/SS/C2OUT
RB2/AN8 11 23 RA4/T0CKI/C1OUT
20
21
22
13
14
15
16
17
18
19
12 RB3/CCP2(1)/AN9

RB4/AN11
RB5/AN13/CCP3

MCLR/VPP/RE3
RA0/AN0
RA1/AN1
RA2/AN2/VREF-/CVREF
NC

RB6/PGC
RB7/PGD

RA3/AN3/VREF+

Note 1: RB3 is the alternate pin for the CCP2 pin multiplexing.

DS30498B-page 2 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
Pin Diagrams (Continued)

PDIP (40-pin)

MCLR/VPP/RE3 1 40 RB7/PGD
RA0/AN0 2 39 RB6/PGC
RA1/AN1 3 38 RB5/AN13/CCP3
RA2/AN2/VREF-/CVREF 4 37 RB4/AN11
RA3/AN3/VREF+ 5 36 RB3/CCP2(1)/AN9
RA4/T0CKI/C1OUT 6 35 RB2/AN8
RA5/AN4/LVDIN/SS/C2OUT 7 34 RB1/AN10

PIC16F747/777
RE0/RD/AN5 8 33 RB0/INT/AN12
RE1/WR/AN6 9 32 VDD
RE2/CS/AN7 10 31 VSS
VDD 11 30 RD7/PSP7
VSS 12 29 RD6/PSP6
OSC1/CLKI/RA7 13 28 RD5/PSP5
OSC2/CLKO/RA6 14 27 RD4/PSP4
RC0/T1OSO/T1CKI 15 26 RC7/RX/DT
RC1/T1OSI/CCP2 16 25 RC6/TX/CK
RC2/CCP1 17 24 RC5/SDO
RC3/SCK/SCL 18 23 RC4/SDI/SDA
RD0/PSP0 19 22 RD3/PSP3
RD1/PSP1 20 21 RD2/PSP2

RC1/T1OSI/CCP2

TQFP (44-pin)
RC3/SCK/SCL
RC4/SDI/SDA
RC6/TX/CK

RC2/CCP1
RD3/PSP3
RD2/PSP2
RD1/PSP1
RD0/PSP0
RC5/SDO

NC
44
43
42
41
40
39
38
37
36
35
34

RC7/RX/DT 1 33 NC
RD4/PSP4 2 32 RC0/T1OSO/T1CKI
RD5/PSP5 3 31 OSC1/CLKI/RA7
RD6/PSP6 4 30 OSC2/CLKO/RA6
RD7/PSP7 5 PIC16F747 29 VSS
VSS 6 28 VDD
VDD 7 PIC16F777 27 RE2/CS/AN7
RB0/INT/AN12 8 26 RE1/WR/AN6
RB1/AN10 9 25 RE0/RD/AN5
RB2/AN8 10 24 RA5/AN4/LVDIN/SS/C2OUT
RB3/CCP2(1)/AN9 11 23 RA4/T0CKI/C1OUT
12
13
14
15
16
17
18
19
20
21
22
RB4/AN11
RB5/AN13/CCP3

MCLR/VPP/RE3
RA0/AN0
RA1/AN1
RA2/AN2/VREF-/CVREF
NC
NC

RB6/PGC
RB7/PGD

RA3/AN3/VREF+

Note 1: RB3 is the alternate pin for the CCP2 pin multiplexing.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 3

PIC16F7X7
Table of Contents
1.0 Device Overview ......................................................................................................................................................................... 5
2.0 Memory Organization................................................................................................................................................................ 15
3.0 Reading Program Memory........................................................................................................................................................ 31
4.0 Oscillator Configurations........................................................................................................................................................... 33
5.0 I/O Ports.................................................................................................................................................................................... 49
6.0 Timer0 Module .......................................................................................................................................................................... 73
7.0 Timer1 Module .......................................................................................................................................................................... 77
8.0 Timer2 Module .......................................................................................................................................................................... 85
9.0 Capture/Compare/PWM Modules ............................................................................................................................................. 87
10.0 Master Synchronous Serial Port (MSSP) Module..................................................................................................................... 93
11.0 Addressable Universal Synchronous Asynchronous Receiver Transmitter (USART) ............................................................ 133
12.0 Analog-to-Digital Converter (A/D) Module .............................................................................................................................. 151
13.0 Comparator Module ................................................................................................................................................................ 161
14.0 Comparator Voltage Reference Module ................................................................................................................................. 167
15.0 Special Features of the CPU .................................................................................................................................................. 169
16.0 Instruction Set Summary......................................................................................................................................................... 193
17.0 Development Support ............................................................................................................................................................. 201
18.0 Electrical Characteristics......................................................................................................................................................... 207
19.0 DC and AC Characteristics Graphs and Tables ..................................................................................................................... 237
20.0 Packaging Information ............................................................................................................................................................ 239
Appendix A: Revision History ........................................................................................................................................................... 249
Appendix B: Device Differences........................................................................................................................................................ 249
Appendix C: Conversion Considerations........................................................................................................................................... 250
Index .................................................................................................................................................................................................. 251
On-Line Support................................................................................................................................................................................ 259
Systems Information and Upgrade Hot Line ..................................................................................................................................... 259
Reader Response ............................................................................................................................................................................. 260
PIC16F7X7 Product Identification System ........................................................................................................................................ 261

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DS30498B-page 4 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
1.0 DEVICE OVERVIEW • The Timer1 module current consumption has
been greatly reduced from 20 µA (previous PIC16
This document contains device specific information devices) to 1.8 µA typical (32 kHz at 2V), which is
about the following devices: ideal for real-time clock applications. Refer to
• PIC16F737 • PIC16F767 Section 7.0 “Timer1 Module” for further details.
• PIC16F747 • PIC16F777 • Extended Watchdog Timer (WDT) that can have a
programmable period from 1 ms to 268s. The WDT
PIC16F737/767 devices are available only in 28-pin
has its own 16-bit prescaler. Refer to Section 15.17
packages, while PIC16F747/777 devices are available
“Watchdog Timer (WDT)” for further details.
in 40-pin and 44-pin packages. All devices in the
PIC16F7X7 family share common architecture with the • Two-Speed Start-up: When the oscillator is
following differences: configured for LP, XT or HS, this feature will clock
the device from the INTRC while the oscillator is
• The PIC16F737 and PIC16F767 have one-half of warming up. This, in turn, will enable almost
the total on-chip memory of the PIC16F747 and immediate code execution. Refer to
PIC16F777. Section 15.17.3 “Two-Speed Clock Start-up
• The 28-pin devices have 3 I/O ports, while the Mode” for further details.
40/44-pin devices have 5. • Fail-Safe Clock Monitor: This feature will allow the
• The 28-pin devices have 16 interrupts, while the device to continue operation if the primary or
40/44-pin devices have 17. secondary clock source fails, by switching over to
• The 28-pin devices have 11 A/D input channels, the INTRC.
while the 40/44-pin devices have 14. The available features are summarized in Table 1-1.
• The Parallel Slave Port is implemented only on Block diagrams of the PIC16F737/767 and
the 40/44-pin devices. PIC16F747/777 devices are provided in Figure 1-1 and
• Low-Power modes: RC_RUN allows the core and Figure 1-2, respectively. The pinouts for these device
peripherals to be clocked from the INTRC, while families are listed in Table 1-2 and Table 1-3.
SEC_RUN allows the core and peripherals to be Additional information may be found in the PICmicro®
clocked from the low-power Timer1. Refer to Mid-Range MCU Family Reference Manual
Section 4.7 “Power Managed Modes” for (DS33023), which may be obtained from your local
further details. Microchip Sales Representative or downloaded from
• Internal RC oscillator with eight selectable the Microchip web site. The Reference Manual should
frequencies, including 31.25 kHz, 125 kHz, be considered a complementary document to this data
250 kHz, 500 kHz, 1 MHz, 2 MHz, 4 MHz and sheet and is highly recommended reading for a better
8 MHz. The INTRC can be configured as a primary understanding of the device architecture and operation
or secondary clock source. Refer to Section 4.5 of the peripheral modules.
“Internal Oscillator Block” for further details.

TABLE 1-1: PIC16F7X7 DEVICE FEATURES

Key Features PIC16F737 PIC16F747 PIC16F767 PIC16F777
Operating Frequency DC – 20 MHz DC – 20 MHz DC – 20 MHz DC – 20 MHz
Resets (and Delays) POR, BOR POR, BOR POR, BOR POR, BOR
(PWRT, OST) (PWRT, OST) (PWRT, OST) (PWRT, OST)
Flash Program Memory (14-bit words) 4K 4K 8K 8K
Data Memory (bytes) 368 368 368 368
Interrupts 16 17 16 17
I/O Ports Ports A, B, C Ports A, B, C, D, E Ports A, B, C Ports A, B, C, D, E
Timers 3 3 3 3
Capture/Compare/PWM Modules 3 3 3 3
Master Serial Communications MSSP, USART MSSP, USART MSSP, USART MSSP, USART
Parallel Communications — PSP — PSP
10-bit Analog-to-Digital Module 11 Input Channels 14 Input Channels 11 Input Channels 14 Input Channels
Instruction Set 35 Instructions 35 Instructions 35 Instructions 35 Instructions
Packaging 28-pin PDIP 40-pin PDIP 28-pin PDIP 40-pin PDIP
28-pin SOIC 44-pin QFN 28-pin SOIC 44-pin QFN
28-pin SSOP 44-pin TQFP 28-pin SSOP 44-pin TQFP
28-pin QFN 28-pin QFN

 2003 Microchip Technology Inc. Preliminary DS30498B-page 5

PIC16F7X7
FIGURE 1-1: PIC16F737 AND PIC16F767 BLOCK DIAGRAM

PORTA

13 8 RA0/AN0
Data Bus
Program Counter RA1/AN1
Standard RA2/AN2/VREF-/CVREF
Flash RA3/AN3/VREF+
Program RA4/T0CKI/C1OUT
Memory RAM
8-Level Stack File RA5/AN4/LVDIN/
4K/8K x 14 (13-bit) SS/C2OUT
Registers
OSC2/CLKO/RA6
368 x 8
Program OSC1/CLKI/RA7
14
Bus RAM Addr(1) 9 PORTB
RB0/INT/AN12
Addr MUX
Instruction Register RB1/AN10
7 Indirect RB2/AN8
Direct Addr
8 Addr RB3/CCP2(1)/AN9
RB4/AN11
FSR reg
RB5/AN13/CCP3
RB7/PGD:RB6/PGC
Status reg
8 PORTC
RC0/T1OSO/T1CKI
RC1/T1OSI/CCP2(1)
3 MUX
Power-up RC2/CCP1
Timer RC3/SCK/SCL
Instruction Oscillator RC4/SDI/SDA
Decode & Start-up Timer RC5/SDO
ALU
Control RC6/TX/CK
Power-on
Reset 8 RC7/RX/DT
Timing Watchdog
Generation Timer WREG
OSC1/CLKI Brown-out
OSC2/CLKO Reset

PORTE
VDD, VSS
MCLR/VPP/RE3

Timer0 Timer1 Timer2 10-bit A/D

MSSP Addressable BOR/LVD

Comparators CCP1, 2, 3
USART

Note 1: Pin location of CCP2 is determined by CCPMX in Configuration Word Register 1.

DS30498B-page 6 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 1-2: PIC16F747 AND PIC16F777 BLOCK DIAGRAM

PORTA
13 8 RA0/AN0
Data Bus
Program Counter RA1/AN1
Standard
RA2/AN2/VREF-/CVREF
Flash
Program RA3/AN3/VREF+
Memory RAM RA4/T0CKI/C1OUT
4K/8K x 14 8-Level Stack RA5/AN4/LVDIN/
File
(13-bit) Registers SS/C2OUT
OSC2/CLKO/RA6
368 x 8 OSC1/CLKI/RA7
Program
14
Bus RAM Addr(1) 9 PORTB
RB0/INT/AN12
Addr MUX
Instruction Register RB1/AN10
7 Indirect RB2/AN8
Direct Addr
8 Addr RB3/CCP2(1)/AN9
RB4/AN11
FSR reg
RB5/AN13/CCP3
RB7/PGD:RB6/PGC
Status reg
8 PORTC
RC0/T1OSO/T1CKI
RC1/T1OSI/CCP2(1)
3 RC2/CCP1
Power-up MUX
RC3/SCK/SCL
Timer
RC4/SDI/SDA
Instruction Oscillator RC5/SDO
Decode & Start-up Timer RC6/TX/CK
ALU
Control RC7/RX/DT
Power-on
Reset 8 PORTD
Timing Watchdog
Generation Timer WREG
OSC1/CLKI Brown-out
OSC2/CLKO Reset RD7/PSP7:RD0/PSP0

Parallel Slave Port

VDD, VSS PORTE

RE0/RD/AN5

RE1/WR/AN6
Timer0 Timer1 Timer2 10-bit A/D RE2/CS/AN7
MCLR/VPP/RE3

Comparators MSSP Addressable BOR/LVD

CCP1, 2, 3
USART

Note 1: Pin location of CCP2 is determined by CCPMX in Configuration Word Register 1.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 7

PIC16F7X7
TABLE 1-2: PIC16F737 AND PIC16F767 PINOUT DESCRIPTION
PDIP
SSOP QFN I/O/P Buffer
Pin Name Description
SOIC Pin # Type Type
Pin #

OSC1/CLKI/RA7 9 7 ST/CMOS(3) Oscillator crystal or external clock input.

OSC1 I Oscillator crystal input or external clock source input. ST
buffer when configured in RC mode; otherwise CMOS.
CLKI I External clock source input. Always associated with pin
function OSC1 (see OSC1/CLKI, OSC2/CLKO pins).
RA7 I/O ST Digital I/O.
OSC2/CLKO/RA6 10 6 — Oscillator crystal or clock output.
OSC2 O Oscillator crystal output.
Connects to crystal or resonator in Crystal Oscillator
mode.
CLKO O In RC mode, OSC2 pin outputs CLKO, which has 1/4 the
frequency of OSC1 and denotes the instruction cycle rate.
RA6 I/O ST Digital I/O.
MCLR/VPP/RE3 1 26 ST Master Clear (input) or programming voltage (output).
MCLR I Master Clear (Reset) input. This pin is an active-low
Reset to the device.
VPP P Programming voltage input.
RE3 I Digital input only pin.
PORTA is a bidirectional I/O port.
RA0/AN0 2 27 TTL
RA0 I/O Digital I/O.
AN0 I Analog input 0.
RA1/AN1 3 28 TTL
RA1 I/O Digital I/O.
AN1 I Analog input 1.
RA2/AN2/VREF-/CVREF 4 1 TTL
RA2 I/O Digital I/O.
AN2 I Analog input 2.
VREF- I A/D reference voltage input (low).
CVREF 0 Comparator voltage reference output.
RA3/AN3/VREF+ 5 2 TTL
RA3 I/O Digital I/O.
AN3 I Analog input 3.
VREF+ I A/D reference voltage input (high).
RA4/T0CKI/C1OUT 6 3 ST
RA4 I/O Digital I/O – Open-drain when configured as output.
T0CKI I Timer0 external clock input.
C1OUT O Comparator 1 output bit.
RA5/AN4/LVDIN/SS/C2OUT 7 4 TTL
RA5 I/O Digital I/O.
AN4 I Analog input 4.
LVDIN I/O Low-voltage detect input.
SS I SPI slave select input.
C2OUT O Comparator 2 output bit.
Legend: I = input O = output I/O = input/output P = power
— = Not used TTL = TTL input ST = Schmitt Trigger input
Note 1: This buffer is a Schmitt Trigger input when configured as the external interrupt.
2: This buffer is a Schmitt Trigger input when used in Serial Programming mode.
3: This buffer is a Schmitt Trigger input when configured in RC Oscillator mode and a CMOS input otherwise.

DS30498B-page 8 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
TABLE 1-2: PIC16F737 AND PIC16F767 PINOUT DESCRIPTION (CONTINUED)
PDIP
SSOP QFN I/O/P Buffer
Pin Name Description
SOIC Pin # Type Type
Pin #

PORTB is a bidirectional I/O port. PORTB can be software

programmed for internal weak pull-up on all inputs.
RB0/INT/AN12 21 18 TTL/ST(1)
RB0 I/O Digital I/O.
INT I External interrupt.
AN12 I Analog input channel 12.
RB1/AN10 22 19 TTL
RB1 I/O Digital I/O.
AN10 I Analog input channel 10.
RB2/AN8 23 20 TTL
RB2 I/O Digital I/O.
AN8 I Analog input channel 8.
RB3/CCP2/AN9 24 21 TTL
RB3 I/O Digital I/O.
CCP2 I/O CCP2 capture input, compare output, PWM output.
AN9 I Analog input channel 9.
RB4/AN11 25 22 TTL
RB4 I/O Digital I/O.
AN11 I Analog input channel 11.
RB5/AN13/CCP3 26 23 TTL
RB5 I/O Digital I/O.
AN13 I Analog input channel 13.
CCP3 I/O CCP3 capture input, compare output, PWM output.
RB6/PGC 27 24 TTL/ST(2)
RB6 I/O Digital I/O.
PGC I/O In-circuit debugger and ICSP programming clock.
RB7/PGD 28 25 TTL/ST(2)
RB7 I/O Digital I/O.
PGD I/O In-circuit debugger and ICSP programming data.
Legend: I = input O = output I/O = input/output P = power
— = Not used TTL = TTL input ST = Schmitt Trigger input
Note 1: This buffer is a Schmitt Trigger input when configured as the external interrupt.
2: This buffer is a Schmitt Trigger input when used in Serial Programming mode.
3: This buffer is a Schmitt Trigger input when configured in RC Oscillator mode and a CMOS input otherwise.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 9

PIC16F7X7
TABLE 1-2: PIC16F737 AND PIC16F767 PINOUT DESCRIPTION (CONTINUED)
PDIP
SSOP QFN I/O/P Buffer
Pin Name Description
SOIC Pin # Type Type
Pin #
PORTC is a bidirectional I/O port.
RC0/T1OSO/T1CKI 11 8 ST
RC0 I/O Digital I/O.
T1OSO O Timer1 oscillator output.
T1CKI I Timer1 external clock input.
RC1/T1OSI/CCP2 12 9 ST
RC1 I/O Digital I/O.
T1OSI I Timer1 oscillator input.
CCP2 I/O Capture2 input, Compare2 output, PWM2 output.
RC2/CCP1 13 10 ST
RC2 I/O Digital I/O.
CCP1 I/O Capture1 input, Compare1 output, PWM1 output.
RC3/SCK/SCL 14 11 ST
RC3 I/O Digital I/O.
SCK I/O Synchronous serial clock input/output for SPI mode.
SCL I/O Synchronous serial clock input/output for I2C mode.
RC4/SDI/SDA 15 12 ST
RC4 I/O Digital I/O.
SDI I SPI data in.
SDA I/O I2C data I/O.
RC5/SDO 16 13 ST
RC5 I/O Digital I/O.
SDO O SPI data out.
RC6/TX/CK 17 14 ST
RC6 I/O Digital I/O.
TX O USART asynchronous transmit.
CK I/O USART1 synchronous clock.
RC7/RX/DT 18 15 ST
RC7 I/O Digital I/O.
RX I USART asynchronous receive.
DT I/O USART synchronous data.
VSS 8, 19 5, 16 P — Ground reference for logic and I/O pins.
VDD 20 17 P — Positive supply for logic and I/O pins.
Legend: I = input O = output I/O = input/output P = power
— = Not used TTL = TTL input ST = Schmitt Trigger input
Note 1: This buffer is a Schmitt Trigger input when configured as the external interrupt.
2: This buffer is a Schmitt Trigger input when used in Serial Programming mode.
3: This buffer is a Schmitt Trigger input when configured in RC Oscillator mode and a CMOS input otherwise.

DS30498B-page 10 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
TABLE 1-3: PIC16F747 AND PIC16F777 PINOUT DESCRIPTION
PDIP QFN TQFP I/O/P Buffer
Pin Name Description
Pin # Pin # Pin # Type Type

OSC1/CLKI/RA7 13 32 31 ST/CMOS(4) Oscillator crystal or external clock input.

OSC1 I Oscillator crystal input or external clock source input.
ST buffer when configured in RC mode; otherwise
CMOS.
CLKI I External clock source input. Always associated with
pin function OSC1 (see OSC1/CLKI, OSC2/CLKO
pins).
RA7 I/O ST Bidirectional I/O pin.
OSC2/CLKO/RA6 14 33 30 — Oscillator crystal or clock output.
OSC2 O Oscillator crystal output. Connects to crystal or
resonator in Crystal Oscillator mode.
CLKO O In RC mode, OSC2 pin outputs CLKO, which has
1/4 the frequency of OSC1 and denotes the
instruction cycle rate.
RA6 I/O ST Bidirectional I/O pin.
MCLR/VPP/RE3 1 18 18 ST Master Clear (input) or programming voltage (output).
MCLR I Master Clear (Reset) input. This pin is an
active- low Reset to the device.
VPP P Programming voltage input.
RE3 I Digital input only pin.
PORTA is a bidirectional I/O port.
RA0/AN0 2 19 19 TTL
RA0 I/O Digital I/O.
AN0 I Analog input 0.
RA1/AN1 3 20 20 TTL
RA1 I/O Digital I/O.
AN1 I Analog input 1.
RA2/AN2/VREF-/CVREF 4 21 21 TTL
RA2 I/O Digital I/O.
AN2 I Analog input 2.
VREF- I A/D reference voltage input (low).
CVREF I Comparator voltage reference output.
RA3/AN3/VREF+ 5 22 22 TTL
RA3 I/O Digital I/O.
AN3 I Analog input 3.
VREF+ I A/D reference voltage input (high).
RA4/T0CKI/C1OUT 6 23 23 ST
RA4 I/O Digital I/O – Open-drain when configured as output.
T0CKI I Timer0 external clock input.
C1OUT O Comparator 1 output.
RA5/AN4/LVDIN/SS/C2OUT 7 24 24 TTL
RA5 I/O Digital I/O.
AN4 I Analog input 4.
LVDIN I Low-voltage detect input.
SS I SPI slave select input.
C2OUT I Comparator 2 output.
Legend: I = input O = output I/O = input/output P = power
— = Not used TTL = TTL input ST = Schmitt Trigger input
Note 1: This buffer is a Schmitt Trigger input when configured as an external interrupt.
2: This buffer is a Schmitt Trigger input when used in Serial Programming mode.
3: This buffer is a Schmitt Trigger input when configured as a general purpose I/O and a TTL input when used in the Parallel
Slave Port mode (for interfacing to a microprocessor bus).
4: This buffer is a Schmitt Trigger input when configured in RC Oscillator mode and a CMOS input otherwise.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 11

PIC16F7X7
TABLE 1-3: PIC16F747 AND PIC16F777 PINOUT DESCRIPTION (CONTINUED)
PDIP QFN TQFP I/O/P Buffer
Pin Name Description
Pin # Pin # Pin # Type Type

PORTB is a bidirectional I/O port. PORTB can be

software programmed for internal weak pull-up on all
inputs.
RB0/INT/AN12 33 9 8 TTL/ST(1)
RB0 I/O Digital I/O.
INT I External interrupt.
AN12 I Analog input channel 12.
RB1/AN10 34 10 9 TTL
RB1 I/O Digital I/O.
AN10 I Analog input channel 10.
RB2/AN8 35 11 10 TTL
RB2 I/O Digital I/O.
AN8 I Analog input channel 8.
RB3/CCP2/AN9 36 12 11 TTL
RB3 I/O Digital I/O.
CCP2 I/O CCP2 capture input, compare output, PWM output.
AN9 I Analog input channel 9.
RB4/AN11 37 14 14 TTL
RB4 I/O Digital I/O.
AN11 I Analog input channel 11
RB5/AN13/CCP3 38 15 15 TTL
RB5 I/O Digital I/O.
AN13 I Analog input channel 13.
CCP3 I CCP3 capture input, compare output, PWM output.
RB6/PGC 39 16 16 TTL/ST(2)
RB6 I/O Digital I/O.
PGC I/O In-circuit debugger and ICSP programming clock.
RB7/PGD 40 17 17 TTL/ST(2)
RB7 I/O Digital I/O.
PGD I/O In-circuit debugger and ICSP programming data.
Legend: I = input O = output I/O = input/output P = power
— = Not used TTL = TTL input ST = Schmitt Trigger input
Note 1: This buffer is a Schmitt Trigger input when configured as an external interrupt.
2: This buffer is a Schmitt Trigger input when used in Serial Programming mode.
3: This buffer is a Schmitt Trigger input when configured as a general purpose I/O and a TTL input when used in the Parallel
Slave Port mode (for interfacing to a microprocessor bus).
4: This buffer is a Schmitt Trigger input when configured in RC Oscillator mode and a CMOS input otherwise.

DS30498B-page 12 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
TABLE 1-3: PIC16F747 AND PIC16F777 PINOUT DESCRIPTION (CONTINUED)
PDIP QFN TQFP I/O/P Buffer
Pin Name Description
Pin # Pin # Pin # Type Type

PORTC is a bidirectional I/O port.

RC0/T1OSO/T1CKI 15 34 32 ST
RC0 I/O Digital I/O.
T1OSO O Timer1 oscillator output.
T1CKI I Timer1 external clock input.
RC1/T1OSI/CCP2 16 35 35 ST
RC1 I/O Digital I/O.
T1OSI I Timer1 oscillator input.
CCP2 I/O Capture2 input, Compare2 output, PWM2 output.
RC2/CCP1 17 36 36 ST
RC2 I/O Digital I/O.
CCP1 I/O Capture1 input, Compare1 output, PWM1 output.
RC3/SCK/SCL 18 37 37 ST
RC3 I/O Digital I/O.
SCK I/O Synchronous serial clock input/output for SPI mode.
SCL I/O Synchronous serial clock input/output for I2C mode.
RC4/SDI/SDA 23 42 42 ST
RC4 I/O Digital I/O.
SDI I SPI data in.
SDA I/O I2C data I/O.
RC5/SDO 24 43 43 ST
RC5 I/O Digital I/O.
SDO O SPI data out.
RC6/TX/CK 25 44 44 ST
RC6 I/O Digital I/O.
TX O USART asynchronous transmit.
CK I/O USART1 synchronous clock.
RC7/RX/DT 26 1 1 ST
RC7 I/O Digital I/O.
RX I USART asynchronous receive.
DT I/O USART synchronous data.
Legend: I = input O = output I/O = input/output P = power
— = Not used TTL = TTL input ST = Schmitt Trigger input
Note 1: This buffer is a Schmitt Trigger input when configured as an external interrupt.
2: This buffer is a Schmitt Trigger input when used in Serial Programming mode.
3: This buffer is a Schmitt Trigger input when configured as a general purpose I/O and a TTL input when used in the Parallel
Slave Port mode (for interfacing to a microprocessor bus).
4: This buffer is a Schmitt Trigger input when configured in RC Oscillator mode and a CMOS input otherwise.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 13

PIC16F7X7
TABLE 1-3: PIC16F747 AND PIC16F777 PINOUT DESCRIPTION (CONTINUED)
PDIP QFN TQFP I/O/P Buffer
Pin Name Description
Pin # Pin # Pin # Type Type

PORTD is a bidirectional I/O port or Parallel Slave Port

when interfacing to a microprocessor bus.
RD0/PSP0 19 38 38 ST/TTL(3)
RD0 I/O Digital I/O.
PSP0 I/O Parallel Slave Port data.
RD1/PSP1 20 39 39 ST/TTL(3)
RD1 I/O Digital I/O.
PSP1 I/O Parallel Slave Port data.
RD2/PSP2 21 40 40 ST/TTL(3)
RD2 I/O Digital I/O.
PSP2 I/O Parallel Slave Port data.
RD3/PSP3 22 41 41 ST/TTL(3)
RD3 I/O Digital I/O.
PSP3 I/O Parallel Slave Port data.
RD4/PSP4 27 2 2 ST/TTL(3)
RD4 I/O Digital I/O.
PSP4 I/O Parallel Slave Port data.
RD5/PSP5 28 3 3 ST/TTL(3)
RD5 I/O Digital I/O.
PSP5 I/O Parallel Slave Port data.
RD6/PSP6 29 4 4 ST/TTL(3)
RD6 I/O Digital I/O.
PSP6 I/O Parallel Slave Port data.
RD7/PSP7 30 5 5 ST/TTL(3)
RD7 I/O Digital I/O.
PSP7 I/O Parallel Slave Port data.
PORTE is a bidirectional I/O port.
RE0/RD/AN5 8 25 25 ST/TTL(3)
RE0 I/O Digital I/O.
RD I Read control for Parallel Slave Port.
AN5 I Analog input 5.
RE1/WR/AN6 9 26 26 ST/TTL(3)
RE1 I/O Digital I/O.
WR I Write control for Parallel Slave Port.
AN6 I Analog input 6.
RE2/CS/AN7 10 27 27 ST/TTL(3)
RE2 I/O Digital I/O.
CS I Chip select control for Parallel Slave Port.
AN7 I Analog input 7.
VSS — 31 — P — Analog ground reference.
VSS 12, 31 6, 30 6, 29 P — Ground reference for logic and I/O pins.
VDD — 8 — P — Analog positive supply.
VDD 11, 32 7, 28 7, 28 P — Positive supply for logic and I/O pins.
NC — 13, 29 12, 13, — — These pins are not internally connected. These pins
33, 34 should be left unconnected.
Legend: I = input O = output I/O = input/output P = power
— = Not used TTL = TTL input ST = Schmitt Trigger input
Note 1: This buffer is a Schmitt Trigger input when configured as an external interrupt.
2: This buffer is a Schmitt Trigger input when used in Serial Programming mode.
3: This buffer is a Schmitt Trigger input when configured as a general purpose I/O and a TTL input when used in the Parallel
Slave Port mode (for interfacing to a microprocessor bus).
4: This buffer is a Schmitt Trigger input when configured in RC Oscillator mode and a CMOS input otherwise.

DS30498B-page 14 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
2.0 MEMORY ORGANIZATION 2.2 Data Memory Organization
There are two memory blocks in each of these The data memory is partitioned into multiple banks
PICmicro® MCUs. The program memory and data which contain the General Purpose Registers and the
memory have separate buses so that concurrent Special Function Registers. Bits RP1 (Status<6>) and
access can occur and is detailed in this section. The RP0 (Status<5>) are the bank select bits:
program memory can be read internally by user code
(see Section 3.0 “Reading Program Memory”). RP1:RP0 Bank

Additional information on device memory may be found 00 0

in the PICmicro® Mid-Range MCU Family Reference 01 1
Manual (DS33023). 10 2
11 3
2.1 Program Memory Organization
Each bank extends up to 7Fh (128 bytes). The lower
The PIC16F7X7 devices have a 13-bit program counter locations of each bank are reserved for the Special
capable of addressing an 8K word x 14-bit program Function Registers. Above the Special Function Regis-
memory space. The PIC16F767/777 devices have ters are General Purpose Registers, implemented as
8K words of Flash program memory and the static RAM. All implemented banks contain Special
PIC16F737/747 devices have 4K words. The program Function Registers. Some frequently used Special
memory maps for PIC16F7X7 devices are shown in Function Registers from one bank may be mirrored in
Figure 2-1. Accessing a location above the physically another bank for code reduction and quicker access.
implemented address will cause a wraparound.
The Reset vector is at 0000h and the interrupt vector is 2.2.1 GENERAL PURPOSE REGISTER
at 0004h. FILE
The register file (shown in Figure 2-2 and Figure 2-3)
can be accessed either directly, or indirectly, through
the File Select Register (FSR).

FIGURE 2-1: PROGRAM MEMORY MAPS AND STACKS FOR PIC16F7X7 DEVICES

PC<12:0>
CALL, RETURN 13
RETFIE, RETLW

Stack Level 1
Stack Level 2

Stack Level 8

Reset Vector 0000h

Interrupt Vector 0004h

0005h
Page 0
07FFh Memory available on all
0800h PIC16F7X7.
Page 1
On-Chip
0FFFh
Program
Memory 1000h
Page2 Memory available on PIC16F767
17FFh and PIC16F777. The memory
1800h wraps to 000h through 0FFFh on
Page 3 the PIC16F737 and PIC16F747.
1FFFh

 2003 Microchip Technology Inc. Preliminary DS30498B-page 15

PIC16F7X7
FIGURE 2-2: DATA MEMORY MAP FOR PIC16F737 AND THE PIC16F767

File File File File

Address Address Address Address

Indirect addr.(*) 00h Indirect addr.(*) 80h Indirect addr.(*) 100h Indirect addr.(*) 180h
TMR0 01h OPTION_REG 81h TMR0 101h OPTION_REG 181h
PCL 02h PCL 82h PCL 102h PCL 182h
STATUS 03h STATUS 83h STATUS 103h STATUS 183h
FSR 04h FSR 84h FSR 104h FSR 184h
PORTA 05h TRISA 85h WDTCON 105h 185h
PORTB 06h TRISB 86h PORTB 106h TRISB 186h
PORTC 07h TRISC 87h 107h 187h
08h 88h 108h 188h
PORTE 09h TRISE 89h LVDCON 109h 189h
PCLATH 0Ah PCLATH 8Ah PCLATH 10Ah PCLATH 18Ah
INTCON 0Bh INTCON 8Bh INTCON 10Bh INTCON 18Bh
PIR1 0Ch PIE1 8Ch PMDATA 10Ch PMCON1 18Ch
PIR2 0Dh PIE2 8Dh PMADR 10Dh 18Dh
TMR1L 0Eh PCON 8Eh PMDATH 10Eh 18Eh
TMR1H 0Fh OSCCON 8Fh PMADRH 10Fh 18Fh
T1CON 10h OSCTUNE 90h 110h 190h
TMR2 11h SSPCON2 91h
T2CON 12h PR2 92h
SSPBUF 13h SSPADD 93h
SSPCON 14h SSPSTAT 94h
CCPR1L 15h CCPR3L 95h
CCPR1H 16h CCPR3H 96h
General General
CCP1CON 17h CCP3CON 97h Purpose Purpose
RCSTA 18h TXSTA 98h Register Register
TXREG 19h SPBRG 99h 16 Bytes 16 Bytes
RCREG 1Ah 9Ah
CCPR2L 1Bh ADCON2 9Bh
CCPR2H 1Ch CMCON 9Ch
CCP2CON 1Dh CVRCON 9Dh
ADRESH 1Eh ADRESL 9Eh
ADCON0 1Fh ADCON1 9Fh 11Fh 19Fh
20h A0h 120h 1A0h
General General General
Purpose Purpose Purpose
General Register Register Register
Purpose 80 Bytes 80 Bytes 80 Bytes
Register EFh 16Fh 1EFh
F0h 170h 1F0h
96 Bytes
accesses accesses accesses
70h-7Fh 70h-7Fh 70h-7Fh

7Fh FFh 17Fh 1FFh

Bank 0 Bank 1 Bank 2 Bank 3

Unimplemented data memory locations read as ‘0’.

* Not a physical register.

DS30498B-page 16 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 2-3: DATA MEMORY MAP FOR PIC16F747 AND THE PIC16F777

File File File File

Address Address Address Address
Indirect addr.(*) 00h Indirect addr.(*) 80h Indirect addr.(*) 100h Indirect addr.(*) 180h
TMR0 01h OPTION_REG 81h TMR0 101h OPTION_REG 181h
PCL 02h PCL 82h PCL 102h PCL 182h
STATUS 03h STATUS 83h STATUS 103h STATUS 183h
FSR 04h FSR 84h FSR 104h FSR 184h
PORTA 05h TRISA 85h WDTCON 105h 185h
PORTB 06h TRISB 86h PORTB 106h TRISB 186h
PORTC 07h TRISC 87h 107h 187h
PORTD 08h TRISD 88h 108h 188h
PORTE 09h TRISE 89h LVDCON 109h 189h
PCLATH 0Ah PCLATH 8Ah PCLATH 10Ah PCLATH 18Ah
INTCON 0Bh INTCON 8Bh INTCON 10Bh INTCON 18Bh
PIR1 0Ch PIE1 8Ch PMDATA 10Ch PMCON1 18Ch
PIR2 0Dh PIE2 8Dh PMADR 10Dh 18Dh
TMR1L 0Eh PCON 8Eh PMDATH 10Eh 18Eh
TMR1H 0Fh OSCCON 8Fh PMADRH 10Fh 18Fh
T1CON 10h OSCTUNE 90h 110h 190h
TMR2 11h SSPCON2 91h
T2CON 12h PR2 92h
SSPBUF 13h SSPADD 93h
SSPCON 14h SSPSTAT 94h
CCPR1L 15h CCPR3L 95h
CCPR1H 16h CCPR3H 96h
General General
CCP1CON 17h CCP3CON 97h Purpose Purpose
RCSTA 18h TXSTA 98h Register Register
TXREG 19h SPBRG 99h 16 Bytes 16 Bytes
RCREG 1Ah 9Ah
CCPR2L 1Bh ADCON2 9Bh
CCPR2H 1Ch CMCON 9Ch
CCP2CON 1Dh CVRCON 9Dh
ADRESH 1Eh ADRESL 9Eh
ADCON0 1Fh ADCON1 9Fh 11Fh 19Fh
20h A0h 120h 1A0h
General General General
Purpose Purpose Purpose
General Register Register Register
Purpose 80 Bytes 80 Bytes 80 Bytes
Register EFh 16Fh 1EFh
F0h 170h 1F0h
96 Bytes
accesses accesses accesses
70h-7Fh 70h-7Fh 70h-7Fh

7Fh FFh 17Fh 1FFh

Bank 0 Bank 1 Bank 2 Bank 3

Unimplemented data memory locations read as ‘0’.

* Not a physical register.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 17

PIC16F7X7
2.2.2 SPECIAL FUNCTION REGISTERS The Special Function Registers can be classified into
two sets: core (CPU) and peripheral. Those registers
The Special Function Registers are registers used by
associated with the core functions are described in
the CPU and peripheral modules for controlling the
detail in this section. Those related to the operation of
desired operation of the device. These registers are
the peripheral features are described in detail in the
implemented as static RAM. A list of these registers is
peripheral feature section.
given in Table 2-1.

TABLE 2-1: SPECIAL FUNCTION REGISTER SUMMARY

Value on: Details
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
POR, BOR on page
Bank 0
00h(4) INDF Addressing this location uses contents of FSR to address data memory (not a physical register) 0000 0000 30, 180
01h TMR0 Timer0 Module Register xxxx xxxx 76, 180
02h(4) PCL Program Counter (PC) Least Significant Byte 0000 0000 29, 180

03h(4) STATUS IRP RP1 RP0 TO PD Z DC C 0001 1xxx 21, 180

04h(4) FSR Indirect Data Memory Address Pointer xxxx xxxx 30, 180
05h PORTA PORTA Data Latch when written: PORTA pins when read xx0x 0000 55, 180
06h PORTB PORTB Data Latch when written: PORTB pins when read xx00 0000 64, 180
07h PORTC PORTC Data Latch when written: PORTC pins when read xxxx xxxx 66, 180
08h(5) PORTD PORTD Data Latch when written: PORTD pins when read xxxx xxxx 67, 180

09h(5) PORTE — — — — RE3 RE2 RE1 RE0 ---- x000 68, 180

0Ah(1,4) PCLATH — — — Write Buffer for the upper 5 bits of the Program Counter ---0 0000 29, 180

0Bh(4) INTCON GIE PEIE TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 23, 180
0Ch PIR1 (3) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 25, 180
PSPIF
0Dh PIR2 OSFIF CMIF LVDIF — BCLIF — CCP3IF CCP2IF 000- 0-00 27, 180
0Eh TMR1L Holding Register for the Least Significant Byte of the 16-bit TMR1 Register xxxx xxxx 83, 180
0Fh TMR1H Holding Register for the Most Significant Byte of the 16-bit TMR1 Register xxxx xxxx 83, 180
10h T1CON — T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON -000 0000 83, 180
11h TMR2 Timer2 Module Register 0000 0000 86, 180
12h T2CON — TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 86, 180
13h SSPBUF Synchronous Serial Port Receive Buffer/Transmit Register xxxx xxxx 101, 180
14h SSPCON WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 0000 0000 101, 180
15h CCPR1L Capture/Compare/PWM Register 1 (LSB) xxxx xxxx 90, 180
16h CCPR1H Capture/Compare/PWM Register 1 (MSB) xxxx xxxx 90, 180
17h CCP1CON — — CCP1X CCP1Y CCP1M3 CCP1M2 CCP1M1 CCP1M0 --00 0000 88, 180
18h RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 134, 180
19h TXREG USART Transmit Data Register 0000 0000 139, 180
1Ah RCREG USART Receive Data Register 0000 0000 141, 180
1Bh CCPR2L Capture/Compare/PWM Register 2 (LSB) xxxx xxxx 92, 180
1Ch CCPR2H Capture/Compare/PWM Register 2 (MSB) xxxx xxxx 92, 180
1Dh CCP2CON — — CCP2X CCP2Y CCP2M3 CCP2M2 CCP2M1 CCP2M0 --00 0000 88, 180
1Eh ADRESH A/D Result Register Byte xxxx xxxx 160, 180
1Fh ADCON0 ADCS1 ADCS0 CHS2 CHS1 CHS0 GO/DONE CHS3 ADON 0000 0000 152, 180
Legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ‘0’, r = reserved.
Shaded locations are unimplemented, read as ‘0’.
Note 1: The upper byte of the program counter is not directly accessible. PCLATH is a holding register for the PC<12:8>, whose contents are
transferred to the upper byte of the program counter during branches (CALL or GOTO).
2: Other (non Power-up) Resets include external Reset through MCLR and Watchdog Timer Reset.
3: Bits PSPIE and PSPIF are reserved on the 28-pin devices; always maintain these bits clear.
4: These registers can be addressed from any bank.
5: PORTD, PORTE, TRISD and TRISE are not physically implemented on the 28-pin devices (except for RE3), read as ‘0’.
6: This bit always reads as a ‘1’.
7: OSCON<OSTS> bit resets to ‘0’ with dual-speed start-up and LP, HS or HS-PLL selected as the oscillator.
8: RE3 is an input only. The state of the TRISE3 bit has no effect and will always read ‘1’.

DS30498B-page 18 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
TABLE 2-1: SPECIAL FUNCTION REGISTER SUMMARY (CONTINUED)
Value on: Details
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
POR, BOR on page
Bank 1
80h(4) INDF Addressing this location uses contents of FSR to address data memory (not a physical register) 0000 0000 30, 180

81h OPTION_REG RBPU INTEDG T0CS T0SE PSA PS2 PS1 PS0 1111 1111 22, 180
82h(4) PCL Program Counter’s (PC) Least Significant Byte 0000 0000 29, 180

83h(4) STATUS IRP RP1 RP0 TO PD Z DC C 0001 1xxx 21, 180

84h(4) FSR Indirect Data Memory Address Pointer xxxx xxxx 30, 180

85h TRISA PORTA Data Direction Register 1111 1111 55, 181
86h TRISB PORTB Data Direction Register 1111 1111 64, 181
87h TRISC PORTC Data Direction Register 1111 1111 66, 181

88h(5) TRISD PORTD Data Direction Register 1111 1111 67, 181

89h(5) TRISE IBF (5) OBF(5) IBOV(5) PSPMODE(5) —(8) PORTE Data Direction bits 0000 1111 69, 181

8Ah(1,4) PCLATH — — — Write Buffer for the upper 5 bits of the Program Counter ---0 0000 23, 180

8Bh(4) INTCON GIE PEIE TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 25, 180
8Ch PIE1 (3) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 24, 181
PSPIE
8Dh PIE2 OSFIE CMIE LVDIE — BCLIE — CCP3IE CCP2IE 000- 0-00 26, 181
8Eh PCON — — — — — SBOREN POR BOR ---- -1qq 28, 181
8Fh OSCCON — IRCF2 IRCF1 IRCF0 OSTS (8) IOFS SCS1 SCS0 -000 1000 38, 181
90h OSCTUNE — — TUN5 TUN4 TUN3 TUN2 TUN1 TUN0 --00 0000 36, 181
91h SSPCON2 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN 0000 0000 105
92h PR2 Timer2 Period Register 1111 1111 86, 181
93h SSPADD Synchronous Serial Port (I2C mode) Address Register 0000 0000 101, 181

94h SSPSTAT SMP CKE D/A P S R/W UA BF 0000 0000 101, 181
95h CCPR3L Capture/Compare/PWM Register 1 (LSB) xxxx xxxx 92
96h CCPR3H Capture/Compare/PWM Register 1 (MSB) xxxx xxxx 92
97h CCP3CON — — CCP3X CCP3Y CCP3M3 CCP3M2 CCP3M1 CCP3M0 --00 0000 92
98h TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 145, 181
99h SPBRG Baud Rate Generator Register 0000 0000 145, 181
9Ah — Unimplemented — —
9Bh ADCON2 — — ACQT2 ACQT1 ACQT0 — — — --00 0--- 154
9Ch CMCON C2OUT C1OUT C2INV C1INV CIS CM2 CM1 CM0 0000 0111 55, 161
9Dh CVRCON CVREN CVROE CVRR — CVR3 CVR2 CVR1 CVR0 000- 0000 55, 167
9Eh ADRESL A/D Result Register Low Byte xxxx xxxx 180
9Fh ADCON1 ADFM ADCS2 VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 0000 0000 153, 181
Legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ‘0’, r = reserved.
Shaded locations are unimplemented, read as ‘0’.
Note 1: The upper byte of the program counter is not directly accessible. PCLATH is a holding register for the PC<12:8>, whose contents are
transferred to the upper byte of the program counter during branches (CALL or GOTO).
2: Other (non Power-up) Resets include external Reset through MCLR and Watchdog Timer Reset.
3: Bits PSPIE and PSPIF are reserved on the 28-pin devices; always maintain these bits clear.
4: These registers can be addressed from any bank.
5: PORTD, PORTE, TRISD and TRISE are not physically implemented on the 28-pin devices (except for RE3), read as ‘0’.
6: This bit always reads as a ‘1’.
7: OSCON<OSTS> bit resets to ‘0’ with dual-speed start-up and LP, HS or HS-PLL selected as the oscillator.
8: RE3 is an input only. The state of the TRISE3 bit has no effect and will always read ‘1’.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 19

PIC16F7X7
TABLE 2-1: SPECIAL FUNCTION REGISTER SUMMARY (CONTINUED)
Value on: Details
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
POR, BOR on page
Bank 2
100h(4) INDF Addressing this location uses contents of FSR to address data memory (not a physical register) 0000 0000 30, 180
101h TMR0 Timer0 Module Register xxxx xxxx 76, 180
102h(4) PCL Program Counter (PC) Least Significant Byte 0000 0000 29, 180

103h(4) STATUS IRP RP1 RP0 TO PD Z DC C 0001 1xxx 21, 180

104h(4) FSR Indirect Data Memory Address Pointer xxxx xxxx 30, 180
105h WDTCON — — — WDTPS3 WDTPS2 WDTPS1 WDTPS0 SWDTEN ---0 1000 187
106h PORTB PORTB Data Latch when written: PORTB pins when read xxxx xxxx 64, 180
107h — Unimplemented — —
108h — Unimplemented — —
109h LVDCON — — IRVST LVDEN LVDL3 LVDL2 LVDL1 LVDL0 --00 0101 176
10Ah(1,4) PCLATH — — — Write Buffer for the upper 5 bits of the Program Counter ---0 0000 23, 180

10Bh(4) INTCON GIE PEIE TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 25, 180
10Ch PMDATA EEPROM Data Register Low Byte xxxx xxxx 32, 181
10Dh PMADR EEPROM Address Register Low Byte xxxx xxxx 32, 181
10Eh PMDATH — — EEPROM Data Register High Byte --xx xxxx 32, 181
10Fh PMADRH — — — — EEPROM Address Register High Byte ---- xxxx 32, 181
Bank 3
180h(4) INDF Addressing this location uses contents of FSR to address data memory (not a physical register) 0000 0000 30, 180

181h OPTION_REG RBPU INTEDG T0CS T0SE PSA PS2 PS1 PS0 1111 1111 22, 180
182h(4) PCL Program Counter (PC) Least Significant Byte 0000 0000 29, 180

183h(4) STATUS IRP RP1 RP0 TO PD Z DC C 0001 1xxx 21, 180

184h(4) FSR Indirect Data Memory Address Pointer xxxx xxxx 30, 180
185h — Unimplemented — —
186h TRISB PORTB Data Direction Register 1111 1111 64, 181
187h — Unimplemented — —
188h — Unimplemented — —
189h — Unimplemented — —
(1,4) PCLATH — — — Write Buffer for the upper 5 bits of the Program Counter ---0 0000 23, 180
18Ah
18Bh(4) INTCON GIE PEIE TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 25, 180
18Ch PMCON1 — — — — — — — RD ---- ---0 32, 181
18Dh — Reserved, maintain clear 0000 0000 —
18Eh — Reserved, maintain clear 0000 0000 —
18Fh — Reserved, maintain clear 0000 0000 —
Legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ‘0’, r = reserved.
Shaded locations are unimplemented, read as ‘0’.
Note 1: The upper byte of the program counter is not directly accessible. PCLATH is a holding register for the PC<12:8>, whose contents are
transferred to the upper byte of the program counter during branches (CALL or GOTO).
2: Other (non Power-up) Resets include external Reset through MCLR and Watchdog Timer Reset.
3: Bits PSPIE and PSPIF are reserved on the 28-pin devices; always maintain these bits clear.
4: These registers can be addressed from any bank.
5: PORTD, PORTE, TRISD and TRISE are not physically implemented on the 28-pin devices (except for RE3), read as ‘0’.
6: This bit always reads as a ‘1’.
7: OSCON<OSTS> bit resets to ‘0’ with dual-speed start-up and LP, HS or HS-PLL selected as the oscillator.
8: RE3 is an input only. The state of the TRISE3 bit has no effect and will always read ‘1’.

DS30498B-page 20 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
2.2.2.1 Status Register For example, CLRF STATUS, will clear the upper three
bits and set the Z bit. This leaves the Status register as
The Status register contains the arithmetic status of the
000u u1uu (where u = unchanged).
ALU, the Reset status and the bank select bits for data
memory. It is recommended, therefore, that only BCF, BSF,
SWAPF and MOVWF instructions are used to alter the
The Status register can be the destination for any
Status register because these instructions do not affect
instruction, as with any other register. If the Status reg-
the Z, C or DC bits from the Status register. For other
ister is the destination for an instruction that affects the
instructions not affecting any Status bits, see
Z, DC or C bits, then the write to these three bits is dis-
Section 16.0 “Instruction Set Summary”.
abled. These bits are set or cleared according to the
device logic. Furthermore, the TO and PD bits are not Note 1: The C and DC bits operate as a borrow
writable, therefore, the result of an instruction with the and digit borrow bit, respectively, in sub-
Status register as destination may be different than traction. See the SUBLW and SUBWF
intended. instructions for examples.

REGISTER 2-1: STATUS REGISTER (ADDRESS 03h, 83h, 103h, 183h)

R/W-0 R/W-0 R/W-0 R-1 R-1 R/W-x R/W-x R/W-x
IRP RP1 RP0 TO PD Z DC C
bit 7 bit 0

bit 7 IRP: Register Bank Select bit (used for indirect addressing)
1 = Bank 2, 3 (100h-1FFh)
0 = Bank 0, 1 (00h-FFh)
bit 6-5 RP1:RP0: Register Bank Select bits (used for direct addressing)
11 = Bank 3 (180h-1FFh)
10 = Bank 2 (100h-17Fh)
01 = Bank 1 (80h-FFh)
00 = Bank 0 (00h-7Fh)
Each bank is 128 bytes.
bit 4 TO: Time-out bit
1 = After power-up, CLRWDT instruction or SLEEP instruction
0 = A WDT time-out occurred
bit 3 PD: Power-down bit
1 = After power-up or by the CLRWDT instruction
0 = By execution of the SLEEP instruction
bit 2 Z: Zero bit
1 = The result of an arithmetic or logic operation is zero
0 = The result of an arithmetic or logic operation is not zero
bit 1 DC: Digit Carry/borrow bit (ADDWF, ADDLW, SUBLW, SUBWF instructions)
1 = A carry-out from the 4th low order bit of the result occurred
0 = No carry-out from the 4th low order bit of the result
bit 0 C: Carry/borrow bit (ADDWF, ADDLW, SUBLW, SUBWF instructions)
1 = A carry-out from the Most Significant bit of the result occurred
0 = No carry-out from the Most Significant bit of the result occurred
Note: For borrow, the polarity is reversed. A subtraction is executed by adding the two’s
complement of the second operand. For rotate (RRF, RLF) instructions, this bit is
loaded with either the high or low order bit of the source register.

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

 2003 Microchip Technology Inc. Preliminary DS30498B-page 21

PIC16F7X7
2.2.2.2 OPTION_REG Register Note: To achieve a 1:1 prescaler assignment for
The OPTION_REG register is a readable and writable the TMR0 register, assign the prescaler to
register which contains various control bits to configure the Watchdog Timer.
the TMR0 prescaler/WDT postscaler (single assign-
able register known also as the prescaler), the external
INT interrupt, TMR0 and the weak pull-ups on PORTB.

REGISTER 2-2: OPTION_REG REGISTER (ADDRESS 81h, 181h)

R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
RBPU INTEDG T0CS T0SE PSA PS2 PS1 PS0
bit 7 bit 0

bit 7 RBPU: PORTB Pull-up Enable bit

1 = PORTB pull-ups are disabled
0 = PORTB pull-ups are enabled by individual port latch values
bit 6 INTEDG: Interrupt Edge Select bit
1 = Interrupt on rising edge of RB0/INT pin
0 = Interrupt on falling edge of RB0/INT pin
bit 5 T0CS: TMR0 Clock Source Select bit
1 = Transition on RA4/T0CKI pin
0 = Internal instruction cycle clock (CLKO)
bit 4 T0SE: TMR0 Source Edge Select bit
1 = Increment on high-to-low transition on RA4/T0CKI pin
0 = Increment on low-to-high transition on RA4/T0CKI pin
bit 3 PSA: Prescaler Assignment bit
1 = Prescaler is assigned to the WDT
0 = Prescaler is assigned to the Timer0 module
bit 2-0 PS2:PS0: Prescaler Rate Select bits
Bit Value TMR0 Rate WDT Rate
000 1:2 1:1
001 1:4 1:2
010 1:8 1:4
011 1 : 16 1:8
100 1 : 32 1 : 16
101 1 : 64 1 : 32
110 1 : 128 1 : 64
111 1 : 256 1 : 128

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

DS30498B-page 22 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
2.2.2.3 INTCON Register Note: Interrupt flag bits are set when an interrupt
The INTCON register is a readable and writable regis- condition occurs regardless of the state of
ter which contains various enable and flag bits for the its corresponding enable bit or the global
TMR0 register overflow, RB port change and external enable bit, GIE (INTCON<7>). User
RB0/INT pin interrupts. software should ensure the appropriate
interrupt flag bits are clear prior to
enabling an interrupt.

REGISTER 2-3: INTCON REGISTER (ADDRESS 0Bh, 8Bh, 10Bh, 18Bh)

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-x
GIE PEIE TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF
bit 7 bit 0

bit 7 GIE: Global Interrupt Enable bit

1 = Enables all unmasked interrupts
0 = Disables all interrupts
bit 6 PEIE: Peripheral Interrupt Enable bit
1 = Enables all unmasked peripheral interrupts
0 = Disables all peripheral interrupts
bit 5 TMR0IE: TMR0 Overflow Interrupt Enable bit
1 = Enables the TMR0 interrupt
0 = Disables the TMR0 interrupt
bit 4 INT0IE: RB0/INT External Interrupt Enable bit
1 = Enables the RB0/INT external interrupt
0 = Disables the RB0/INT external interrupt
bit 3 RBIE: RB Port Change Interrupt Enable bit
1 = Enables the RB port change interrupt
0 = Disables the RB port change interrupt
bit 2 TMR0IF: TMR0 Overflow Interrupt Flag bit
1 = TMR0 register has overflowed (must be cleared in software)
0 = TMR0 register did not overflow
bit 1 INT0IF: RB0/INT External Interrupt Flag bit
1 = The RB0/INT external interrupt occurred (must be cleared in software)
0 = The RB0/INT external interrupt did not occur
bit 0 RBIF: RB Port Change Interrupt Flag bit
A mismatch condition will continue to set flag bit RBIF. Reading PORTB will end the mismatch
condition and allow flag bit RBIF to be cleared.
1 = At least one of the RB7:RB4 pins changed state (must be cleared in software)
0 = None of the RB7:RB4 pins have changed state

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

 2003 Microchip Technology Inc. Preliminary DS30498B-page 23

PIC16F7X7
2.2.2.4 PIE1 Register Note: Bit PEIE (INTCON<6>) must be set to
The PIE1 register contains the individual enable bits for enable any peripheral interrupt.
the peripheral interrupts.

REGISTER 2-4: PIE1 REGISTER (ADDRESS 8Ch)

R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
(1)
PSPIE ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE
bit 7 bit 0

bit 7 PSPIE(1): Parallel Slave Port Read/Write Interrupt Enable bit

1 = Enables the PSP read/write interrupt
0 = Disables the PSP read/write interrupt
Note 1: PSPIE is reserved on 28-pin devices; always maintain this bit clear.
bit 6 ADIE: A/D Converter Interrupt Enable bit
1 = Enables the A/D converter interrupt
0 = Disables the A/D converter interrupt
bit 5 RCIE: USART Receive Interrupt Enable bit
1 = Enables the USART receive interrupt
0 = Disables the USART receive interrupt
bit 4 TXIE: USART Transmit Interrupt Enable bit
1 = Enables the USART transmit interrupt
0 = Disables the USART transmit interrupt
bit 3 SSPIE: Synchronous Serial Port Interrupt Enable bit
1 = Enables the SSP interrupt
0 = Disables the SSP interrupt
bit 2 CCP1IE: CCP1 Interrupt Enable bit
1 = Enables the CCP1 interrupt
0 = Disables the CCP1 interrupt
bit 1 TMR2IE: TMR2 to PR2 Match Interrupt Enable bit
1 = Enables the TMR2 to PR2 match interrupt
0 = Disables the TMR2 to PR2 match interrupt
bit 0 TMR1IE: TMR1 Overflow Interrupt Enable bit
1 = Enables the TMR1 overflow interrupt
0 = Disables the TMR1 overflow interrupt

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

DS30498B-page 24 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
2.2.2.5 PIR1 Register
Note: Interrupt flag bits are set when an interrupt
The PIR1 register contains the individual flag bits for condition occurs regardless of the state of its
the peripheral interrupts. corresponding enable bit or the global enable
bit, GIE (INTCON<7>). User software should
ensure the appropriate interrupt bits are clear
prior to enabling an interrupt.

REGISTER 2-5: PIR1 REGISTER (ADDRESS 0Ch)

R/W-0 R/W-0 R-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0
PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF
bit 7 bit 0

bit 7 PSPIF(1): Parallel Slave Port Read/Write Interrupt Flag bit

1 = A read or a write operation has taken place (must be cleared in software)
0 = No read or write has occurred
Note: PSPIF is reserved on 28-pin devices; always maintain this bit clear.
bit 6 ADIF: A/D Converter Interrupt Flag bit
1 = An A/D conversion is completed (must be cleared in software)
0 = The A/D conversion is not complete
bit 5 RCIF: USART Receive Interrupt Flag bit
1 = The USART receive buffer is full
0 = The USART receive buffer is empty
bit 4 TXIF: USART Transmit Interrupt Flag bit
1 = The USART transmit buffer is empty
0 = The USART transmit buffer is full
bit 3 SSPIF: Synchronous Serial Port (SSP) Interrupt Flag bit
1 = The SSP interrupt condition has occurred and must be cleared in software before returning
from the Interrupt Service Routine. The conditions that will set this bit are:
SPI:
A transmission/reception has taken place.
I2 C Slave:
A transmission/reception has taken place.
I2 C Master:
A transmission/reception has taken place.
The initiated Start condition was completed by the SSP module.
The initiated Stop condition was completed by the SSP module.
The initiated Restart condition was completed by the SSP module.
The initiated Acknowledge condition was completed by the SSP module.
A Start condition occurred while the SSP module was Idle (multi-master system).
A Stop condition occurred while the SSP module was Idle (multi-master system).
0 = No SSP interrupt condition has occurred
bit 2 CCP1IF: CCP1 Interrupt Flag bit
Capture mode:
1 = A TMR1 register capture occurred (must be cleared in software)
0 = No TMR1 register capture occurred
Compare mode:
1 = A TMR1 register compare match occurred (must be cleared in software)
0 = No TMR1 register compare match occurred
PWM mode:
Unused in this mode.
bit 1 TMR2IF: TMR2 to PR2 Match Interrupt Flag bit
1 = TMR2 to PR2 match occurred (must be cleared in software)
0 = No TMR2 to PR2 match occurred
bit 0 TMR1IF: TMR1 Overflow Interrupt Flag bit
1 = TMR1 register overflowed (must be cleared in software)
0 = TMR1 register did not overflow

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

 2003 Microchip Technology Inc. Preliminary DS30498B-page 25

PIC16F7X7
2.2.2.6 PIE2 Register
The PIE2 register contains the individual enable bits for
the CCP2 and CCP3 peripheral interrupts.

REGISTER 2-6: PIE2 REGISTER (ADDRESS 8Dh)

R/W-0 R/W-0 R/W-0 U-0 R/W-0 U-0 R/W-0 R/W-0
OSFIE CMIE LVDIE — BCLIE — CCP3IE CCP2IE
bit 7 bit 0

bit 7 OSFIE: Oscillator Fail Interrupt Enable bit

1 = Enabled
0 = Disabled
bit 6 CMIE: Comparator Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 5 LVDIE: Low-Voltage Detect Interrupt Enable bit
1 = LVD interrupt is enabled
0 = LVD interrupt is disabled
bit 4 Unimplemented: Read as ‘0’
bit 3 BCLIE: Bus Collision Interrupt Enable bit
1 = Enable bus collision interrupt in the SSP when configured for I2C Master mode
0 = Disable bus collision interrupt in the SSP when configured for I2C Master mode
bit 2 Unimplemented: Read as ‘0’
bit 1 CCP3IE: CCP3 Interrupt Enable bit
1 = Enables the CCP3 interrupt
0 = Disables the CCP3 interrupt
bit 0 CCP2IE: CCP2 Interrupt Enable bit
1 = Enables the CCP2 interrupt
0 = Disables the CCP2 interrupt

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

DS30498B-page 26 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
2.2.2.7 PIR2 Register
Note: Interrupt flag bits are set when an interrupt
The PIR2 register contains the flag bits for the CCP2
condition occurs regardless of the state of
interrupt.
its corresponding enable bit or the global
enable bit, GIE (INTCON<7>). User
software should ensure the appropriate
interrupt flag bits are clear prior to
enabling an interrupt.

REGISTER 2-7: PIR2 REGISTER (ADDRESS 0Dh)

R/W-0 R/W-0 R/W-0 U-0 R/W-0 U-0 R/W-0 R/W-0
OSFIF CMIF LVDIF — BCLIF — CCP3IF CCP2IF
bit 7 bit 0

bit 7 OSFIF: Oscillator Fail Interrupt Flag bit

1 = System oscillator failed, clock input has changed to INTRC (must be cleared in software)
0 = System clock operating
bit 6 CMIF: Comparator Interrupt Flag bit
1 = Comparator input has changed (must be cleared in software)
0 = Comparator input has not changed
bit 5 LVDIF: Low-Voltage Detect Interrupt Flag bit
1 = The supply voltage has fallen below the specified LVD voltage (must be cleared in software)
0 = The supply voltage is greater then the specified LVD voltage
bit 4 Unimplemented: Read as ‘0’
bit 3 BCLIF: Bus Collision Interrupt Flag bit
1 = A bus collision has occurred in the SSP when configured for I2C Master mode
0 = No bus collision has occurred
bit 2 Unimplemented: Read as ‘0’
bit 1 CCP3IF: CCP3 Interrupt Flag bit
Capture mode:
1 = A TMR1 register capture occurred (must be cleared in software)
0 = No TMR1 register capture occurred
Compare mode:
1 = A TMR1 register compare match occurred (must be cleared in software)
0 = No TMR1 register compare match occurred
PWM mode:
Unused in this mode.
bit 0 CCP2IF: CCP2 Interrupt Flag bit
Capture mode:
1 = A TMR1 register capture occurred (must be cleared in software)
0 = No TMR1 register capture occurred
Compare mode:
1 = A TMR1 register compare match occurred (must be cleared in software)
0 = No TMR1 register compare match occurred
PWM mode:
Unused.

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

 2003 Microchip Technology Inc. Preliminary DS30498B-page 27

PIC16F7X7
2.2.2.8 PCON Register Note: BOR is unknown on POR. It must be set
The Power Control (PCON) register contains flag bits by the user and checked on subsequent
to allow differentiation between a Power-on Reset Resets to see if BOR is clear, indicating a
(POR), a Brown-out Reset (BOR), a Watchdog Reset brown-out has occurred. The BOR status
(WDT) and an external MCLR Reset. bit is not predictable if the brown-out circuit
is disabled (by clearing the BOREN bit in
the Configuration Word register).

REGISTER 2-8: PCON REGISTER (ADDRESS 8Eh)

U-0 U-0 U-0 U-0 U-0 R/W-1 R/W-0 R/W-1
— — — — — SBOREN POR BOR
bit 7 bit 0

bit 7-3 Unimplemented: Read as ‘0’

bit 2 SBOREN: Software Brown-out Reset Enable bit
If BORSEN in Configuration Word 2 is a ‘1’ and BOREN in Configuration Word 1 is ‘0’, then:
1 = BOR enabled
0 = BOR disabled
bit 1 POR: Power-on Reset Status bit
1 = No Power-on Reset occurred
0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs)
bit 0 BOR: Brown-out Reset Status bit
1 = No Brown-out Reset occurred
0 = A Brown-out Reset occurred (must be set in software after a Brown-out Reset occurs)

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

DS30498B-page 28 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
2.3 PCL and PCLATH The stack operates as a circular buffer. This means that
after the stack has been PUSHed eight times, the ninth
The Program Counter (PC) is 13 bits wide. The low push overwrites the value that was stored from the first
byte comes from the PCL register, which is a readable push. The tenth push overwrites the second push (and
and writable register. The upper bits (PC<12:8>) are so on).
not readable but are indirectly writable through the
PCLATH register. On any Reset, the upper bits of the Note 1: There are no Status bits to indicate stack
PC will be cleared. Figure 2-4 shows the two situations overflow or stack underflow conditions.
for the loading of the PC. The upper example in the
2: There are no instructions/mnemonics
figure shows how the PC is loaded on a write to PCL
called PUSH or POP. These are actions
(PCLATH<4:0> → PCH). The lower example in the
that occur from the execution of the
figure shows how the PC is loaded during a CALL or
CALL, RETURN, RETLW and RETFIE
GOTO instruction (PCLATH<4:3> → PCH).
instructions or the vectoring to an
interrupt address.
FIGURE 2-4: LOADING OF PC IN
DIFFERENT SITUATIONS 2.4 Program Memory Paging
PCH PCL PIC16F7X7 devices are capable of addressing a con-
tinuous 8K word block of program memory. The CALL
12 8 7 0 Instruction with and GOTO instructions provide only 11 bits of address to
PC PCL as
Destination allow branching within any 2K program memory page.
PCLATH<4:0> 8 When doing a CALL or GOTO instruction, the upper
5 ALU
2 bits of the address are provided by PCLATH<4:3>.
When doing a CALL or GOTO instruction, the user must
PCLATH ensure that the page select bits are programmed so
that the desired program memory page is addressed. If
PCH PCL
a return from a CALL instruction (or interrupt) is exe-
12 11 10 8 7 0
cuted, the entire 13-bit PC is POPed off the stack.
PC GOTO,CALL
Therefore, manipulation of the PCLATH<4:3> bits is
PCLATH<4:3> 11 not required for the RETURN instructions (which POPs
2 Opcode <10:0> the address from the stack).
PCLATH Note: The contents of the PCLATH are
unchanged after a RETURN or RETFIE
instruction is executed. The user must set
up the PCLATH for any subsequent CALLs
2.3.1 COMPUTED GOTO
or GOTOs.
A computed GOTO is accomplished by adding an offset
Example 2-1 shows the calling of a subroutine in
to the program counter (ADDWF PCL). When doing a
page 1 of the program memory. This example assumes
table read using a computed GOTO method, care
that PCLATH is saved and restored by the Interrupt
should be exercised if the table location crosses a PCL
Service Routine (if interrupts are used).
memory boundary (each 256-byte block). Refer to the
Application Note, AN556, “Implementing a Table Read”
(DS00556). EXAMPLE 2-1: CALL OF A SUBROUTINE
IN PAGE 1 FROM PAGE 0
2.3.2 STACK ORG 0x500
The PIC16F7X7 family has an 8-level deep x 13-bit BCF PCLATH, 4
BSF PCLATH, 3 ;Select page 1
wide hardware stack. The stack space is not part of
;(800h-FFFh)
either program or data space and the stack pointer is
CALL SUB1_P1 ;Call subroutine in
not readable or writable. The PC is PUSHed onto the : ;page 1 (800h-FFFh)
stack when a CALL instruction is executed or an :
interrupt causes a branch. The stack is POPed in the ORG 0x900 ;page 1 (800h-FFFh)
event of a RETURN, RETLW or a RETFIE instruction SUB1_P1
execution. PCLATH is not affected by a PUSH or POP : ;called subroutine
operation. : ;page 1 (800h-FFFh)
:
RETURN ;return to Call
;subroutine in page 0
;(000h-7FFh)

 2003 Microchip Technology Inc. Preliminary DS30498B-page 29

PIC16F7X7
2.5 Indirect Addressing, INDF and EXAMPLE 2-2: INDIRECT ADDRESSING
FSR Registers MOVLW 0x20 ;initialize pointer
MOVWF FSR ;to RAM
The INDF register is not a physical register. Addressing NEXT CLRF INDF ;clear INDF register
the INDF register will cause indirect addressing. INCF FSR, F ;inc pointer
BTFSS FSR, 4 ;all done?
Indirect addressing is possible by using the INDF
GOTO NEXT ;no clear next
register. Any instruction using the INDF register actu-
CONTINUE
ally accesses the register pointed to by the File Select : ;yes continue
Register, FSR. Reading the INDF register itself indi-
rectly (FSR = 0) will read 00h. Writing to the INDF reg-
ister indirectly results in a no operation (although Status
bits may be affected). An effective 9-bit address is
obtained by concatenating the 8-bit FSR register and
the IRP bit (Status<7>) as shown in Figure 2-5.
A simple program to clear RAM locations 20h-2Fh
using indirect addressing is shown in Example 2-2.

FIGURE 2-5: DIRECT/INDIRECT ADDRESSING

Direct Addressing Indirect Addressing

RP1:RP0 6 From Opcode 0 IRP 7 FSR Register 0

Bank Select Location Select Bank Select Location Select

00 01 10 11
00h 80h 100h 180h

Data
Memory(1)

7Fh FFh 17Fh 1FFh

Bank 0 Bank 1 Bank 2 Bank 3

Note 1: For register file map detail, see Figure 2-2.

DS30498B-page 30 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
3.0 READING PROGRAM MEMORY When interfacing to the program memory block, the
PMDATH:PMDATA registers form a two-byte word
The Flash program memory is readable during normal which holds the 14-bit data for reads. The
operation over the entire VDD range. It is indirectly PMADRH:PMADR registers form a two-byte word
addressed through Special Function Registers (SFR). which holds the 13-bit address of the Flash location
Up to 14-bit numbers can be stored in memory for use being accessed. These devices can have up to
as calibration parameters, serial numbers, packed 7-bit 8K words of program Flash, with an address range
ASCII, etc. Executing a program memory location con- from 0h to 3FFFh. The unused upper bits in both the
taining data that forms an invalid instruction results in a PMDATH and PMADRH registers are not implemented
NOP. and read as ‘0’s.
There are five SFRs used to read the program and
memory. These registers are: 3.1 PMADR
• PMCON1 The address registers can address up to a maximum of
• PMDATA 8K words of program Flash.
• PMDATH When selecting a program address value, the MSByte
• PMADR of the address is written to the PMADRH register and
• PMADRH the LSByte is written to the PMADR register. The upper
MSbits of PMADRH must always be clear.
The program memory allows word reads. Program
memory access allows for checksum calculation and
reading calibration tables. 3.2 PMCON1 Register
PMCON1 is the control register for memory accesses.
The control bit, RD, initiates read operations. This bit
cannot be cleared, only set, in software. It is cleared in
hardware at the completion of the read operation.

REGISTER 3-1: PMCON1 REGISTER (ADDRESS 18Ch)

R-1 U-0 U-0 U-0 U-x U-0 U-0 R/S-0
reserved — — — — — — RD
bit 7 bit 0

bit 7 Reserved: Read as ‘1’

bit 6-1 Unimplemented: Read as ‘0’
bit 0 RD: Read Control bit
1 = Initiates a Flash read, RD is cleared in hardware. The RD bit can only be set (not cleared)
in software.
0 = Flash read completed

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

 2003 Microchip Technology Inc. Preliminary DS30498B-page 31

PIC16F7X7
3.3 Reading the Flash Program 3.4 Operation During Code-Protect
Memory Flash program memory has its own code-protect
A program memory location may be read by writing two mechanism. External read and write operations by
bytes of the address to the PMADR and PMADRH reg- programmers are disabled if this mechanism is
isters and then setting control bit, RD (PMCON1<0>). enabled.
Once the read control bit is set, the microcontroller will The microcontroller can read and execute instructions
use the next two instruction cycles to read the data. The out of the internal Flash program memory, regardless
data is available in the PMDATA and PMDATH regis- of the state of the code-protect configuration bits.
ters after the second NOP instruction. Therefore, it can
be read as two bytes in the following instructions. The
PMDATA and PMDATH registers will hold this value
until the next read operation.

EXAMPLE 3-1: FLASH PROGRAM READ

BSF STATUS, RP1 ;
BCF STATUS, RP0 ; Bank 2
MOVF ADDRH, W ;
MOVWF PMADRH ; MSByte of Program Address to read
MOVF ADDRL, W ;
MOVWF PMADR ; LSByte of Program Address to read
BSF STATUS, RP0 ; Bank 3 Required

Required BSF PMCON1, RD ; EEPROM Read Sequence

Sequence NOP ; memory is read in the next two cycles after BSF PMCON1,RD
NOP ;

BCF STATUS, RP0 ; Bank 2

MOVF PMDATA, W ; W = LSByte of Program PMDATA
MOVF PMDATH, W ; W = MSByte of Program PMDATH

TABLE 3-1: REGISTERS ASSOCIATED WITH PROGRAM FLASH

Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
10Dh PMADR Address Register Low Byte xxxx xxxx uuuu uuuu
10Fh PMADRH — — — Address Register High Byte ---x xxxx ---u uuuu
10Ch PMDATA Data Register Low Byte xxxx xxxx uuuu uuuu
10Eh PMDATH — — Data Register High Byte --xx xxxx --uu uuuu
18Ch PMCON1 —(1) — — — — — — RD 1--- ---0 1--- ---0
Legend: x = unknown, u = unchanged, r = reserved, - = unimplemented, read as ‘0’. Shaded cells are not used
during Flash access.
Note 1: This bit always reads as a ‘1’.

DS30498B-page 32 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
4.0 OSCILLATOR TABLE 4-1: CAPACITOR SELECTION FOR
CONFIGURATIONS CRYSTAL OSCILLATOR (FOR
DESIGN GUIDANCE ONLY)
4.1 Oscillator Types Typical Capacitor Values
Crystal Tested:
The PIC16F7X7 can be operated in eight different oscil- Osc Type
Freq
lator modes. The user can program three configuration C1 C2
bits (FOSC2:FOSC0) to select one of these eight modes
LP 32 kHz 33 pF 33 pF
(modes 5-8 are new PIC16 oscillator configurations):
200 kHz 15 pF 15 pF
1. LP Low-Power Crystal
XT 200 kHz 56 pF 56 pF
2. XT Crystal/Resonator
1 MHz 15 pF 15 pF
3. HS High-Speed Crystal/Resonator
4. RC External Resistor/Capacitor with 4 MHz 15 pF 15 pF
FOSC/4 output on RA6 HS 4 MHz 15 pF 15 pF
5. RCIO External Resistor/Capacitor with 8 MHz 15 pF 15 pF
I/O on RA6 20 MHz 15 pF 15 pF
6. INTIO1 Internal Oscillator with FOSC/4 Capacitor values are for design guidance only.
output on RA6 and I/O on RA7
These capacitors were tested with the crystals listed
7. INTIO2 Internal Oscillator with I/O on RA6
below for basic start-up and operation. These values
and RA7
were not optimized.
8. ECIO External Clock with I/O on RA6
Different capacitor values may be required to produce
acceptable oscillator operation. The user should test
4.2 Crystal Oscillator/Ceramic
the performance of the oscillator over the expected
Resonators VDD and temperature range for the application.
In XT, LP or HS modes, a crystal or ceramic resonator See the notes following this table for additional
is connected to the OSC1/CLKI and OSC2/CLKO pins information.
to establish oscillation (see Figure 4-1 and Figure 4-2).
The PIC16F7X7 oscillator design requires the use of a Note 1: Higher capacitance increases the stability
parallel cut crystal. Use of a series cut crystal may give of oscillator but also increases the
a frequency out of the crystal manufacturer’s start-up time.
specifications.
2: Since each crystal has its own character-
istics, the user should consult the crystal
FIGURE 4-1: CRYSTAL OPERATION
manufacturer for appropriate values of
(HS, XT OR LP OSC external components.
CONFIGURATION)
3: Rs may be required in HS mode, as well
OSC1 PIC16F7X7 as XT mode, to avoid overdriving crystals
C1(1) with low drive level specification.

XTAL
4: Always verify oscillator performance over
RF(3) Sleep
the VDD and temperature range that is
OSC2 expected for the application.
RS(2)
C2(1) To Internal
Logic

Note 1: See Table 4-1 for typical values of C1 and C2.

2: A series resistor (RS) may be required for AT
strip cut crystals.
3: RF varies with the crystal chosen (typically
between 2 MΩ to 10 MΩ).

 2003 Microchip Technology Inc. Preliminary DS30498B-page 33

PIC16F7X7
FIGURE 4-2: CERAMIC RESONATOR 4.3 External Clock Input
OPERATION (HS OR XT
The ECIO Oscillator mode requires an external clock
OSC CONFIGURATION)
source to be connected to the OSC1 pin. There is no
OSC1 PIC16F7X7 oscillator start-up time required after a Power-on Reset
or after an exit from Sleep mode.
C1(1)
In the ECIO Oscillator mode, the OSC2 pin becomes
RES Sleep
RF(3) an additional general purpose I/O pin. The I/O pin
OSC2 becomes bit 6 of PORTA (RA6). Figure 4-3 shows the
RS (2) pin connections for the ECIO Oscillator mode.
C2(1) To Internal
Logic FIGURE 4-3: EXTERNAL CLOCK INPUT
OPERATION
Note 1: See Table 4-2 for typical values of C1 and C2. (ECIO CONFIGURATION)
2: A series resistor (RS) may be required.
3: RF varies with the resonator chosen (typically Clock from OSC1/CLKI
between 2 MΩ to 10 MΩ). Ext. System PIC16F7X7
RA6 I/O (OSC2)

TABLE 4-2: CERAMIC RESONATORS (FOR

DESIGN GUIDANCE ONLY)
Typical Capacitor Values Used:

Mode Freq OSC1 OSC2

XT 455 kHz 56 pF 56 pF
2.0 MHz 47 pF 47 pF
4.0 MHz 33 pF 33 pF
HS 8.0 MHz 27 pF 27 pF
16.0 MHz 22 pF 22 pF
Capacitor values are for design guidance only.
These capacitors were tested with the resonators
listed below for basic start-up and operation. These
values were not optimized.
Different capacitor values may be required to produce
acceptable oscillator operation. The user should test
the performance of the oscillator over the expected
VDD and temperature range for the application.
See the notes following this table for additional
information.

Note: When using resonators with frequencies

above 3.5 MHz, the use of HS mode rather
than XT mode is recommended. HS mode
may be used at any VDD for which the
controller is rated. If HS is selected, it is
possible that the gain of the oscillator will
overdrive the resonator. Therefore, a
series resistor should be placed between
the OSC2 pin and the resonator. As a
good starting point, the recommended
value of RS is 330Ω.

DS30498B-page 34 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
4.4 RC Oscillator 4.5 Internal Oscillator Block
For timing insensitive applications, the “RC” and “RCIO” The PIC16F7X7 devices include an internal oscillator
device options offer additional cost savings. The RC block which generates two different clock signals;
oscillator frequency is a function of the supply voltage, either can be used as the system’s clock source. This
the resistor (REXT) and capacitor (CEXT) values and the can eliminate the need for external oscillator circuits on
operating temperature. In addition to this, the oscillator the OSC1 and/or OSC2 pins.
frequency will vary from unit to unit due to normal man- The main output (INTOSC) is an 8 MHz clock source
ufacturing variation. Furthermore, the difference in lead which can be used to directly drive the system clock. It
frame capacitance between package types will also also drives the INTOSC postscaler which can provide a
affect the oscillation frequency, especially for low CEXT range of six clock frequencies, from 125 kHz to 4 MHz.
values. The user also needs to take into account varia-
tion due to tolerance of external R and C components The other clock source is the internal RC oscillator
used. Figure 4-4 shows how the R/C combination is (INTRC), which provides a 31.25 kHz (32 µs nominal
connected. period) output. The INTRC oscillator is enabled by
selecting the INTRC as the system clock source or
In the RC Oscillator mode, the oscillator frequency when any of the following are enabled:
divided by 4 is available on the OSC2 pin. This signal may
be used for test purposes or to synchronize other logic. • Power-up Timer
• Watchdog Timer
FIGURE 4-4: RC OSCILLATOR MODE • Two-Speed Start-up
VDD • Fail-Safe Clock Monitor
These features are discussed in greater detail in
REXT Section 15.0 “Special Features of the CPU”.
Internal
OSC1
Clock The clock source frequency (INTOSC direct, INTRC
direct or INTOSC postscaler) is selected by configuring
CEXT the IRCF bits of the OSCCON register (page 38).
PIC16F7X7
VSS
OSC2/CLKO
Note: Throughout this data sheet, when referring
FOSC/4 specifically to a generic clock source, the
Recommended values: 3 kΩ ≤ REXT ≤ 100 kΩ term “INTRC” may also be used to refer to
CEXT > 20 pF the clock modes using the internal
oscillator block. This is regardless of
The RCIO Oscillator mode (Figure 4-5) functions like whether the actual frequency used is
the RC mode, except that the OSC2 pin becomes an INTOSC (8 MHz), the INTOSC postscaler
additional general purpose I/O pin. The I/O pin or INTRC (31.25 kHz).
becomes bit 6 of PORTA (RA6).

FIGURE 4-5: RCIO OSCILLATOR MODE

VDD

REXT
OSC1 Internal
Clock

CEXT
VSS PIC16F7X7
RA6 I/O (OSC2)

Recommended values: 3 kΩ ≤ REXT ≤ 100 kΩ

CEXT > 20 pF

 2003 Microchip Technology Inc. Preliminary DS30498B-page 35

PIC16F7X7
4.5.1 INTRC MODES 4.5.2 OSCTUNE REGISTER
Using the internal oscillator as the clock source can The internal oscillator’s output has been calibrated at the
eliminate the need for up to two external oscillator pins, factory but can be adjusted in the application. This is
after which it can be used for digital I/O. Two distinct done by writing to the OSCTUNE register (Register 4-1).
configurations are available: The tuning sensitivity is constant throughout the tuning
• In INTIO1 mode, the OSC2 pin outputs FOSC/4, range. The OSCTUNE register has a tuning range of
while OSC1 functions as RA7 for digital input and ±12.5%.
output. When the OSCTUNE register is modified, the INTOSC
• In INTIO2 mode, OSC1 functions as RA7 and and INTRC frequencies will begin shifting to the new fre-
OSC2 functions as RA6, both for digital input and quency. The INTRC clock will reach the new frequency
output. within 8 clock cycles (approximately 8 * 32 µs = 256 µs);
the INTOSC clock will stabilize within 1 ms. Code execu-
tion continues during this shift. There is no indication that
the shift has occurred. Operation of features that depend
on the 31.25 kHz INTRC clock source frequency, such
as the WDT, Fail-Safe Clock Monitor and peripherals,
will also be affected by the change in frequency.

REGISTER 4-1: OSCTUNE: OSCILLATOR TUNING REGISTER (ADDRESS 90h)

U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
— — TUN5 TUN4 TUN3 TUN2 TUN1 TUN0
bit 7 bit 0

bit 7-6 Unimplemented: Read as ‘0’

bit 5-0 TUN<5:0>: Frequency Tuning bits
011111 = Maximum frequency
011110 =
•
•
•
000001 =
000000 = Center frequency. Oscillator module is running at the calibrated frequency.
111111 =
•
•
•
100000 = Minimum frequency

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

DS30498B-page 36 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
4.6 Clock Sources and Oscillator the main oscillator that is selected by the FOSC2:FOSC0
Switching configuration bits in Configuration Register 1. When the
bits are set in any other manner, the system clock
The PIC16F7X7 devices include a feature that allows source is provided by the Timer1 oscillator
the system clock source to be switched from the main (SCS1:SCS0 = 01) or from the internal oscillator block
oscillator to an alternate low-frequency clock source. (SCS1:SCS0 = 10). After a Reset, SCS<1:0> are
PIC16F7X7 devices offer three alternate clock sources. always set to ‘00’.
When enabled, these give additional options for
The internal oscillator select bits, IRCF2:IRCF0, select
switching to the various power managed operating
the frequency output of the internal oscillator block that
modes.
is used to drive the system clock. The choices are the
Essentially, there are three clock sources for these INTRC source (31.25 kHz), the INTOSC source
devices: (8 MHz) or one of the six frequencies derived from the
• Primary oscillators INTOSC postscaler (125 kHz to 4 MHz). Changing the
configuration of these bits has an immediate change on
• Secondary oscillators
the internal oscillator’s output.
• Internal oscillator block (INTRC)
The OSTS and IOFS bits indicate the status of the
The primary oscillators include the External Crystal primary oscillator and INTOSC source; these bits are
and Resonator modes, the External RC modes, the set when their respective oscillators are stable. In par-
External Clock mode and the internal oscillator block. ticular, OSTS indicates that the Oscillator Start-up
The particular mode is defined on POR by the contents Timer has timed out.
of Configuration Word 1. The details of these modes
are covered earlier in this chapter. 4.6.2 CLOCK SWITCHING
The secondary oscillators are those external sources Clock switching will occur for the following reasons:
not connected to the OSC1 or OSC2 pins. These
sources may continue to operate even after the • The FCMEN (CONFIG2<0>) bit is set, the device
controller is placed in a power managed mode. is running from the primary oscillator and the
primary oscillator fails. The clock source will be
PIC16F7X7 devices offer the Timer1 oscillator as a 31.25 kHz INTRC.
secondary oscillator. This oscillator continues to run
• The FCMEN bit is set, the device is running from
when a SLEEP instruction is executed and is often the
the T1OSC and T1OSC fails. The clock source
time base for functions, such as a real-time clock.
will be 31.25 kHz INTRC.
Most often, a 32.768 kHz watch crystal is connected • Following a wake-up due to a Reset or a POR,
between the RC0/T1OSO/T1CKI and RC1/T1OSI/CCP2 when the device is configured for Two-Speed
pins. Like the LP mode oscillator circuit, loading capaci- mode, switching will occur between the INTRC and
tors are also connected from each pin to ground. The the system clock defined by the FOSC<2:0> bits.
Timer1 oscillator is discussed in greater detail in
• A wake-up from Sleep occurs due to interrupt or
Section 7.6 “Timer1 Oscillator”.
WDT wake-up and Two-Speed Start-up is
In addition to being a primary clock source, the internal enabled. If the primary clock is XT, HS or LP, the
oscillator block is available as a power managed clock will switch between the INTRC and the
mode clock source. The 31.25 kHz INTRC source is primary system clock after 1024 clocks (OST) and
also used as the clock source for several special fea- 8 clocks of the primary oscillator. This is
tures, such as the WDT, Fail-Safe Clock Monitor, conditional upon the SCS bits being set equal
Power-up Timer and Two-Speed Start-up. to ‘00’.
The clock sources for the PIC16F7X7 devices are shown • SCS bits are modified from their original value.
in Figure 4-6. See Section 7.0 “Timer1 Module” for fur- • IRCF bits are modified from their original value.
ther details of the Timer1 oscillator. See Section 15.1
“Configuration Bits” for Configuration register details. Note: Because the SCS bits are cleared on any
Reset, no clock switching will occur on a
4.6.1 OSCCON REGISTER Reset unless the Two-Speed Start-up is
enabled and the primary clock is XT, HS or
The OSCCON register (Register 4-2) controls several
LP. The device will wait for the primary
aspects of the system clock’s operation, both in full
clock to become stable before execution
power operation and in power managed modes.
begins (Two-Speed Start-up disabled).
The system clock select bits, SCS1:SCS0, select the
clock source that is used when the device is operating
in power managed modes. When the bits are cleared
(SCS<1:0> = 00), the system clock source comes from

 2003 Microchip Technology Inc. Preliminary DS30498B-page 37

PIC16F7X7
4.6.3 CLOCK TRANSITION AND WDT Once the clock transition is complete (i.e., new oscilla-
tor selection switch has occurred), the Watchdog
When clock switching is performed, the Watchdog
Counter is re-enabled with the Counter Reset. This
Timer is disabled because the Watchdog Ripple
allows the user to synchronize the Watchdog Timer to
Counter is used as the Oscillator Start-up Timer.
the start of execution at the new clock frequency.
Note: The OST is only used when switching to
XT, HS and LP Oscillator modes.

REGISTER 4-2: OSCCON: OSCILLATOR CONTROL REGISTER

U-0 R/W-0 R/W-0 R/W-0 R-0 R-0 R/W-0 R/W-0
— IRCF2 IRCF1 IRCF0 OSTS(1) IOFS SCS1 SCS0
bit 7 bit 0

bit 7 Unimplemented: Read as ‘0’

bit 6-4 IRCF<2:0>: Internal RC Oscillator Frequency Select bits
000 = 31.25 kHz
001 = 125 kHz
010 = 250 kHz
011 = 500 kHz
100 = 1 MHz
101 = 2 MHz
110 = 4 MHz
111 = 8 MHz
bit 3 OSTS: Oscillator Start-up Time-out Status bit(1)
1 = Device is running from the primary system clock
0 = Device is running from T1OSC or INTRC as a secondary system clock
Note 1: Bit resets to ‘0’ with Two-Speed Start-up and LP, XT or HS selected as the oscillator
mode.
bit 2 IOFS: INTOSC Frequency Stable bit
1 = Frequency is stable
0 = Frequency is not stable
bit 1-0 SCS<1:0>: Oscillator Mode Select bits
00 = Oscillator mode defined by FOSC<2:0>
01 = T1OSC is used for system clock
10 = Internal RC is used for system clock
11 = Reserved

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

DS30498B-page 38 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 4-6: PIC16F7X7 CLOCK DIAGRAM

CONFIG1 (FOSC2:FOSC0)
Primary Oscillator
SCS<1:0> (T1OSC)
OSC2

Sleep
LP, XT, HS, RC, EC
OSC1
Secondary Oscillator Peripherals
T1OSC

MUX
T1OSO

T1OSCEN To Timer1
Enable
T1OSI Oscillator OSCCON<6:4> Internal Oscillator

8 MHz CPU
111
4 MHz
Internal 110
Oscillator 2 MHz
101
Block

Postscaler
1 MHz

MUX
100
500 kHz
8 MHz 011
31.25 kHz (INTOSC) 250 kHz
Source 010
125 kHz
001
31.25 kHz
31.25 kHz 000
WDT, FSCM
(INTRC)

4.6.4 MODIFYING THE IRCF BITS If the IRCF bits are modified while the internal oscillator
is running at any other frequency than INTRC
The IRCF bits can be modified at any time, regardless
(31.25 kHz, IRCF<2:0> ≠ 000), there is no need for a
of which clock source is currently being used as the
4 ms clock switch delay. The new INTOSC frequency
system clock. The internal oscillator allows users to
will be stable immediately after the eight falling edges.
change the frequency during run-time. This is achieved
The IOFS bit will remain set after clock switching
by modifying the IRCF bits in the OSCCON register.
occurs.
The sequence of events that occur after the IRCF bits
are modified is dependent upon the initial value of the Note: Caution must be taken when modifying the
IRCF bits before they are modified. If the INTRC IRCF bits using BCF or BSF instructions. It
(31.25 kHz, IRCF<2:0> = 000) is running and the IRCF is possible to modify the IRCF bits to a fre-
bits are modified to any other value than ‘000’, a 4 ms quency that may be out of the VDD specifi-
clock switch delay is turned on. Code execution contin- cation range; for example, VDD = 2.0V and
ues at a higher than expected frequency while the new IRCF = 111 (8 MHz).
frequency stabilizes. Time sensitive code should wait
for the IOFS bit in the OSCCON register to become set
before continuing. This bit can be monitored to ensure
that the frequency is stable before using the system
clock in time critical applications.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 39

PIC16F7X7
4.6.5 CLOCK TRANSITION SEQUENCE • Clock before switch: One of INTOSC/INTOSC
postscaler (IRCF<2:0> ≠ 000)
The following are three different sequences for
switching the internal RC oscillator frequency: 1. IRCF bits are modified to a different INTOSC/
INTOSC postscaler frequency.
• Clock before switch: 31.25 kHz
2. The clock switching circuitry waits for a falling
(IRCF<2:0> = 000)
edge of the current clock, at which point CLKO
1. IRCF bits are modified to an INTOSC/INTOSC is held low.
postscaler frequency.
3. The clock switching circuitry then waits for
2. The clock switching circuitry waits for a falling eight falling edges of requested clock, after
edge of the current clock, at which point CLKO which it switches CLKO to this new clock
is held low. source.
3. The clock switching circuitry then waits for eight 4. The IOFS bit is set.
falling edges of requested clock, after which it
5. Oscillator switchover is complete.
switches CLKO to this new clock source.
4. The IOFS bit is clear to indicate that the clock is 4.6.6 OSCILLATOR DELAY UPON
unstable and a 4 ms delay is started. Time POWER-UP, WAKE-UP AND CLOCK
dependent code should wait for IOFS to
SWITCHING
become set.
5. Switchover is complete. Table 4-3 shows the different delays invoked for
various clock switching sequences. It also shows the
• Clock before switch: One of INTOSC/INTOSC
delays invoked for POR and wake-up.
postscaler (IRCF<2:0> ≠ 000)
1. IRCF bits are modified to INTRC
(IRCF<2:0> = 000).
2. The clock switching circuitry waits for a falling
edge of the current clock, at which point CLKO
is held low.
3. The clock switching circuitry then waits for eight
falling edges of requested clock, after which it
switches CLKO to this new clock source.
4. Oscillator switchover is complete.

TABLE 4-3: OSCILLATOR DELAY EXAMPLES

Switch From Switch To Frequency Oscillator Delay Comments
INTRC 31.25 kHz
T1OSC 32.768 kHz
Sleep/POR Following a wake-up from Sleep
INTOSC/INTOSC 125 kHz-8 MHz
Postscaler 5 µs-10 µs (approx.) mode or POR, CPU start-up is
CPU Start-up(1) invoked to allow the CPU to
INTRC/Sleep EC, RC DC – 20 MHz
become ready for code execution.
INTRC
EC, RC DC – 20 MHz
(31.25 kHz)
1024 Clock Cycles Following a change from INTRC, an
Sleep LP, XT, HS 32.768 kHz-20 MHz
(OST) OST of 1024 cycles must occur.
INTRC INTOSC/INTOSC Refer to Section 4.6.4 “Modifying
125 kHz-8 MHz 4 ms
(31.25 kHz) Postscaler the IRCF bits” for further details.
Note 1: The 5 µs-10 µs start-up delay is based on a 1 MHz system clock.

DS30498B-page 40 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
4.7 Power Managed Modes If the system clock does not come from the INTRC
(31.25 kHz) when the SCS bits are changed and the
4.7.1 RC_RUN MODE IRCF bits in the OSCCON register are configured for a
frequency other than INTRC, the frequency may not be
When SCS bits are configured to run from the INTRC,
stable immediately. The IOFS bit (OSCCON<2> will be
a clock transition is generated if the system clock is not
set when the INTOSC or postscaler frequency is stable,
already using the INTRC. The event will clear the
after approximately 4 ms.
OSTS bit and switch the system clock from the primary
system clock (if SCS<1:0> = 00) determined by the After a clock switch has been executed, the OSTS bit
value contained in the configuration bits, or from the is cleared, indicating a low-power mode and the device
T1OSC (if SCS<1:0> = 01) to the INTRC clock option, does not run from the primary system clock. The inter-
and shut down the primary system clock to conserve nal Q clocks are held in the Q1 state until eight falling
power. Clock switching will not occur if the primary edge clocks are counted on the INTRC oscillator. After
system clock is already configured as INTRC. the eight clock periods have transpired, the clock input
to the Q clocks is released and operation resumes (see
Figure 4-7).

FIGURE 4-7: TIMING DIAGRAM FOR XT, HS, LP, EC, EXTRC TO RC_RUN MODE

Q1 Q2 Q3 Q4 Q1 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1
TINP(1)
INTOSC
TSCS(3)
OSC1
TOSC(2)
System
Clock

TDLY(4)

SCS<1:0>
Program
Counter PC PC + 1 PC + 2 PC + 3

Note 1: TINP = 32 µs typical.

2: TOSC = 50 ns minimum.
3: TSCS = 8 TINP.
4: TDLY = 1 TINP.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 41

PIC16F7X7
4.7.2 SEC_RUN MODE
The core and peripherals can be configured to be Note 1: The T1OSCEN bit must be enabled and it
clocked by T1OSC using a 32.768 kHz crystal. The is the user’s responsibility to ensure
crystal must be connected to the T1OSO and T1OSI T1OSC is stable before clock switching to
pins. This is the same configuration as the low-power the T1OSC input clock can occur.
timer circuit (see Section 7.6 “Timer1 Oscillator”). 2: When T1OSCEN = 0, the following
When SCS bits are configured to run from T1OSC, a possible effects result.
clock transition is generated. It will clear the OSTS bit, Original Modified Final
switch the system clock from either the primary system SCS<1:0> SCS<1:0> SCS<1:0>
clock or INTRC, depending on the value of SCS<1:0>
and FOSC<2:0>, to the external low-power Timer1 00 01 00 – no change
oscillator input (T1OSC) and shut down the primary 00 11 10 – INTRC
system clock to conserve power. 10 11 10 – no change
After a clock switch has been executed, the internal Q 10 01 00 – OSC
clocks are held in the Q1 state until eight falling edge defined by
clocks are counted on the T1OSC. After the eight clock FOSC<2:0>
periods have transpired, the clock input to the Q clocks A clock switching event will occur if the
is released and operation resumes (see Figure 4-8). In final state of the SCS bits is different from
addition, T1RUN (in T1CON) is set to indicate that the original.
T1OSC is being used as the system clock.

FIGURE 4-8: TIMING DIAGRAM FOR SWITCHING TO SEC_RUN MODE

Q1 Q2 Q3 Q4 Q1 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1
TT1P(1)

T1OSI
TSCS(3)
OSC1
TOSC(2)
System
Clock

TDLY(4)
SCS<1:0>
Program
Counter PC PC + 1 PC + 2 PC + 3

Note 1: TT1P = 30.52 µs.

2: TOSC = 50 ns minimum.
3: TSCS = 8 TT1P
4: TDLY = 1 TT1P.

DS30498B-page 42 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
4.7.3 SEC_RUN/RC_RUN TO PRIMARY 4.7.3.1 Returning to Primary Clock Source
CLOCK SOURCE Sequence
When switching from a SEC_RUN or RC_RUN mode Changing back to the primary oscillator from
back to the primary system clock, following a change of SEC_RUN or RC_RUN can be accomplished by either
SCS<1:0> to ‘00’, the sequence of events that take changing SCS<1:0> to ‘00’ or clearing the T1OSCEN
place will depend upon the value of the FOSC bits in the bit in the T1CON register (if T1OSC was the secondary
Configuration register. If the primary clock source is clock).
configured as a crystal (HS, XT or LP), then the The sequence of events that follows is the same for
transition will take place after 1024 clock cycles. This is both modes:
necessary because the crystal oscillator has been pow-
ered down until the time of the transition. In order to 1. If the primary system clock is configured as EC,
provide the system with a reliable clock when the RC or INTRC, then the OST time-out is skipped.
changeover has occurred, the clock will not be Skip to step 3.
released to the changeover circuit until the 1024 counts 2. If the primary system clock is configured as an
have expired. external oscillator (HS, XT, LP), then the OST
will be active, waiting for 1024 clocks of the
During the oscillator start-up time, the system clock
primary system clock.
comes from the current system clock. Instruction exe-
cution and/or peripheral operation continues using the 3. On the following Q1, the device holds the
currently selected oscillator as the CPU clock source system clock in Q1.
until the necessary clock count has expired to ensure 4. The device stays in Q1 while eight falling edges
that the primary system clock is stable. of the primary system clock are counted.
To know when the OST has expired, the OSTS bit 5. Once the eight counts transpire, the device
should be monitored. OSTS = 1 indicates that the begins to run from the primary oscillator.
Oscillator Start-up Timer has timed out and the system 6. If the secondary clock was INTRC and the
clock comes from the primary clock source. primary is not INTRC, the INTRC will be shut
down to save current, providing that the INTRC
Following the oscillator start-up time, the internal Q
is not being used for any other function, such as
clocks are held in the Q1 state until eight falling edge
WDT or Fail-Safe Clock Monitoring.
clocks are counted from the primary system clock. The
clock input to the Q clocks is then released and 7. If the secondary clock was T1OSC, the T1OSC
operation resumes with the primary system clock will continue to run if T1OSCEN is still set;
determined by the FOSC bits (see Figure 4-10). otherwise, the T1 oscillator will be shut down.

When in SEC_RUN mode, the act of clearing the

T1OSCEN bit in the T1CON register will cause
SCS<0> to be cleared, which causes the SCS<1:0>
bits to revert to ‘00’ or ‘10’ depending on what SCS<1>
is. Although the T1OSCEN bit was cleared, T1OSC will
be enabled and instruction execution will continue until
the OST time-out for the main system clock is com-
plete. At that time, the system clock will switch from the
T1OSC to the primary clock or the INTRC. Following
this, the T1 oscillator will be shut down.
Note: If the primary system clock is either RC or
EC, an internal delay timer (5-10 µs) will
suspend operation after exiting Secondary
Clock mode to allow the CPU to become
ready for code execution.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 43

PIC16F7X7
FIGURE 4-9: TIMING FOR TRANSITION BETWEEN SEC_RUN/RC_RUN AND
PRIMARY CLOCK
TT1P(1) or TINP(2)
Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

Sec. Osc
OSC1
TOST(6)
OSC2

TOSC(3) TSCS(4)
Primary Clock

System Clock

SCS<1:0> TDLY(5)

OSTS
Program
Counter PC PC + 1 PC + 2 PC + 3

Note 1: TT1P = 30.52 µs.

2: TINP = 32 µs typical.
3: TOSC = 50 ns minimum.
4: TSCS = 8 TINP OR 8 TT1P.
5: TDLY = 1 TINP OR 1 TT1P.
6: Refer to parameter “D032” in Section 18.0 “Electrical Characteristics”.

DS30498B-page 44 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
4.7.3.2 Returning to Primary Oscillator with no oscillator start-up time required because the pri-
a Reset mary clock is already stable; however, there is a delay
between the wake-up event and the following Q2. An
A Reset will clear SCS<1:0> back to ‘00’. The
internal delay timer of 5-10 µs will suspend operation
sequence for starting the primary oscillator following a
after the Reset to allow the CPU to become ready for
Reset is the same for all forms of Reset, including
code execution. The CPU and peripheral clock will be
POR. There is no transition sequence from the
held in the first Q1.
alternate system clock to the primary system clock on
a Reset condition. Instead, the device will reset the The sequence of events is as follows:
state of the OSCCON register and default to the 1. A device Reset is asserted from one of many
primary system clock. The sequence of events that sources (WDT, BOR, MCLR, etc.).
take place after this will depend upon the value of the 2. The device resets and the CPU start-up timer is
FOSC bits in the Configuration register. If the external enabled if in Sleep mode. The device is held in
oscillator is configured as a crystal (HS, XT or LP), the Reset until the CPU start-up time-out is
CPU will be held in the Q1 state until 1024 clock cycles complete.
have transpired on the primary clock. This is
3. If the primary system clock is configured as an
necessary because the crystal oscillator had been
external oscillator (HS, XT, LP), then the OST
powered down until the time of the transition.
will be active waiting for 1024 clocks of the pri-
During the oscillator start-up time, instruction mary system clock. While waiting for the OST,
execution and/or peripheral operation is suspended. the device will be held in Reset. The OST and
Note: If Two-Speed Clock Start-up mode is CPU start-up timers run in parallel.
enabled, the INTRC will act as the system 4. After both the CPU start-up and OST timers
clock until the OST timer has timed out. have timed out, the device will wait for one
additional clock cycle and instruction execution
If the primary system clock is either RC, EC or INTRC,
will begin.
the CPU will begin operating on the first Q1 cycle
following the wake-up event. This means that there is

FIGURE 4-10: TIMING LP CLOCK TO PRIMARY SYSTEM CLOCK AFTER RESET (HS, XT, LP)
TT1P(1)
Q4 Q1 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

T1OSI
OSC1
TOST(4)
OSC2
TEPU(3)
TOSC(2)
CPU Start-up

System Clock

Peripheral
Clock
Reset
Sleep

OSTS
Program
Counter PC 0000h 0001h 0003h 0004h 0005h

Note 1: TT1P = 30.52 µs.

2: TOSC = 50 ns minimum.
3: TEPU = 5-10 µs.
4: Refer to parameter “D032” in Section 18.0 “Electrical Characteristics”.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 45

PIC16F7X7
FIGURE 4-11: TIMING LP CLOCK TO PRIMARY SYSTEM CLOCK AFTER RESET
(EC, RC, INTRC)
TT1P(1)

Q4 Q1 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

T1OSI

OSC1

OSC2 TCPU(2)

CPU Start-up

System Clock

MCLR

OSTS
Program
Counter PC 0000h 0001h 0002h 0003h 0004h

Note 1: TT1P = 30.52 µs.

2: TCPU = 5-10 µs.

DS30498B-page 46 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
TABLE 4-4: CLOCK SWITCHING MODES
Current New
SCS bits <1:0> OSTS IOFS T1RUN
System Delay System Comments
Modified to: bit bit bit
Clock Clock
LP, XT, HS, 10 8 Clocks of 0 1(1) 0 INTRC The internal RC oscillator
T1OSC, (INTRC) INTRC or frequency is dependant upon
EC, RC FOSC<2:0> = LP, INTOSC the IRCF bits.
XT or HS or
INTOSC
Postscaler
LP, XT, HS, 01 8 Clocks of 0 N/A 1 T1OSC T1OSCEN bit must be
INTRC, (T1OSC) T1OSC enabled.
EC, RC FOSC<2:0> = LP,
XT or HS
INTRC 00 8 Clocks of 1 N/A 0 EC
T1OSC FOSC<2:0> = EC EC or
or or RC
FOSC<2:0> = RC RC
INTRC 00 1024 Clocks 1 N/A 0 LP, XT, HS During the 1024 clocks,
T1OSC FOSC<2:0> = LP, (OST) program execution is
XT, HS + clocked from the secondary
8 Clocks of oscillator until the primary
LP, XT, HS oscillator becomes stable.
LP, XT, HS 00 1024 Clocks 1 N/A 0 LP, XT, HS When a Reset occurs, there
(Due to Reset) (OST) is no clock transition
LP, XT, HS sequence. Instruction
execution and/or peripheral
operation is suspended
unless Two-Speed Start-up
mode is enabled, after which
the INTRC will act as the
system clock until the OST
timer has expired.
Note 1: If the new clock source is INTOSC or INTOSC postscaler, then the IOFS bit will be set 4 ms after the clock
change.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 47

PIC16F7X7
4.7.4 EXITING SLEEP WITH AN If SCS<1:0> = 01 or 10:
INTERRUPT 1. The device is held in Sleep until the CPU start-up
Any interrupt, such as WDT or INT0, will cause the part time-out is complete.
to leave the Sleep mode. 2. After the CPU start-up timer has timed out, the
The SCS bits are unaffected by a SLEEP command and device will exit Sleep and begin instruction
are the same before and after entering and leaving execution with the selected oscillator mode.
Sleep. The clock source used after an exit from Sleep Note: If a user changes SCS<1:0> just before
is determined by the SCS bits. entering Sleep mode, the system clock
used when exiting Sleep mode could be
4.7.4.1 Sequence of Events
different than the system clock used when
If SCS<1:0> = 00: entering Sleep mode.
1. The device is held in Sleep until the CPU start-up As an example, if SCS<1:0> = 01, T1OSC
time-out is complete. is the system clock and the following
2. If the primary system clock is configured as an instructions are executed:
external oscillator (HS, XT, LP), then the OST will BCF OSCCON,SCS0
be active waiting for 1024 clocks of the primary SLEEP
system clock. While waiting for the OST, the
device will be held in Sleep unless Two-Speed then a clock change event is executed. If
Start-up is enabled. The OST and CPU start-up the primary oscillator is XT, LP or HS, the
timers run in parallel. Refer to Section 15.17.3 core will continue to run off T1OSC and
“Two-Speed Clock Start-up Mode” for details execute the SLEEP command.
on Two-Speed Start-up. When Sleep is exited, the part will resume
3. After both the CPU start-up and OST timers operation with the primary oscillator after
have timed out, the device will exit Sleep and the OST has expired.
begin instruction execution with the primary
clock defined by the FOSC bits.

DS30498B-page 48 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
5.0 I/O PORTS The other PORTA pins are multiplexed with analog
inputs, the analog VREF+ and VREF- inputs and the com-
Some pins for these I/O ports are multiplexed with an parator voltage reference output. The operation of pins
alternate function for the peripheral features on the RA3:RA0 and RA5 as A/D converter inputs is selected
device. In general, when a peripheral is enabled, that by clearing/setting the control bits in the ADCON1 reg-
pin may not be used as a general purpose I/O pin. ister (A/D Control Register 1). Pins RA0 through RA5
Additional information on I/O ports may be found in the may also be used as comparator inputs or outputs by
PICmicro® Mid-Range MCU Family Reference Manual, setting the appropriate bits in the CMCON register.
(DS33023). Note: On a Power-on Reset, RA5 and RA3:RA0
are configured as analog inputs and read
5.1 PORTA and the TRISA Register as ‘0’. RA4 is configured as a digital input.
PORTA is a 8-bit wide, bidirectional port. The corre- The RA4/T0CKI/C1OUT pin is a Schmitt Trigger input
sponding data direction register is TRISA. Setting a and an open-drain output. All other PORTA pins have
TRISA bit (= 1) will make the corresponding PORTA pin TTL input levels and full CMOS output drivers.
an input (i.e., put the corresponding output driver in a
The TRISA register controls the direction of the RA pins
high-impedance mode). Clearing a TRISA bit (= 0) will
even when they are being used as analog inputs. The
make the corresponding PORTA pin an output (i.e., put
user must ensure the bits in the TRISA register are
the contents of the output latch on the selected pin).
maintained set when using them as analog inputs.
Reading the PORTA register reads the status of the
pins, whereas writing to it, will write to the port latch. EXAMPLE 5-1: INITIALIZING PORTA
The RA4 pin is multiplexed with the Timer0 module BCF STATUS, RP0 ;
clock input and one of the comparator outputs to BCF STATUS, RP1 ; Bank0
become the RA4/T0CKI/C1OUT pin. Pins RA6 and CLRF PORTA ; Initialize PORTA by
RA7 are multiplexed with the main oscillator pins; they ; clearing output
are enabled as oscillator or I/O pins by the selection of ; data latches
BSF STATUS, RP0 ; Select Bank 1
the main oscillator in Configuration Register 1H (see
MOVLW 0x0F ; Configure all pins
Section 15.1 “Configuration Bits” for details). When
MOVWF ADCON1 ; as digital inputs
they are not used as port pins, RA6 and RA7 and their MOVLW 0xCF ; Value used to
associated TRIS and LAT bits are read as ‘0’. ; initialize data
; direction
MOVWF TRISA ; Set RA<3:0> as inputs
; RA<5:4> as outputs
; TRISA<7:6>are always
; read as '0'.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 49

PIC16F7X7
FIGURE 5-1: BLOCK DIAGRAM OF FIGURE 5-2: BLOCK DIAGRAM OF
RA0/AN0:RA1/AN1 PINS RA3/AN3/VREF+ PIN

Data
Data Bus
Bus D Q
D Q VDD
VDD WR
WR PORTA
PORTA CK Q
CK Q P
P Data Latch
Data Latch
D Q
D Q I/O pin
I/O pin WR N
WR N TRISA
TRISA CK Q
CK Q
TRIS Latch VSS
TRIS Latch VSS Analog
Analog Input Mode
Input Mode
TTL
TTL Input Buffer
Input Buffer RD TRISA
RD TRISA
Q D
Q D

EN
EN
RD PORTA
RD PORTA

To Comparator
To Comparator
To A/D Module Channel Input
To A/D Module Channel Input
To A/D Module VREF+ Input

DS30498B-page 50 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 5-3: BLOCK DIAGRAM OF RA2/AN2/VREF-/CVREF PIN
Data
Bus D Q

WR VDD
PORTA
CK Q
P
Data Latch
D Q
N RA2/AN2/VREF-/
WR CVREF pin
TRISA CK Q
TRIS Latch VSS
Analog
Input Mode

TTL
RD TRISA Input Buffer

Q D

EN

RD PORTA

To Comparator
To A/D Module VREF-
To A/D Module Channel Input

CVROE
CVREF

FIGURE 5-4: BLOCK DIAGRAM OF RA4/T0CKI/C1OUT PIN

Data Comparator Mode = 011, 101, 001
Bus D Q
Comparator 1 Output
WR
PORTA 1
CK Q
Data Latch 0

D Q
RA4/T0CKI/
WR N
C1OUT pin
TRISA
CK Q
TRIS Latch Analog VSS
Input Mode
Schmitt Trigger
Input Buffer

RD TRISA

Q D

EN

RD PORTA

TMR0 Clock Input

 2003 Microchip Technology Inc. Preliminary DS30498B-page 51

PIC16F7X7
FIGURE 5-5: BLOCK DIAGRAM OF RA5/AN4/LVDIN/SS/C2OUT PIN

Data Comparator Mode = 011, 101

Bus
D Q
WR Comparator 2 Output
VDD
PORTA 1
CK Q
0 P
Data Latch

D Q
RA5/AN4/LVDIN/
WR N
TRISA SS/C2OUT pin
CK Q
TRIS Latch Analog VSS
Input Mode
TTL
Buffer

RD TRISA

Q D

EN

RD PORTA

SS Input

LVDIN

To A/D Module Channel Input

DS30498B-page 52 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 5-6: BLOCK DIAGRAM OF OSC2/CLKO/RA6 PIN

(FOSC = 1x1)
CLKO (FOSC/4) From OSC1 Oscillator
1 Circuit

0
VDD

Data OSC2/CLKO
Bus D Q VDD RA6 pin
WR
PORTA CK Q P
Data Latch
D Q
WR N
TRISA
CK Q
TRIS Latch (FOSC = 1x1)
EMUL VSS
EMUL + FOSC = 00x,010
(FOSC = 1x0,011)
RD TRISA
TTL
Q D EMUL Buffer

EN 1

0
RD PORTA
ERA6 pin
(FOSC = 1x0,011)
VDD

N
(FOSC = 1x1)

EMUL + FOSC = 00x, 010

VSS

Note 1: CLKO signal is 1/4 of the FOSC frequency.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 53

PIC16F7X7
FIGURE 5-7: BLOCK DIAGRAM OF OSC1/CLKI/RA7 PIN

Oscillator
Circuit

VDD

(FOSC = 011)
Data
Bus OSC1/CLKI
D Q
VDD RA7 pin
WR
PORTA
CK Q P
Data Latch

D Q
WR N
TRISA
CK Q
TRIS Latch (FOSC = 10x) + EMUL
VSS

(FOSC = 10x)
RD TRISA

Q D
NEMUL
TTL
1 Buffer
EN
0
RD PORTA
ERA7 pin

(FOSC = 10x)
VDD

(FOSC = 10x) + EMUL

VSS

DS30498B-page 54 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
TABLE 5-1: PORTA FUNCTIONS
Name Bit# Buffer Function
RA0/AN0 bit 0 TTL Input/output or analog input.
RA1/AN1 bit 1 TTL Input/output or analog input.
RA2/AN2/VREF-/CVREF bit 2 TTL Input/output or analog input or VREF-.
RA3/AN3/VREF+ bit 3 TTL Input/output or analog input or VREF+.
RA4/T0CKI/C1OUT bit 4 ST Input/output or external clock input for Timer0. Output is
open-drain type.
RA5/AN4/LVDIN/SS/C2OUT bit 5 TTL Input/output or slave select input for synchronous serial port or
analog input.
OSC2/CLKO/RA6 bit 6 ST Input/output, connects to crystal or resonator, oscillator output or
1/4 the frequency of OSC1 and denotes the instruction cycle in
RC mode.
OSC1/CLKI/RA7 bit 7 ST/CMOS(1) Input/output, connects to crystal or resonator or oscillator input.
Legend: TTL = TTL input, ST = Schmitt Trigger input
Note 1: This buffer is a Schmitt Trigger input when configured in RC Oscillator mode and a CMOS input otherwise.

TABLE 5-2: SUMMARY OF REGISTERS ASSOCIATED WITH PORTA

Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
05h PORTA RA7 RA6 RA5 RA4 RA3 RA2 RA1 RA0 xx0x 0000 uu0u 0000
85h TRISA PORTA Data Direction Register 1111 1111 1111 1111
9Fh ADCON1 — — VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 --00 0000 --00 0000
9Ch CMCON C2OUT C1OUT C2INV C1INV CIS CM2 CM1 CM0 0000 0111 0000 0111
9Dh CVRCON CVREN CVROE CVRR — CVR3 CVR2 CVR1 CVR0 000- 0000 000- 0000
Legend: x = unknown, u = unchanged, - = unimplemented locations read as ‘0’. Shaded cells are not used by PORTA.

Note: When using the SSP module in SPI Slave mode and SS enabled, the A/D converter must be set to one of
the following modes, where PCFG2:PCFG0 = 100, 101, 11x.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 55

PIC16F7X7
5.2 PORTB and the TRISB Register The interrupt-on-change feature is recommended for
wake-up on key depression operation and operations
PORTB is an 8-bit wide, bidirectional port. The corre- where PORTB is only used for the interrupt-on-change
sponding data direction register is TRISB. Setting a feature. Polling of PORTB is not recommended while
TRISB bit (= 1) will make the corresponding PORTB using the interrupt-on-change feature.
pin an input (i.e., put the corresponding output driver in
a high-impedance mode). Clearing a TRISB bit (= 0) This interrupt on mismatch feature, together with soft-
will make the corresponding PORTB pin an output (i.e., ware configureable pull-ups on these four pins, allow
put the contents of the output latch on the selected pin). easy interface to a keypad and make it possible for
wake-up on key depression. Refer to the Application
Each of the PORTB pins has a weak internal pull-up. A Note AN552, “Implementing Wake-up on Key Stroke”
single control bit can turn on all the pull-ups. This is per- (DS00552).
formed by clearing bit RBPU (OPTION_REG<7>). The
weak pull-up is automatically turned off when the port RB0/INT is an external interrupt input pin and is
pin is configured as an output. The pull-ups are configured using the INTEDG bit (OPTION_REG<6>).
disabled on a Power-on Reset. RB0/INT is discussed in detail in Section 15.15.1 “INT
Interrupt”.
PORTB pins are multiplexed with analog inputs. The
operation of each pin is selected by clearing/setting the PORTB is multiplexed with several peripheral functions
appropriate control bits in the ADCON1 register. (see Table 5-3). PORTB pins have Schmitt Trigger
input buffers.
Note: On a Power-on Reset, these pins are
When enabling peripheral functions, care should be
configured as analog inputs and read as
taken in defining TRIS bits for each PORTB pin. Some
‘0’.
peripherals override the TRIS bit to make a pin an out-
Four of the PORTB pins (RB7:RB4) have an interrupt- put, while other peripherals override the TRIS bit to
on-change feature. Only pins configured as inputs can make a pin an input. Since the TRIS bit override is in
cause this interrupt to occur (i.e., any RB7:RB4 pin effect while the peripheral is enabled, read-modify-
configured as an output is excluded from the interrupt- write instructions (BSF, BCF, XORWF) with TRISB as
on-change comparison). The input pins (of RB7:RB4) destination should be avoided. The user should refer to
are compared with the old value latched on the last the corresponding peripheral section for the correct
read of PORTB. The “mismatch” outputs of RB7:RB4 TRIS bit settings.
are ORed together to generate the RB port change
interrupt with flag bit, RBIF (INTCON<0>).
This interrupt can wake the device from Sleep. The
user, in the Interrupt Service Routine, can clear the
interrupt in the following manner:
a) Any read or write of PORTB. This will end the
mismatch condition.
b) Clear flag bit RBIF.
A mismatch condition will continue to set flag bit RBIF.
Reading PORTB will end the mismatch condition and
allow flag bit RBIF to be cleared.

DS30498B-page 56 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 5-8: BLOCK DIAGRAM OF RB0/INT/AN12 PIN
VDD
Analog RBPU (1) Weak
Input Mode P Pull-up
Data Latch
Data Bus
D Q
WR PORTB I/O pin
CK
TRIS Latch
D Q
WR TRISB CK Analog
Input Mode
TTL
RD TRISB Input Buffer

Q D

RD PORTB EN

Analog
Input Mode
RD PORTB
To INT

To A/D Channel Input

Note 1: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit.

FIGURE 5-9: BLOCK DIAGRAM OF RB1/AN10 PIN

VDD
Analog RBPU (1) Weak
Input Mode P Pull-up
Data Latch
Data Bus
D Q
WR PORTB I/O pin
CK
TRIS Latch
D Q
WR TRISB CK Analog
Input Mode

TTL
RD TRISB Input Buffer

Q D

RD PORTB EN

RD PORTB
To A/D Channel Input

Note 1: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 57

PIC16F7X7
FIGURE 5-10: BLOCK DIAGRAM OF RB2/AN8 PIN
VDD
RBPU(1)
Weak
P Pull-up
Data Latch
Data Bus
D Q
I/O pin
WR PORTB
CK
TRIS Latch
D Q
Analog
WR TRISB Input Mode
CK

TTL
Input Buffer
RD TRISB

Q D

RD PORTB EN

RD PORTB
To A/D Channel Input

Note 1: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit.

DS30498B-page 58 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 5-11: BLOCK DIAGRAM OF RB3/CCP2/AN9 PIN

Analog
Input Mode

CCP2 Output Select and CCPMX

CCP2 Output
1

VDD
RBPU(1)
Weak
P Pull-up

Data Latch VDD

Data Bus
D
Q P
WR PORTB
CK

I/O pin
N

VSS

TRIS Latch
D Q
WR TRISB CK Q Analog
Input Mode
TTL
Input Buffer
RD TRISB

Q D
RD PORTB EN

To A/D Channel Input RD PORTB

Schmitt Trigger Analog

Buffer Input Mode
To CCP Module Input

Note 1: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit.
2: The SDA Schmitt conforms to the I2C specification.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 59

PIC16F7X7
FIGURE 5-12: BLOCK DIAGRAM OF RB4/AN11 PIN

Analog
Input Mode

RBPU(1) VDD
Weak
P Pull-up

VDD

P
Data Latch
Data Bus
D Q
N I/O pin
WR PORTB CK
TRIS Latch
VSS
D Q
WR TRISB CK

RD TRISB
Analog
Input Mode

TTL
Input Buffer

Latch
Q D

RD PORTB EN Q1
Set RBIF
Analog
Input Mode

From other Q D RD PORTB

RB7:RB4 pins
EN
Q3
To A/D channel input

Note 1: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit.
2: The SCL Schmitt conforms to the I2C specification.

DS30498B-page 60 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 5-13: BLOCK DIAGRAM OF RB5/AN13/CCP3 PIN

Analog
Input Mode
CCP3 Output Select
CCP3 Output
1

0 VDD
(1) Weak
RBPU P Pull-up
Data Latch
Data Bus
D Q
I/O pin
WR PORTB CK
TRIS Latch
D Q
WR TRISB CK
Analog
Input Mode
TTL
RD TRISB Input Buffer

Latch
Q D

RD PORTB EN Q1
Set RBIF Analog
Input Mode

From other Q D RD PORTB

RB7:RB4 pins
Analog
EN
Schmitt Trigger Input Mode Q3
Buffer
To CCP Module Input

To A/D Channel Input

Note 1: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 61

PIC16F7X7
FIGURE 5-14: BLOCK DIAGRAM OF RB6/PGC PIN

Program Mode/ICD VDD

RBPU(1) Weak
P Pull-up
Data Latch
Data Bus
D Q
I/O pin
WR PORTB CK
TRIS Latch
D Q
WR TRISB CK

TTL
RD TRISB Input Buffer

Latch
Q D

RD PORTB EN Q1
Set RBIF Program Mode/ICD

From other Q D
RB7:RB4 pins RD PORTB
EN
Q3
Schmitt Trigger
Buffer
PGC

Note 1: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit.

DS30498B-page 62 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 5-15: BLOCK DIAGRAM OF RB7/PGD PIN

PORT/Program Mode/ICD
PGD
1

0 VDD
RBPU(1)
Weak
P Pull-up
Data Latch
Data Bus
D Q
WR PORTB I/O pin
CK

TRIS Latch
D Q 0
WR TRISB
CK 1

TTL
RD TRISB Input Buffer

PGD DRVEN

Latch
Q D

RD PORTB Program Mode/ICD EN Q1

Set RBIF

From other Q D
RD PORTB
RB7:RB4 pins
EN
Q3

PGD

Note 1: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 63

PIC16F7X7
TABLE 5-3: PORTB FUNCTIONS
Name Bit# Buffer Function
RB0/INT/AN12 bit 0 TTL/ST(1) Input/output pin or external interrupt input. Internal software
programmable weak pull-up or analog input.
RB1/AN10 bit 1 TTL Input/output pin. Internal software programmable weak pull-up or
analog input.
RB2/AN8 bit 2 TTL Input/output pin. Internal software programmable weak pull-up or
analog input.
RB3/CCP2/AN9 bit 3 TTL Input/output pin or Capture 2 input/Compare 2 output/PWM 2 output.
Internal software programmable weak pull-up or analog input.
RB4/AN11 bit 4 TTL Input/output pin (with interrupt-on-change). Internal software
programmable weak pull-up or analog input.
RB5/AN13/CCP3 bit 5 TTL Input/output pin (with interrupt-on-change). Internal software
programmable weak pull-up or analog input or Capture 2 input/
Compare 2 output/PWM 2 output.
RB6/PGC bit 6 TTL/ST(2) Input/output pin (with interrupt-on-change). Internal software
programmable weak pull-up. Serial programming clock.
RB7/PGD bit 7 TTL/ST(2) Input/output pin (with interrupt-on-change). Internal software
programmable weak pull-up. Serial programming data.
Legend: TTL = TTL input, ST = Schmitt Trigger input
Note 1: This buffer is a Schmitt Trigger input when configured as the external interrupt.
2: This buffer is a Schmitt Trigger input when used in Serial Programming mode.

TABLE 5-4: SUMMARY OF REGISTERS ASSOCIATED WITH PORTB

Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
06h, 106h PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 xx00 0000 uu00 0000
86h, 186h TRISB PORTB Data Direction Register 1111 1111 1111 1111
81h, 181h OPTION_REG RBPU INTEDG T0CS T0SE PSA PS2 PS1 PS0 1111 1111 1111 1111
9Fh ADCON1 ADFM ADCS2 VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 0000 0000 0000 0000
Legend: x = unknown, u = unchanged. Shaded cells are not used by PORTB.

DS30498B-page 64 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
5.3 PORTC and the TRISC Register FIGURE 5-17: PORTC BLOCK DIAGRAM
(PERIPHERAL OUTPUT
PORTC is an 8-bit wide, bidirectional port. The corre-
OVERRIDE) RC<4:3> PINS
sponding data direction register is TRISC. Setting a
TRISC bit (= 1) will make the corresponding PORTC Port/Peripheral Select(2)
pin an input (i.e., put the corresponding output driver in
a high-impedance mode). Clearing a TRISC bit (= 0) Peripheral Data Out
0
will make the corresponding PORTC pin an output (i.e., VDD
Data Bus
put the contents of the output latch on the selected pin). WR
D Q P I/O
Port 1 pin(1)
PORTC is multiplexed with several peripheral functions CK Q
(Table 5-5). PORTC pins have Schmitt Trigger input Data Latch
buffers.
D Q
When enabling peripheral functions, care should be WR
TRIS
taken in defining TRIS bits for each PORTC pin. Some CK Q N
peripherals override the TRIS bit to make a pin an TRIS Latch
output, while other peripherals override the TRIS bit to RD
Vss
make a pin an input. Since the TRIS bit override is in TRIS
Schmitt
effect while the peripheral is enabled, read-modify- Trigger
write instructions (BSF, BCF, XORWF) with TRISC as Peripheral
destination should be avoided. The user should refer to OE(3) Q D Schmitt
the corresponding peripheral section for the correct Trigger
EN with
TRIS bit settings and to Section 16.1 “Read-Modify- RD SMBus
Write Operations” for additional information on Port 0 Levels
read-modify-write operations. SSPl Input

1
FIGURE 5-16: PORTC BLOCK DIAGRAM CKE
(PERIPHERAL OUTPUT SSPSTAT<6>
OVERRIDE) RC<2:0>,
Note 1: I/O pins have diode protection to VDD and VSS.
RC<7:5> PINS 2: Port/Peripheral Select signal selects between port data
and peripheral output.
Port/Peripheral Select(2) 3: Peripheral OE (Output Enable) is only activated if
Peripheral Select is active.
Peripheral Data Out
0 VDD
Data Bus
D Q
WR P I/O
Port CK Q 1 pin(1)

Data Latch

D Q
WR
TRIS CK Q N
TRIS Latch
VSS
RD
TRIS
Schmitt
Trigger
Peripheral
OE(3) Q D

RD EN
Port

Peripheral Input

Note 1: I/O pins have diode protection to VDD and VSS.

2: Port/Peripheral Select signal selects between port
data and peripheral output.
3: Peripheral OE (Output Enable) is only activated if
Peripheral Select is active.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 65

PIC16F7X7
TABLE 5-5: PORTC FUNCTIONS
Name Bit# Buffer Type Function
RC0/T1OSO/T1CKI bit 0 ST Input/output port pin or Timer1 oscillator output/Timer1 clock input.
RC1/T1OSI/CCP2 bit 1 ST Input/output port pin or Timer1 oscillator input or Capture2 input/
Compare2 output/PWM2 output.
RC2/CCP1 bit 2 ST Input/output port pin or Capture1 input/Compare1 output/PWM1 output.
RC3/SCK/SCL bit 3 ST RC3 can also be the synchronous serial clock for both SPI and I2C
modes.
RC4/SDI/SDA bit 4 ST RC4 can also be the SPI data in (SPI mode) or data I/O (I2C mode).
RC5/SDO bit 5 ST Input/output port pin or Synchronous Serial Port data output.
RC6/TX/CK bit 6 ST Input/output port pin or USART asynchronous transmit or synchronous
clock.
RC7/RX/DT bit 7 ST Input/output port pin or USART asynchronous receive or synchronous
data.
Legend: ST = Schmitt Trigger input

TABLE 5-6: SUMMARY OF REGISTERS ASSOCIATED WITH PORTC

Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
07h PORTC RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 xxxx xxxx uuuu uuuu
87h TRISC PORTC Data Direction Register 1111 1111 1111 1111
Legend: x = unknown, u = unchanged

DS30498B-page 66 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
5.4 PORTD and TRISD Registers FIGURE 5-18: PORTD BLOCK DIAGRAM
(IN I/O PORT MODE)
This section is not applicable to the PIC16F737 or
PIC16F767. Data Bus D Q
PORTD is an 8-bit port with Schmitt Trigger input buff-
ers. Each pin is individually configureable as an input or I/O pin(1)
WR Port CK
output.
Data Latch
PORTD can be configured as an 8-bit wide micro-
processor port (Parallel Slave Port) by setting control D Q
bit, PSPMODE (TRISE<4>). In this mode, the input
WR TRIS Schmitt
buffers are TTL. CK Trigger
TRIS Latch Input
Buffer

RD TRIS

Q D

ENEN

RD Port

Note 1: I/O pins have protection diodes to VDD and VSS.

TABLE 5-7: PORTD FUNCTIONS

Name Bit# Buffer Type Function
RD0/PSP0 bit 0 ST/TTL(1) Input/output port pin or Parallel Slave Port bit 0.
RD1/PSP1 bit 1 ST/TTL(1) Input/output port pin or Parallel Slave Port bit 1.
RD2/PSP2 bit 2 ST/TTL (1) Input/output port pin or Parallel Slave Port bit 2.
RD3/PSP3 bit 3 ST/TTL (1) Input/output port pin or Parallel Slave Port bit 3.
RD4/PSP4 bit 4 ST/TTL(1) Input/output port pin or Parallel Slave Port bit 4.
RD5/PSP5 bit 5 ST/TTL(1) Input/output port pin or Parallel Slave Port bit 5.
RD6/PSP6 bit 6 ST/TTL(1) Input/output port pin or Parallel Slave Port bit 6.
RD7/PSP7 bit 7 ST/TTL(1) Input/output port pin or Parallel Slave Port bit 7.
Legend: ST = Schmitt Trigger input, TTL = TTL input
Note 1: Input buffers are Schmitt Triggers when in I/O mode and TTL buffers when in Parallel Slave Port mode.

TABLE 5-8: SUMMARY OF REGISTERS ASSOCIATED WITH PORTD

Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
08h PORTD RD7 RD6 RD5 RD4 RD3 RD2 RD1 RD0 xxxx xxxx uuuu uuuu
88h TRISD PORTD Data Direction Register 1111 1111 1111 1111
(1)
89h TRISE IBF OBF IBOV PSPMODE — PORTE Data Direction bits 0000 1111 0000 1111
Legend: x = unknown, u = unchanged, - = unimplemented, read as ‘0’. Shaded cells are not used by PORTD.
Note 1: RE3 is an input only. The state of the TRISE3 bit has no effect and will always read ‘1’.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 67

PIC16F7X7
5.5 PORTE and TRISE Register FIGURE 5-19: PORTE BLOCK DIAGRAM
(IN I/O PORT MODE)
This section is not applicable to the PIC16F737 or
PIC16F767.
Data Bus D Q
PORTE has four pins, RE0/RD/AN5, RE1/WR/AN6,
RE2/CS/AN7 and MCLR/VPP/RE3, which are individu- I/O pin(1)
WR Port CK
ally configureable as inputs or outputs. These pins have
Schmitt Trigger input buffers. RE3 is only available as an Data Latch
input if MCLRE is ‘0’ in Configuration Word 1. D Q
I/O PORTE becomes control inputs for the micro-
WR TRIS Schmitt
processor port when bit, PSPMODE (TRISE<4>), is CK Trigger
set. In this mode, the user must make sure that the TRIS Latch Input
TRISE<2:0> bits are set (pins are configured as digital Buffer
inputs). Ensure ADCON1 is configured for digital I/O. In
this mode, the input buffers are TTL. RD TRIS
Register 5-1 shows the TRISE register, which also
controls the Parallel Slave Port operation. Q D
PORTE pins are multiplexed with analog inputs. When
selected as an analog input, these pins will read as ‘0’s. ENEN

TRISE controls the direction of the RE pins, even when RD Port

they are being used as analog inputs. The user must
make sure to keep the pins configured as inputs when
Note 1: I/O pins have protection diodes to VDD and VSS.
using them as analog inputs.
Note: On a Power-on Reset, these pins are
configured as analog inputs and read as ‘0’.

TABLE 5-9: PORTE FUNCTIONS

Name Bit# Buffer Type Function
(1)
RE0/RD/AN5 bit 0 ST/TTL Input/output port pin or read control input in Parallel Slave Port mode or analog input.
For RD (PSP mode):
1 = Idle
0 = Read operation. Contents of PORTD register output to PORTD I/O pins (if chip selected).
RE1/WR/AN6 bit 1 ST/TTL(1) Input/output port pin or write control input in Parallel Slave Port mode or analog input.
For WR (PSP mode):
1 = Idle
0 = Write operation. Value of PORTD I/O pins latched into PORTD register (if chip selected).
RE2/CS/AN7 bit 2 ST/TTL(1) Input/output port pin or chip select control input in Parallel Slave Port mode or analog input.
For CS (PSP mode):
1 = Device is not selected
0 = Device is selected
MCLR/VPP/RE3 bit 3 ST Input, Master Clear (Reset) or programming input voltage.
Legend: ST = Schmitt Trigger input, TTL = TTL input
Note 1: Input buffers are Schmitt Triggers when in I/O mode and TTL buffers when in Parallel Slave Port mode.

TABLE 5-10: SUMMARY OF REGISTERS ASSOCIATED WITH PORTE

Value on
Value on:
Addr Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
09h PORTE — — — — RE3 RE2 RE1 RE0 ---- x000 ---- -uuu
89h TRISE IBF OBF IBOV PSPMODE — (1) PORTE Data Direction bits 0000 1111 0000 1111
9Fh ADCON1 ADFM ADCS2 VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 0000 0000 0000 0000
Legend: x = unknown, u = unchanged, - = unimplemented, read as ‘0’. Shaded cells are not used by PORTE.
Note 1: RE3 is an input only. The state of the TRISE3 bit has no effect and will always read ‘1’.

DS30498B-page 68 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
REGISTER 5-1: TRISE REGISTER (ADDRESS 89h)
R-0 R-0 R/W-0 R/W-0 U-0 R/W-1 R/W-1 R/W-1
IBF OBF IBOV PSPMODE —(1) TRISE2 TRISE1 TRISE0
bit 7 bit 0

bit 7 Parallel Slave Port Status/Control bits:

IBF: Input Buffer Full Status bit
1 = A word has been received and is waiting to be read by the CPU
0 = No word has been received
bit 6 OBF: Output Buffer Full Status bit
1 = The output buffer still holds a previously written word
0 = The output buffer has been read
bit 5 IBOV: Input Buffer Overflow Detect bit (in Microprocessor mode)
1 = A write occurred when a previously input word has not been read (must be cleared in
software)
0 = No overflow occurred
bit 4 PSPMODE: Parallel Slave Port Mode Select bit
1 = Parallel Slave Port mode
0 = General Purpose I/O mode
bit 3 Unimplemented: Read as ‘1’(1)
Note 1: RE3 is an input only. The state of the TRISE3 bit has no effect and will always read ‘1’.
bit 2 PORTE Data Direction bits:
TRISE2: Direction Control bit for pin RE2/CS/AN7
1 = Input
0 = Output
bit 1 TRISE1: Direction Control bit for pin RE1/WR/AN6
1 = Input
0 = Output
bit 0 TRISE0: Direction Control bit for pin RE0/RD/AN5
1 = Input
0 = Output

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

 2003 Microchip Technology Inc. Preliminary DS30498B-page 69

PIC16F7X7
5.6 Parallel Slave Port When either the CS or RD pins are detected high, the
PORTD outputs are disabled and the interrupt flag bit
The Parallel Slave Port (PSP) is not implemented on PSPIF is set on the Q4 clock cycle following the next
the PIC16F737 or PIC16F767. Q2 cycle, indicating that the read is complete. OBF
PORTD operates as an 8-bit wide Parallel Slave Port or remains low until firmware writes new data to PORTD.
microprocessor port when control bit, PSPMODE When not in PSP mode, the IBF and OBF bits are held
(TRISE<4>), is set. In Slave mode, it is asynchronously clear. Flag bit IBOV remains unchanged. The PSPIF bit
readable and writable by an external system using the must be cleared by the user in firmware; the interrupt
read control input pin RE0/RD/AN5, the write control can be disabled by clearing the interrupt enable bit,
input pin RE1/WR/AN6 and the chip select control input PSPIE (PIE1<7>).
pin RE2/CS/AN7.
The PSP can directly interface to an 8-bit micro- FIGURE 5-20: PORTD AND PORTE
processor data bus. The external microprocessor can BLOCK DIAGRAM
read or write the PORTD latch as an 8-bit latch. Setting (PARALLEL SLAVE PORT)
bit PSPMODE enables port pin RE0/RD/AN5 to be the
RD input, RE1/WR/AN6 to be the WR input and
RE2/CS/AN7 to be the CS (Chip Select) input. For this Data Bus
D Q
functionality, the corresponding data direction bits of
WR RDx pin
the TRISE register (TRISE<2:0>) must be configured Port
as inputs (i.e., set). The A/D port configuration bits, CK
PCFG3:PCFG0 (ADCON1<3:0>), must be set to TTL
configure pins RE2:RE0 as digital I/O.
Q D
There are actually two 8-bit latches, one for data output
(external reads) and one for data input (external RD ENEN
writes). The firmware writes 8-bit data to the PORTD Port
output data latch and reads data from the PORTD input
One bit of PORTD
data latch (note that they have the same address). In
this mode, the TRISD register is ignored since the Set Interrupt Flag
external device is controlling the direction of data flow. PSPIF (PIR1<7>)
An external write to the PSP occurs when the CS and
WR lines are both detected low. Firmware can read the
actual data on the PORTD pins during this time. When
either the CS or WR lines become high (level trig- Read
TTL RD
gered), the data on the PORTD pins is latched and the
Input Buffer Full (IBF) status flag bit (TRISE<7>) and Chip Select
TTL CS
interrupt flag bit, PSPIF (PIR1<7>), are set on the Q4
clock cycle following the next Q2 cycle to signal the Write
write is complete (Figure 5-21). Firmware clears the TTL WR
IBF flag by reading the latched PORTD data and clears
the PSPIF bit. Note: I/O pin has protection diodes to VDD and VSS.

The Input Buffer Overflow (IBOV) status flag bit

(TRISE<5>) is set if an external write to the PSP occurs
while the IBF flag is set from a previous external write.
The previous PORTD data is overwritten with the new
data. IBOV is cleared by reading PORTD and clearing
IBOV.
A read from the PSP occurs when both the CS and RD
lines are detected low. The data in the PORTD output
latch is output to the PORTD pins. The Output Buffer
Full (OBF) status flag bit (TRISE<6>) is cleared imme-
diately (Figure 5-22), indicating that the PORTD latch is
being read or has been read by the external bus. If
firmware writes new data to the output latch during this
time, it is immediately output to the PORTD pins but
OBF will remain cleared.

DS30498B-page 70 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 5-21: PARALLEL SLAVE PORT WRITE WAVEFORMS

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

CS

WR

RD

PORTD<7:0>

IBF

OBF

PSPIF

FIGURE 5-22: PARALLEL SLAVE PORT READ WAVEFORMS

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

CS

WR

RD

PORTD<7:0>

IBF

OBF

PSPIF

TABLE 5-11: REGISTERS ASSOCIATED WITH PARALLEL SLAVE PORT

Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
08h PORTD Port Data Latch when written: Port pins when read xxxx xxxx uuuu uuuu
09h PORTE — — — — RE3 RE2 RE1 RE0 ---- x000 ---- x000
89h TRISE IBF OBF IBOV PSPMODE —(2) PORTE Data Direction bits 0000 1111 0000 1111
0Ch PIR1 PSPIF (1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
8Ch PIE1 PSPIE (1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
9Fh ADCON1 ADFM ADCS2 VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 0000 0000 0000 0000
Legend: x = unknown, u = unchanged, - = unimplemented, read as ‘0’. Shaded cells are not used by the Parallel Slave Port.
Note 1: Bits PSPIE and PSPIF are reserved on the PIC16F737/767; always maintain these bits clear.
2: RE3 is an input only. The state of the TRISE3 bit has no effect and will always read ‘1’.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 71

PIC16F7X7
NOTES:

DS30498B-page 72 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
6.0 TIMER0 MODULE Counter mode is selected by setting bit, T0CS
(OPTION_REG<5>). In Counter mode, Timer0 will
The Timer0 module timer/counter has the following increment, either on every rising or falling edge of pin
features: RA4/T0CKI/C1OUT. The incrementing edge is deter-
• 8-bit timer/counter mined by the Timer0 Source Edge Select bit, T0SE
• Readable and writable (OPTION_REG<4>). Clearing bit T0SE selects the rising
edge. Restrictions on the external clock input are
• 8-bit software programmable prescaler
discussed in detail in Section 6.3 “Using Timer0 With
• Internal or external clock select an External Clock”.
• Interrupt on overflow from FFh to 00h
The prescaler is mutually, exclusively shared between
• Edge select for external clock the Timer0 module and the Watchdog Timer. The
Additional information on the Timer0 module is prescaler is not readable or writable. Section 6.4
available in the PICmicro® Mid-Range MCU Family “Prescaler” details the operation of the prescaler.
Reference Manual (DS33023).
Figure 6-1 is a block diagram of the Timer0 module and 6.2 Timer0 Interrupt
the prescaler shared with the WDT. The TMR0 interrupt is generated when the TMR0 reg-
ister overflows from FFh to 00h. This overflow sets bit
6.1 Timer0 Operation TMR0IF (INTCON<2>). The interrupt can be masked
by clearing bit TMR0IE (INTCON<5>). Bit TMR0IF
Timer0 operation is controlled through the
must be cleared in software by the Timer0 module
OPTION_REG register (see Register 2-2). Timer mode
Interrupt Service Routine before re-enabling this inter-
is selected by clearing bit T0CS (OPTION_REG<5>).
rupt. The TMR0 interrupt cannot awaken the processor
In Timer mode, the Timer0 module will increment every
from Sleep since the timer is shut-off during Sleep.
instruction cycle (without prescaler). If the TMR0 regis-
ter is written, the increment is inhibited for the following
two instruction cycles. The user can work around this
by writing an adjusted value to the TMR0 register.

FIGURE 6-1: BLOCK DIAGRAM OF THE TIMER0/WDT PRESCALER

CLKO (= FOSC/4) Data Bus

8
0 M 1
U M
Sync
X U 2 TMR0 Reg
1 0
RA4/T0CKI/C1OUT X Cycles
pin
T0SE
T0CS Set Flag bit TMR0IF
PSA
on Overflow

Prescaler

0
M 8-bit Prescaler
WDT Timer
U
1 X
16-bit 8
31.25 kHz
Prescaler
8 - to - 1 MUX PS2:PS0

WDT Enable bit PSA

0 1

MUX PSA

WDT Time-out

Note: T0CS, T0SE, PSA and PS2:PS0 are (OPTION_REG<5:0>).

 2003 Microchip Technology Inc. Preliminary DS30498B-page 73

PIC16F7X7
6.3 Using Timer0 With an External Note: Although the prescaler can be assigned to
Clock either the WDT or Timer0, but not both, a
When no prescaler is used, the external clock input is new divide counter is implemented in the
the same as the prescaler output. The synchronization WDT circuit to give multiple WDT time-out
of T0CKI with the internal phase clocks is accom- selections. This allows TMR0 and WDT to
plished by sampling the prescaler output on the Q2 and each have their own scaler. Refer to
Q4 cycles of the internal phase clocks. Therefore, it is Section 15.17 “Watchdog Timer (WDT)”
necessary for T0CKI to be high for at least 2 TOSC (and for further details.
a small RC delay of 20 ns) and low for at least 2 TOSC
The PSA and PS2:PS0 bits (OPTION_REG<3:0>)
(and a small RC delay of 20 ns). Refer to the electrical
determine the prescaler assignment and prescale ratio.
specification of the desired device.
When assigned to the Timer0 module, all instructions
6.4 Prescaler writing to the TMR0 register (e.g., CLRF 1, MOVWF 1,
BSF 1,x....etc.) will clear the prescaler. When assigned
There is only one prescaler available, which is mutually to WDT, a CLRWDT instruction will clear the prescaler
exclusively shared between the Timer0 module and the along with the Watchdog Timer. The prescaler is not
Watchdog Timer. A prescaler assignment for the readable or writable.
Timer0 module means that the prescaler cannot be
Note: Writing to TMR0 when the prescaler is
used by the Watchdog Timer and vice versa. This
assigned to Timer0 will clear the prescaler
prescaler is not readable or writable (see Figure 6-1).
count but will not change the prescaler
assignment.

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 PIC16F7X7
REGISTER 6-1: OPTION_REG REGISTER
R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
RBPU INTEDG T0CS T0SE PSA(1) PS2 PS1 PS0
bit 7 bit 0

bit 7 RBPU: PORTB Pull-up Enable bit

1 = PORTB pull-ups are disabled
0 = PORTB pull-ups are enabled
bit 6 INTEDG: Interrupt Edge Select bit
1 = Interrupt on rising edge of RB0/INT pin
0 = Interrupt on falling edge of RB0/INT pin
bit 5 T0CS: TMR0 Clock Source Select bit
1 = Transition on T0CKI pin
0 = Internal instruction cycle clock (CLKO)
bit 4 T0SE: TMR0 Source Edge Select bit
1 = Increment on high-to-low transition on T0CKI pin
0 = Increment on low-to-high transition on T0CKI pin
bit 3 PSA: Prescaler Assignment bit(1)
1 = Prescaler is assigned to the WDT
0 = Prescaler is assigned to the Timer0 module
Note 1: To avoid an unintended device Reset, the instruction sequence shown in the
PICmicro® Mid-Range MCU Family Reference Manual (DS33023) must be
executed when changing the prescaler assignment from Timer0 to the WDT. This
sequence must be followed even if the WDT is disabled.
bit 2-0 PS<2:0>: Prescaler Rate Select bits
Bit Value TMR0 Rate WDT Rate
000 1:2 1:1
001 1:4 1:2
010 1:8 1:4
011 1 : 16 1:8
100 1 : 32 1 : 16
101 1 : 64 1 : 32
110 1 : 128 1 : 64
111 1 : 256 1 : 128

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

 2003 Microchip Technology Inc. Preliminary DS30498B-page 75

PIC16F7X7
EXAMPLE 6-1: CHANGING THE PRESCALER ASSIGNMENT FROM WDT TO TIMER0
CLRWDT ; Clear WDT and prescaler
BANKSEL OPTION ; Select Bank of OPTION
MOVLW b'xxxx0xxx' ; Select TMR0, new prescale
MOVWF OPTION ; value and clock source

TABLE 6-1: REGISTERS ASSOCIATED WITH TIMER0

Value on
Value on
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
01h,101h TMR0 Timer0 Module Register xxxx xxxx uuuu uuuu
0Bh,8Bh, INTCON GIE PEIE TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u
10Bh,18Bh
81h,181h OPTION RBPU INTEDG T0CS T0SE PSA PS2 PS1 PS0 1111 1111 1111 1111
Legend: x = unknown, u = unchanged, - = unimplemented locations read as ‘0’. Shaded cells are not used by Timer0.

DS30498B-page 76 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
7.0 TIMER1 MODULE 7.1 Timer1 Operation
The Timer1 module is a 16-bit timer/counter consisting Timer1 can operate in one of three modes:
of two 8-bit registers (TMR1H and TMR1L), which are • as a Timer
readable and writable. The TMR1 register pair
• as a Synchronous Counter
(TMR1H:TMR1L) increments from 0000h to FFFFh
and rolls over to 0000h. The TMR1 interrupt, if enabled, • as an Asynchronous Counter
is generated on overflow which is latched in interrupt The operating mode is determined by the clock select
flag bit, TMR1IF (PIR1<0>). This interrupt can be bit, TMR1CS (T1CON<1>).
enabled/disabled by setting/clearing TMR1 interrupt In Timer mode, Timer1 increments every instruction
enable bit, TMR1IE (PIE1<0>). cycle. In Counter mode, it increments on every rising
The Timer1 oscillator can be used as a secondary clock edge of the external clock input.
source in low-power modes. When the T1RUN bit is set Timer1 can be enabled/disabled by setting/clearing
along with SCS<1:0> = 01, the Timer1 oscillator is pro- control bit, TMR1ON (T1CON<0>).
viding the system clock. If the Fail-Safe Clock Monitor
is enabled and the Timer1 oscillator fails while Timer1 also has an internal “Reset input”. This Reset
providing the system clock, polling the T1RUN bit will can be generated by the CCP1 module as the special
indicate whether the clock is being provided by the event trigger (see Section 9.4 “Capture Mode”).
Timer1 oscillator or another source. Register 7-1 shows the Timer1 Control register.

Timer1 can also be used to provide Real-Time Clock When the Timer1 oscillator is enabled (T1OSCEN is
(RTC) functionality to applications with only a minimal set), the RC0/T1OSO/T1CKI and RC1/T1OSI/CCP2
addition of external components and code overhead. pins become inputs. That is, the TRISB<7:6> value is
ignored and these pins read as ‘0’.
Additional information on timer modules is available in
the PICmicro® Mid-Range MCU Family Reference
Manual (DS33023).

 2003 Microchip Technology Inc. Preliminary DS30498B-page 77

PIC16F7X7
REGISTER 7-1: T1CON: TIMER1 CONTROL REGISTER (ADDRESS 10h)
U-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
— T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON
bit 7 bit 0

bit 7 Unimplemented: Read as ‘0’

bit 6 T1RUN: Timer1 System Clock Status bit
1 = System clock is derived from Timer1 oscillator
0 = System clock is derived from another source
bit 5-4 T1CKPS<1:0>: Timer1 Input Clock Prescale Select bits
11 = 1:8 prescale value
10 = 1:4 prescale value
01 = 1:2 prescale value
00 = 1:1 prescale value
bit 3 T1OSCEN: Timer1 Oscillator Enable Control bit
1 = Oscillator is enabled
0 = Oscillator is shut-off (the oscillator inverter is turned off to eliminate power drain)
bit 2 T1SYNC: Timer1 External Clock Input Synchronization Control bit
TMR1CS = 1:
1 = Do not synchronize external clock input
0 = Synchronize external clock input
TMR1CS = 0:
This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0.
bit 1 TMR1CS: Timer1 Clock Source Select bit
1 = External clock from pin RC0/T1OSO/T1CKI (on the rising edge)
0 = Internal clock (FOSC/4)
bit 0 TMR1ON: Timer1 On bit
1 = Enables Timer1
0 = Stops Timer1

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

DS30498B-page 78 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
7.2 Timer1 Operation in Timer Mode 7.4 Timer1 Operation in Synchronized
Timer mode is selected by clearing the TMR1CS
Counter Mode
(T1CON<1>) bit. In this mode, the input clock to the Counter mode is selected by setting bit TMR1CS. In
timer is FOSC/4. The synchronize control bit, T1SYNC this mode, the timer increments on every rising edge of
(T1CON<2>), has no effect since the internal clock is clock input on pin RC1/T1OSI/CCP2, when bit
always in sync. T1OSCEN is set, or on pin RC0/T1OSO/T1CKI, when
bit T1OSCEN is cleared.
7.3 Timer1 Counter Operation If T1SYNC is cleared, then the external clock input is
Timer1 may operate in Asynchronous or Synchronous synchronized with internal phase clocks. The synchro-
mode depending on the setting of the TMR1CS bit. nization is done after the prescaler stage. The
prescaler stage is an asynchronous ripple counter.
When Timer1 is being incremented via an external
source, increments occur on a rising edge. After Timer1 In this configuration during Sleep mode, Timer1 will not
is enabled in Counter mode, the module must first have increment, even if the external clock is present since
a falling edge before the counter begins to increment. the synchronization circuit is shut-off. The prescaler,
however, will continue to increment.

FIGURE 7-1: TIMER1 INCREMENTING EDGE

T1CKI
(Default High)

T1CKI
(Default Low)

Note: Arrows indicate counter increments.

FIGURE 7-2: TIMER1 BLOCK DIAGRAM

Set Flag bit
TMR1IF on
Overflow Synchronized
TMR1 0
Clock Input
TMR1H TMR1L
1
TMR1ON
On/Off T1SYNC
T1OSC
1
Synchronize
Prescaler
T1OSO/T1CKI 1, 2, 4, 8
T1OSCEN FOSC/4 det
Enable Internal 0
Oscillator(1) Clock 2 Q Clock
T1OSI T1CKPS1:T1CKPS0
TMR1CS

Note 1: When the T1OSCEN bit is cleared, the inverter is turned off. This eliminates power drain.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 79

PIC16F7X7
7.5 Timer1 Operation in 7.5.1 READING AND WRITING TIMER1 IN
Asynchronous Counter Mode ASYNCHRONOUS COUNTER MODE
If control bit, T1SYNC (T1CON<2>), is set, the external Reading TMR1H or TMR1L while the timer is running
clock input is not synchronized. The timer continues to from an external asynchronous clock will ensure a valid
increment asynchronous to the internal phase clocks. read (taken care of in hardware). However, the user
The timer will continue to run during Sleep and can should keep in mind that reading the 16-bit timer in two
generate an interrupt on overflow that will wake-up the 8-bit values itself, poses certain problems, since the
processor. However, special precautions in software timer may overflow between the reads.
are needed to read/write the timer (Section 7.5.1 For writes, it is recommended that the user simply stop
“Reading and Writing Timer1 in Asynchronous the timer and write the desired values. A write conten-
Counter Mode”). tion may occur by writing to the Timer registers while
In Asynchronous Counter mode, Timer1 cannot be the register is incrementing. This may produce an
used as a time base for capture or compare operations. unpredictable value in the Timer register.
Reading the 16-bit value requires some care. The
example codes provided in Example 7-1 and
Example 7-2 demonstrate how to write to and read
Timer1 while it is running in Asynchronous mode.

EXAMPLE 7-1: WRITING A 16-BIT FREE RUNNING TIMER

; All interrupts are disabled
CLRF TMR1L ; Clear Low byte, Ensures no rollover into TMR1H
MOVLW HI_BYTE ; Value to load into TMR1H
MOVWF TMR1H, F ; Write High byte
MOVLW LO_BYTE ; Value to load into TMR1L
MOVWF TMR1H, F ; Write Low byte
; Re-enable the Interrupt (if required)
CONTINUE ; Continue with your code

EXAMPLE 7-2: READING A 16-BIT FREE RUNNING TIMER

; All interrupts are disabled
MOVF TMR1H, W ; Read high byte
MOVWF TMPH
MOVF TMR1L, W ; Read low byte
MOVWF TMPL
MOVF TMR1H, W ; Read high byte
SUBWF TMPH, W ; Sub 1st read with 2nd read
BTFSC STATUS,Z ; Is result = 0
GOTO CONTINUE ; Good 16-bit read
; TMR1L may have rolled over between the read of the high and low bytes.
; Reading the high and low bytes now will read a good value.
MOVF TMR1H, W ; Read high byte
MOVWF TMPH
MOVF TMR1L, W ; Read low byte
MOVWF TMPL ; Re-enable the Interrupt (if required)
CONTINUE ; Continue with your code

DS30498B-page 80 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
7.6 Timer1 Oscillator 7.7 Timer1 Oscillator Layout
A crystal oscillator circuit is built between pins T1OSI
Considerations
(input) and T1OSO (amplifier output). It is enabled by The Timer1 oscillator circuit draws very little power dur-
setting control bit, T1OSCEN (T1CON<3>). The oscil- ing operation. Due to the low-power nature of the oscil-
lator is a low-power oscillator, rated up to 32.768 kHz. lator, it may also be sensitive to rapidly changing
It will continue to run during all power managed modes. signals in close proximity.
It is primarily intended for a 32 kHz crystal. The circuit
The oscillator circuit, shown in Figure 7-3, should be
for a typical LP oscillator is shown in Figure 7-3.
located as close as possible to the microcontroller.
Table 7-1 shows the capacitor selection for the Timer1
There should be no circuits passing within the oscillator
oscillator.
circuit boundaries other than VSS or VDD.
The user must provide a software time delay to ensure
If a high-speed circuit must be located near the oscilla-
proper oscillator start-up.
tor, a grounded guard ring around the oscillator circuit,
as shown in Figure 7-4, may be helpful when used on
FIGURE 7-3: EXTERNAL a single sided PCB or in addition to a ground plane.
COMPONENTS FOR THE
TIMER1 LP OSCILLATOR FIGURE 7-4: OSCILLATOR CIRCUIT
WITH GROUNDED
C1 PIC16F7X7
33 pF
GUARD RING
T1OSI
VSS
XTAL
32.768 kHz OSC1

T1OSO OSC2
C2
33 pF
Note: See the Notes with Table 7-1 for additional
information about capacitor selection. RC0

RC1

TABLE 7-1: CAPACITOR SELECTION FOR RC2

THE TIMER1 OSCILLATOR
Osc Type Freq C1 C2
LP 32 kHz 33 pF 33 pF 7.8 Resetting Timer1 Using a CCP
Trigger Output
Note 1: Microchip suggests this value as a starting If the CCP1 module is configured in Compare mode to
point in validating the oscillator circuit. generate a “special event trigger" signal
2: Higher capacitance increases the stability (CCP1M3:CCP1M0 = 1011), the signal will reset
of the oscillator but also increases the Timer1 and start an A/D conversion (if the A/D module
start-up time. is enabled).
3: Since each resonator/crystal has its own Note: The special event triggers from the CCP1
characteristics, the user should consult module will not set interrupt flag bit,
the resonator/crystal manufacturer for TMR1IF (PIR1<0>).
appropriate values of external Timer1 must be configured for either Timer or Synchro-
components. nized Counter mode to take advantage of this feature.
4: Capacitor values are for design guidance If Timer1 is running in Asynchronous Counter mode,
only. this Reset operation may not work.
In the event that a write to Timer1 coincides with a
special event trigger from CCP1, the write will take
precedence.
In this mode of operation, the CCPR1H:CCPR1L
register pair effectively becomes the period register for
Timer1.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 81

PIC16F7X7
7.9 Resetting Timer1 Register Pair battery or supercapacitor as a power source, it can
(TMR1H, TMR1L) completely eliminate the need for a separate RTC
device and battery backup.
TMR1H and TMR1L registers are not reset to 00h on a
The application code routine, RTCisr, shown in
POR, or any other Reset, except by the CCP1 special
Example 7-3, demonstrates a simple method to incre-
event triggers.
ment a counter at one-second intervals using an Inter-
T1CON register is reset to 00h on a Power-on Reset or rupt Service Routine. Incrementing the TMR1 register
a Brown-out Reset, which shuts off the timer and pair to overflow, triggers the interrupt and calls the rou-
leaves a 1:1 prescale. In all other Resets, the register tine which increments the seconds counter by one;
is unaffected. additional counters for minutes and hours are
incremented as the previous counter overflows.
7.10 Timer1 Prescaler Since the register pair is 16 bits wide, counting up to
The prescaler counter is cleared on writes to the overflow the register directly from a 32.768 kHz clock
TMR1H or TMR1L registers. would take 2 seconds. To force the overflow at the
required one-second intervals, it is necessary to
preload it; the simplest method is to set the MSbit of
7.11 Using Timer1 as a Real-Time Clock TMR1H with a BSF instruction. Note that the TMR1L
Adding an external LP oscillator to Timer1 (such as the register is never preloaded or altered; doing so may
one described in Section 7.6 “Timer1 Oscillator”) introduce cumulative error over many cycles.
gives users the option to include RTC functionality in For this method to be accurate, Timer1 must operate in
their applications. This is accomplished with an inex- Asynchronous mode and the Timer1 overflow interrupt
pensive watch crystal to provide an accurate time base must be enabled (PIE1<0> = 1) as shown in the
and several lines of application code to calculate the routine, RTCinit. The Timer1 oscillator must also be
time. When operating in Sleep mode and using a enabled and running at all times.

EXAMPLE 7-3: IMPLEMENTING A REAL-TIME CLOCK USING A TIMER1 INTERRUPT SERVICE

RTCinit BANKSEL TMR1H
MOVLW 0x80 ; Preload TMR1 register pair
MOVWF TMR1H ; for 1 second overflow
CLRF TMR1L
MOVLW b’00001111’ ; Configure for external clock,
MOVWF T1CON ; Asynchronous operation, external oscillator
CLRF secs ; Initialize timekeeping registers
CLRF mins
MOVLW .12
MOVWF hours
BANKSEL PIE1
BSF PIE1, TMR1IE ; Enable Timer1 interrupt
RETURN
RTCisr BANKSEL TMR1H
BSF TMR1H, 7 ; Preload for 1 sec overflow
BCF PIR1, TMR1IF ; Clear interrupt flag
INCF secs, F ; Increment seconds
MOVF secs, w
SUBLW .60
BTFSS STATUS, Z ; 60 seconds elapsed?
RETURN ; No, done
CLRF seconds ; Clear seconds
INCF mins, f ; Increment minutes
MOVF mins, w
SUBLW .60
BTFSS STATUS, Z ; 60 seconds elapsed?
RETURN ; No, done
CLRF mins ; Clear minutes
INCF hours, f ; Increment hours
MOVF hours, w
SUBLW .24
BTFSS STATUS, Z ; 24 hours elapsed?
RETURN ; No, done
CLRF hours ; Clear hours
RETURN ; Done

DS30498B-page 82 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
TABLE 7-2: REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER
Value on
Value on
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
0Bh, 8Bh, INTCON GIE PEIE TMR0IE INTE RBIE TMR0IF INTF RBIF 0000 000x 0000 000u
10Bh, 18Bh
0Ch PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
8Ch PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
0Eh TMR1L Holding Register for the Least Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu
0Fh TMR1H Holding Register for the Most Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu
10h T1CON — T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON -000 0000 -uuu uuuu
Legend: x = unknown, u = unchanged, - = unimplemented, read as ‘0’. Shaded cells are not used by the Timer1 module.
Note 1: Bits PSPIE and PSPIF are reserved on the PIC16F737/767 devices; always maintain these bits clear.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 83

PIC16F7X7
NOTES:

DS30498B-page 84 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
8.0 TIMER2 MODULE 8.1 Timer2 Prescaler and Postscaler
Timer2 is an 8-bit timer with a prescaler and a The prescaler and postscaler counters are cleared
postscaler. It can be used as the PWM time base for the when any of the following occurs:
PWM mode of the CCP module(s). The TMR2 register • a write to the TMR2 register
is readable and writable and is cleared on any device
• a write to the T2CON register
Reset.
• any device Reset (POR, MCLR Reset, WDT
The input clock (FOSC/4) has a prescale option of 1:1, Reset or BOR)
1:4 or 1:16, selected by control bits,
T2CKPS1:T2CKPS0 (T2CON<1:0>). TMR2 is not cleared when T2CON is written.

The Timer2 module has an 8-bit period register, PR2.

8.2 Output of TMR2
Timer2 increments from 00h until it matches PR2 and
then resets to 00h on the next increment cycle. PR2 is The output of TMR2 (before the postscaler) is fed to the
a readable and writable register. The PR2 register is SSP module which optionally uses it to generate the
initialized to FFh upon Reset. shift clock.
The match output of TMR2 goes through a 4-bit
postscaler (which gives a 1:1 to 1:16 scaling inclusive) FIGURE 8-1: TIMER2 BLOCK DIAGRAM
to generate a TMR2 interrupt, latched in flag bit,
Sets Flag
TMR2IF (PIR1<1>). bit TMR2IF
TMR2
Output(1)
Timer2 can be shut-off by clearing control bit, TMR2ON
(T2CON<2>), to minimize power consumption. Reset Prescaler
TMR2 Reg FOSC/4
Register 8-1 shows the Timer2 Control register. 1:1, 1:4, 1:16
Postscaler
Additional information on timer modules is available in Comparator 2
1:1 to 1:16 EQ
the PICmicro® Mid-Range MCU Family Reference T2CKPS1:
Manual (DS33023). 4 PR2 Reg T2CKPS0
T2OUTPS3:
T2OUTPS0

Note 1: TMR2 register output can be software selected by the

SSP module as a baud clock.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 85

PIC16F7X7
REGISTER 8-1: T2CON: TIMER2 CONTROL REGISTER (ADDRESS 12h)
U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
— TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0
bit 7 bit 0

bit 7 Unimplemented: Read as ‘0’

bit 6-3 TOUTPS3:TOUTPS0: Timer2 Output Postscale Select bits
0000 = 1:1 postscale
0001 = 1:2 postscale
0010 = 1:3 postscale
•
•
•
1111 = 1:16 postscale
bit 2 TMR2ON: Timer2 On bit
1 = Timer2 is on
0 = Timer2 is off
bit 1-0 T2CKPS1:T2CKPS0: Timer2 Clock Prescale Select bits
00 = Prescaler is 1
01 = Prescaler is 4
1x = Prescaler is 16

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

TABLE 8-1: REGISTERS ASSOCIATED WITH TIMER2 AS A TIMER/COUNTER

Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
0Bh,8Bh, INTCON GIE PEIE TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u
10Bh, 18Bh
0Ch PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
8Ch PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
11h TMR2 Timer2 Module Register 0000 0000 0000 0000
12h T2CON — TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 -000 0000
92h PR2 Timer2 Period Register 1111 1111 1111 1111
Legend: x = unknown, u = unchanged, - = unimplemented, read as ‘0’. Shaded cells are not used by the Timer2 module.
Note 1: Bits PSPIE and PSPIF are reserved on the PIC16F737/767 devices; always maintain these bits clear.

DS30498B-page 86 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
9.0 CAPTURE/COMPARE/PWM 9.2 CCP2 Module
MODULES Capture/Compare/PWM Register 1 (CCPR1) is com-
Each Capture/Compare/PWM (CCP) module contains prised of two 8-bit registers: CCPR1L (low byte) and
a 16-bit register which can operate as a: CCPR1H (high byte). The CCP2CON register controls
the operation of CCP2. The special event trigger is gen-
• 16-bit Capture register erated by a compare match; it will clear both TMR1H and
• 16-bit Compare register TMR1L registers and start an A/D conversion (if the A/D
• PWM Master/Slave Duty Cycle register module is enabled).
The CCP1, CCP2 and CCP3 modules are identical in Additional information on CCP modules is available in
operation, with the exception being the operation of the the PICmicro® Mid-Range MCU Family Reference
special event trigger. Table 9-1 and Table 9-2 show the Manual (DS33023) and in Application Note AN594,
resources and interactions of the CCP module(s). In “Using the CCP Module(s)” (DS00594).
the following sections, the operation of a CCP module
is described with respect to CCP1. CCP2 and CCP3 9.3 CCP3 Module
operate the same as CCP1, except where noted.
Capture/Compare/PWM Register 1 (CCPR1) is com-
prised of two 8-bit registers: CCPR1L (low byte) and
9.1 CCP1 Module
CCPR1H (high byte). The CCP3CON register controls
Capture/Compare/PWM Register 1 (CCPR1) is the operation of CCP3.
comprised of two 8-bit registers: CCPR1L (low byte)
and CCPR1H (high byte). The CCP1CON register con- TABLE 9-1: CCP MODE – TIMER
trols the operation of CCP1. The special event trigger RESOURCES REQUIRED
is generated by a compare match and will clear both
TMR1H and TMR1L registers. CCP Mode Timer Resource
Capture Timer1
Compare Timer1
PWM Timer2

TABLE 9-2: INTERACTION OF TWO CCP MODULES

CCPx Mode CCPy Mode Interaction
Capture Capture Same TMR1 time base.
Capture Compare Same TMR1 time base.
Compare Compare Same TMR1 time base.
PWM PWM The PWMs will have the same frequency and update rate (TMR2 interrupt).
The rising edges are aligned.
PWM Capture None.
PWM Compare None.

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PIC16F7X7
REGISTER 9-1: CCPxCON REGISTER (ADDRESS 17h, 1Dh, 97h)
U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
— — CCPxX CCPxY CCPxM3 CCPxM2 CCPxM1 CCPxM0
bit 7 bit 0

bit 7-6 Unimplemented: Read as ‘0’

bit 5-4 CCPxX:CCPxY: PWM Least Significant bits
Capture mode:
Unused.
Compare mode:
Unused.
PWM mode:
These bits are the two LSbs of the PWM duty cycle. The eight MSbs are found in CCPRxL.
bit 3-0 CCPxM3:CCPxM0: CCPx Mode Select bits
0000 = Capture/Compare/PWM disabled (resets CCPx module)
0100 = Capture mode, every falling edge
0101 = Capture mode, every rising edge
0110 = Capture mode, every 4th rising edge
0111 = Capture mode, every 16th rising edge
1000 = Compare mode, set output on match (CCPxIF bit is set)
1001 = Compare mode, clear output on match (CCPxIF bit is set)
1010 = Compare mode, generate software interrupt on match (CCPxIF bit is set, CCPx pin is
unaffected)
1011 = Compare mode, trigger special event (CCPxIF bit is set, CCPx pin is unaffected);
CCP1 clears Timer1; CCP2 clears Timer1 and starts an A/D conversion (if A/D module
is enabled)
11xx = PWM mode

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

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 PIC16F7X7
9.4 Capture Mode 9.4.4 CCP PRESCALER
In Capture mode, CCPR1H:CCPR1L captures the There are four prescaler settings specified by bits,
16-bit value of the TMR1 register when an event occurs CCP1M3:CCP1M0. Whenever the CCP module is
on pin RC2/CCP1. An event is defined as one of the turned off, or the CCP module is not in Capture mode,
following and is configured by CCPxCON<3:0>: the prescaler counter is cleared. Any Reset will clear
the prescaler counter.
• Every falling edge
Switching from one capture prescaler to another may
• Every rising edge
generate an interrupt. Also, the prescaler counter will
• Every 4th rising edge not be cleared, therefore, the first capture may be from
• Every 16th rising edge a non-zero prescaler. Example 9-1 shows the
An event is selected by control bits, CCP1M3:CCP1M0 recommended method for switching between capture
(CCP1CON<3:0>). When a capture is made, the inter- prescalers. This example also clears the prescaler
rupt request flag bit, CCP1IF (PIR1<2>), is set. The counter and will not generate the “false” interrupt.
interrupt flag must be cleared in software. If another
capture occurs before the value in register CCPR1 is EXAMPLE 9-1: CHANGING BETWEEN
read, the old captured value is overwritten by the new CAPTURE PRESCALERS
captured value. CLRF CCP1CON ;Turn CCP module off
MOVLW NEW_CAPT_PS ;Load the W reg with
9.4.1 CCP PIN CONFIGURATION ;the new prescaler
;move value and CCP ON
In Capture mode, the RC2/CCP1 pin should be
MOVWF CCP1CON ;Load CCP1CON with this
configured as an input by setting the TRISC<2> bit.
;value
Note: If the RC2/CCP1 pin is configured as an
output, a write to the port can cause a
capture condition. 9.5 Compare Mode
In Compare mode, the 16-bit CCPR1 register value is
FIGURE 9-1: CAPTURE MODE constantly compared against the TMR1 register pair
OPERATION BLOCK value. When a match occurs, the RC2/CCP1 pin is:
DIAGRAM • Driven high
Set Flag bit CCP1IF • Driven low
(PIR1<2>)
Prescaler • Remains unchanged
÷ 1, 4, 16
RC2/CCP1 CCPR1H CCPR1L The action on the pin is based on the value of control
pin bits, CCP1M3:CCP1M0 (CCP1CON<3:0>). At the
and Capture same time, interrupt flag bit CCP1IF is set.
Edge Detect Enable

TMR1H TMR1L FIGURE 9-2: COMPARE MODE

CCP1CON<3:0> OPERATION BLOCK
Q’s DIAGRAM
CCP1CON<3:0>
Mode Select
9.4.2 TIMER1 MODE SELECTION
Timer1 must be running in Timer mode or Synchro- Set Flag bit CCP1IF
(PIR1<2>)
nized Counter mode for the CCP module to use the
capture feature. In Asynchronous Counter mode, the CCPR1H CCPR1L

capture operation may not work. Q S Output

Logic Comparator
RC2/CCP1 R Match
9.4.3 SOFTWARE INTERRUPT pin
TMR1H TMR1L
When the Capture mode is changed, a false capture TRISC<2>
Output Enable
interrupt may be generated. The user should keep bit,
CCP1IE (PIE1<2>), clear to avoid false interrupts and Special Event Trigger
should clear the flag bit, CCP1IF, following any such
Special Event Trigger will:
change in operating mode.
• clear TMR1H and TMR1L registers
• NOT set interrupt flag bit, TMR1F (PIR1<0>)
• (for CCP2 only) set the GO/DONE bit (ADCON0<2>)

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PIC16F7X7
9.5.1 CCP PIN CONFIGURATION 9.5.4 SPECIAL EVENT TRIGGER
The user must configure the RC2/CCP1 pin as an In this mode, an internal hardware trigger is generated
output by clearing the TRISC<2> bit. which may be used to initiate an action.
Note: Clearing the CCP1CON register will force The special event trigger output of CCP1 resets the
the RC2/CCP1 compare output latch to TMR1 register pair. This allows the CCPR1 register to
the default low level. This is not the effectively be a 16-bit programmable period register for
PORTC I/O data latch. Timer1.
The special event trigger output of CCP2 resets the
9.5.2 TIMER1 MODE SELECTION TMR1 register pair and starts an A/D conversion (if the
Timer1 must be running in Timer mode or Synchro- A/D module is enabled).
nized Counter mode if the CCP module is using the
Note: The special event trigger from the CCP1
compare feature. In Asynchronous Counter mode, the
and CCP2 modules will not set interrupt
compare operation may not work.
flag bit, TMR1IF (PIR1<0>).
9.5.3 SOFTWARE INTERRUPT MODE
When Generate Software Interrupt mode is chosen, the
CCP1 pin is not affected. The CCP1IF or CCP2IF bit is
set, causing a CCP interrupt (if enabled).

TABLE 9-3: REGISTERS ASSOCIATED WITH CAPTURE, COMPARE AND TIMER1

Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
0Bh,8Bh, INTCON GIE PEIE TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u
10Bh,18Bh
0Ch PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
0Dh PIR2 OSFIF CMIF LVDIF — BCLIF — CCP3IF CCP2IF 000- 0--0 000- 0--0
8Ch PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
8Dh PIE2 OSFIE CMIE LVDIE — BCLIE — CCP3IE CCP2IE 000- 0--0 000- 0--0
87h TRISC PORTC Data Direction Register 1111 1111 1111 1111
0Eh TMR1L Holding Register for the Least Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu
0Fh TMR1H Holding Register for the Most Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu
10h T1CON — — T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON --00 0000 --uu uuuu
15h CCPR1L Capture/Compare/PWM Register 1 (LSB) xxxx xxxx uuuu uuuu
16h CCPR1H Capture/Compare/PWM Register 1 (MSB) xxxx xxxx uuuu uuuu
17h CCP1CON — — CCP1X CCP1Y CCP1M3 CCP1M2 CCP1M1 CCP1M0 --00 0000 --00 0000
1Bh CCPR2L Capture/Compare/PWM Register 2 (LSB) xxxx xxxx uuuu uuuu
1Ch CCPR2H Capture/Compare/PWM Register 2 (MSB) xxxx xxxx uuuu uuuu
1Dh CCP2CON — — CCP2X CCP2Y CCP2M3 CCP2M2 CCP2M1 CCP2M0 --00 0000 --00 0000
95h CCPR3L Capture/Compare/PWM Register 3 (LSB) xxxx xxxx uuuu uuuu
96h CCPR3H Capture/Compare/PWM Register 3 (MSB) xxxx xxxx uuuu uuuu
97h CCP3CON — — CCP3X CCP3Y CCP3M3 CCP3M2 CCP3M1 CCP3M0 --00 0000 --00 0000
Legend: x = unknown, u = unchanged, - = unimplemented, read as ‘0’. Shaded cells are not used by Capture and Timer1.
Note 1: The PSP is not implemented on the PIC16F737/767 devices; always maintain these bits clear.

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 PIC16F7X7
9.6 PWM Mode (PWM) 9.6.1 PWM PERIOD
In Pulse Width Modulation mode, the CCPx pin The PWM period is specified by writing to the PR2
produces up to a 10-bit resolution PWM output. Since register. The PWM period can be calculated using the
the CCP1 pin is multiplexed with the PORTC data latch, following formula:
the TRISC<2> bit must be cleared to make the CCP1 PWM Period = [(PR2) + 1] • 4 • TOSC •
pin an output. (TMR2 Prescale Value)
Note: Clearing the CCP1CON register will force PWM frequency is defined as 1/[PWM period].
the CCP1 PWM output latch to the default When TMR2 is equal to PR2, the following three events
low level. This is not the PORTC I/O data occur on the next increment cycle:
latch.
• TMR2 is cleared
Figure 9-3 shows a simplified block diagram of the
• The CCP1 pin is set (exception: if PWM duty
CCP module in PWM mode.
cycle = 0%, the CCP1 pin will not be set)
For a step-by-step procedure on how to set up the CCP • The PWM duty cycle is latched from CCPR1L into
module for PWM operation, see Section 9.6.3 “Setup CCPR1H
for PWM Operation”.
Note: The Timer2 postscaler (see Section 9.4
FIGURE 9-3: SIMPLIFIED PWM BLOCK “Capture Mode”) is not used in the deter-
DIAGRAM mination of the PWM frequency. The
CCP1CON<5:4>
postscaler could be used to have a servo
Duty Cycle Registers
update rate at a different frequency than
CCPR1L the PWM output.

9.6.2 PWM DUTY CYCLE

The PWM duty cycle is specified by writing to the
CCPR1H (Slave) CCPR1L register and to the CCP1CON<5:4> bits. Up
to 10-bit resolution is available. The CCPR1L contains
Comparator R Q the eight MSbs and the CCP1CON<5:4> contains the
two LSbs. This 10-bit value is represented by
RC2/CCP1
TMR2 (1)
CCPR1L:CCP1CON<5:4>. The following equation is
S used to calculate the PWM duty cycle in time:
(Note 1)
PWM Duty Cycle = (CCPR1L:CCP1CON<5:4>) •
Comparator TRISC<2>
TOSC • (TMR2 Prescale Value)
Clear Timer,
CCP1 pin and CCPR1L and CCP1CON<5:4> can be written to at any
latch D.C.
PR2 time, but the duty cycle value is not latched into
CCPR1H until after a match between PR2 and TMR2
Note 1: The 8-bit timer is concatenated with the 2-bit occurs (i.e., the period is complete). In PWM mode,
internal Q clock or the 2 bits of the prescaler to
create the 10-bit time base. CCPR1H is a read-only register.
The CCPR1H register and a 2-bit internal latch are
A PWM output (Figure 9-4) has a time base (period) used to double-buffer the PWM duty cycle. This
and a time that the output stays high (duty cycle). The double-buffering is essential for glitchless PWM
frequency of the PWM is the inverse of the period operation.
(1/period).
When the CCPR1H and 2-bit latch match TMR2,
concatenated with an internal 2-bit Q clock or 2 bits of
FIGURE 9-4: PWM OUTPUT
the TMR2 prescaler, the CCP1 pin is cleared.
TMR2 TMR2 The maximum PWM resolution (bits) for a given PWM
Reset Reset
Period frequency is given by the formula:

(FOSC
log FPWM )
Resolution = bits
log(2)
Duty Cycle

TMR2 = PR2 Note: If the PWM duty cycle value is longer than
the PWM period, the CCP1 pin will not be
TMR2 = Duty Cycle
cleared.
TMR2 = PR2

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PIC16F7X7
9.6.3 SETUP FOR PWM OPERATION 3. Make the CCP1 pin an output by clearing the
TRISC<2> bit.
The following steps should be taken when configuring
the CCP module for PWM operation: 4. Set the TMR2 prescale value and enable Timer2
by writing to T2CON.
1. Set the PWM period by writing to the PR2 register.
5. Configure the CCP1 module for PWM operation.
2. Set the PWM duty cycle by writing to the
CCPR1L register and CCP1CON<5:4> bits.

TABLE 9-4: EXAMPLE PWM FREQUENCIES AND RESOLUTIONS (FOSC = 20 MHz)

PWM Frequency 1.22 kHz 4.88 kHz 19.53 kHz 78.12 kHz 156.3 kHz 208.3 kHz
Timer Prescale (1, 4, 16) 16 4 1 1 1 1
PR2 Value 0xFF 0xFF 0xFF 0x3F 0x1F 0x17
Maximum Resolution (bits) 10 10 10 8 7 6.6

TABLE 9-5: REGISTERS ASSOCIATED WITH PWM AND TIMER2

Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
0Bh,8Bh, INTCON GIE PEIE TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u
10Bh,18Bh
0Ch PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
0Dh PIR2 OSFIF CMIF LVDIF — BCLIF — CCP3IF CCP2IF 000- 0-00 000- 0-00
8Ch PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
8Dh PIE2 OSFIE CMIE LVDIE — BCLIE — CCP3IE CCP2IE 000- 0-00 000- 0-00
87h TRISC PORTC Data Direction Register 1111 1111 1111 1111
11h TMR2 Timer2 Module Register 0000 0000 0000 0000
92h PR2 Timer2 Module Period Register 1111 1111 1111 1111
12h T2CON — TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 -000 0000
15h CCPR1L Capture/Compare/PWM Register 1 (LSB) xxxx xxxx uuuu uuuu
16h CCPR1H Capture/Compare/PWM Register 1 (MSB) xxxx xxxx uuuu uuuu
17h CCP1CON — — CCP1X CCP1Y CCP1M3 CCP1M2 CCP1M1 CCP1M0 --00 0000 --00 0000
1Bh CCPR2L Capture/Compare/PWM Register 2 (LSB) xxxx xxxx uuuu uuuu
1Ch CCPR2H Capture/Compare/PWM Register 2 (MSB) xxxx xxxx uuuu uuuu
1Dh CCP2CON — — CCP2X CCP2Y CCP2M3 CCP2M2 CCP2M1 CCP2M0 --00 0000 --00 0000
95h CCPR3L Capture/Compare/PWM Register 3 (LSB) xxxx xxxx uuuu uuuu
96h CCPR3H Capture/Compare/PWM Register 3 (MSB) xxxx xxxx uuuu uuuu
97h CCP3CON — — CCP3X CCP3Y CCP3M3 CCP3M2 CCP3M1 CCP3M0 --00 0000 --00 0000
Legend: x = unknown, u = unchanged, - = unimplemented, read as ‘0’. Shaded cells are not used by PWM and Timer2.
Note 1: Bits PSPIE and PSPIF are reserved on the PIC16F737/767 devices; always maintain these bits clear.

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 PIC16F7X7
10.0 MASTER SYNCHRONOUS FIGURE 10-1: MSSP BLOCK DIAGRAM
SERIAL PORT (MSSP) (SPI MODE)
MODULE Internal
Data Bus
Read Write
10.1 Master SSP (MSSP) Module
Overview
SSPBUF Reg
The Master Synchronous Serial Port (MSSP) module is
a serial interface, useful for communicating with other RC4/SDI/
peripheral or microcontroller devices. These peripheral SDA
devices may be serial EEPROMs, shift registers, dis- SSPSR Reg
play drivers, A/D converters, etc. The MSSP module RC5/SDO bit0 Shift
can operate in one of two modes: Clock

• Serial Peripheral Interface (SPI™)

• Inter-Integrated Circuit (I2C™)
- Full Master mode Peripheral OE
RA5/AN4/
- Slave mode (with general address call) LVDIN/SS/
The I2C interface supports the following modes in C2OUT SS Control
hardware: Enable

• Master mode Edge

Select
• Multi-Master mode
• Slave mode 2
Clock Select
10.2 Control Registers
SSPM3:SSPM0
The MSSP module has three associated registers. RC3/ SMP:CKE 4
These include a status register (SSPSTAT) and two SCK/
SCL
2 (
TMR2 Output
2 )
control registers (SSPCON and SSPCON2). The use Edge
of these registers and their individual configuration bits Select Prescaler TOSC
differ significantly, depending on whether the MSSP 4, 16, 64
module is operated in SPI or I2C mode.
Data to TX/RX in SSPSR
Additional details are provided under the individual TRIS bit
sections.

10.3 SPI Mode

The SPI mode allows 8 bits of data to be synchronously Note: When the SPI is in Slave mode with SS pin
transmitted and received simultaneously. All four modes control enabled (SSPCON<3:0> = 0100),
of SPI are supported. To accomplish communication, the state of the SS pin can affect the state
typically three pins are used: read back from the TRISC<5> bit. The
Peripheral OE signal, from the SSP mod-
• Serial Data Out (SDO) – RC5/SDO
ule into PORTC, controls the state that is
• Serial Data In (SDI) – RC4/SDI/SDA read back from the TRISC<5> bit (see
• Serial Clock (SCK) – RC3/SCK/SCL Section 5.3 “PORTC and the TRISC
Additionally, a fourth pin may be used when in a Slave Register” for information on PORTC). If
mode of operation: Read-Modify-Write instructions, such as
BSF are performed on the TRISC register
• Slave Select (SS) – RA5/AN4/LVDIN/SS/C2OUT while the SS pin is high, this will cause the
Figure 10-1 shows the block diagram of the MSSP TRISC<5> bit to be set, thus disabling the
module when operating in SPI mode. SDO output.

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PIC16F7X7
10.3.1 REGISTERS SSPSR is the shift register used for shifting data in or
out. SSPBUF is the buffer register to which data bytes
The MSSP module has four registers for SPI mode
are written to or read from.
operation. These are:
In receive operations, SSPSR and SSPBUF together
• MSSP Control Register (SSPCON)
create a double-buffered receiver. When SSPSR
• MSSP Status Register (SSPSTAT) receives a complete byte, it is transferred to SSPBUF
• Serial Receive/Transmit Buffer (SSPBUF) and the SSPIF interrupt is set.
• MSSP Shift Register (SSPSR) – Not directly During transmission, the SSPBUF is not double-
accessible buffered. A write to SSPBUF will write to both SSPBUF
SSPCON and SSPSTAT are the control and status and SSPSR.
registers in SPI mode operation. The SSPCON
register is readable and writable. The lower 6 bits of
the SSPSTAT are read-only. The upper two bits of the
SSPSTAT are read/write.

REGISTER 10-1: SSPSTAT: MSSP STATUS (SPI MODE) REGISTER (ADDRESS 94h)
R/W-0 R/W-0 R-0 R-0 R-0 R-0 R-0 R-0
SMP CKE D/A P S R/W UA BF
bit 7 bit 0

bit 7 SMP: Sample bit

SPI Master mode:
1 = Input data sampled at end of data output time
0 = Input data sampled at middle of data output time
SPI Slave mode:
SMP must be cleared when SPI is used in Slave mode.
bit 6 CKE: SPI Clock Edge Select bit
When CKP = 0:
1 = Data transmitted on rising edge of SCK
0 = Data transmitted on falling edge of SCK
When CKP = 1:
1 = Data transmitted on falling edge of SCK
0 = Data transmitted on rising edge of SCK
bit 5 D/A: Data/Address bit
Used in I2C mode only.
bit 4 P: Stop bit
Used in I2C mode only. This bit is cleared when the MSSP module is disabled, SSPEN is cleared.
bit 3 S: Start bit
Used in I2C mode only.
bit 2 R/W: Read/Write bit Information
Used in I2C mode only.
bit 1 UA: Update Address bit
Used in I2C mode only.
bit 0 BF: Buffer Full Status bit (Receive mode only)
1 = Receive complete, SSPBUF is full
0 = Receive not complete, SSPBUF is empty

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

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 PIC16F7X7
REGISTER 10-2: SSPCON: MSSP CONTROL (SPI MODE) REGISTER 1 (ADDRESS 14h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0
bit 7 bit 0

bit 7 WCOL: Write Collision Detect bit (Transmit mode only)

1 = The SSPBUF register is written while it is still transmitting the previous word.
(Must be cleared in software.)
0 = No collision
bit 6 SSPOV: Receive Overflow Indicator bit
SPI Slave mode:
1 = A new byte is received while the SSPBUF register is still holding the previous data. In case
of overflow, the data in SSPSR is lost. Overflow can only occur in Slave mode. The user
must read the SSPBUF, even if only transmitting data, to avoid setting overflow.
(Must be cleared in software.)
0 = No overflow
Note: In Master mode, the overflow bit is not set since each new reception (and
transmission) is initiated by writing to the SSPBUF register.
bit 5 SSPEN: Synchronous Serial Port Enable bit
1 = Enables serial port and configures SCK, SDO, SDI and SS as serial port pins
0 = Disables serial port and configures these pins as I/O port pins
Note: When enabled, these pins must be properly configured as input or output.
bit 4 CKP: Clock Polarity Select bit
1 = Idle state for clock is a high level
0 = Idle state for clock is a low level
bit 3-0 SSPM3:SSPM0: Synchronous Serial Port Mode Select bits
0101 = SPI Slave mode, clock = SCK pin. SS pin control disabled. SS can be used as I/O pin.
0100 = SPI Slave mode, clock = SCK pin. SS pin control enabled.
0011 = SPI Master mode, clock = TMR2 output/2
0010 = SPI Master mode, clock = FOSC/64
0001 = SPI Master mode, clock = FOSC/16
0000 = SPI Master mode, clock = FOSC/4
Note: Bit combinations not specifically listed here are either reserved or implemented in
I2C mode only.

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

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PIC16F7X7
10.3.2 OPERATION reading the data that was just received. Any write to the
SSPBUF register during transmission/reception of data
When initializing the SPI, several options need to be
will be ignored and the write collision detect bit, WCOL
specified. This is done by programming the appropriate
(SSPCON<7>), will be set. User software must clear
control bits (SSPCON<5:0> and SSPSTAT<7:6>).
the WCOL bit so that it can be determined if the follow-
These control bits allow the following to be specified:
ing write(s) to the SSPBUF register completed
• Master mode (SCK is the clock output) successfully.
• Slave mode (SCK is the clock input) When the application software is expecting to receive
• Clock Polarity (Idle state of SCK) valid data, the SSPBUF should be read before the next
• Data Input Sample Phase (middle or end of data byte of data to transfer is written to the SSPBUF. Buffer
output time) Full bit, BF (SSPSTAT<0>), indicates when SSPBUF
• Clock Edge (output data on rising/falling edge of has been loaded with the received data (transmission
SCK) is complete). When the SSPBUF is read, the BF bit is
• Clock Rate (Master mode only) cleared. This data may be irrelevant if the SPI is only a
transmitter. Generally, the MSSP interrupt is used to
• Slave Select mode (Slave mode only)
determine when the transmission/reception has com-
The MSSP consists of a transmit/receive shift register pleted. The SSPBUF must be read and/or written. If the
(SSPSR) and a buffer register (SSPBUF). The SSPSR interrupt method is not going to be used, then software
shifts the data in and out of the device, MSb first. The polling can be done to ensure that a write collision does
SSPBUF holds the data that was written to the SSPSR not occur. Example 10-1 shows the loading of the
until the received data is ready. Once the 8 bits of data SSPBUF (SSPSR) for data transmission.
have been received, that byte is moved to the SSPBUF
The SSPSR is not directly readable or writable, and
register. Then, the Buffer Full detect bit, BF
can only be accessed by addressing the SSPBUF
(SSPSTAT<0>), and the interrupt flag bit, SSPIF, are
register. Additionally, the MSSP Status register
set. This double-buffering of the received data
(SSPSTAT) indicates the various status conditions.
(SSPBUF) allows the next byte to start reception before

EXAMPLE 10-1: LOADING THE SSPBUF (SSPSR) REGISTER

LOOP BTFSS SSPSTAT, BF ;Has data been received (transmit complete)?
BRA LOOP ;No
MOVF SSPBUF, W ;WREG reg = contents of SSPBUF
MOVWF RXDATA ;Save in user RAM, if data is meaningful
MOVF TXDATA, W ;W reg = contents of TXDATA
MOVWF SSPBUF ;New data to xmit

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 PIC16F7X7
10.3.3 ENABLING SPI I/O 10.3.4 TYPICAL CONNECTION
To enable the serial port, SSP Enable bit, SSPEN Figure 10-2 shows a typical connection between two
(SSPCON<5>), must be set. To reset or reconfigure microcontrollers. The master controller (Processor 1)
SPI mode, clear the SSPEN bit, reinitialize the initiates the data transfer by sending the SCK signal.
SSPCON registers and then set the SSPEN bit. This Data is shifted out of both shift registers on their pro-
configures the SDI, SDO, SCK and SS pins as serial grammed clock edge and latched on the opposite edge
port pins. For the pins to behave as the serial port func- of the clock. Both processors should be programmed to
tion, some must have their data direction bits (in the the same Clock Polarity (CKP), then both controllers
TRIS register) appropriately programmed. That is: would send and receive data at the same time.
• SDI is automatically controlled by the SPI module Whether the data is meaningful (or dummy data)
depends on the application software. This leads to
• SDO must have TRISC<5> bit cleared
three scenarios for data transmission:
• SCK (Master mode) must have TRISC<3> bit
cleared • Master sends data – Slave sends dummy data
• SCK (Slave mode) must have TRISC<3> bit set • Master sends data – Slave sends data
• SS must have TRISA<5> bit set • Master sends dummy data – Slave sends data

Any serial port function that is not desired may be

overridden by programming the corresponding data
direction (TRIS) register to the opposite value.

FIGURE 10-2: SPI MASTER/SLAVE CONNECTION

SPI Master SSPM3:SSPM0 = 00xxb SPI Slave SSPM3:SSPM0 = 010xb

SDO SDI

Serial Input Buffer Serial Input Buffer

(SSPBUF) (SSPBUF)

Shift Register SDI SDO Shift Register

(SSPSR) (SSPSR)

MSb LSb MSb LSb

Serial Clock
SCK SCK
PROCESSOR 1 PROCESSOR 2

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PIC16F7X7
10.3.5 MASTER MODE Figure 10-3, Figure 10-5 and Figure 10-6, where the
MSB is transmitted first. In Master mode, the SPI clock
The master can initiate the data transfer at any time
rate (bit rate) is user programmable to be one of the
because it controls the SCK. The master determines
following:
when the slave (Processor 2, Figure 10-2) is to
broadcast data by the software protocol. • FOSC/4 (or TCY)
In Master mode, the data is transmitted/received as • FOSC/16 (or 4 • TCY)
soon as the SSPBUF register is written to. If the SPI is • FOSC/64 (or 16 • TCY)
only going to receive, the SDO output could be dis- • Timer2 output/2
abled (programmed as an input). The SSPSR register
This allows a maximum data rate (at 40 MHz) of
will continue to shift in the signal present on the SDI pin
10.00 Mbps.
at the programmed clock rate. As each byte is
received, it will be loaded into the SSPBUF register as Figure 10-3 shows the waveforms for Master mode.
if a normal received byte (interrupts and status bits When the CKE bit is set, the SDO data is valid before
appropriately set). This could be useful in receiver there is a clock edge on SCK. The change of the input
applications as a “Line Activity Monitor” mode. sample is shown based on the state of the SMP bit. The
time when the SSPBUF is loaded with the received
The clock polarity is selected by appropriately program-
data is shown.
ming the CKP bit (SSPCON<4>). This then, would give
waveforms for SPI communication as shown in

FIGURE 10-3: SPI MODE WAVEFORM (MASTER MODE)

Write to
SSPBUF

SCK
(CKP = 0
CKE = 0)

SCK
(CKP = 1
CKE = 0)
4 Clock
SCK Modes
(CKP = 0
CKE = 1)

SCK
(CKP = 1
CKE = 1)

SDO bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0

(CKE = 0)

SDO bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0

(CKE = 1)
SDI
(SMP = 0) bit 7 bit 0
Input
Sample
(SMP = 0)
SDI
(SMP = 1)
bit 7 bit 0

Input
Sample
(SMP = 1)
SSPIF
Next Q4 Cycle
SSPSR to after Q2↓
SSPBUF

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 PIC16F7X7
10.3.6 SLAVE MODE even if in the middle of a transmitted byte and becomes
a floating output. External pull-up/pull-down resistors
In Slave mode, the data is transmitted and received as
may be desirable, depending on the application.
the external clock pulses appear on SCK. When the
last bit is latched, the SSPIF interrupt flag bit is set. Note 1: When the SPI is in Slave mode with SS pin
While in Slave mode, the external clock is supplied by control enabled (SSPCON<3:0> = 0100),
the external clock source on the SCK pin. This external the SPI module will reset if the SS pin is set
clock must meet the minimum high and low times, as to VDD.
specified in the electrical specifications. 2: If the SPI is used in Slave mode with CKE
While in Sleep mode, the slave can transmit/receive set, then the SS pin control must be
data. When a byte is received, the device will wake-up enabled.
from Sleep. When the SPI module resets, the bit counter is forced
to ‘0’. This can be done by either forcing the SS pin to
10.3.7 SLAVE SELECT a high level or clearing the SSPEN bit.
SYNCHRONIZATION
To emulate two-wire communication, the SDO pin can
The SS pin allows a Synchronous Slave mode. The be connected to the SDI pin. When the SPI needs to
SPI must be in Slave mode with SS pin control enabled operate as a receiver, the SDO pin can be configured
(SSPCON<3:0> = 4h). The pin must not be driven low as an input. This disables transmissions from the SDO.
for the SS pin to function as an input. The data latch The SDI can always be left as an input (SDI function)
must be high. When the SS pin is low, transmission and since it cannot create a bus conflict.
reception are enabled and the SDO pin is driven. When
the SS pin goes high, the SDO pin is no longer driven,

FIGURE 10-4: SLAVE SYNCHRONIZATION WAVEFORM

SS

SCK
(CKP = 0
CKE = 0)

SCK
(CKP = 1
CKE = 0)

Write to
SSPBUF

SDO bit 7 bit 6 bit 7 bit 0

SDI bit 0
(SMP = 0) bit 7 bit 7
Input
Sample
(SMP = 0)
SSPIF
Interrupt
Flag
Next Q4 Cycle
SSPSR to after Q2↓
SSPBUF

 2003 Microchip Technology Inc. Preliminary DS30498B-page 99

PIC16F7X7
FIGURE 10-5: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 0)

SS
Optional

SCK
(CKP = 0
CKE = 0)

SCK
(CKP = 1
CKE = 0)
Write to
SSPBUF

SDO bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0

SDI
(SMP = 0) bit 7 bit 0
Input
Sample
(SMP = 0)
SSPIF
Interrupt
Flag
Next Q4 Cycle
SSPSR to after Q2↓
SSPBUF

FIGURE 10-6: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 1)

SS
Not Optional

SCK
(CKP = 0
CKE = 1)

SCK
(CKP = 1
CKE = 1)
Write to
SSPBUF

SDO bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0

SDI
(SMP = 0) bit 7 bit 0

Input
Sample
(SMP = 0)

SSPIF
Interrupt
Flag
Next Q4 Cycle
after Q2↓
SSPSR to
SSPBUF

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 PIC16F7X7
10.3.8 SLEEP OPERATION 10.3.10 BUS MODE COMPATIBILITY
In Master mode, all module clocks are halted and the Table 10-1 shows the compatibility between the
transmission/reception will remain in that state until the standard SPI modes and the states of the CKP and
device wakes from Sleep. After the device returns to CKE control bits.
normal mode, the module will continue to transmit/
receive data. TABLE 10-1: SPI BUS MODES
In Slave mode, the SPI Transmit/Receive Shift register Control Bits State
Standard SPI Mode
operates asynchronously to the device. This allows the
device to be placed in Sleep mode and data to be Terminology CKP CKE
shifted into the SPI Transmit/Receive Shift register. 0, 0 0 1
When all 8 bits have been received, the MSSP interrupt
flag bit will be set and if enabled, will wake the device 0, 1 0 0
from Sleep. 1, 0 1 1
1, 1 1 0
10.3.9 EFFECTS OF A RESET
There is also an SMP bit which controls when the data
A Reset disables the MSSP module and terminates the is sampled.
current transfer.

TABLE 10-2: REGISTERS ASSOCIATED WITH SPI OPERATION

Value on
Value on
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u
PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
TRISC PORTC Data Direction Register 1111 1111 1111 1111
SSPBUF Synchronous Serial Port Receive Buffer/Transmit Register xxxx xxxx uuuu uuuu
SSPCON WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 0000 0000 0000 0000
TRISA PORTA Data Direction Register 1111 1111 1111 1111
SSPSTAT SMP CKE D/A P S R/W UA BF 0000 0000 0000 0000
Legend: x = unknown, u = unchanged, - = unimplemented, read as ‘0’. Shaded cells are not used by the MSSP in SPI mode.
Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on 28-pin devices; always maintain these bits clear.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 101

PIC16F7X7
10.4 I2C Mode 10.4.1 REGISTERS
The MSSP module in I 2C mode fully implements all The MSSP module has six registers for I2C operation.
master and slave functions (including general call sup- These are:
port) and provides interrupts on Start and Stop bits in • MSSP Control Register (SSPCON)
hardware to determine a free bus (multi-master func- • MSSP Control Register 2 (SSPCON2)
tion). The MSSP module implements the standard
• MSSP Status Register (SSPSTAT)
mode specifications, as well as 7-bit and 10-bit
addressing. • Serial Receive/Transmit Buffer (SSPBUF)
• MSSP Shift Register (SSPSR) – Not directly
Two pins are used for data transfer:
accessible
• Serial clock (SCL) – RC3/SCK/SCL • MSSP Address Register (SSPADD)
• Serial data (SDA) – RC4/SDI/SDA
SSPCON, SSPCON2 and SSPSTAT are the control
The user must configure these pins as inputs or outputs and status registers in I2C mode operation. The
through the TRISC<4:3> bits. SSPCON and SSPCON2 registers are readable and
writable. The lower 6 bits of the SSPSTAT are
FIGURE 10-7: MSSP BLOCK DIAGRAM read-only. The upper two bits of the SSPSTAT are
(I2C MODE) read/write.
SSPSR is the shift register used for shifting data in or
Internal out. SSPBUF is the buffer register to which data bytes
Data Bus
are written to or read from.
Read Write
SSPADD register holds the slave device address
RC3/SCK/
when the SSP is configured in I2C Slave mode. When
SSPBUF Reg
SCL the SSP is configured in Master mode, the lower
seven bits of SSPADD act as the baud rate generator
Shift
Clock
reload value.

SSPSR Reg
In receive operations, SSPSR and SSPBUF together
create a double-buffered receiver. When SSPSR
RC4/ MSb LSb
SDI/ receives a complete byte, it is transferred to SSPBUF
SDA and the SSPIF interrupt is set.
Match Detect Addr Match
During transmission, the SSPBUF is not double-
buffered. A write to SSPBUF will write to both SSPBUF
SSPADD Reg
and SSPSR.

Start and Set, Reset

Stop bit Detect S, P bits
(SSPSTAT Reg)

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 PIC16F7X7
REGISTER 10-3: SSPSTAT: MSSP STATUS (I2C MODE) REGISTER (ADDRESS 94h)
R/W-0 R/W-0 R-0 R-0 R-0 R-0 R-0 R-0
SMP CKE D/A P S R/W UA BF
bit 7 bit 0

bit 7 SMP: Slew Rate Control bit

In Master or Slave mode:
1 = Slew rate control disabled for standard speed mode (100 kHz and 1 MHz)
0 = Slew rate control enabled for high-speed mode (400 kHz)
bit 6 CKE: SMBus Select bit
In Master or Slave mode:
1 = Enable SMBus specific inputs
0 = Disable SMBus specific inputs
bit 5 D/A: Data/Address bit
In Master mode:
Reserved.
In Slave mode:
1 = Indicates that the last byte received or transmitted was data
0 = Indicates that the last byte received or transmitted was address
bit 4 P: Stop bit
1 = Indicates that a Stop bit has been detected last
0 = Stop bit was not detected last
Note: This bit is cleared on Reset and when SSPEN is cleared.
bit 3 S: Start bit
1 = Indicates that a Start bit has been detected last
0 = Start bit was not detected last
Note: This bit is cleared on Reset and when SSPEN is cleared.
bit 2 R/W: Read/Write bit Information bit (I2C mode only)
In Slave mode:
1 = Read
0 = Write
Note: This bit holds the R/W bit information following the last address match. This bit is
only valid from the address match to the next Start bit, Stop bit or not ACK bit.
In Master mode:
1 = Transmit is in progress
0 = Transmit is not in progress
Note: ORing this bit with SEN, RSEN, PEN, RCEN or ACKEN will indicate if the MSSP is
in Idle mode.
bit 1 UA: Update Address bit (10-bit Slave mode only)
1 = Indicates that the user needs to update the address in the SSPADD register
0 = Address does not need to be updated
bit 0 BF: Buffer Full Status bit
In Transmit mode:
1 = Receive complete, SSPBUF is full
0 = Receive not complete, SSPBUF is empty
In Receive mode:
1 = Data transmit in progress (does not include the ACK and Stop bits), SSPBUF is full
0 = Data transmit complete (does not include the ACK and Stop bits), SSPBUF is empty

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

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PIC16F7X7
REGISTER 10-4: SSPCON: MSSP CONTROL (I2C MODE) REGISTER 1 (ADDRESS 14h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0
bit 7 bit 0

bit 7 WCOL: Write Collision Detect bit

In Master Transmit mode:
1 = A write to the SSPBUF register was attempted while the I2C conditions were not valid for
a transmission to be started. (Must be cleared in software.)
0 = No collision
In Slave Transmit mode:
1 = The SSPBUF register is written while it is still transmitting the previous word. (Must be
cleared in software.)
0 = No collision
In Receive mode (Master or Slave modes):
This is a “don’t care” bit.
bit 6 SSPOV: Receive Overflow Indicator bit
In Receive mode:
1 = A byte is received while the SSPBUF register is still holding the previous byte. (Must be
cleared in software.)
0 = No overflow
In Transmit mode:
This is a “don’t care” bit in Transmit mode.
bit 5 SSPEN: Synchronous Serial Port Enable bit
1 = Enables the serial port and configures the SDA and SCL pins as the serial port pins
0 = Disables serial port and configures these pins as I/O port pins
Note: When enabled, the SDA and SCL pins must be properly configured as input or output.
bit 4 CKP: SCK Release Control bit
In Slave mode:
1 = Release clock
0 = Holds clock low (clock stretch). (Used to ensure data setup time.)
In Master mode:
Unused in this mode.
bit 3-0 SSPM3:SSPM0: Synchronous Serial Port Mode Select bits
1111 = I2C Slave mode, 10-bit address with Start and Stop bit interrupts enabled
1110 = I2C Slave mode, 7-bit address with Start and Stop bit interrupts enabled
1011 = I2C Firmware Controlled Master mode (slave Idle)
1000 = I2C Master mode, clock = FOSC/(4 * (SSPADD + 1))
0111 = I2C Slave mode, 10-bit address
0110 = I2C Slave mode, 7-bit address
Note: Bit combinations not specifically listed here are either reserved or implemented in
SPI mode only.

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

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 PIC16F7X7
REGISTER 10-5: SSPCON2: MSSP CONTROL (I2C MODE) REGISTER 2 (ADDRESS 91h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN
bit 7 bit 0

bit 7 GCEN: General Call Enable bit (Slave mode only)

1 = Enable interrupt when a general call address (0000h) is received in the SSPSR
0 = General call address disabled
bit 6 ACKSTAT: Acknowledge Status bit (Master Transmit mode only)
1 = Acknowledge was not received from slave
0 = Acknowledge was received from slave
bit 5 ACKDT: Acknowledge Data bit (Master Receive mode only)
1 = Not Acknowledge
0 = Acknowledge
Note: Value that will be transmitted when the user initiates an Acknowledge sequence at
the end of a receive.
bit 4 ACKEN: Acknowledge Sequence Enable bit (Master Receive mode only)
1 = Initiate Acknowledge sequence on SDA and SCL pins and transmit ACKDT data bit.
Automatically cleared by hardware.
0 = Acknowledge sequence Idle
bit 3 RCEN: Receive Enable bit (Master mode only)
1 = Enables Receive mode for I2C
0 = Receive Idle
bit 2 PEN: Stop Condition Enable bit (Master mode only)
1 = Initiate Stop condition on SDA and SCL pins. Automatically cleared by hardware.
0 = Stop condition Idle
bit 1 RSEN: Repeated Start Condition Enabled bit (Master mode only)
1 = Initiate Repeated Start condition on SDA and SCL pins. Automatically cleared by hardware.
0 = Repeated Start condition Idle
bit 0 SEN: Start Condition Enabled/Stretch Enabled bit
In Master mode:
1 = Initiate Start condition on SDA and SCL pins. Automatically cleared by hardware.
0 = Start condition Idle
In Slave mode:
1 = Clock stretching is enabled for both slave transmit and slave receive (stretch enabled)
0 = Clock stretching is enabled for slave transmit only (PIC16F87X compatibility)
Note: For bits ACKEN, RCEN, PEN, RSEN, SEN: If the I2C module is not in the Idle mode,
this bit may not be set (no spooling) and the SSPBUF may not be written (or writes
to the SSPBUF are disabled).

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

 2003 Microchip Technology Inc. Preliminary DS30498B-page 105

PIC16F7X7
10.4.2 OPERATION 10.4.3.1 Addressing
The MSSP module functions are enabled by setting Once the MSSP module has been enabled, it waits for
MSSP enable bit, SSPEN (SSPCON<5>). a Start condition to occur. Following the Start condition,
The SSPCON register allows control of the I 2C opera- the 8 bits are shifted into the SSPSR register. All incom-
tion. Four mode selection bits (SSPCON<3:0>) allow ing bits are sampled with the rising edge of the clock
one of the following I 2C modes to be selected: (SCL) line. The value of register SSPSR<7:1> is com-
pared to the value of the SSPADD register. The
• I2C Master mode, clock = Osc/4 (SSPADD + 1) address is compared on the falling edge of the eighth
• I 2C Slave mode (7-bit address) clock (SCL) pulse. If the addresses match and the BF
• I 2C Slave mode (10-bit address) and SSPOV bits are clear, the following events occur:
• I 2C Slave mode (7-bit address), with Start and 1. The SSPSR register value is loaded into the
Stop bit interrupts enabled SSPBUF register.
• I 2C Slave mode (10-bit address), with Start and 2. The Buffer Full bit, BF, is set.
Stop bit interrupts enabled 3. An ACK pulse is generated.
• I 2C Firmware Controlled Master mode, slave is 4. MSSP Interrupt Flag bit, SSPIF (PIR1<3>), is
Idle set (interrupt is generated if enabled) on the
Selection of any I 2C mode, with the SSPEN bit set, falling edge of the ninth SCL pulse.
forces the SCL and SDA pins to be open-drain, pro- In 10-bit Address mode, two address bytes need to be
vided these pins are programmed to inputs by setting received by the slave. The five Most Significant bits
the appropriate TRISC bits. To ensure proper operation (MSbs) of the first address byte specify if this is a 10-bit
of the module, pull-up resistors must be provided address. Bit R/W (SSPSTAT<2>) must specify a write
externally to the SCL and SDA pins. so the slave device will receive the second address
byte. For a 10-bit address, the first byte would equal
10.4.3 SLAVE MODE ‘11110 A9 A8 0’, where ‘A9’ and ‘A8’ are the two
In Slave mode, the SCL and SDA pins must be config- MSbs of the address. The sequence of events for
ured as inputs (TRISC<4:3> set). The MSSP module 10-bit address is as follows, with steps 7 through 9 for
will override the input state with the output data when the slave-transmitter:
required (slave-transmitter). 1. Receive first (high) byte of address (bits SSPIF,
The I 2C Slave mode hardware will always generate an BF and bit UA (SSPSTAT<1>) are set).
interrupt on an address match. Through the mode 2. Update the SSPADD register with second (low)
select bits, the user can also choose to interrupt on byte of address (clears bit UA and releases the
Start and Stop bits. SCL line).
When an address is matched, or the data transfer after 3. Read the SSPBUF register (clears bit BF) and
an address match is received, the hardware automati- clear flag bit SSPIF.
cally will generate the Acknowledge (ACK) pulse and 4. Receive second (low) byte of address (bits
load the SSPBUF register with the received value SSPIF, BF and UA are set).
currently in the SSPSR register. 5. Update the SSPADD register with the first (high)
Any combination of the following conditions will cause byte of address. If match releases SCL line, this
the MSSP module not to give this ACK pulse: will clear bit UA.
• The Buffer Full bit, BF (SSPSTAT<0>), was set 6. Read the SSPBUF register (clears bit BF) and
before the transfer was received. clear flag bit SSPIF.
• The overflow bit, SSPOV (SSPCON<6>), was set 7. Receive Repeated Start condition.
before the transfer was received. 8. Receive first (high) byte of address (bits SSPIF
In this case, the SSPSR register value is not loaded and BF are set).
into the SSPBUF, but bit SSPIF (PIR1<3>) is set. The 9. Read the SSPBUF register (clears bit BF) and
BF bit is cleared by reading the SSPBUF register, while clear flag bit SSPIF.
bit SSPOV is cleared through software.
The SCL clock input must have a minimum high and
low for proper operation. The high and low times of the
I2C specification, as well as the requirement of the
MSSP module, are shown in timing parameter #100
and parameter #101.

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 PIC16F7X7
10.4.3.2 Reception 10.4.3.3 Transmission
When the R/W bit of the address byte is clear and an When the R/W bit of the incoming address byte is set
address match occurs, the R/W bit of the SSPSTAT and an address match occurs, the R/W bit of the
register is cleared. The received address is loaded into SSPSTAT register is set. The received address is loaded
the SSPBUF register and the SDA line is held low into the SSPBUF register. The ACK pulse will be sent on
(ACK). the ninth bit and pin RC3/SCK/SCL is held low regard-
When the address byte overflow condition exists, then less of SEN (see Section 10.4.4 “Clock Stretching”
the no Acknowledge (ACK) pulse is given. An overflow for more detail). By stretching the clock, the master will
condition is defined as either bit BF (SSPSTAT<0>) is be unable to assert another clock pulse until the slave is
set or bit SSPOV (SSPCON<6>) is set. done preparing the transmit data. The transmit data
must be loaded into the SSPBUF register, which also
An MSSP interrupt is generated for each data transfer loads the SSPSR register. Then pin RC3/SCK/SCL
byte. Flag bit, SSPIF (PIR1<3>), must be cleared in should be enabled by setting bit CKP (SSPCON<4>).
software. The SSPSTAT register is used to determine The eight data bits are shifted out on the falling edge of
the status of the byte. the SCL input. This ensures that the SDA signal is valid
If SEN is enabled (SSPCON<0> = 1), RC3/SCK/SCL during the SCL high time (Figure 10-9).
will be held low (clock stretch) following each data The ACK pulse from the master-receiver is latched on
transfer. The clock must be released by setting bit, the rising edge of the ninth SCL input pulse. If the SDA
CKP (SSPCON<4>). See Section 10.4.4 “Clock line is high (not ACK), then the data transfer is com-
Stretching” for more detail. plete. In this case, when the ACK is latched by the
slave, the slave logic is reset (resets SSPSTAT regis-
ter) and the slave monitors for another occurrence of
the Start bit. If the SDA line was low (ACK), the next
transmit data must be loaded into the SSPBUF register.
Again, pin RC3/SCK/SCL must be enabled by setting
bit CKP.
An MSSP interrupt is generated for each data transfer
byte. The SSPIF bit must be cleared in software and
the SSPSTAT register is used to determine the status
of the byte. The SSPIF bit is set on the falling edge of
the ninth clock pulse.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 107

 FIGURE 10-8:

DS30498B-page 108
PIC16F7X7

Receiving Address R/W = 0 Receiving Data ACK Receiving Data ACK

SDA A7 A6 A5 A4 A3 A2 A1 ACK D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0

SCL 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
S P

SSPIF
Bus master
(PIR1<3>) terminates
transfer

BF (SSPSTAT<0>)

Preliminary
Cleared in software
SSPBUF is read

SSPOV (SSPCON<6>)

SSPOV is set
because SSPBUF is
still full. ACK is not sent.

CKP (CKP does not reset to ‘0’ when SEN = 0)

I2C SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 7-BIT ADDRESS)

 2003 Microchip Technology Inc.

 FIGURE 10-9:

Receiving Address R/W = 1 Transmitting Data Transmitting Data

ACK ACK

 2003 Microchip Technology Inc.

SDA A7 A6 A5 A4 A3 A2 A1 ACK D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0

SCL
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
S
Data in SCL held low P
sampled while CPU
responds to SSPIF

SSPIF (PIR1<3>)

BF (SSPSTAT<0>)
Cleared in software Cleared in software

Preliminary
From SSPIF ISR From SSPIF ISR
SSPBUF is written in software SSPBUF is written in software

CKP
I2C SLAVE MODE TIMING (TRANSMISSION, 7-BIT ADDRESS)

CKP is set in software CKP is set in software

DS30498B-page 109
PIC16F7X7
 FIGURE 10-10:

DS30498B-page 110
Clock is held low until Clock is held low until
update of SSPADD has update of SSPADD has
taken place taken place

Receive First Byte of Address Receive Second Byte of Address Receive Data Byte Receive Data Byte
R/W = 0 ACK
PIC16F7X7

SDA 1 1 1 1 0 A9 A8 ACK A7 A6 A5 A4 A3 A2 A1 A0 ACK D7 D6 D5 D4 D3 D2 D1 D0 ACK D7 D6 D5 D4 D3 D2 D1 D0

SCL 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
S P

Bus master
terminates
SSPIF transfer
(PIR1<3>)
Cleared in software Cleared in software Cleared in software
Cleared in software

BF (SSPSTAT<0>)

SSPBUF is written with Dummy read of SSPBUF

contents of SSPSR to clear BF flag
SSPOV (SSPCON<6>)

SSPOV is set

Preliminary
because SSPBUF is
still full. ACK is not sent.

UA (SSPSTAT<1>)

UA is set indicating that Cleared by hardware Cleared by hardware when

the SSPADD needs to be when SSPADD is updated SSPADD is updated with high
updated with low byte of address byte of address

UA is set indicating that

SSPADD needs to be
updated

CKP (CKP does not reset to ‘0’ when SEN = 0)

I2C SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 10-BIT ADDRESS)

 2003 Microchip Technology Inc.

 FIGURE 10-11:

Bus master
terminates
Clock is held low until Clock is held low until transfer
update of SSPADD has update of SSPADD has Clock is held low until

 2003 Microchip Technology Inc.

taken place taken place CKP is set to ‘1’
R/W = 0
Receive First Byte of Address Receive Second Byte of Address Receive First Byte of Address R/W = 1 Transmitting Data Byte ACK
SDA 1 1 1 1 0 A9 A8 ACK A7 A6 A5 A4 A3 A2 A1 A0 ACK 1 1 1 1 0 A9 A8 ACK D7 D6 D5 D4 D3 D2 D1 D0

SCL 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
S Sr P

SSPIF
(PIR1<3>)
Cleared in software Cleared in software Cleared in software

BF (SSPSTAT<0>)

SSPBUF is written with Dummy read of SSPBUF

Preliminary
Dummy read of SSPBUF Write of SSPBUF Completion of
contents of SSPSR to clear BF flag BF flag is clear
to clear BF flag initiates transmit data transmission
at the end of the
UA (SSPSTAT<1>) third address sequence clears BF flag

UA is set indicating that Cleared by hardware when Cleared by hardware when

the SSPADD needs to be SSPADD is updated with low SSPADD is updated with high
updated byte of address. byte of address.

UA is set indicating that

SSPADD needs to be
updated
CKP (SSPCON<4>)

CKP is set in software

I2C SLAVE MODE TIMING (TRANSMISSION, 10-BIT ADDRESS)

CKP is automatically cleared in hardware holding SCL low

DS30498B-page 111
PIC16F7X7
PIC16F7X7
10.4.4 CLOCK STRETCHING 10.4.4.3 Clock Stretching for 7-bit Slave
Both 7-bit and 10-bit Slave modes implement Transmit Mode
automatic clock stretching during a transmit sequence. 7-bit Slave Transmit mode implements clock stretching
The SEN bit (SSPCON2<0>) allows clock stretching to by clearing the CKP bit after the falling edge of the
be enabled during receives. Setting SEN will cause ninth clock, if the BF bit is clear. This occurs
the SCL pin to be held low at the end of each data regardless of the state of the SEN bit.
receive sequence. The user’s ISR must set the CKP bit before transmis-
sion is allowed to continue. By holding the SCL line
10.4.4.1 Clock Stretching for 7-bit Slave low, the user has time to service the ISR and load the
Receive Mode (SEN = 1) contents of the SSPBUF before the master device can
In 7-bit Slave Receive mode, on the falling edge of the initiate another transmit sequence (see Figure 10-9).
ninth clock, at the end of the ACK sequence if the BF bit Note 1: If the user loads the contents of SSPBUF,
is set, the CKP bit in the SSPCON register is automati- setting the BF bit before the falling edge of
cally cleared, forcing the SCL output to be held low. The the ninth clock, the CKP bit will not be
CKP being cleared to ‘0’ will assert the SCL line low. cleared and clock stretching will not occur.
The CKP bit must be set in the user’s ISR before recep-
tion is allowed to continue. By holding the SCL line low, 2: The CKP bit can be set in software
the user has time to service the ISR and read the regardless of the state of the BF bit.
contents of the SSPBUF before the master device can
10.4.4.4 Clock Stretching for 10-bit Slave
initiate another receive sequence. This will prevent
buffer overruns from occurring (see Figure 10-13). Transmit Mode
In 10-bit Slave Transmit mode, clock stretching is con-
Note 1: If the user reads the contents of the
trolled during the first two address sequences by the
SSPBUF before the falling edge of the
state of the UA bit, just as it is in 10-bit Slave Receive
ninth clock, thus clearing the BF bit, the
mode. The first two addresses are followed by a third
CKP bit will not be cleared and clock
address sequence, which contains the high order bits
stretching will not occur.
of the 10-bit address and the R/W bit set to ‘1’. After
2: The CKP bit can be set in software the third address sequence is performed, the UA bit is
regardless of the state of the BF bit. The not set, the module is now configured in Transmit
user should be careful to clear the BF bit mode and clock stretching is controlled by the BF flag
in the ISR before the next receive as in 7-bit Slave Transmit mode (see Figure 10-11).
sequence in order to prevent an overflow
condition.

10.4.4.2 Clock Stretching for 10-bit Slave

Receive Mode (SEN = 1)
In 10-bit Slave Receive mode during the address
sequence, clock stretching automatically takes place
but CKP is not cleared. During this time, if the UA bit is
set after the ninth clock, clock stretching is initiated.
The UA bit is set after receiving the upper byte of the
10-bit address and following the receive of the second
byte of the 10-bit address, with the R/W bit cleared to
‘0’. The release of the clock line occurs upon updating
SSPADD. Clock stretching will occur on each data
receive sequence as described in 7-bit mode.
Note: If the user polls the UA bit and clears it by
updating the SSPADD register before the
falling edge of the ninth clock occurs and if
the user hasn’t cleared the BF bit by read-
ing the SSPBUF register before that time,
then the CKP bit will still NOT be asserted
low. Clock stretching on the basis of the
state of the BF bit only occurs during a
data sequence, not an address sequence.

DS30498B-page 112 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
10.4.4.5 Clock Synchronization
and the CKP Bit
When the CKP bit is cleared, the SCL output is forced
to ‘0’; however, setting the CKP bit will not assert the
SCL output low until the SCL output is already sam-
pled low. Therefore, the CKP bit will not assert the
SCL line until an external I2C master device has
already asserted the SCL line. The SCL output will
remain low until the CKP bit is set and all other
devices on the I2C bus have deasserted SCL. This
ensures that a write to the CKP bit will not violate the
minimum high time requirement for SCL (see
Figure 10-12).

FIGURE 10-12: CLOCK SYNCHRONIZATION TIMING

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

SDA DX DX-1

SCL

Master device
CKP asserts clock

Master device
deasserts clock
WR
SSPCON

 2003 Microchip Technology Inc. Preliminary DS30498B-page 113

 FIGURE 10-13:

DS30498B-page 114
Clock is not held low
PIC16F7X7

because buffer full bit is

clear prior to falling edge Clock is held low until Clock is not held low
of 9th clock CKP is set to ‘1’ because ACK = 1

Receiving Address R/W = 0 Receiving Data ACK Receiving Data ACK

SDA A7 A6 A5 A4 A3 A2 A1 ACK D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0

SCL 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
S P

SSPIF
Bus master
(PIR1<3>) terminates
transfer

BF (SSPSTAT<0>)

Preliminary
Cleared in software
SSPBUF is read

SSPOV (SSPCON<6>)

SSPOV is set
because SSPBUF is
still full. ACK is not sent.

CKP

CKP
If BF is cleared written
prior to the falling to ‘1’ in
edge of the 9th clock, software
CKP will not be reset BF is set after falling
to ‘0’ and no clock edge of the 9th clock,
stretching will occur CKP is reset to ‘0’ and
clock stretching occurs
I2C SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 7-BIT ADDRESS)

 2003 Microchip Technology Inc.

 FIGURE 10-14:

Clock is held low until Clock is held low until

update of SSPADD has update of SSPADD has Clock is not held low
Clock is held low until
taken place taken place because ACK = 1
CKP is set to ‘1’
Receive First Byte of Address Receive Second Byte of Address Receive Data Byte Receive Data Byte
R/W = 0 ACK
ACK ACK
SDA 1 1 1 1 0 A9 A8 ACK A7 A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0

 2003 Microchip Technology Inc.

SCL 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
S P

SSPIF
Bus master
(PIR1<3>) terminates
Cleared in software Cleared in software Cleared in software transfer
Cleared in software

BF (SSPSTAT<0>)

SSPBUF is written with Dummy read of SSPBUF Dummy read of SSPBUF

contents of SSPSR to clear BF flag to clear BF flag
SSPOV (SSPCON<6>)

SSPOV is set

Preliminary
because SSPBUF is
still full. ACK is not sent.

UA (SSPSTAT<1>)

UA is set indicating that Cleared by hardware when Cleared by hardware when

the SSPADD needs to be SSPADD is updated with low SSPADD is updated with high
updated byte of address after falling edge byte of address after falling edge
of ninth clock of ninth clock

UA is set indicating that

SSPADD needs to be
updated
CKP
Note: An update of the SSPADD
register before the falling
edge of the ninth clock will CKP written to ‘1’
have no effect on UA and in software
UA will remain set.

Note: An update of the SSPADD register before the falling edge of

the ninth clock will have no effect on UA and UA will remain
I2C SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 10-BIT ADDRESS)

set.

DS30498B-page 115
PIC16F7X7
PIC16F7X7
10.4.5 GENERAL CALL ADDRESS If the general call address matches, the SSPSR is
SUPPORT transferred to the SSPBUF, the BF flag bit is set (eighth
bit) and on the falling edge of the ninth bit (ACK bit), the
The addressing procedure for the I2C bus is such that
SSPIF interrupt flag bit is set.
the first byte after the Start condition usually deter-
mines which device will be the slave addressed by the When the interrupt is serviced, the source for the inter-
master. The exception is the general call address, rupt can be checked by reading the contents of the
which can address all devices. When this address is SSPBUF. The value can be used to determine if the
used, all devices should, in theory, respond with an address was device specific or a general call address.
Acknowledge. In 10-bit mode, the SSPADD is required to be updated
The general call address is one of eight addresses for the second half of the address to match and the UA
reserved for specific purposes by the I2C protocol. It bit is set (SSPSTAT<1>). If the general call address is
consists of all ‘0’s with R/W = 0. sampled when the GCEN bit is set and while the slave
is configured in 10-bit Address mode, then the second
The general call address is recognized when the Gen-
half of the address is not necessary, the UA bit will not
eral Call Enable bit (GCEN) is enabled (SSPCON2<7>
be set and the slave will begin receiving data after the
set). Following a Start bit detect, 8 bits are shifted into
Acknowledge (Figure 10-15).
the SSPSR and the address is compared against the
SSPADD. It is also compared to the general call
address and fixed in hardware.

FIGURE 10-15: SLAVE MODE GENERAL CALL ADDRESS SEQUENCE

(7 OR 10-BIT ADDRESS MODE)

Address is compared to general call address

after ACK, set interrupt

Receiving Data ACK

R/W = 0
SDA General Call Address ACK D7 D6 D5 D4 D3 D2 D1 D0

SCL
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
S

SSPIF

BF (SSPSTAT<0>)

Cleared in software
SSPBUF is read
SSPOV (SSPCON<6>) ‘0’

GCEN (SSPCON2<7>) ‘1’

DS30498B-page 116 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
10.4.6 MASTER MODE Note: The MSSP module, when configured in
Master mode is enabled by setting and clearing the I2C Master mode, does not allow queueing
appropriate SSPM bits in SSPCON and by setting the of events. For instance, the user is not
SSPEN bit. In Master mode, the SCL and SDA lines allowed to initiate a Start condition and
are manipulated by the MSSP hardware. immediately write the SSPBUF register to
initiate transmission before the Start condi-
Master mode of operation is supported by interrupt
tion is complete. In this case, the SSPBUF
generation on the detection of the Start and Stop con-
will not be written to and the WCOL bit will
ditions. The Stop (P) and Start (S) bits are cleared from
be set, indicating that a write to the
a Reset or when the MSSP module is disabled. Control
SSPBUF did not occur.
of the I 2C bus may be taken when the P bit is set or the
bus is Idle, with both the S and P bits clear. The following events will cause SSP Interrupt Flag bit,
In Firmware Controlled Master mode, user code SSPIF, to be set (SSP interrupt if enabled):
conducts all I 2C bus operations based on Start and • Start condition
Stop bit conditions.
• Stop condition
Once Master mode is enabled, the user has six • Data transfer byte transmitted/received
options:
• Acknowledge Transmit
1. Assert a Start condition on SDA and SCL. • Repeated Start
2. Assert a Repeated Start condition on SDA and
SCL.
3. Write to the SSPBUF register, initiating
transmission of data/address.
4. Configure the I2C port to receive data.
5. Generate an Acknowledge condition at the end
of a received byte of data.
6. Generate a Stop condition on SDA and SCL.

FIGURE 10-16: MSSP BLOCK DIAGRAM (I2C MASTER MODE)

Internal SSPM3:SSPM0
Data Bus SSPADD<6:0>
Read Write

SSPBUF Baud
Rate
Generator
SDA Shift
Clock Arbitrate/WCOL Detect

SDA In Clock
SSPSR
(hold off clock source)

MSb LSb
Receive Enable

Start bit, Stop bit,

Clock Cntl

Acknowledge
Generate
SCL

Start bit Detect

Stop bit Detect
SCL In Write Collision Detect Set/Reset S, P, WCOL (SSPSTAT)
Clock Arbitration Set SSPIF, BCLIF
Bus Collision State Counter for Reset ACKSTAT, PEN (SSPCON2)
end of XMIT/RCV

 2003 Microchip Technology Inc. Preliminary DS30498B-page 117

PIC16F7X7
10.4.6.1 I2C Master Mode Operation A typical transmit sequence would go as follows:
The master device generates all of the serial clock 1. The user generates a Start condition by setting
pulses and the Start and Stop conditions. A transfer is the Start enable bit, SEN (SSPCON2<0>).
ended with a Stop condition or with a Repeated Start 2. SSPIF is set. The MSSP module will wait the
condition. Since the Repeated Start condition is also required Start time before any other operation
the beginning of the next serial transfer, the I2C bus will takes place.
not be released. 3. The user loads the SSPBUF with the slave
In Master Transmitter mode, serial data is output address to transmit.
through SDA while SCL outputs the serial clock. The 4. Address is shifted out the SDA pin until all 8 bits
first byte transmitted contains the slave address of the are transmitted.
receiving device (7 bits) and the Read/Write (R/W) bit. 5. The MSSP module shifts in the ACK bit from the
In this case, the R/W bit will be logic ‘0’. Serial data is slave device and writes its value into the
transmitted 8 bits at a time. After each byte is transmit- SSPCON2 register (SSPCON2<6>).
ted, an Acknowledge bit is received. Start and Stop
6. The MSSP module generates an interrupt at the
conditions are output to indicate the beginning and the
end of the ninth clock cycle by setting the SSPIF
end of a serial transfer.
bit.
In Master Receive mode, the first byte transmitted con- 7. The user loads the SSPBUF with eight bits of
tains the slave address of the transmitting device data.
(7 bits) and the R/W bit. In this case, the R/W bit will be
8. Data is shifted out the SDA pin until all 8 bits are
logic ‘1’. Thus, the first byte transmitted is a 7-bit slave
transmitted.
address followed by a ‘1’ to indicate a receive bit. Serial
data is received via SDA while SCL outputs the serial 9. The MSSP module shifts in the ACK bit from the
clock. Serial data is received 8 bits at a time. After each slave device and writes its value into the
byte is received, an Acknowledge bit is transmitted. SSPCON2 register (SSPCON2<6>).
Start and Stop conditions indicate the beginning and 10. The MSSP module generates an interrupt at the
end of transmission. end of the ninth clock cycle by setting the SSPIF
bit.
The baud rate generator used for the SPI mode opera-
tion is used to set the SCL clock frequency for either 11. The user generates a Stop condition by setting
100 kHz, 400 kHz or 1 MHz I2C operation. See the Stop enable bit, PEN (SSPCON2<2>).
Section 10.4.7 “Baud Rate Generator” for more 12. Interrupt is generated once the Stop condition is
detail. complete.

DS30498B-page 118 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
10.4.7 BAUD RATE GENERATOR Once the given operation is complete (i.e., transmis-
2 sion of the last data bit is followed by ACK), the internal
In I C Master mode, the Baud Rate Generator (BRG)
clock will automatically stop counting and the SCL pin
reload value is placed in the lower 7 bits of the
will remain in its last state.
SSPADD register (Figure 10-17). When a write occurs
to SSPBUF, the Baud Rate Generator will automatically Table 10-3 demonstrates clock rates based on
begin counting. The BRG counts down to 0 and stops instruction cycles and the BRG value loaded into
until another reload has taken place. The BRG count is SSPADD.
decremented twice per instruction cycle (TCY) on the
Q2 and Q4 clocks. In I2C Master mode, the BRG is
reloaded automatically.

FIGURE 10-17: BAUD RATE GENERATOR BLOCK DIAGRAM

SSPM3:SSPM0 SSPADD<6:0>

SSPM3:SSPM0 Reload Reload

SCL Control

CLKO BRG Down Counter FOSC/4

TABLE 10-3: I2C CLOCK RATE w/BRG

FSCL
FCY FCY*2 BRG VALUE
(2 Rollovers of BRG)
10 MHz 20 MHz 19h 400 kHz(1)
10 MHz 20 MHz 20h 312.5 kHz
10 MHz 20 MHz 3Fh 100 kHz
4 MHz 8 MHz 0Ah 400 kHz(1)
4 MHz 8 MHz 0Dh 308 kHz
4 MHz 8 MHz 28h 100 kHz
1 MHz 2 MHz 03h 333 kHz(1)
1 MHz 2 MHz 0Ah 100 kHz
1 MHz 2 MHz 00h 1 MHz(1)
Note 1: The I2C interface does not conform to the 400 kHz I2C specification (which applies to rates greater than
100 kHz) in all details, but may be used with care where higher rates are required by the application.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 119

PIC16F7X7
10.4.7.1 Clock Arbitration
Clock arbitration occurs when the master, during any
receive, transmit or Repeated Start/Stop condition,
deasserts the SCL pin (SCL allowed to float high).
When the SCL pin is allowed to float high, the Baud
Rate Generator (BRG) is suspended from counting
until the SCL pin is actually sampled high. When the
SCL pin is sampled high, the Baud Rate Generator is
reloaded with the contents of SSPADD<6:0> and
begins counting. This ensures that the SCL high time
will always be at least one BRG rollover count in the
event that the clock is held low by an external device
(Figure 10-18).

FIGURE 10-18: BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION

SDA DX DX-1

SCL deasserted but slave holds SCL allowed to transition high

SCL low (clock arbitration)
SCL

BRG decrements on
Q2 and Q4 cycles

BRG
03h 02h 01h 00h (hold off) 03h 02h
Value

SCL is sampled high, reload takes

place and BRG starts its count
BRG
Reload

DS30498B-page 120 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
10.4.8 I2C MASTER MODE START 10.4.8.1 WCOL Status Flag
CONDITION TIMING If the user writes the SSPBUF when a Start sequence
To initiate a Start condition, the user sets the Start Con- is in progress, the WCOL is set and the contents of the
dition Enable bit, SEN (SSPCON2<0>). If the SDA and buffer are unchanged (the write doesn’t occur).
SCL pins are sampled high, the Baud Rate Generator
Note: Because queueing of events is not
is reloaded with the contents of SSPADD<6:0> and
allowed, writing to the lower 5 bits of
starts its count. If SCL and SDA are both sampled high
SSPCON2 is disabled until the Start
when the Baud Rate Generator times out (TBRG), the
condition is complete.
SDA pin is driven low. The action of the SDA being
driven low while SCL is high is the Start condition and
causes the S bit (SSPSTAT<3>) to be set. Following
this, the Baud Rate Generator is reloaded with the con-
tents of SSPADD<6:0> and resumes its count. When
the Baud Rate Generator times out (TBRG), the SEN bit
(SSPCON2<0>) will be automatically cleared by hard-
ware, the Baud Rate Generator is suspended, leaving
the SDA line held low and the Start condition is
complete.
Note: If at the beginning of the Start condition,
the SDA and SCL pins are already sam-
pled low, or if during the Start condition, the
SCL line is sampled low before the SDA
line is driven low, a bus collision occurs,
the Bus Collision Interrupt Flag, BCLIF, is
set, the Start condition is aborted and the
I2C module is reset into its Idle state.

FIGURE 10-19: FIRST START BIT TIMING

Set S bit (SSPSTAT<3>)

Write to SEN bit occurs here
SDA = 1,
At completion of Start bit,
SCL = 1
hardware clears SEN bit
and sets SSPIF bit
TBRG TBRG Write to SSPBUF occurs here

1st bit 2nd bit

SDA
TBRG

SCL
TBRG
S

 2003 Microchip Technology Inc. Preliminary DS30498B-page 121

PIC16F7X7
10.4.9 I2C MASTER MODE REPEATED Immediately following the SSPIF bit getting set, the
START CONDITION TIMING user may write the SSPBUF with the 7-bit address in
7-bit mode or the default first address in 10-bit mode.
A Repeated Start condition occurs when the RSEN bit
After the first eight bits are transmitted and an ACK is
(SSPCON2<1>) is programmed high and the I2C logic
received, the user may then transmit an additional eight
module is in the Idle state. When the RSEN bit is set,
bits of address (10-bit mode) or eight bits of data (7-bit
the SCL pin is asserted low. When the SCL pin is sam-
mode).
pled low, the Baud Rate Generator is loaded with the
contents of SSPADD<5:0> and begins counting. The 10.4.9.1 WCOL Status Flag
SDA pin is released (brought high) for one Baud Rate
Generator count (TBRG). When the Baud Rate Genera- If the user writes the SSPBUF when a Repeated Start
tor times out, if SDA is sampled high, the SCL pin will sequence is in progress, the WCOL is set and the con-
be deasserted (brought high). When SCL is sampled tents of the buffer are unchanged (the write doesn’t
high, the Baud Rate Generator is reloaded with the occur).
contents of SSPADD<6:0> and begins counting. SDA Note: Because queueing of events is not
and SCL must be sampled high for one TBRG. This allowed, writing of the lower 5 bits of
action is then followed by assertion of the SDA pin SSPCON2 is disabled until the Repeated
(SDA = 0) for one TBRG while SCL is high. Following Start condition is complete.
this, the RSEN bit (SSPCON2<1>) will be automatically
cleared and the Baud Rate Generator will not be
reloaded, leaving the SDA pin held low. As soon as a
Start condition is detected on the SDA and SCL pins,
the S bit (SSPSTAT<3>) will be set. The SSPIF bit will
not be set until the Baud Rate Generator has timed out.
Note 1: If RSEN is programmed while any other
event is in progress, it will not take effect.
2: A bus collision during the Repeated Start
condition occurs if:
• SDA is sampled low when SCL goes
from low-to-high.
• SCL goes low before SDA is
asserted low. This may indicate that
another master is attempting to
transmit a data ‘1’.

FIGURE 10-20: REPEAT START CONDITION WAVEFORM

Set S (SSPSTAT<3>)
Write to SSPCON2
SDA = 1,
occurs here. At completion of Start bit,
SDA = 1, SCL = 1
hardware clears RSEN bit
SCL (no change). and sets SSPIF

TBRG TBRG TBRG

1st bit
SDA
Falling edge of ninth clock. Write to SSPBUF occurs here
End of Xmit.
TBRG

SCL TBRG

Sr = Repeated Start

DS30498B-page 122 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
10.4.10 I2C MASTER MODE 10.4.10.3 ACKSTAT Status Flag
TRANSMISSION In Transmit mode, the ACKSTAT bit (SSPCON2<6>) is
Transmission of a data byte, a 7-bit address or the cleared when the slave has sent an Acknowledge
other half of a 10-bit address, is accomplished by sim- (ACK = 0) and is set when the slave does not Acknowl-
ply writing a value to the SSPBUF register. This action edge (ACK = 1). A slave sends an Acknowledge when
will set the Buffer Full flag bit, BF, and allow the Baud it has recognized its address (including a general call)
Rate Generator to begin counting and start the next or when the slave has properly received its data.
transmission. Each bit of address/data will be shifted
out onto the SDA pin after the falling edge of SCL is 10.4.11 I2C MASTER MODE RECEPTION
asserted (see data hold time specification parameter Master mode reception is enabled by programming the
#106). SCL is held low for one Baud Rate Generator Receive Enable bit, RCEN (SSPCON2<3>).
rollover count (TBRG). Data should be valid before SCL
is released high (see data setup time specification Note: The MSSP module must be in an Idle state
parameter #107). When the SCL pin is released high, it before the RCEN bit is set or the RCEN bit
is held that way for TBRG. The data on the SDA pin will be disregarded.
must remain stable for that duration and some hold The Baud Rate Generator begins counting and on each
time after the next falling edge of SCL. After the eighth rollover, the state of the SCL pin changes (high-to-low/
bit is shifted out (the falling edge of the eighth clock), low-to-high) and data is shifted into the SSPSR. After
the BF flag is cleared and the master releases SDA. the falling edge of the eighth clock, the receive enable
This allows the slave device being addressed to flag is automatically cleared, the contents of the
respond with an ACK bit during the ninth bit time, if an SSPSR are loaded into the SSPBUF, the BF flag bit is
address match occurred or if data was received prop- set, the SSPIF flag bit is set and the Baud Rate Gener-
erly. The status of ACK is written into the ACKDT bit on ator is suspended from counting, holding SCL low. The
the falling edge of the ninth clock. If the master receives MSSP is now in Idle state, awaiting the next command.
an Acknowledge, the Acknowledge Status bit, When the buffer is read by the CPU, the BF flag bit is
ACKSTAT, is cleared. If not, the bit is set. After the ninth automatically cleared. The user can then send an
clock, the SSPIF bit is set and the master clock (Baud Acknowledge bit at the end of reception by setting the
Rate Generator) is suspended until the next data byte Acknowledge Sequence Enable bit, ACKEN
is loaded into the SSPBUF, leaving SCL low and SDA (SSPCON2<4>).
unchanged (Figure 10-21).
After the write to the SSPBUF, each bit of address will 10.4.11.1 BF Status Flag
be shifted out on the falling edge of SCL until all seven In receive operation, the BF bit is set when an address
address bits and the R/W bit are completed. On the fall- or data byte is loaded into SSPBUF from SSPSR. It is
ing edge of the eighth clock, the master will deassert cleared when the SSPBUF register is read.
the SDA pin, allowing the slave to respond with an
Acknowledge. On the falling edge of the ninth clock, the 10.4.11.2 SSPOV Status Flag
master will sample the SDA pin to see if the address
In receive operation, the SSPOV bit is set when 8 bits
was recognized by a slave. The status of the ACK bit is
are received into the SSPSR and the BF flag bit is
loaded into the ACKSTAT status bit (SSPCON2<6>).
already set from a previous reception.
Following the falling edge of the ninth clock transmis-
sion of the address, the SSPIF is set, The BF flag Is 10.4.11.3 WCOL Status Flag
cleared and the Baud Rate Generator is turned off until
another write to the SSPBUF takes place, holding SCL If the user writes the SSPBUF when a receive is
low and allowing SDA to float. already in progress (i.e., SSPSR is still shifting in a data
byte), the WCOL bit is set and the contents of the buffer
10.4.10.1 BF Status Flag are unchanged (the write doesn’t occur).
In Transmit mode, the BF bit (SSPSTAT<0>) is set
when the CPU writes to SSPBUF and is cleared when
all 8 bits are shifted out.

10.4.10.2 WCOL Status Flag

If the user writes the SSPBUF when a transmit is
already in progress (i.e., SSPSR is still shifting out a
data byte), the WCOL is set and the contents of the
buffer are unchanged (the write doesn’t occur).
WCOL must be cleared in software.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 123

 FIGURE 10-21:

DS30498B-page 124
Write SSPCON2<0> SEN = 1 ACKSTAT in
Start condition begins SSPCON2 = 1
From Slave, clear ACKSTAT bit SSPCON2<6>
PIC16F7X7

SEN = 0
Transmit Address to Slave R/W = 0 Transmitting Data or Second Half of 10-bit Address ACK

SDA A7 A6 A5 A4 A3 A2 A1 ACK = 0 D7 D6 D5 D4 D3 D2 D1 D0

SSPBUF written with 7-bit address and R/W

starts transmit
SCL 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
S P
SCL held low
while CPU
responds to SSPIF
SSPIF
Cleared in software service routine
Cleared in software from SSP interrupt
Cleared in software

Preliminary
BF (SSPSTAT<0>)

SSPBUF written SSPBUF is written in software

SEN

After Start condition, SEN cleared by hardware

PEN

R/W
I 2C MASTER MODE WAVEFORM (TRANSMISSION, 7 OR 10-BIT ADDRESS)

 2003 Microchip Technology Inc.

 FIGURE 10-22:

Write to SSPCON2<4>
to start Acknowledge sequence,
SDA = ACKDT (SSPCON2<5>) = 0
Write to SSPCON2<0> (SEN = 1).
Begin Start condition. ACK from Master Set ACKEN, start Acknowledge sequence
Master configured as a receiver SDA = ACKDT = 0 SDA = ACKDT = 1
SEN = 0 by programming SSPCON2<3> (RCEN = 1)

 2003 Microchip Technology Inc.

PEN bit = 1
Write to SSPBUF occurs here. RCEN cleared RCEN = 1, start RCEN cleared
ACK from Slave next receive automatically written here
Start XMIT. automatically
Transmit Address to Slave R/W = 1 Receiving Data from Slave Receiving Data from Slave
SDA A7 A6 A5 A4 A3 A2 A1 ACK D7 D6 D5 D4 D3 D2 D1 D0 ACK D7 D6 D5 D4 D3 D2 D1 D0 ACK

Bus master
ACK is not sent terminates
transfer
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
SCL S P
Data shifted in on falling edge of CLK Set SSPIF at end
of receive Set SSPIF interrupt
Set SSPIF interrupt at end of Acknow-
Set SSPIF interrupt ledge sequence
at end of receive
at end of Acknowledge
SSPIF sequence

Set P bit
Cleared in software Cleared in software Cleared in software Cleared in software (SSPSTAT<4>)
SDA = 0, SCL = 1 Cleared in

Preliminary
while CPU software and SSPIF
responds to SSPIF

BF
(SSPSTAT<0>) Last bit is shifted into SSPSR and
contents are unloaded into SSPBUF

SSPOV

SSPOV is set because

SSPBUF is still full

ACKEN
I 2C MASTER MODE WAVEFORM (RECEPTION, 7-BIT ADDRESS)

DS30498B-page 125
PIC16F7X7
PIC16F7X7
10.4.12 ACKNOWLEDGE SEQUENCE 10.4.13 STOP CONDITION TIMING
TIMING A Stop bit is asserted on the SDA pin at the end of a
An Acknowledge sequence is enabled by setting the receive/transmit by setting the Stop Sequence Enable
Acknowledge Sequence Enable bit, ACKEN bit, PEN (SSPCON2<2>). At the end of a receive/
(SSPCON2<4>). When this bit is set, the SCL pin is transmit, the SCL line is held low after the falling edge
pulled low and the contents of the Acknowledge data bit of the ninth clock. When the PEN bit is set, the master
are presented on the SDA pin. If the user wishes to gen- will assert the SDA line low. When the SDA line is sam-
erate an Acknowledge, then the ACKDT bit should be pled low, the Baud Rate Generator is reloaded and
cleared. If not, the user should set the ACKDT bit before counts down to ‘0’. When the Baud Rate Generator
starting an Acknowledge sequence. The Baud Rate times out, the SCL pin will be brought high and one
Generator then counts for one rollover period (TBRG) TBRG (Baud Rate Generator rollover count) later, the
and the SCL pin is deasserted (pulled high). When the SDA pin will be deasserted. When the SDA pin is sam-
SCL pin is sampled high (clock arbitration), the Baud pled high while SCL is high, the P bit (SSPSTAT<4>) is
Rate Generator counts for TBRG. The SCL pin is then set. A TBRG later, the PEN bit is cleared and the SSPIF
pulled low. Following this, the ACKEN bit is automatically bit is set (Figure 10-24).
cleared, the Baud Rate Generator is turned off and the
MSSP module then goes into Idle mode (Figure 10-23). 10.4.13.1 WCOL Status Flag
If the user writes the SSPBUF when a Stop sequence
10.4.12.1 WCOL Status Flag is in progress, then the WCOL bit is set and the
If the user writes the SSPBUF when an Acknowledge contents of the buffer are unchanged (the write doesn’t
sequence is in progress, then WCOL is set and the occur).
contents of the buffer are unchanged (the write doesn’t
occur).

FIGURE 10-23: ACKNOWLEDGE SEQUENCE WAVEFORM

Acknowledge sequence starts here, ACKEN automatically cleared
write to SSPCON2
ACKEN = 1, ACKDT = 0
TBRG TBRG
SDA D0 ACK

SCL 8 9

SSPIF

Cleared in
Set SSPIF at the end Cleared in software
of receive software Set SSPIF at the end
of Acknowledge sequence
Note: TBRG = one Baud Rate Generator period.

FIGURE 10-24: STOP CONDITION RECEIVE OR TRANSMIT MODE

Write to SSPCON2, SCL = 1 for TBRG, followed by SDA = 1 for TBRG
set PEN after SDA sampled high. P bit (SSPSTAT<4>) is set.

Falling edge of PEN bit (SSPCON2<2>) is cleared by

9th clock hardware and the SSPIF bit is set
TBRG
SCL

SDA ACK

P
TBRG TBRG TBRG
SCL brought high after TBRG
SDA asserted low before rising edge of clock to setup Stop condition

Note: TBRG = one Baud Rate Generator period.

DS30498B-page 126 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
10.4.14 SLEEP OPERATION 10.4.17 MULTI-MASTER COMMUNICATION,
2
While in Sleep mode, the I C module can receive BUS COLLISION AND BUS
addresses or data and when an address match or ARBITRATION
complete byte transfer occurs, wake the processor Multi-Master mode support is achieved by bus arbitra-
from Sleep (if the MSSP interrupt is enabled). tion. When the master outputs address/data bits onto
the SDA pin, arbitration takes place when the master
10.4.15 EFFECT OF A RESET outputs a ‘1’ on SDA by letting SDA float high and
A Reset disables the MSSP module and terminates the another master asserts a ‘0’. When the SCL pin floats
current transfer. high, data should be stable. If the expected data on
SDA is a ‘1’ and the data sampled on the SDA pin = 0,
10.4.16 MULTI-MASTER MODE then a bus collision has taken place. The master will set
In Multi-Master mode, the interrupt generation on the the Bus Collision Interrupt Flag, BCLIF, and reset the
detection of the Start and Stop conditions allows the I2C port to its Idle state (Figure 10-25).
determination of when the bus is free. The Stop (P) and If a transmit was in progress when the bus collision
Start (S) bits are cleared from a Reset or when the occurred, the transmission is halted, the BF flag is
MSSP module is disabled. Control of the I 2C bus may cleared, the SDA and SCL lines are deasserted and the
be taken when the P bit (SSPSTAT<4>) is set or the SSPBUF can be written to. When the user services the
bus is Idle, with both the S and P bits clear. When the bus collision Interrupt Service Routine and if the I2C
bus is busy, enabling the SSP interrupt will generate bus is free, the user can resume communication by
the interrupt when the Stop condition occurs. asserting a Start condition.
In multi-master operation, the SDA line must be moni- If a Start, Repeated Start, Stop or Acknowledge condi-
tored for arbitration to see if the signal level is at the tion was in progress when the bus collision occurred,
expected output level. This check is performed in the condition is aborted, the SDA and SCL lines are
hardware with the result placed in the BCLIF bit. deasserted and the respective control bits in the
The states where arbitration can be lost are: SSPCON2 register are cleared. When the user
services the bus collision Interrupt Service Routine and
• Address Transfer if the I2C bus is free, the user can resume
• Data Transfer communication by asserting a Start condition.
• A Start Condition The master will continue to monitor the SDA and SCL
• A Repeated Start Condition pins. If a Stop condition occurs, the SSPIF bit will be set.
• An Acknowledge Condition A write to the SSPBUF will start the transmission of
data at the first data bit, regardless of where the
transmitter left off when the bus collision occurred.
In Multi-Master mode, the interrupt generation on the
detection of Start and Stop conditions allows the determi-
nation of when the bus is free. Control of the I2C bus can
be taken when the P bit is set in the SSPSTAT register or
the bus is Idle and the S and P bits are cleared.

FIGURE 10-25: BUS COLLISION TIMING FOR TRANSMIT AND ACKNOWLEDGE

Data changes SDA line pulled low Sample SDA. While SCL is high,
while SCL = 0 by another source data doesn’t match what is driven
by the master. Bus collision has occurred.
SDA released
by master

SDA

SCL Set bus collision

interrupt (BCLIF)

BCLIF

 2003 Microchip Technology Inc. Preliminary DS30498B-page 127

PIC16F7X7
10.4.17.1 Bus Collision During a Start If the SDA pin is sampled low during this count, the
Condition BRG is reset and the SDA line is asserted early
(Figure 10-28). If, however, a ‘1’ is sampled on the SDA
During a Start condition, a bus collision occurs if:
pin, the SDA pin is asserted low at the end of the BRG
a) SDA or SCL are sampled low at the beginning of count. The Baud Rate Generator is then reloaded and
the Start condition (Figure 10-26). counts down to 0 and during this time, if the SCL pin is
b) SCL is sampled low before SDA is asserted low sampled as ‘0’, a bus collision does not occur. At the
(Figure 10-27). end of the BRG count, the SCL pin is asserted low.
During a Start condition, both the SDA and the SCL Note: The reason that bus collision is not a factor
pins are monitored. during a Start condition is that no two bus
If the SDA pin is already low, or the SCL pin is already masters can assert a Start condition at the
low, then all of the following occur: exact same time. Therefore, one master
will always assert SDA before the other.
• the Start condition is aborted,
This condition does not cause a bus colli-
• the BCLIF flag is set and sion because the two masters must be
• the MSSP module is reset to its Idle state allowed to arbitrate the first address fol-
(Figure 10-26). lowing the Start condition. If the address is
The Start condition begins with the SDA and SCL pins the same, arbitration must be allowed to
deasserted. When the SDA pin is sampled high, the continue into the data portion, Repeated
Baud Rate Generator is loaded from SSPADD<6:0> Start or Stop conditions.
and counts down to 0. If the SCL pin is sampled low
while SDA is high, a bus collision occurs because it is
assumed that another master is attempting to drive a
data ‘1’ during the Start condition.

FIGURE 10-26: BUS COLLISION DURING START CONDITION (SDA ONLY)

SDA goes low before the SEN bit is set.

Set BCLIF,
S bit and SSPIF set because
SDA = 0, SCL = 1.

SDA

SCL
Set SEN, enable Start SEN cleared automatically because of bus collision.
condition if SDA = 1, SCL = 1 SSP module resets into Idle state.
SEN
SDA sampled low before
Start condition. Set BCLIF.
S bit and SSPIF set because
BCLIF SDA = 0, SCL = 1.
SSPIF and BCLIF are
cleared in software

SSPIF

SSPIF and BCLIF are

cleared in software

DS30498B-page 128 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 10-27: BUS COLLISION DURING START CONDITION (SCL = 0)

SDA = 0, SCL = 1

TBRG TBRG

SDA

SCL Set SEN, enable Start

sequence if SDA = 1, SCL = 1
SCL = 0 before SDA = 0,
bus collision occurs. Set BCLIF.
SEN
SCL = 0 before BRG time-out,
bus collision occurs. Set BCLIF.
BCLIF
Interrupt cleared
in software
S ‘0’ ‘0’

SSPIF ‘0’ ‘0’

FIGURE 10-28: BRG RESET DUE TO SDA ARBITRATION DURING START CONDITION
SDA = 0, SCL = 1
Set S Set SSPIF
Less than TBRG
TBRG

SDA SDA pulled low by other master.

Reset BRG and assert SDA.

SCL S
SCL pulled low after BRG
time-out
SEN
Set SEN, enable Start
sequence if SDA = 1, SCL = 1
BCLIF ‘0’

SSPIF
SDA = 0, SCL = 1, Interrupts cleared
set SSPIF in software

 2003 Microchip Technology Inc. Preliminary DS30498B-page 129

PIC16F7X7
10.4.17.2 Bus Collision During a Repeated If SDA is low, a bus collision has occurred (i.e., another
Start Condition master is attempting to transmit a data ‘0’, see
Figure 10-29). If SDA is sampled high, the BRG is
During a Repeated Start condition, a bus collision
reloaded and begins counting. If SDA goes from high-
occurs if:
to-low before the BRG times out, no bus collision
a) A low level is sampled on SDA when SCL goes occurs because no two masters can assert SDA at
from low level to high level. exactly the same time.
b) SCL goes low before SDA is asserted low, If SCL goes from high-to-low before the BRG times out
indicating that another master is attempting to and SDA has not already been asserted, a bus collision
transmit a data ‘1’. occurs. In this case, another master is attempting to
When the user deasserts SDA and the pin is allowed to transmit a data ‘1’ during the Repeated Start condition
float high, the BRG is loaded with SSPADD<6:0> and (Figure 10-30).
counts down to 0. The SCL pin is then deasserted and If at the end of the BRG time-out, both SCL and SDA are
when sampled high, the SDA pin is sampled. still high, the SDA pin is driven low and the BRG is
reloaded and begins counting. At the end of the count,
regardless of the status of the SCL pin, the SCL pin is
driven low and the Repeated Start condition is complete.

FIGURE 10-29: BUS COLLISION DURING A REPEATED START CONDITION (CASE 1)

SDA

SCL

Sample SDA when SCL goes high.

If SDA = 0, set BCLIF and release SDA and SCL.

RSEN

BCLIF

Cleared in software
S ‘0’

SSPIF ‘0’

FIGURE 10-30: BUS COLLISION DURING A REPEATED START CONDITION (CASE 2)

TBRG TBRG

SDA

SCL

SCL goes low before SDA,

BCLIF set BCLIF. Release SDA and SCL.
Interrupt cleared
in software
RSEN

S ‘0’

SSPIF

DS30498B-page 130 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
10.4.17.3 Bus Collision During a Stop The Stop condition begins with SDA asserted low.
Condition When SDA is sampled low, the SCL pin is allowed to
float. When the pin is sampled high (clock arbitration),
Bus collision occurs during a Stop condition if:
the Baud Rate Generator is loaded with SSPADD<6:0>
a) After the SDA pin has been deasserted and and counts down to 0. After the BRG times out, SDA is
allowed to float high, SDA is sampled low after sampled. If SDA is sampled low, a bus collision has
the BRG has timed out. occurred. This is due to another master attempting to
b) After the SCL pin is deasserted, SCL is sampled drive a data ‘0’ (Figure 10-31). If the SCL pin is
low before SDA goes high. sampled low before SDA is allowed to float high, a bus
collision occurs. This is another case of another master
attempting to drive a data ‘0’ (Figure 10-32).

FIGURE 10-31: BUS COLLISION DURING A STOP CONDITION (CASE 1)

TBRG TBRG TBRG SDA sampled

low after TBRG,
set BCLIF
SDA

SDA asserted low

SCL

PEN

BCLIF

P ‘0’

SSPIF ‘0’

FIGURE 10-32: BUS COLLISION DURING A STOP CONDITION (CASE 2)

TBRG TBRG TBRG

SDA

Assert SDA SCL goes low before SDA goes high,

set BCLIF
SCL

PEN

BCLIF

P ‘0’

SSPIF ‘0’

 2003 Microchip Technology Inc. Preliminary DS30498B-page 131

PIC16F7X7
NOTES:

DS30498B-page 132 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
11.0 ADDRESSABLE UNIVERSAL The USART can be configured in the following modes:
SYNCHRONOUS • Asynchronous (full-duplex)
ASYNCHRONOUS RECEIVER • Synchronous – Master (half-duplex)
TRANSMITTER (USART) • Synchronous – Slave (half-duplex)
Bit SPEN (RCSTA<7>) and bits TRISC<7:6> have
The Universal Synchronous Asynchronous Receiver
to be set in order to configure pins RC6/TX/CK and
Transmitter (USART) module is one of the two serial
RC7/RX/DT as the Universal Synchronous
I/O modules. (USART is also known as a Serial
Asynchronous Receiver Transmitter.
Communications Interface or SCI.) The USART can be
configured as a full-duplex asynchronous system that The USART module also has a multi-processor
can communicate with peripheral devices, such as communication capability using 9-bit address detection.
CRT terminals and personal computers, or it can be
configured as a half-duplex synchronous system that
can communicate with peripheral devices, such as A/D
or D/A integrated circuits, serial EEPROMs, etc.

REGISTER 11-1: TXSTA: TRANSMIT STATUS AND CONTROL REGISTER (ADDRESS 98h)
R/W-0 R/W-0 R/W-0 R/W-0 U-0 R/W-0 R-1 R/W-0
CSRC TX9 TXEN SYNC — BRGH TRMT TX9D
bit 7 bit 0

bit 7 CSRC: Clock Source Select bit

Asynchronous mode:
Don’t care.
Synchronous mode:
1 = Master mode (clock generated internally from BRG)
0 = Slave mode (clock from external source)
bit 6 TX9: 9-bit Transmit Enable bit
1 = Selects 9-bit transmission
0 = Selects 8-bit transmission
bit 5 TXEN: Transmit Enable bit
1 = Transmit enabled
0 = Transmit disabled
Note: SREN/CREN overrides TXEN in Sync mode.
bit 4 SYNC: USART Mode Select bit
1 = Synchronous mode
0 = Asynchronous mode
bit 3 Unimplemented: Read as ‘0’
bit 2 BRGH: High Baud Rate Select bit
Asynchronous mode:
1 = High speed
0 = Low speed
Synchronous mode:
Unused in this mode.
bit 1 TRMT: Transmit Shift Register Status bit
1 = TSR empty
0 = TSR full
bit 0 TX9D: 9th bit of Transmit Data, can be Parity bit

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

 2003 Microchip Technology Inc. Preliminary DS30498B-page 133

PIC16F7X7
REGISTER 11-2: RCSTA: RECEIVE STATUS AND CONTROL REGISTER (ADDRESS 18h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-0 R-0 R-x
SPEN RX9 SREN CREN ADDEN FERR OERR RX9D
bit 7 bit 0

bit 7 SPEN: Serial Port Enable bit

1 = Serial port enabled (configures RC7/RX/DT and RC6/TX/CK pins as serial port pins)
0 = Serial port disabled
bit 6 RX9: 9-bit Receive Enable bit
1 = Selects 9-bit reception
0 = Selects 8-bit reception
bit 5 SREN: Single Receive Enable bit
Asynchronous mode:
Don’t care.
Synchronous mode – Master:
1 = Enables single receive
0 = Disables single receive
This bit is cleared after reception is complete.
Synchronous mode – Slave:
Don’t care.
bit 4 CREN: Continuous Receive Enable bit
Asynchronous mode:
1 = Enables continuous receive
0 = Disables continuous receive
Synchronous mode:
1 = Enables continuous receive until enable bit CREN is cleared (CREN overrides SREN)
0 = Disables continuous receive
bit 3 ADDEN: Address Detect Enable bit
Asynchronous mode 9-bit (RX9 = 1):
1 = Enables address detection, enables interrupt and load of the receive buffer when
RSR<8> is set
0 = Disables address detection, all bytes are received and ninth bit can be used as parity bit
bit 2 FERR: Framing Error bit
1 = Framing error (can be updated by reading RCREG register and receiving next valid byte)
0 = No framing error
bit 1 OERR: Overrun Error bit
1 = Overrun error (can be cleared by clearing bit CREN)
0 = No overrun error
bit 0 RX9D: 9th bit of Received Data (can be parity bit, but must be calculated by user firmware)

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

DS30498B-page 134 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
11.1 USART Baud Rate Generator It may be advantageous to use the high baud rate
(BRG) (BRGH = 1), even for slower baud clocks. This is
because the FOSC/(16(X + 1)) equation can reduce the
The BRG supports both the Asynchronous and Syn- baud rate error in some cases.
chronous modes of the USART. It is a dedicated 8-bit
Writing a new value to the SPBRG register causes the
Baud Rate Generator. The SPBRG register controls
BRG timer to be reset (or cleared). This ensures the
the period of a free-running 8-bit timer. In Asynchro-
BRG does not wait for a timer overflow before
nous mode, bit BRGH (TXSTA<2>) also controls the
outputting the new baud rate.
baud rate. In Synchronous mode, bit BRGH is ignored.
Table 11-1 shows the formula for computation of the 11.1.1 SAMPLING
baud rate for different USART modes, which only apply
in Master mode (internal clock). The data on the RC7/RX/DT pin is sampled three times
by a majority detect circuit to determine if a high or a
Given the desired baud rate and FOSC, the nearest low level is present at the RX pin.
integer value for the SPBRG register can be calculated
using the formula in Table 11-1. From this, the error in
baud rate can be determined.

TABLE 11-1: BAUD RATE FORMULA

SYNC BRGH = 0 (Low Speed) BRGH = 1 (High Speed)
0 (Asynchronous) Baud Rate = FOSC/(64(X + 1)) Baud Rate = FOSC/(16(X + 1))
1 (Synchronous) Baud Rate = FOSC/(4(X + 1)) N/A
X = value in SPBRG (0 to 255)

TABLE 11-2: REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR

Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
98h TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010
18h RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 0000 000x
99h SPBRG Baud Rate Generator Register 0000 0000 0000 0000
Legend: x = unknown, - = unimplemented, read as ‘0’. Shaded cells are not used by the BRG.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 135

PIC16F7X7
TABLE 11-3: BAUD RATES FOR ASYNCHRONOUS MODE (BRGH = 0)
FOSC = 20 MHz FOSC = 16 MHz FOSC = 10 MHz
BAUD
RATE SPBRG SPBRG SPBRG
% % %
(K) value value value
KBAUD ERROR KBAUD ERROR KBAUD ERROR
(decimal) (decimal) (decimal)
0.3 - - - - - - - - -
1.2 1.221 1.75 255 1.202 0.17 207 1.202 0.17 129
2.4 2.404 0.17 129 2.404 0.17 103 2.404 0.17 64
9.6 9.766 1.73 31 9.615 0.16 25 9.766 1.73 15
19.2 19.531 1.72 15 19.231 0.16 12 19.531 1.72 7
28.8 31.250 8.51 9 27.778 3.55 8 31.250 8.51 4
33.6 34.722 3.34 8 35.714 6.29 6 31.250 6.99 4
57.6 62.500 8.51 4 62.500 8.51 3 52.083 9.58 2
HIGH 1.221 - 255 0.977 - 255 0.610 - 255
LOW 312.500 - 0 250.000 - 0 156.250 - 0

FOSC = 4 MHz FOSC = 3.6864 MHz

BAUD
RATE SPBRG SPBRG
% %
(K) value value
KBAUD ERROR KBAUD ERROR
(decimal) (decimal)
0.3 0.300 0 207 0.3 0 191
1.2 1.202 0.17 51 1.2 0 47
2.4 2.404 0.17 25 2.4 0 23
9.6 8.929 6.99 6 9.6 0 5
19.2 20.833 8.51 2 19.2 0 2
28.8 31.250 8.51 1 28.8 0 1
33.6 - - - - - -
57.6 62.500 8.51 0 57.6 0 0
HIGH 0.244 - 255 0.225 - 255
LOW 62.500 - 0 57.6 - 0

TABLE 11-4: BAUD RATES FOR ASYNCHRONOUS MODE (BRGH = 1)

FOSC = 20 MHz FOSC = 16 MHz FOSC = 10 MHz
BAUD
RATE SPBRG SPBRG SPBRG
% % %
(K) value value value
KBAUD ERROR KBAUD ERROR KBAUD ERROR
(decimal) (decimal) (decimal)
0.3 - - - - - - - - -
1.2 - - - - - - - - -
2.4 - - - - - - 2.441 1.71 255
9.6 9.615 0.16 129 9.615 0.16 103 9.615 0.16 64
19.2 19.231 0.16 64 19.231 0.16 51 19.531 1.72 31
28.8 29.070 0.94 42 29.412 2.13 33 28.409 1.36 21
33.6 33.784 0.55 36 33.333 0.79 29 32.895 2.10 18
57.6 59.524 3.34 20 58.824 2.13 16 56.818 1.36 10
HIGH 4.883 - 255 3.906 - 255 2.441 - 255
LOW 1250.000 - 0 1000.000 0 625.000 - 0

FOSC = 4 MHz FOSC = 3.6864 MHz

BAUD
RATE SPBRG SPBRG
% %
(K) value value
KBAUD ERROR KBAUD ERROR
(decimal) (decimal)
0.3 - - - - - -
1.2 1.202 0.17 207 1.2 0 191
2.4 2.404 0.17 103 2.4 0 95
9.6 9.615 0.16 25 9.6 0 23
19.2 19.231 0.16 12 19.2 0 11
28.8 27.798 3.55 8 28.8 0 7
33.6 35.714 6.29 6 32.9 2.04 6
57.6 62.500 8.51 3 57.6 0 3
HIGH 0.977 - 255 0.9 - 255
LOW 250.000 - 0 230.4 - 0

DS30498B-page 136 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
TABLE 11-5: INTRC BAUD RATES FOR ASYNCHRONOUS MODE (BRGH = 0)
FOSC = 8 MHz FOSC = 4 MHz FOSC = 2 MHz FOSC = 1 MHz
BAUD
RATE SPBRG SPBRG SPBRG SPBRG
% % % %
(K) value value value value
KBAUD ERROR KBAUD ERROR KBAUD ERROR KBAUD ERROR
(decimal) (decimal) (decimal) (decimal)
0.3 NA — — 0.300 0 207 0.300 0 103 0.300 0 51
1.2 1.202 +0.16 103 1.202 +0.16 51 1.202 +0.16 25 1.202 +0.16 12
2.4 2.404 +0.16 51 2.404 +0.16 25 2.404 +0.16 12 2.232 -6.99 6
9.6 9.615 +0.16 12 8.929 -6.99 6 10.417 +8.51 2 NA — —
19.2 17.857 -6.99 6 20.833 +8.51 2 NA — — NA — —
28.8 31.250 +8.51 3 31.250 +8.51 1 31.250 +8.51 0 NA — —
38.4 41.667 +8.51 2 NA — — NA — — NA — —
57.6 62.500 +8.51 1 62.500 8.51 0 NA — — NA — —

TABLE 11-6: INTRC BAUD RATES FOR ASYNCHRONOUS MODE (BRGH = 1)

FOSC = 8 MHz FOSC = 4 MHz FOSC = 2 MHz FOSC = 1 MHz
BAUD
RATE SPBRG SPBRG SPBRG SPBRG
% % % %
(K) value value value value
KBAUD ERROR KBAUD ERROR KBAUD ERROR KBAUD ERROR
(decimal) (decimal) (decimal) (decimal)
0.3 NA — — NA — — NA — — 0.300 0 207
1.2 NA — — 1.202 +0.16 207 1.202 +0.16 103 1.202 +0.16 51
2.4 2.404 +0.16 207 2.404 +0.16 103 2.404 +0.16 51 2.404 +0.16 25
9.6 9.615 +0.16 51 9.615 +0.16 25 9.615 +0.16 12 8.929 -6.99 6
19.2 19.231 +0.16 25 19.231 +0.16 12 17.857 -6.99 6 20.833 +8.51 2
28.8 29.412 +2.12 16 27.778 -3.55 8 31.250 +8.51 3 31.250 +8.51 1
38.4 38.462 +0.16 12 35.714 -6.99 6 41.667 +8.51 2 NA — —
57.6 55.556 -3.55 8 62.500 +8.51 3 62.500 +8.51 1 62.500 +8.51 0

 2003 Microchip Technology Inc. Preliminary DS30498B-page 137

PIC16F7X7
11.2 USART Asynchronous Mode rupt can be enabled/disabled by setting/clearing
enable bit, TXIE (PIE1<4>). Flag bit TXIF will be set
In this mode, the USART uses standard Non-Return- regardless of the state of enable bit TXIE and cannot be
to-Zero (NRZ) format (one Start bit, eight or nine data cleared in software. It will reset only when new data is
bits and one Stop bit). The most common data format loaded into the TXREG register. While flag bit TXIF
is 8-bits. An on-chip, dedicated, 8-bit Baud Rate Gen- indicates the status of the TXREG register, another bit,
erator can be used to derive standard baud rate fre- TRMT (TXSTA<1>), shows the status of the TSR reg-
quencies from the oscillator. The USART transmits and ister. Status bit TRMT is a read-only bit which is set
receives the LSb first. The transmitter and receiver are when the TSR register is empty. No interrupt logic is
functionally independent but use the same data format tied to this bit, so the user has to poll this bit in order to
and baud rate. The Baud Rate Generator produces a determine if the TSR register is empty.
clock, either x16 or x64 of the bit shift rate, depending
on bit BRGH (TXSTA<2>). Parity is not supported by Note 1: The TSR register is not mapped in data
the hardware but can be implemented in software (and memory so it is not available to the user.
stored as the ninth data bit). Asynchronous mode is 2: Flag bit TXIF is set when enable bit TXEN
stopped during Sleep. is set. TXIF is cleared by loading TXREG.
Asynchronous mode is selected by clearing bit, SYNC Transmission is enabled by setting enable bit, TXEN
(TXSTA<4>). (TXSTA<5>). The actual transmission will not occur
The USART asynchronous module consists of the until the TXREG register has been loaded with data
following important elements: and the Baud Rate Generator (BRG) has produced a
shift clock (Figure 11-2). The transmission can also be
• Baud Rate Generator
started by first loading the TXREG register and then
• Sampling Circuit setting enable bit TXEN. Normally, when transmission
• Asynchronous Transmitter is first started, the TSR register is empty. At that point,
• Asynchronous Receiver transfer to the TXREG register will result in an immedi-
ate transfer to TSR, resulting in an empty TXREG. A
11.2.1 USART ASYNCHRONOUS back-to-back transfer is thus possible (Figure 11-3).
TRANSMITTER Clearing enable bit TXEN during a transmission will
cause the transmission to be aborted and will reset the
The USART transmitter block diagram is shown in
transmitter. As a result, the RC6/TX/CK pin will revert
Figure 11-1. The heart of the transmitter is the Transmit
to high-impedance.
(Serial) Shift Register (TSR). The Shift register obtains
its data from the Read/Write Transmit Buffer register, In order to select 9-bit transmission, transmit bit TX9
TXREG. The TXREG register is loaded with data in (TXSTA<6>) should be set and the ninth bit should be
software. The TSR register is not loaded until the Stop written to TX9D (TXSTA<0>). The ninth bit must be
bit has been transmitted from the previous load. As written before writing the 8-bit data to the TXREG
soon as the Stop bit is transmitted, the TSR is loaded register. This is because a data write to the TXREG
with new data from the TXREG register (if available). register can result in an immediate transfer of the data
Once the TXREG register transfers the data to the TSR to the TSR register (if the TSR is empty). In such a
register (occurs in one TCY), the TXREG register is case, an incorrect ninth data bit may be loaded in the
empty and flag bit, TXIF (PIR1<4>), is set. This inter- TSR register.

FIGURE 11-1: USART TRANSMIT BLOCK DIAGRAM

Data Bus
TXIF TXREG Register
TXIE
8
MSb LSb
(8) • • • 0 Pin Buffer
and Control
TSR Register RC6/TX/CK pin
Interrupt

TXEN Baud Rate CLK

TRMT SPEN
SPBRG

Baud Rate Generator TX9

TX9D

DS30498B-page 138 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
When setting up an Asynchronous Transmission, 5. Enable the transmission by setting bit TXEN,
follow these steps: which will also set bit TXIF.
1. Initialize the SPBRG register for the appropriate 6. If 9-bit transmission is selected, the ninth bit
baud rate. If a high-speed baud rate is desired, should be loaded in bit TX9D.
set bit BRGH (Section 11.1 “USART Baud 7. Load data to the TXREG register (starts
Rate Generator (BRG)”). transmission).
2. Enable the asynchronous serial port by clearing 8. If using interrupts, ensure that GIE and PEIE
bit SYNC and setting bit SPEN. (bits 7 and 6) of the INTCON register are set.
3. If interrupts are desired, then set enable bit TXIE.
4. If 9-bit transmission is desired, then set transmit
bit TX9.

FIGURE 11-2: ASYNCHRONOUS MASTER TRANSMISSION

Write to TXREG
Word 1
BRG Output
(Shift Clock)
RC6/TX/CK (pin)
Start bit bit 0 bit 1 bit 7/8 Stop bit
Word 1
TXIF bit
(Transmit Buffer
Reg. Empty Flag)

TRMT bit Word 1

Transmit Shift Reg
(Transmit Shift
Reg. Empty Flag)

FIGURE 11-3: ASYNCHRONOUS MASTER TRANSMISSION (BACK TO BACK)

Write to TXREG
Word 1 Word 2
BRG Output
(Shift Clock)
RC6/TX/CK (pin)
Start bit bit 0 bit 1 bit 7/8 Stop bit Start bit bit 0
TXIF bit Word 1 Word 2
(Interrupt Reg. Flag)

TRMT bit Word 1 Word 2

(Transmit Shift Transmit Shift Reg. Transmit Shift Reg.
Reg. Empty Flag)

Note: This timing diagram shows two consecutive transmissions.

TABLE 11-7: REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION

Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
0Bh, 8Bh, INTCON GIE PEIE TMR0IE INTE RBIE TMR0IF INTF R0IF 0000 000x 0000 000u
10Bh,18Bh
0Ch PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
18h RCSTA SPEN RX9 SREN CREN — FERR OERR RX9D 0000 -00x 0000 -00x
19h TXREG USART Transmit Register 0000 0000 0000 0000
8Ch PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
98h TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010
99h SPBRG Baud Rate Generator Register 0000 0000 0000 0000
Legend: x = unknown, - = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous transmission.
Note 1: Bits PSPIE and PSPIF are reserved on 28-pin devices; always maintain these bits clear.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 139

PIC16F7X7
11.2.2 USART ASYNCHRONOUS is possible for two bytes of data to be received and
RECEIVER transferred to the RCREG FIFO and a third byte to
begin shifting to the RSR register. On the detection of
The receiver block diagram is shown in Figure 11-4.
the Stop bit of the third byte, if the RCREG register is
The data is received on the RC7/RX/DT pin and drives
still full, the Overrun Error bit, OERR (RCSTA<1>), will
the data recovery block. The data recovery block is
be set. The word in the RSR will be lost. The RCREG
actually a high-speed shifter, operating at x16 times the
register can be read twice to retrieve the two bytes in
baud rate; whereas, the main receive serial shifter
the FIFO. Overrun bit OERR has to be cleared in soft-
operates at the bit rate or at FOSC.
ware. This is done by resetting the receive logic (CREN
Once Asynchronous mode is selected, reception is is cleared and then set). If bit OERR is set, transfers
enabled by setting bit, CREN (RCSTA<4>). from the RSR register to the RCREG register are inhib-
The heart of the receiver is the Receive (Serial) Shift ited and no further data will be received. It is, therefore,
Register (RSR). After sampling the Stop bit, the essential to clear error bit OERR if it is set. Framing
received data in the RSR is transferred to the RCREG Error bit, FERR (RCSTA<2>), is set if a Stop bit is
register (if it is empty). If the transfer is complete, flag detected as clear. Bit FERR and the 9th receive bit are
bit, RCIF (PIR1<5>), is set. The actual interrupt can be buffered the same way as the receive data. Reading
enabled/disabled by setting/clearing enable bit, RCIE the RCREG will load bits RX9D and FERR with new
(PIE1<5>). Flag bit RCIF is a read-only bit which is values, therefore, it is essential for the user to read the
cleared by the hardware. It is cleared when the RCREG RCSTA register before reading the RCREG register, in
register has been read and is empty. The RCREG is a order not to lose the old FERR and RX9D information.
double-buffered register (i.e., it is a two-deep FIFO). It

FIGURE 11-4: USART RECEIVE BLOCK DIAGRAM

x64 Baud Rate CLK
CREN OERR FERR
FOSC
SPBRG
÷64 MSb RSR Register LSb
or
Baud Rate Generator ÷16 Stop (8) 7 • • • 1 0 Start

Pin Buffer Data

and Control Recovery RX9

RC7/RX/DT

SPEN RX9D RCREG Register

FIFO

RCIF 8
Interrupt
RCIE Data Bus

FIGURE 11-5: ASYNCHRONOUS RECEPTION

Start Start Start
RX (pin) bit bit
bit 0 bit 1 bit 7/8 Stop bit bit 0 bit 7/8 Stop bit 7/8 Stop
bit bit bit
Rcv Shift
Reg
Rcv Buffer Reg
Word 1 Word 2
RCREG RCREG
Read Rcv
Buffer Reg
RCREG

RCIF
(Interrupt Flag)

OERR bit
CREN

Note: This timing diagram shows three words appearing on the RX input. The RCREG (receive buffer) is read after the third word,
causing the OERR (overrun) bit to be set.

DS30498B-page 140 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
When setting up an Asynchronous Reception, follow 6. Flag bit RCIF will be set when reception is
these steps: complete and an interrupt will be generated if
1. Initialize the SPBRG register for the appropriate enable bit RCIE is set.
baud rate. If a high-speed baud rate is desired, 7. Read the RCSTA register to get the ninth bit (if
set bit BRGH (Section 11.1 “USART Baud enabled) and determine if any error occurred
Rate Generator (BRG)”). during reception.
2. Enable the asynchronous serial port by clearing 8. Read the 8-bit received data by reading the
bit SYNC and setting bit SPEN. RCREG register.
3. If interrupts are desired, then set enable bit 9. If any error occurred, clear the error by clearing
RCIE. enable bit CREN.
4. If 9-bit reception is desired, then set bit RX9. 10. If using interrupts, ensure that GIE and PEIE
5. Enable the reception by setting bit CREN. (bits 7 and 6) of the INTCON register are set.

TABLE 11-8: REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION

Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
0Bh, 8Bh, INTCON GIE PEIE TMR0IE INTE RBIE TMR0IF INTF R0IF 0000 000x 0000 000u
10Bh,18Bh
0Ch PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
18h RCSTA SPEN RX9 SREN CREN — FERR OERR RX9D 0000 -00x 0000 -00x
1Ah RCREG USART Receive Register 0000 0000 0000 0000
8Ch PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
98h TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010
99h SPBRG Baud Rate Generator Register 0000 0000 0000 0000
Legend: x = unknown, - = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous reception.
Note 1: Bits PSPIE and PSPIF are reserved on 28-pin devices; always maintain these bits clear.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 141

PIC16F7X7
11.2.3 SETTING UP 9-BIT MODE WITH • Flag bit RCIF will be set when reception is
ADDRESS DETECT complete and an interrupt will be generated if
enable bit RCIE was set.
When setting up an Asynchronous Reception with
address detect enabled: • Read the RCSTA register to get the ninth bit and
determine if any error occurred during reception.
• Initialize the SPBRG register for the appropriate
• Read the 8-bit received data by reading the
baud rate. If a high-speed baud rate is desired,
RCREG register to determine if the device is
set bit BRGH.
being addressed.
• Enable the asynchronous serial port by clearing
• If any error occurred, clear the error by clearing
bit SYNC and setting bit SPEN.
enable bit CREN.
• If interrupts are desired, then set enable bit RCIE.
• If the device has been addressed, clear the
• Set bit RX9 to enable 9-bit reception. ADDEN bit to allow data bytes and address bytes
• Set ADDEN to enable address detect. to be read into the receive buffer and interrupt the
• Enable the reception by setting enable bit CREN. CPU.

FIGURE 11-6: USART RECEIVE BLOCK DIAGRAM

x64 Baud Rate CLK
OERR FERR
CREN
FOSC
SPBRG
÷ 64 MSb RSR Register LSb
or
Baud Rate Generator ÷ 16 Stop (8) 7 • • • 1 0 Start

Pin Buffer Data

and Control Recovery RX9

RC7/RX/DT
8

SPEN

RX9 Enable
ADDEN Load of

RX9 Receive
Buffer
ADDEN
RSR<8> 8

RX9D RCREG Register

FIFO

Interrupt RCIF
Data Bus
RCIE

DS30498B-page 142 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 11-7: ASYNCHRONOUS RECEPTION WITH ADDRESS DETECT

RC7/RX/DT (pin) Start Start

bit bit 0 bit 1 bit 8 Stop bit bit 0 bit 8 Stop
bit bit

Load RSR
bit 8 = 0, Data Byte bit 8 = 1, Address Byte Word 1
RCREG
Read

RCIF

Note: This timing diagram shows a data byte followed by an address byte. The data byte is not read into the RCREG (receive buffer)
because ADDEN = 1.

FIGURE 11-8: ASYNCHRONOUS RECEPTION WITH ADDRESS BYTE FIRST

RC7/RX/DT (pin) Start Start
bit bit 0 bit 1 bit 8 Stop bit bit 0 bit 8 Stop
bit bit

Load RSR
bit 8 = 1, Address Byte bit 8 = 0, Data Byte Word 1
RCREG
Read

RCIF

Note: This timing diagram shows a data byte followed by an address byte. The data byte is not read into the RCREG (receive buffer)
because ADDEN was not updated and still = 0.

TABLE 11-9: REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION

Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
0Bh, 8Bh, INTCON GIE PEIE TMR0IE INTE RBIE TMR0IF INTF R0IF 0000 000x 0000 000u
10Bh,18Bh
0Ch PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
18h RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 0000 000x
1Ah RCREG USART Receive Register 0000 0000 0000 0000
8Ch PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
98h TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010
99h SPBRG Baud Rate Generator Register 0000 0000 0000 0000
Legend: x = unknown, - = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous reception.
Note 1: Bits PSPIE and PSPIF are reserved on 28-pin devices; always maintain these bits clear.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 143

PIC16F7X7
11.3 USART Synchronous Clearing enable bit TXEN during a transmission will
Master Mode cause the transmission to be aborted and will reset the
transmitter. The DT and CK pins will revert to high-
In Synchronous Master mode, the data is transmitted in impedance. If either bit CREN or bit SREN is set during
a half-duplex manner (i.e., transmission and reception a transmission, the transmission is aborted and the DT
do not occur at the same time). When transmitting data, pin reverts to a high-impedance state (for a reception).
the reception is inhibited and vice versa. Synchronous The CK pin will remain an output if bit CSRC is set
mode is entered by setting bit, SYNC (TXSTA<4>). In (internal clock). The transmitter logic, however, is not
addition, enable bit, SPEN (RCSTA<7>), is set in order reset, although it is disconnected from the pins. In order
to configure the RC6/TX/CK and RC7/RX/DT I/O pins to reset the transmitter, the user has to clear bit TXEN.
to CK (clock) and DT (data) lines, respectively. The If bit SREN is set (to interrupt an on-going transmission
Master mode indicates that the processor transmits the and receive a single word), then after the single word is
master clock on the CK line. The Master mode is received, bit SREN will be cleared and the serial port
entered by setting bit, CSRC (TXSTA<7>). will revert back to transmitting since bit TXEN is still set.
The DT line will immediately switch from High-
11.3.1 USART SYNCHRONOUS MASTER Impedance Receive mode to transmit and start driving.
TRANSMISSION To avoid this, bit TXEN should be cleared.
The USART transmitter block diagram is shown in In order to select 9-bit transmission, the TX9
Figure 11-6. The heart of the transmitter is the Transmit (TXSTA<6>) bit should be set and the ninth bit should
(Serial) Shift Register (TSR). The Shift register obtains be written to bit TX9D (TXSTA<0>). The ninth bit must
its data from the Read/Write Transmit Buffer register, be written before writing the 8-bit data to the TXREG
TXREG. The TXREG register is loaded with data in register. This is because a data write to the TXREG can
software. The TSR register is not loaded until the last result in an immediate transfer of the data to the TSR
bit has been transmitted from the previous load. As register (if the TSR is empty). If the TSR was empty and
soon as the last bit is transmitted, the TSR is loaded the TXREG was written before writing the “new” TX9D,
with new data from the TXREG (if available). Once the the “present” value of bit TX9D is loaded.
TXREG register transfers the data to the TSR register
Steps to follow when setting up a Synchronous Master
(occurs in one TCYCLE), the TXREG is empty and inter-
Transmission:
rupt bit, TXIF (PIR1<4>), is set. The interrupt can be
enabled/disabled by setting/clearing enable bit, TXIE 1. Initialize the SPBRG register for the appropriate
(PIE1<4>). Flag bit TXIF will be set regardless of the baud rate (Section 11.1 “USART Baud Rate
state of enable bit TXIE and cannot be cleared in soft- Generator (BRG)”).
ware. It will reset only when new data is loaded into the 2. Enable the synchronous master serial port by
TXREG register. While flag bit TXIF indicates the status setting bits SYNC, SPEN and CSRC.
of the TXREG register, another bit, TRMT (TXSTA<1>), 3. If interrupts are desired, set enable bit TXIE.
shows the status of the TSR register. TRMT is a read- 4. If 9-bit transmission is desired, set bit TX9.
only bit which is set when the TSR is empty. No
5. Enable the transmission by setting bit TXEN.
interrupt logic is tied to this bit so the user has to poll
this bit in order to determine if the TSR register is 6. If 9-bit transmission is selected, the ninth bit
empty. The TSR is not mapped in data memory so it is should be loaded in bit TX9D.
not available to the user. 7. Start transmission by loading data to the TXREG
register.
Transmission is enabled by setting enable bit, TXEN
(TXSTA<5>). The actual transmission will not occur 8. If using interrupts, ensure that GIE and PEIE
until the TXREG register has been loaded with data. (bits 7 and 6) of the INTCON register are set.
The first data bit will be shifted out on the next available
rising edge of the clock on the CK line. Data out is sta-
ble around the falling edge of the synchronous clock
(Figure 11-9). The transmission can also be started by
first loading the TXREG register and then setting bit
TXEN (Figure 11-10). This is advantageous when slow
baud rates are selected, since the BRG is kept in Reset
when bits TXEN, CREN and SREN are clear. Setting
enable bit TXEN will start the BRG, creating a shift
clock immediately. Normally, when transmission is first
started, the TSR register is empty so a transfer to the
TXREG register will result in an immediate transfer to
TSR, resulting in an empty TXREG. Back-to-back
transfers are possible.

DS30498B-page 144 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
TABLE 11-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION
Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
0Bh, 8Bh, INTCON GIE PEIE TMR0IE INTE RBIE TMR0IF INTF R0IF 0000 000x 0000 000u
10Bh,18Bh
0Ch PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
18h RCSTA SPEN RX9 SREN CREN — FERR OERR RX9D 0000 -00x 0000 -00x
19h TXREG USART Transmit Register 0000 0000 0000 0000
8Ch PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
98h TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010
99h SPBRG Baud Rate Generator Register 0000 0000 0000 0000
Legend: x = unknown, - = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master transmission.
Note 1: Bits PSPIE and PSPIF are reserved on 28-pin devices; always maintain these bits clear.

FIGURE 11-9: SYNCHRONOUS TRANSMISSION

Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4 Q3 Q4 Q1 Q2 Q3Q4 Q1Q2 Q3 Q4 Q1 Q2Q3 Q4Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4

RC7/RX/DT
bit 0 bit 1 bit 2 bit 7 bit 0 bit 1 bit 7
pin
Word 1 Word 2
RC6/TX/CK
pin
Write to
TXREG Reg
Write Word 1 Write Word 2
TXIF bit
(Interrupt Flag)

TRMT bit

TXEN bit ‘1’ ‘1’

Note: Sync Master mode, SPBRG = 0. Continuous transmission of two 8-bit words.

FIGURE 11-10: SYNCHRONOUS TRANSMISSION (THROUGH TXEN)

RC7/RX/DT pin bit 0 bit 1 bit 2 bit 6 bit 7

RC6/TX/CK pin

Write to
TXREG Reg

TXIF bit

TRMT bit

TXEN bit

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PIC16F7X7
11.3.2 USART SYNCHRONOUS MASTER data. Reading the RCREG register will load bit RX9D
RECEPTION with a new value, therefore, it is essential for the user
to read the RCSTA register before reading RCREG, in
Once Synchronous mode is selected, reception is
order not to lose the old RX9D information.
enabled by setting either enable bit, SREN
(RCSTA<5>) or enable bit, CREN (RCSTA<4>). Data is When setting up a Synchronous Master Reception:
sampled on the RC7/RX/DT pin on the falling edge of 1. Initialize the SPBRG register for the appropriate
the clock. If enable bit SREN is set, then only a single baud rate (Section 11.1 “USART Baud Rate
word is received. If enable bit CREN is set, the recep- Generator (BRG)”).
tion is continuous until CREN is cleared. If both bits are 2. Enable the synchronous master serial port by
set, CREN takes precedence. After clocking the last bit, setting bits SYNC, SPEN and CSRC.
the received data in the Receive Shift Register (RSR)
3. Ensure bits CREN and SREN are clear.
is transferred to the RCREG register (if it is empty).
When the transfer is complete, interrupt flag bit, RCIF 4. If interrupts are desired, then set enable bit
(PIR1<5>), is set. The actual interrupt can be enabled/ RCIE.
disabled by setting/clearing enable bit, RCIE 5. If 9-bit reception is desired, then set bit RX9.
(PIE1<5>). Flag bit RCIF is a read-only bit which is 6. If a single reception is required, set bit SREN.
reset by the hardware. In this case, it is reset when the For continuous reception, set bit CREN.
RCREG register has been read and is empty. The 7. Interrupt flag bit RCIF will be set when reception
RCREG is a double-buffered register (i.e., it is a two- is complete and an interrupt will be generated if
deep FIFO). It is possible for two bytes of data to be enable bit RCIE was set.
received and transferred to the RCREG FIFO and a
8. Read the RCSTA register to get the ninth bit (if
third byte to begin shifting into the RSR register. On the
enabled) and determine if any error occurred
clocking of the last bit of the third byte, if the RCREG
during reception.
register is still full, then Overrun Error bit, OERR
(RCSTA<1>), is set. The word in the RSR will be lost. 9. Read the 8-bit received data by reading the
The RCREG register can be read twice to retrieve the RCREG register.
two bytes in the FIFO. Bit OERR has to be cleared in 10. If any error occurred, clear the error by clearing
software (by clearing bit CREN). If bit OERR is set, bit CREN.
transfers from the RSR to the RCREG are inhibited so 11. If using interrupts, ensure that GIE and PEIE
it is essential to clear bit OERR if it is set. The ninth (bits 7 and 6) of the INTCON register are set.
receive bit is buffered the same way as the receive

TABLE 11-11: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION

Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
0Bh, 8Bh, INTCON GIE PEIE TMR0IE INTE RBIE TMR0IF INTF R0IF 0000 000x 0000 000u
10Bh,18Bh
0Ch PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
18h RCSTA SPEN RX9 SREN CREN — FERR OERR RX9D 0000 -00x 0000 -00x
1Ah RCREG USART Receive Register 0000 0000 0000 0000
(1)
8Ch PIE1 PSPIE ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
98h TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010
99h SPBRG Baud Rate Generator Register 0000 0000 0000 0000
Legend: x = unknown, - = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master reception.
Note 1: Bits PSPIE and PSPIF are reserved on 28-pin devices; always maintain these bits clear.

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 PIC16F7X7
FIGURE 11-11: SYNCHRONOUS RECEPTION (MASTER MODE, SREN)

Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

RC7/RX/DT pin bit 0 bit 1 bit 2 bit 3 bit 4 bit 5 bit 6 bit 7

RC6/TX/CK pin

Write to
bit SREN

SREN bit

CREN bit ‘0’ ‘0’

RCIF bit
(Interrupt)
Read
RXREG

Note: Timing diagram demonstrates Sync Master mode with bit SREN = 1 and bit BRG = 0.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 147

PIC16F7X7
11.4 USART Synchronous Slave Mode When setting up a Synchronous Slave Transmission,
follow these steps:
Synchronous Slave mode differs from the Master mode
in the fact that the shift clock is supplied externally at 1. Enable the synchronous slave serial port by
the RC6/TX/CK pin (instead of being supplied internally setting bits SYNC and SPEN and clearing bit
in Master mode). This allows the device to transfer or CSRC.
receive data while in Sleep mode. Slave mode is 2. Clear bits CREN and SREN.
entered by clearing bit, CSRC (TXSTA<7>). 3. If interrupts are desired, then set enable bit
TXIE.
11.4.1 USART SYNCHRONOUS SLAVE 4. If 9-bit transmission is desired, then set bit TX9.
TRANSMIT 5. Enable the transmission by setting enable bit
The operation of the Synchronous Master and Slave TXEN.
modes is identical, except in the case of the Sleep mode. 6. If 9-bit transmission is selected, the ninth bit
If two words are written to the TXREG and then the should be loaded in bit TX9D.
SLEEP instruction is executed, the following will occur: 7. Start transmission by loading data to the TXREG
a) The first word will immediately transfer to the register.
TSR register and transmit. 8. If using interrupts, ensure that GIE and PEIE
b) The second word will remain in TXREG register. (bits 7 and 6) of the INTCON register are set.
c) Flag bit TXIF will not be set.
d) When the first word has been shifted out of TSR,
the TXREG register will transfer the second word
to the TSR and flag bit TXIF will now be set.
e) If enable bit TXIE is set, the interrupt will wake
the chip from Sleep and if the global interrupt is
enabled, the program will branch to the interrupt
vector (0004h).

TABLE 11-12: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION

Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
0Bh, 8Bh, INTCON GIE PEIE TMR0IE INTE RBIE TMR0IF INTF R0IF 0000 000x 0000 000u
10Bh,18Bh
0Ch PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
18h RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 0000 000x
19h TXREG USART Transmit Register 0000 0000 0000 0000
8Ch PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
98h TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010
99h SPBRG Baud Rate Generator Register 0000 0000 0000 0000
Legend: x = unknown, - = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave transmission.
Note 1: Bits PSPIE and PSPIF are reserved on 28-pin devices; always maintain these bits clear.

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 PIC16F7X7
11.4.2 USART SYNCHRONOUS SLAVE When setting up a Synchronous Slave Reception,
RECEPTION follow these steps:
The operation of the Synchronous Master and Slave 1. Enable the synchronous master serial port by
modes is identical, except in the case of the Sleep setting bits SYNC and SPEN and clearing bit
mode. Bit SREN is a “don't care” in Slave mode. CSRC.
If receive is enabled by setting bit CREN prior to the 2. If interrupts are desired, set enable bit RCIE.
SLEEP instruction, then a word may be received during 3. If 9-bit reception is desired, set bit RX9.
Sleep. On completely receiving the word, the RSR reg- 4. To enable reception, set enable bit CREN.
ister will transfer the data to the RCREG register and if 5. Flag bit RCIF will be set when reception is com-
enable bit RCIE bit is set, the interrupt generated will plete and an interrupt will be generated if enable
wake the chip from Sleep. If the global interrupt is bit RCIE was set.
enabled, the program will branch to the interrupt vector 6. Read the RCSTA register to get the ninth bit (if
(0004h). enabled) and determine if any error occurred
during reception.
7. Read the 8-bit received data by reading the
RCREG register.
8. If any error occurred, clear the error by clearing
bit CREN.
9. If using interrupts, ensure that GIE and PEIE
(bits 7 and 6) of the INTCON register are set.

TABLE 11-13: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION

Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
0Bh, 8Bh, INTCON GIE PEIE TMR0IE INTE RBIE TMR0IF INTF R0IF 0000 000x 0000 000u
10Bh,18Bh
0Ch PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
18h RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 0000 000x
1Ah RCREG USART Receive Register 0000 0000 0000 0000
8Ch PIE1 PSPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
98h TXSTA CSRC TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010
99h SPBRG Baud Rate Generator Register 0000 0000 0000 0000
Legend: x = unknown, - = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave reception.
Note 1: Bits PSPIE and PSPIF are reserved on 28-pin devices, always maintain these bits clear.

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PIC16F7X7
NOTES:

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 PIC16F7X7
12.0 ANALOG-TO-DIGITAL The module has five registers:
CONVERTER (A/D) MODULE • A/D Result High Register (ADRESH)
• A/D Result Low Register (ADRESL)
The Analog-to-Digital (A/D) Converter module has 11
inputs for the PIC16F737 and PIC16F767 devices and • A/D Control Register 0 (ADCON0)
14 for the PIC16F747 AND PIC16F777 devices. • A/D Control Register 1 (ADCON1)
The A/D allows conversion of an analog input signal to • A/D Control Register 2 (ADCON2)
a corresponding 10-bit digital number. The ADCON0 register, shown in Register 12-1, controls
A new feature for the A/D converter is the addition of the operation of the A/D module and clock source. The
programmable acquisition time. This feature allows the ADCON1 register, shown in Register 12-2, configures
user to select a new channel for conversion and to set the functions of the port pins, justification and voltage
the GO/DONE bit immediately. When the GO/DONE bit reference sources. The ADCON2, shown in
is set, the selected channel is sampled for the pro- Register 12-3, configures the programmed acquisition
grammed acquisition time before a conversion is actu- time.
ally started. This removes the firmware overhead Additional information on using the A/D module can be
required to allow for an acquisition (sampling) period found in the PICmicro® Mid-Range MCU Family
(see Register 12-3 and Section 12.2 “Selecting and Reference Manual (DS33023) and in Application Note
Configuring Automatic Acquisition Time”). AN546, “Using the Analog-to-Digital (A/D) Converter”
(DS00546).

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PIC16F7X7
REGISTER 12-1: ADCON0: A/D CONTROL REGISTER 0 (ADDRESS 1Fh)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
ADCS1 ADCS0 CHS2 CHS1 CHS0 GO/DONE CHS3 ADON
bit 7 bit 0

bit 7-6 ADCS1:ADCS0: A/D Conversion Clock Select bits

If ADCS2 = 0:
000 = FOSC/2
001 = FOSC/8
010 = FOSC/32
011 = FRC (clock derived from an RC oscillation)
If ADCS2 = 1:
00 = FOSC/4
01 = FOSC/16
10 = FOSC/64
11 = FRC (clock derived from an RC oscillation)
bit 5-3 CHS<2:0>: Analog Channel Select bits
0000 = Channel 00 (AN0)
0001 = Channel 01 (AN1)
0010 = Channel 02 (AN2)
0011 = Channel 03 (AN3)
0100 = Channel 04 (AN4)
0101 = Channel 05 (AN5)(1)
0110 = Channel 06 (AN6)(1)
0111 = Channel 07 (AN7)(1)
1000 = Channel 08 (AN8)
1001 = Channel 09 (AN9)
1010 = Channel 10 (AN10)
1011 = Channel 11 (AN11)
1100 = Channel 12 (AN12)
1101 = Channel 13 (AN13)
111x = Unused
Note 1:Selecting AN5 through AN7 on the 28-pin product variant (PIC16F737 and
PIC16F767) will result in a full-scale conversion as unimplemented channels are
connected to VDD.
bit 2 GO/DONE: A/D Conversion Status bit
1 = A/D conversion cycle in progress. Setting this bit starts an A/D conversion cycle. This bit is
automatically cleared by hardware when the A/D conversion has completed.
0 = A/D conversion completed/not in progress
bit 1 CHS<3>: Analog Channel Select bit (see bit 5-3 for bit settings)
bit 0 ADON: A/D Conversion Status bit
1 = A/D converter module is operating
0 = A/D converter is shut-off and consumes no operating current

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

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 PIC16F7X7
REGISTER 12-2: ADCON1: A/D CONTROL REGISTER 1 (ADDRESS 9Fh)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
ADFM ADCS2 VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0
bit 7 bit 0

bit 7 ADFM: A/D Result Format Select bit

1 = Right justified. Six Most Significant bits of ADRESH are read as ‘0’.
0 = Left justified. Six Least Significant bits of ADRESL are read as ‘0’.
bit 6 ADCS2: A/D Clock Divide by 2 Select bit
1 = A/D clock source is divided by two when system clock is used
0 = Disabled
bit 5 VCFG1: Voltage Reference Configuration bit 1
0 = VREF- is connected to VSS
1 = VREF- is connected to external VREF- (RA2)
bit 4 VCFG0: Voltage Reference Configuration bit 0
0 = VREF+ is connected to VDD
1 = VREF+ is connected to external VREF+ (RA3)
bit 3-0 PCFG<3:0>: A/D Port Configuration bits

AN13 AN12 AN11 AN10 AN9 AN8 AN7 AN6 AN5 AN4 AN3 AN2 AN1 AN0
0000 A A A A A A A A A A A A A A
0001 A A A A A A A A A A A A A A
0010 D A A A A A A A A A A A A A
0011 D D A A A A A A A A A A A A
0100 D D D A A A A A A A A A A A
0101 D D D D A A A A A A A A A A
0110 D D D D D A A A A A A A A A
0111 D D D D D D A A A A A A A A
1000 D D D D D D D A A A A A A A
1001 D D D D D D D D A A A A A A
1010 D D D D D D D D D A A A A A
1011 D D D D D D D D D D A A A A
1100 D D D D D D D D D D D A A A
1101 D D D D D D D D D D D D A A
1110 D D D D D D D D D D D D D A
1111 D D D D D D D D D D D D D D
Legend: A = Analog input, D = Digital I/O

Note: AN5 through AN7 are only available on the 40-pin product variant (PIC16F747 and
PIC16F777).

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

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PIC16F7X7
REGISTER 12-3: ADCON2: A/D CONTROL REGISTER 2
U-0 U-0 R/W-0 R/W-0 R/W-0 U-0 U-0 U-0
— — ACQT2 ACQT1 ACQT0 — — —
bit 7 bit 0

bit 7-6 Unimplemented: Read as ‘0’

bit 5-3 ACQT<2:0>: A/D Acquisition Time Select bits
000 = 0(1)
001 = 2 TAD
010 = 4 TAD
011 = 6 TAD
100 = 8 TAD
101 = 12TAD
110 = 16 TAD
111 = 20 TAD
Note 1: If the A/D clock source is selected as RC, a time of TCY is added before the A/D
clock starts. This allows the SLEEP instruction to be executed.
bit 2-0 Unimplemented: Read as ‘0’

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

The analog reference voltage is software selectable A device Reset forces all registers to their Reset state.
to either the device’s positive and negative supply This forces the A/D module to be turned off and any
voltage (VDD and VSS) or the voltage level on the conversion in progress is aborted.
RA3/AN3/VREF+ and RA2/AN2/VREF-/CVREF pins. Each port pin associated with the A/D converter can be
The A/D converter has a unique feature of being able configured as an analog input or as a digital I/O. The
to operate while the device is in Sleep mode. To oper- ADRESH and ADRESL registers contain the result of
ate in Sleep, the A/D conversion clock must be derived the A/D conversion. When the A/D conversion is com-
from the A/D’s internal RC oscillator. plete, the result is loaded into the ADRESH/ADRESL
The output of the sample and hold is the input into the registers, the GO/DONE bit (ADCON0 register) is
converter, which generates the result via successive cleared and A/D Interrupt Flag bit, ADIF, is set. The block
approximation. diagram of the A/D module is shown in Figure 12-1.

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 PIC16F7X7
The value in the ADRESH/ADRESL registers is not 2. Configure A/D interrupt (if desired):
modified for a Power-on Reset. The ADRESH/ • Clear ADIF bit
ADRESL registers will contain unknown data after a • Set ADIE bit
Power-on Reset.
• Set PEIE bit
After the A/D module has been configured as desired, • Set GIE bit
the selected channel must be acquired before the con-
3. Wait the required acquisition time (if required).
version is started. The analog input channels must
have their corresponding TRIS bits selected as an 4. Start conversion:
input. To determine acquisition time, see Section 12.1 • Set GO/DONE bit (ADCON0 register)
“A/D Acquisition Requirements”. After this acquisi- 5. Wait for A/D conversion to complete, by either:
tion time has elapsed, the A/D conversion can be • Polling for the GO/DONE bit to be cleared
started. An acquisition time can be programmed to OR
occur between setting the GO/DONE bit and the actual
• Waiting for the A/D interrupt
start of the conversion.
6. Read A/D Result registers (ADRESH:ADRESL);
The following steps should be followed to do an A/D clear bit ADIF, if required.
conversion:
7. For next conversion, go to step 1 or step 2, as
1. Configure the A/D module: required. The A/D conversion time per bit is
• Configure analog pins, voltage reference and defined as TAD. A minimum wait of 2 TAD is
digital I/O (ADCON1) required before the next acquisition starts.
• Select A/D input channel (ADCON0)
• Select A/D acquisition time (ADCON2)
• Select A/D conversion clock (ADCON0)
• Turn on A/D module (ADCON0)

FIGURE 12-1: A/D BLOCK DIAGRAM

CHS<3:0>

1101
AN13

1100
AN12

1011
AN11
S
S

0011
AN3/VREF+

0010
VIN AN2/VREF-

(Input Voltage) 0001

AN1

VDD 0000
AN0
A/D
Converter
VREF+

(Reference
Voltage)

VCFG<1:0>

VREF-

(Reference
Voltage)
VSS
VCFG<1:0>

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PIC16F7X7
12.1 A/D Acquisition Requirements To calculate the minimum acquisition time,
Equation 12-1 may be used. This equation assumes
For the A/D converter to meet its specified accuracy, that 1/2 LSb error is used (1024 steps for the A/D). The
the charge holding capacitor (CHOLD) must be allowed 1/2 LSb error is the maximum error allowed for the A/D
to fully charge to the input channel voltage level. The to meet its specified resolution.
analog input model is shown in Figure 12-2. The
source impedance (RS) and the internal sampling To calculate the minimum acquisition time, TACQ, see
switch (RSS) impedance directly affect the time the PICmicro® Mid-Range MCU Family Reference
required to charge the capacitor CHOLD. The sampling Manual (DS33023).
switch (RSS) impedance varies over the device voltage
(VDD), see Figure 12-2. The maximum recom-
mended impedance for analog sources is 2.5 kΩ.
As the impedance is decreased, the acquisition time
may be decreased. After the analog input channel is
selected (changed), this acquisition must be done
before the conversion can be started.

EQUATION 12-1: ACQUISITION TIME

TACQ = Amplifier Settling Time + Hold Capacitor Charging Time + Temperature Coefficient

= TAMP + TC + TCOFF
= 2 µs + TC + [(Temperature -25°C)(0.05 µs/°C)]
TC = CHOLD (RIC + RSS + RS) In(1/2047)
= -120 pF (1 kΩ + 7 kΩ + 10 kΩ) In(0.0004885)
= 16.47 µs
TACQ = 2 µs + 16.47 µs + [(50°C – 25°C)(0.05 µs/°C)
= 19.72 µs

Note 1: The reference voltage (VREF) has no effect on the equation since it cancels itself out.
2: The charge holding capacitor (CHOLD) is not discharged after each conversion.
3: The maximum recommended impedance for analog sources is 10 kΩ. This is required to meet the pin
leakage specification.
4: After a conversion has completed, a 2.0 TAD delay must complete before acquisition can begin again.
During this time, the holding capacitor is not connected to the selected A/D input channel.

FIGURE 12-2: ANALOG INPUT MODEL

VDD
Sampling
Switch
VT = 0.6V
RS ANx RIC ≤ 1k SS RSS

CHOLD
VA CPIN ILEAKAGE = DAC Capacitance
5 pF VT = 0.6V ± 500 nA = 51.2 pF

VSS

Legend CPIN = input capacitance

6V
VT = threshold voltage 5V
VDD 4V
ILEAKAGE = leakage current at the pin due to
various junctions 3V
2V
RIC = interconnect resistance
SS = sampling switch
5 6 7 8 9 10 11
CHOLD = sample/hold capacitance (from DAC)
Sampling Switch
(kΩ)

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 PIC16F7X7
12.2 Selecting and Configuring 12.3 Selecting the A/D Conversion
Automatic Acquisition Time Clock
The ADCON2 register allows the user to select an The A/D conversion time per bit is defined as TAD. The
acquisition time that occurs each time the GO/DONE A/D conversion requires a minimum 12 TAD per 10-bit
bit is set. conversion. The source of the A/D conversion clock is
When the GO/DONE bit is set, sampling is stopped and software selected. The seven possible options for TAD
a conversion begins. The user is responsible for ensur- are:
ing the required acquisition time has passed between • 2 TOSC
selecting the desired input channel and setting the • 4 TOSC
GO/DONE bit. This occurs when the ACQT2:ACQT0 • 8 TOSC
bits (ADCON2<5:3>) remain in their Reset state (‘000’)
• 16 TOSC
and is compatible with devices that do not offer
programmable acquisition times. • 32 TOSC
• 64 TOSC
If desired, the ACQT bits can be set to select a pro-
grammable acquisition time for the A/D module. When • Internal A/D module, RC oscillator (2-6 µs)
the GO/DONE bit is set, the A/D module continues to For correct A/D conversions, the A/D conversion clock
sample the input for the selected acquisition time, then (TAD) must be selected to ensure a minimum TAD time
automatically begins a conversion. Since the acquisi- of 1.6 µs.
tion time is programmed, there may be no need to wait
Table 12-1 shows the resultant TAD times derived from
for an acquisition time between selecting a channel and
the device operating frequencies and the A/D clock
setting the GO/DONE bit.
source selected.
In either case, when the conversion is completed, the
GO/DONE bit is cleared, the ADIF flag is set and the
A/D begins sampling the currently selected channel
again. If an acquisition time is programmed, there is
nothing to indicate if the acquisition time has ended or
if the conversion has begun.

TABLE 12-1: TAD vs. MAXIMUM DEVICE OPERATING FREQUENCIES (STANDARD DEVICES (F))
AD Clock Source (TAD) Maximum Device Frequency

Operation ADCS2:ADCS1:ADCS0 Max.

2 TOSC 000 1.25 MHz
4 TOSC 100 2.5 MHz
8 TOSC 001 5 MHz
16 TOSC 101 10 MHz
32 TOSC 010 20 MHz
64 TOSC 110 20 MHz
(1, 2, 3)
RC x11 (Note 1)
Note 1: The RC source has a typical TAD time of 4 µs but can vary between 2-6 µs.
2: When the device frequencies are greater than 1 MHz, the RC A/D conversion clock source is only
recommended for Sleep operation.
3: For extended voltage devices (LF), please refer to Section 18.0 “Electrical Characteristics”.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 157

PIC16F7X7
12.4 Operation in Power Managed 12.5 Configuring Analog Port Pins
Modes The ADCON1, TRISA, TRISB and TRISE registers
The selection of the automatic acquisition time and control the operation of the A/D port pins. The port pins
A/D conversion clock is determined in part by the clock that are desired as analog inputs must have their cor-
source and frequency while in a power managed mode. responding TRIS bits set (input). If the TRIS bit is
cleared (output), the digital output level (VOH or VOL)
If the A/D is expected to operate while the device is in
will be converted.
a power managed mode, the ACQT2:ACQT0 and
ADCS2:ADCS0 bits in ADCON2 should be updated in The A/D operation is independent of the state of the
accordance with the power managed mode clock that CHS2:CHS0 bits and the TRIS bits.
will be used. After the power managed mode is entered Note 1: When reading the Port register, all pins
(either of the Power Managed Run modes), an A/D configured as analog input channels will
acquisition or conversion may be started. Once an read as cleared (a low level). Pins config-
acquisition or conversion is started, the device should ured as digital inputs will convert an analog
continue to be clocked by the same power managed input. Analog levels on a digitally config-
mode clock source until the conversion has been ured input will not affect the conversion
completed. accuracy.
If the power managed mode clock frequency is less 2: Analog levels on any pin that is defined as
than 1 MHz, the A/D RC clock source should be a digital input, but not as an analog input,
selected. may cause the digital input buffer to con-
Operation in Sleep mode requires the A/D RC clock to sume current that is out of the device’s
be selected. If bits ACQT2:ACQT0 are set to ‘000’ and specification.
a conversion is started, the conversion will be delayed
one instruction cycle to allow execution of the SLEEP
instruction and entry to Sleep mode.

DS30498B-page 158 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
12.6 A/D Conversions Clearing the GO/DONE bit during a conversion will
abort the current conversion. The A/D Result register
Figure 12-3 shows the operation of the A/D converter pair will NOT be updated with the partially completed
after the GO bit has been set and the ACQT2:ACQT0 A/D conversion sample. This means the
bits are cleared. A conversion is started after the follow- ADRESH:ADRESL registers will continue to contain
ing instruction to allow entry into Sleep mode before the the value of the last completed conversion (or the last
conversion begins. value written to the ADRESH:ADRESL registers).
Figure 12-4 shows the operation of the A/D converter After the A/D conversion is completed or aborted, a
after the GO bit has been set, the ACQT2:ACQT0 bits 2 TAD wait is required before the next acquisition can
are set to ‘010’ and a 4 TAD acquisition time is selected be started. After this wait, acquisition on the selected
before the conversion starts. channel is automatically started.

Note: The GO/DONE bit should NOT be set in

the same instruction that turns on the A/D.

FIGURE 12-3: A/D CONVERSION TAD CYCLES (ACQT<2:0> = 000, TACQ = 0)

TCY - TAD TAD1 TAD2 TAD3 TAD4 TAD5 TAD6 TAD7 TAD8 TAD9 TAD10 TAD11
b9 b8 b7 b6 b5 b4 b3 b2 b1 b0

Conversion starts
Holding capacitor is disconnected from analog input (typically 100 ns)

Set GO bit

Next Q4: ADRESH/ADRESL is loaded, GO bit is cleared,

ADIF bit is set, holding capacitor is connected to analog input.

FIGURE 12-4: A/D CONVERSION TAD CYCLES (ACQT<2:0> = 010, TACQ = 4 TAD)

TACQT Cycles TAD Cycles

1 2 3 4 1 2 3 4 5 6 7 8 9 10 11
b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
Automatic
Acquisition Conversion starts
Time (Holding capacitor is disconnected)

Set GO bit
(Holding capacitor continues
acquiring input) Next Q4: ADRESH:ADRESL is loaded, GO bit is cleared,
ADIF bit is set, holding capacitor is reconnected to analog input.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 159

PIC16F7X7
12.7 A/D Operation During Sleep 12.8 Effects of a Reset
The A/D module can operate during Sleep mode. This A device Reset forces all registers to their Reset state.
requires that the A/D clock source be set to RC The A/D module is disabled and any conversion in
(ADCS1:ADCS0 = 11). When the RC clock source is progress is aborted. All A/D input pins are configured
selected, the A/D module waits one instruction cycle as analog inputs.
before starting the conversion. This allows the SLEEP The ADRES register will contain unknown data after a
instruction to be executed which eliminates all digital Power-on Reset.
switching noise from the conversion. When the conver-
sion is completed, the GO/DONE bit will be cleared and
the result loaded into the ADRES register. If the A/D
12.9 Use of the CCP Trigger
interrupt is enabled, the device will wake-up from An A/D conversion can be started by the “special event
Sleep. If the A/D interrupt is not enabled, the A/D trigger” of the CCP2 module. This requires that the
module will then be turned off, although the ADON bit CCP2M3:CCP2M0 bits (CCP2CON<3:0>) be pro-
will remain set. grammed as ‘1011’ and that the A/D module is enabled
When the A/D clock source is another clock option (not (ADON bit is set). When the trigger occurs, the
RC), a SLEEP instruction will cause the present conver- GO/DONE bit will be set, starting the A/D conversion,
sion to be aborted and the A/D module to be turned off, and the Timer1 counter will be reset to zero. Timer1 is
though the ADON bit will remain set. reset to automatically repeat the A/D acquisition period
with minimal software overhead (moving the ADRES to
Turning off the A/D places the A/D module in its lowest
the desired location). The appropriate analog input
current consumption state.
channel must be selected and an appropriate acquisi-
Note: For the A/D module to operate in Sleep, tion time should pass before the “special event trigger”
the A/D clock source must be set to RC sets the GO/DONE bit (starts a conversion).
(ADCS1:ADCS0 = 11). To perform an A/D If the A/D module is not enabled (ADON is cleared),
conversion in Sleep, ensure the SLEEP then the “special event trigger” will be ignored by the
instruction immediately follows the A/D module but will still reset the Timer1 counter.
instruction that sets the GO/DONE bit.

TABLE 12-2: SUMMARY OF A/D REGISTERS

Value on
Value on:
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets
0Bh,8Bh, INTCON GIE PEIE TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u
10Bh, 18Bh
0Ch PIR1 PSPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
0Dh PIR2 OSFIF CMIF LVDIF — BCLIF — CCP3IF CCP2IF 000- 0-00 000- 0-00
(1)
8Ch PIE1 PSPIE ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
8Dh PIE2 OSFIE CMIE LVDIE — BCLIE — CCP3IE CCP2IE 000- 0--0 000- 0--0
1Eh ADRES A/D Result Register xxxx xxxx uuuu uuuu
1Fh ADCON0 ADCS1 ADCS0 CHS2 CHS1 CHS0 GO/DONE CHS3 ADON 0000 0000 0000 0000
9Fh ADCON1 ADFM ADCS2 VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 0000 000 0000 0000
05h PORTA RA7 RA6 RA5 RA4 RA3 RA2 RA1 RA0 xx0x 0000 uu0u 0000
85h TRISA — — PORTA Data Direction Register --11 1111 --11 1111
(2)
09h PORTE — — — — — RE2 RE1 RE0 ---- x000 ---- x000
89h TRISE(2) IBF OBF IBOV PSPMODE —(3) PORTE Data Direction bits 0000 1111 0000 1111
Legend: x = unknown, u = unchanged, - = unimplemented, read as ‘0’. Shaded cells are not used for A/D conversion.
Note 1: Bits PSPIE and PSPIF are reserved on the PIC16F737/767 devices; always maintain these bits clear.
2: These registers are reserved on the PIC16F737/767 devices.
3: RE3 is an input only. The state of the TRISE3 bit has no effect and will always read ‘1’.

DS30498B-page 160 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
13.0 COMPARATOR MODULE The CMCON register (Register 13-1) controls the com-
parator input and output multiplexers. A block diagram
The comparator module contains two analog com- of the various comparator configurations is shown in
parators. The inputs to the comparators are Figure 13-1.
multiplexed with I/O port pins RA0 through RA3, while
the outputs are multiplexed to pins RA4 and RA5. The
on-chip voltage reference (Section 14.0 “Comparator
Voltage Reference Module”) can also be an input to
the comparators.

REGISTER 13-1: CMCON REGISTER

R-0 R-0 R/W-0 R/W-0 R/W-0 R/W-1 R/W-1 R/W-1
C2OUT C1OUT C2INV C1INV CIS CM2 CM1 CM0
bit 7 bit 0

bit 7 C2OUT: Comparator 2 Output bit

When C2INV = 0:
1 = C2 VIN+ > C2 VIN-
0 = C2 VIN+ < C2 VIN-
When C2INV = 1:
1 = C2 VIN+ < C2 VIN-
0 = C2 VIN+ > C2 VIN-
bit 6 C1OUT: Comparator 1 Output bit
When C1INV = 0:
1 = C1 VIN+ > C1 VIN-
0 = C1 VIN+ < C1 VIN-
When C1INV = 1:
1 = C1 VIN+ < C1 VIN-
0 = C1 VIN+ > C1 VIN-
bit 5 C2INV: Comparator 2 Output Inversion bit
1 = C2 output inverted
0 = C2 output not inverted
bit 4 C1INV: Comparator 1 Output Inversion bit
1 = C1 output inverted
0 = C1 output not inverted
bit 3 CIS: Comparator Input Switch bit
When CM2:CM0 = 110:
1 = C1 VIN- connects to RA3/AN3
C2 VIN- connects to RA2/AN2
0 = C1 VIN- connects to RA0/AN0
C2 VIN- connects to RA1/AN1
bit 2-0 CM2:CM0: Comparator Mode bits
Figure 13-1 shows the Comparator modes and CM2:CM0 bit settings.

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

 2003 Microchip Technology Inc. Preliminary DS30498B-page 161

PIC16F7X7
13.1 Comparator Configuration be valid for the specified mode change delay shown in
the Electrical Specifications (Section 18.0 “Electrical
There are eight modes of operation for the compara- Characteristics”).
tors. The CMCON register is used to select these
modes. Figure 13-1 shows the eight possible modes. Note: Comparator interrupts should be disabled
The TRISA register controls the data direction of the during a Comparator mode change.
comparator pins for each mode. If the Comparator Otherwise, a false interrupt may occur.
mode is changed, the comparator output level may not

FIGURE 13-1: COMPARATOR I/O OPERATING MODES

Comparators Reset Comparators Off (POR Default Mode)
CM2:CM0 = 000 CM2:CM0 = 111
A VIN- D VIN-
RA0/AN0 RA0/AN0
A VIN+ C1 Off (Read as ‘0’) D VIN+ C1 Off (Read as ‘0’)
RA3/AN3 RA3/AN3

A VIN- D VIN-
RA1/AN1 RA1/AN1
A VIN+ C2 Off (Read as ‘0’) D VIN+ C2 Off (Read as ‘0’)
RA2/AN2 RA2/AN2

Two Independent Comparators with Outputs

Two Independent Comparators
CM2:CM0 = 011
CM2:CM0 = 010
A VIN-
A VIN- RA0/AN0
RA0/AN0
A VIN+ C1 C1OUT
A VIN+ C1 C1OUT RA3/AN3
RA3/AN3
RA4/T0CKI/C1OUT

A VIN-
RA1/AN1 A VIN-
RA1/AN1
A VIN+ C2 C2OUT C2OUT
RA2/AN2 A VIN+ C2
RA2/AN2

RA5/AN4/LVDIN/SS/C2OUT

Two Common Reference Comparators Two Common Reference Comparators with Outputs
CM2:CM0 = 100 CM2:CM0 = 101
A VIN- A VIN-
RA0/AN0 RA0/AN0
A VIN+ C1 C1OUT A VIN+ C1 C1OUT
RA3/AN3 RA3/AN3

RA4/T0CKI/C1OUT
A VIN-
RA1/AN1
C2 C2OUT A VIN-
D VIN+ RA1/AN1
RA2/AN2
D VIN+ C2 C2OUT
RA2/AN2

RA5/AN4/LVDIN/SS/C2OUT

One Independent Comparator with Output Four Inputs Multiplexed to Two Comparators
CM2:CM0 = 001 CM2:CM0 = 110
A VIN- A
RA0/AN0 RA0/AN0 CIS = 0 VIN-
A VIN+ C1 C1OUT RA3/AN3 A CIS = 1
RA3/AN3 VIN+ C1 C1OUT

RA4/T0CKI/C1OUT A
RA1/AN1 CIS = 0 VIN-
A CIS = 1
RA2/AN2 VIN+ C2 C2OUT
D VIN-
RA1/AN1
D VIN+ C2 Off (Read as ‘0’)
RA2/AN2 CVREF From Comparator
VREF Module

A = Analog Input, port reads zeros always D = Digital Input CIS (CMCON<3>) is the Comparator Input Switch

DS30498B-page 162 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
13.2 Comparator Operation 13.3.2 INTERNAL REFERENCE SIGNAL
A single comparator is shown in Figure 13-2, along with The comparator module also allows the selection of an
the relationship between the analog input levels and internally generated voltage reference for the compara-
the digital output. When the analog input at VIN+ is less tors. Section 14.0 “Comparator Voltage Reference
than the analog input VIN-, the output of the comparator Module” contains a detailed description of the compar-
is a digital low level. When the analog input at VIN+ is ator voltage reference module that provides this signal.
greater than the analog input VIN-, the output of the The internal reference signal is used when comparators
comparator is a digital high level. The shaded areas of are in mode CM<2:0> = 110 (Figure 13-1). In this
the output of the comparator in Figure 13-2 represent mode, the internal voltage reference is applied to the
the uncertainty due to input offsets and response time. VIN+ pin of both comparators.

13.3 Comparator Reference 13.4 Comparator Response Time

An external or internal reference signal may be used Response time is the minimum time after selecting a
depending on the comparator operating mode. The new reference voltage or input source, before the
analog signal present at VIN- is compared to the signal comparator output has a valid level. If the internal
at VIN+ and the digital output of the comparator is reference is changed, the maximum delay of the inter-
adjusted accordingly (Figure 13-2). nal voltage reference must be considered when using
the comparator outputs. Otherwise, the maximum
delay of the comparators should be used (Section 18.0
FIGURE 13-2: SINGLE COMPARATOR
“Electrical Characteristics”).

13.5 Comparator Outputs

VIN+ +
Output The comparator outputs are read through the CMCON
VIN- – register. These bits are read-only. The comparator
outputs may also be directly output to the RA4 and RA5
I/O pins. When enabled, multiplexors in the output path
of the RA4 and RA5 pins will switch and the output of
each pin will be the unsynchronized output of the com-
parator. The uncertainty of each of the comparators is
VIN-
VIN–
related to the input offset voltage and the response time
VIN+
VIN+ given in the specifications. Figure 13-3 shows the
comparator output block diagram.
The TRISA bits will still function as an output enable/
Output disable for the RA4 and RA5 pins while in this mode.
Output
The polarity of the comparator outputs can be changed
using the C2INV and C1INV bits (CMCON<4:5>).
Note 1: When reading the Port register, all pins
13.3.1 EXTERNAL REFERENCE SIGNAL configured as analog inputs will read as a
‘0’. Pins configured as digital inputs will
When external voltage references are used, the
convert an analog input according to the
comparator module can be configured to have the com-
Schmitt Trigger input specification.
parators operate from the same or different reference
sources. However, threshold detector applications may 2: Analog levels on any pin defined as a dig-
require the same reference. The reference signal must ital input may cause the input buffer to
be between VSS and VDD and can be applied to either consume more current than is specified.
pin of the comparator(s). 3: RA4 is an open collector I/O pin. When
used as an output, a pull-up resistor is
required.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 163

PIC16F7X7
FIGURE 13-3: COMPARATOR OUTPUT BLOCK DIAGRAM
Port pins

MULTIPLEX

+ -

CxINV

To RA4 or
RA5 pin
Bus Q D
Data

Read CMCON EN

Set
CMIF Q D
bit From
Other EN
Comparator
CL Read CMCON

Reset

13.6 Comparator Interrupts Note: If a change in the CMCON register

(C1OUT or C2OUT) should occur when a
The comparator interrupt flag is set whenever there is
read operation is being executed (start of
a change in the output value of either comparator.
the Q2 cycle), then the CMIF (PIR
Software will need to maintain information about the
registers) interrupt flag may not get set.
status of the output bits, as read from CMCON<7:6>, to
determine the actual change that occurred. The CMIF The user, in the Interrupt Service Routine, can clear the
bit (PIR registers) is the Comparator Interrupt Flag. The interrupt in the following manner:
CMIF bit must be reset by clearing it (‘0’). Since it is
a) Any read or write of CMCON will end the
also possible to write a ‘1’ to this register, a simulated
mismatch condition.
interrupt may be initiated.
b) Clear flag bit CMIF.
The CMIE bit (PIE registers) and the PEIE bit (INTCON
register) must be set to enable the interrupt. In addition, A mismatch condition will continue to set flag bit CMIF.
the GIE bit must also be set. If any of these bits are Reading CMCON will end the mismatch condition and
clear, the interrupt is not enabled, though the CMIF bit allow flag bit CMIF to be cleared.
will still be set if an interrupt condition occurs.

DS30498B-page 164 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
13.7 Comparator Operation 13.9 Analog Input Connection
During Sleep Considerations
When a comparator is active and the device is placed A simplified circuit for an analog input is shown in
in Sleep mode, the comparator remains active and the Figure 13-4. Since the analog pins are connected to a
interrupt is functional if enabled. This interrupt will digital output, they have reverse biased diodes to VDD
wake-up the device from Sleep mode when enabled. and VSS. The analog input, therefore, must be between
While the comparator is powered up, higher Sleep VSS and VDD. If the input voltage deviates from this
currents than shown in the power-down current range by more than 0.6V in either direction, one of the
specification will occur. Each operational comparator diodes is forward biased and a latch-up condition may
will consume additional current as shown in the com- occur. A maximum source impedance of 10 kΩ is
parator specifications. To minimize power consumption recommended for the analog sources. Any external
while in Sleep mode, turn off the comparators component connected to an analog input pin, such as
(CM<2:0> = 111) before entering Sleep. If the device a capacitor or a Zener diode, should have very little
wakes up from Sleep, the contents of the CMCON leakage current.
register are not affected.

13.8 Effects of a Reset

A device Reset forces the CMCON register to its Reset
state, causing the comparator module to be in the
Comparator Off mode, CM<2:0> = 111. This ensures
compatibility to the PIC16F87X devices.

FIGURE 13-4: ANALOG INPUT MODEL

VDD

VT = 0.6V RIC
RS < 10K

AIN
CPIN ILEAKAGE
VA VT = 0.6V ±500 nA
5 pF

VSS
Legend: CPIN = Input Capacitance
VT = Threshold Voltage
ILEAKAGE = Leakage Current at the pin due to various junctions
RIC = Interconnect Resistance
RS = Source Impedance
VA = Analog Voltage

TABLE 13-1: REGISTERS ASSOCIATED WITH COMPARATOR MODULE

Value on
Value on
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR
Resets
9Ch CMCON C2OUT C1OUT C2INV C1INV CIS CM2 CM1 CM0 0000 0111 0000 0111
9Dh CVRCON CVREN CVROE CVRR — CVR3 CVR2 CVR1 CVR0 000- 0000 000- 0000
0Bh, 8Bh, INTCON GIE PEIE TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u
10Bh,18Bh
0Dh PIR2 OSFIF CMIF LVDIF — BCLIF — CCP3IF CCP2IF 000- 0-00 000- 0-00
8Dh PIE2 OSFIE CMIE LVDIE — BCLIE — CCP3IE CCP2IE 000- 0-00 000- 0-00
05h PORTA RA7 RA6 RA5 RA4 RA3 RA2 RA1 RA0 xx0x 0000 uu0u 0000
85h TRISA TRISA7 TRISA6 PORTA Data Direction Register 1111 1111 1111 1111
Legend: x = unknown, u = unchanged, - = unimplemented, read as ‘0’. Shaded cells are unused by the comparator module.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 165

PIC16F7X7
NOTES:

DS30498B-page 166 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
14.0 COMPARATOR VOLTAGE supply voltage (also referred to as CVRSRC) comes
directly from VDD. It should be noted, however, that the
REFERENCE MODULE voltage at the top of the ladder is CVRSRC – VSAT,
The comparator voltage reference generator is a 16-tap where VSAT is the saturation voltage of the power
resistor ladder network that provides a fixed voltage switch transistor. This reference will only be as
reference when the comparators are in mode ‘110’. A accurate as the values of CVRSRC and VSAT.
programmable register controls the function of the The output of the reference generator may be
reference generator. Register 14-1 lists the bit functions connected to the RA2/AN2/VREF-/CVREF pin. This can
of the CVRCON register. be used as a simple D/A function by the user if a very
As shown in Figure 14-1, the resistor ladder is seg- high-impedance load is used. The primary purpose of
mented to provide two ranges of CVREF values and has this function is to provide a test path for testing the
a power-down function to conserve power when the reference generator function.
reference is not being used. The comparator reference

REGISTER 14-1: CVRCON CONTROL REGISTER (ADDRESS 9Dh)

R/W-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0
CVREN CVROE CVRR — CVR3 CVR2 CVR1 CVR0
bit 7 bit 0

bit 7 CVREN: Comparator Voltage Reference Enable bit

1 = CVREF circuit powered on
0 = CVREF circuit powered down
bit 6 CVROE: Comparator VREF Output Enable bit
1 = CVREF voltage level is output on RA2/AN2/VREF-/CVREF pin
0 = CVREF voltage level is disconnected from RA2/AN2/VREF-/CVREF pin
bit 5 CVRR: Comparator VREF Range Selection bit
1 = 0 to 0.75 CVRSRC, with CVRSRC/24 step size
0 = 0.25 CVRSRC to 0.75 CVRSRC, with CVRSRC/32 step size
bit 4 Unimplemented: Read as ‘0’
bit 3-0 CVR3:CVR0: Comparator VREF Value Selection bits 0 ≤ VR3:VR0 ≤ 15
When CVRR = 1:
CVREF = (CVR<3:0>/24) • (CVRSRC)
When CVRR = 0:
CVREF = 1/4 • (CVRSRC) + (CVR3:CVR0/32) • (CVRSRC)

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

 2003 Microchip Technology Inc. Preliminary DS30498B-page 167

PIC16F7X7
FIGURE 14-1: COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM

VDD

16 Stages

CVREN
8R R R R R

8R CVRR

RA2/AN2/VREF-/CVREF

CVROE
CVR3
CVREF CVR2
16:1 Analog MUX
Input to CVR1
Comparator CVR0

TABLE 14-1: REGISTERS ASSOCIATED WITH COMPARATOR VOLTAGE REFERENCE

Value on
Value on
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR
Resets
9Dh CVRCON CVREN CVROE CVRR — CVR3 CVR2 CVR1 CVR0 000- 0000 000- 0000
9Ch CMCON C2OUT C1OUT C2INV C1INV CIS CM2 CM1 CM0 0000 0111 0000 0111
Legend: x = unknown, u = unchanged, - = unimplemented, read as ‘0’.
Shaded cells are not used with the comparator voltage reference.

DS30498B-page 168 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
15.0 SPECIAL FEATURES OF THE Sleep mode is designed to offer a very low current
power-down mode. The user can wake-up from Sleep
CPU
through external Reset, Watchdog Timer Wake-up or
These devices have a host of features intended to max- through an interrupt.
imize system reliability, minimize cost through elimina- Several oscillator options are also made available to
tion of external components, provide power saving allow the part to fit the application. The RC oscillator
operating modes and offer code protection: option saves system cost while the LP crystal option
• Reset saves power. Configuration bits are used to select the
- Power-on Reset (POR) desired oscillator mode.
- Power-up Timer (PWRT) Additional information on special features is available
- Oscillator Start-up Timer (OST) in the PICmicro® Mid-Range MCU Family Reference
Manual (DS33023).
- Brown-out Reset (BOR)
- Low-Voltage Detect (LVD)
15.1 Configuration Bits
• Interrupts
• Watchdog Timer (WDT) The configuration bits can be programmed (read as ‘0’)
• Two-Speed Start-up or left unprogrammed (read as ‘1’) to select various
device configurations. These bits are mapped in
• Fail-Safe Clock Monitor
program memory locations 2007h and 2008h.
• Sleep
The user will note that address 2007h is beyond the
• Code Protection
user program memory space which can be accessed
• ID Locations only during programming.
• In-Circuit Serial Programming
There are two timers that offer necessary delays on
power-up. One is the Oscillator Start-up Timer (OST),
intended to keep the chip in Reset until the crystal oscil-
lator is stable. The other is the Power-up Timer
(PWRT), which provides a fixed delay of 72 ms (nomi-
nal) on power-up only. It is designed to keep the part in
Reset while the power supply stabilizes and is enabled
or disabled using a configuration bit. With these two
timers on-chip, most applications need no external
Reset circuitry.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 169

PIC16F7X7
REGISTER 15-1: CONFIGURATION WORD REGISTER 1 (ADDRESS 2007h)
R/P-1 R/P-1 R/P-1 U-1 U-1 R/P-1 R/P-1 R/P-1 R/P-1 R/P-1 R/P-1 R/P-1 R/P-1 R/P-1
CP CCPMX DEBUG — — BORV1 BORV0 BOREN MCLRE FOSC2 PWRTEN WDTEN FOSC1 FOSC0
bit 13 bit 0

bit 13 CP: Flash Program Memory Code Protection bits

1 = Code protection off
0 = 0000h to 1FFFh code-protected for PIC16F767/777 and 0000h to 0FFFh for PIC16F737/747 (all protected)
bit 12 CCPMX: CCP2 Multiplex bit
1 = CCP2 is on RC1
0 = CCP2 is on RB3
bit 11 DEBUG: In-Circuit Debugger Mode bit
1 = In-circuit debugger disabled, RB6 and RB7 are general purpose I/O pins
0 = In-circuit debugger enabled, RB6 and RB7 are dedicated to the debugger
bit 10-9 Unimplemented: Read as ‘1’
bit 8-7 BORV<1:0>: Brown-out Reset Voltage bits
11 = VBOR set to 2.0V
10 = VBOR set to 2.7V
01 = VBOR set to 4.2V
00 = VBOR set to 4.5V
bit 6 BOREN: Brown-out Reset Enable bit
BOREN combines with BORSEN to control when BOR is enabled and how it is controlled.
BOREN:BORSEN:
11 = BOR enabled and always on
10 = BOR enabled during operation and disabled during Sleep by hardware
01 = BOR controlled by software bit SBOREN (refer to PCON register (Register 2-8), bit 2)
00 = BOR disabled
bit 5 MCLRE: MCLR/VPP/RE3 Pin Function Select bit
1 = MCLR/VPP/RE3 pin function is MCLR
0 = MCLR/VPP/RE3 pin function is digital input only, MCLR gated to ‘1’
bit 3 PWRTEN: Power-up Timer Enable bit
1 = PWRT disabled
0 = PWRT enabled
bit 2 WDTEN: Watchdog Timer Enable bit
1 = WDT enabled
0 = WDT disabled
bit 4, 1-0 FOSC2:FOSC0: Oscillator Selection bits
111 = EXTRC oscillator; CLKO function on OSC2/CLKO/RA6
110 = EXTRC oscillator; port I/O function on OSC2/CLKO/RA6
101 = INTRC oscillator; CLKO function on OSC2/CLKO/RA6 and port I/O function on OSC1/CLKI/RA7
100 = INTRC oscillator; port I/O function on OSC1/CLKI/RA7 and OSC2/CLKO/RA6
011 = EXTCLK; port I/O function on OSC2/CLKO/RA6
010 = HS oscillator
001 = XT oscillator
000 = LP oscillator

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

DS30498B-page 170 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
REGISTER 15-2: CONFIGURATION WORD REGISTER 2 (ADDRESS 2008h)
U-1 U-1 U-1 U-1 U-1 U-1 U-1 R/P-1 U-1 U-1 U-1 U-1 R/P-1 R/P-1
— — — — — — — BORSEN — — — — IESO FCMEN
bit 13 bit 0

bit 13-7 Unimplemented: Read as ‘1’

bit 6 BORSEN: Brown-out Reset Software Enable bit
Refer to Configuration Word Register 1, bit 6 for the function of this bit.
bit 5-2 Unimplemented: Read as ‘1’
bit 1 IESO: Internal External Switch Over bit
1 = Internal External Switch Over mode enabled
0 = Internal External Switch Over mode disabled
bit 0 FCMEN: Fail-Safe Clock Monitor Enable bit
1 = Fail-Safe Clock Monitor enabled
0 = Fail-Safe Clock Monitor disabled

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

 2003 Microchip Technology Inc. Preliminary DS30498B-page 171

PIC16F7X7
15.2 Reset Some registers are not affected in any Reset condition.
Their status is unknown on POR and unchanged in any
The PIC16F7X7 differentiates between various kinds of other Reset. Most other registers are reset to a “Reset
Reset: state” on Power-on Reset (POR), on the MCLR and
• Power-on Reset (POR) WDT Reset, on MCLR Reset during Sleep and Brown-
• MCLR Reset during normal operation out Reset (BOR). They are not affected by a WDT
wake-up which is viewed as the resumption of normal
• MCLR Reset during Sleep
operation. The TO and PD bits are set or cleared differ-
• WDT Reset during normal operation ently in different Reset situations, as indicated in
• WDT Wake-up during Sleep Table 15-3. These bits are used in software to deter-
• Brown-out Reset (BOR) mine the nature of the Reset. Upon a POR, BOR or
wake-up from Sleep, the CPU requires approximately
5-10 µs to become ready for code execution. This
delay runs in parallel with any other timers. See
Table 15-4 for a full description of Reset states of all
registers.
A simplified block diagram of the on-chip Reset circuit
is shown in Figure 15-1.

FIGURE 15-1: SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT

External
Reset

MCLR/VPP/RE3 pin
Sleep
WDT WDT
Module Time-out
Reset
VDD Rise
Detect
Power-on Reset
VDD
Brown-out
Detect BOREN
BORSEN S

OST/PWRT
OST
Chip_Reset
10-bit Ripple Counter R Q
OSC1/
CLKI pin

PWRT
INTRC(1) 11-bit Ripple Counter

Enable PWRT

Enable OST

Note 1: This is the 32 kHz INTRC oscillator. See Section 4.0 “Oscillator Configurations” for more information.

DS30498B-page 172 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
15.3 MCLR 15.5 Power-up Timer (PWRT)
PIC16F7X7 devices have a noise filter in the MCLR The Power-up Timer (PWRT) of the PIC16F7X7 is a
Reset path. The filter will detect and ignore small counter that uses the INTRC oscillator as the clock
pulses. input. This yields a count of 72 ms. While the PWRT is
It should be noted that a WDT Reset does not drive counting, the device is held in Reset.
MCLR pin low. The power-up time delay depends on the INTRC and
The behavior of the ESD protection on the MCLR pin will vary from chip-to-chip due to temperature and
has been altered from previous devices of this family. process variation. See DC parameter #33 for details.
Voltages applied to the pin that exceed its specification The PWRT is enabled by clearing configuration bit
can result in both MCLR and excessive current beyond PWRTEN.
the device specification during the ESD event. For this
reason, Microchip recommends that the MCLR pin no 15.6 Oscillator Start-up Timer (OST)
longer be tied directly to VDD. The use of an
RC network, as shown in Figure 15-2, is suggested. The Oscillator Start-up Timer (OST) provides 1024
oscillator cycles (from OSC1 input) delay after the
The MCLR/VPP/RE3 pin can be configured for MCLR
PWRT delay is over (if enabled). This helps to ensure
(default) or as an input pin (RE3). This is configured
that the crystal oscillator or resonator has started and
through the MCLRE bit in Configuration Word
stabilized.
Register 1.
The OST time-out is invoked only for XT, LP and HS
FIGURE 15-2: RECOMMENDED MCLR modes and only on Power-on Reset or wake-up from
Sleep.
CIRCUIT
VDD 15.7 Brown-out Reset (BOR)
PIC16F7X7
Three configuration bits (BOREN – Configuration Word
R1 Register 1, bit 6; BORSEN – Configuration Word Reg-
1 kΩ (or greater) ister 2, bit 6; SBOREN – PCON, bit 2) together disable
MCLR or enable the Brown-out Reset circuit in one of its three
operating modes.
C1
0.1 µF If VDD falls below VBOR (defined by BORV<1:0> bits in
(optional, not critical) Configuration Word Register 1) for longer than TBOR
(parameter #35, about 100 µs), the brown-out situation
will reset the device. If VDD falls below VBOR for less
than TBOR, a Reset may not occur.
15.4 Power-on Reset (POR) Once the brown-out occurs, the device will remain in
A Power-on Reset pulse is generated on-chip when Brown-out Reset until VDD rises above VBOR. The
VDD rise is detected (in the range of 1.2V-1.7V). To take Power-up Timer (if enabled) will keep the device in
advantage of the POR, tie the MCLR pin to VDD, as Reset for TPWRT (parameter #33, about 72 ms). If VDD
described in Section 15.3 “MCLR”. A maximum rise should fall below VBOR during TPWRT, the Brown-out
time for VDD is specified. See Section 18.0 “Electrical Reset process will restart when VDD rises above VBOR
Characteristics” for details. with the Power-up Timer Reset. Unlike previous PIC16
devices, the PWRT is no longer automatically enabled
When the device starts normal operation (exits the when the Brown-out Reset circuit is enabled. The
Reset condition), device operating parameters (volt- PWRTEN and BOREN configuration bits are
age, frequency, temperature,...) must be met to ensure independent of each other.
operation. If these conditions are not met, the device
must be held in Reset until the operating conditions are
met. For more information, see Application Note
AN607, “Power-up Trouble Shooting” (DS00607).

 2003 Microchip Technology Inc. Preliminary DS30498B-page 173

PIC16F7X7
15.8 Low-Voltage Detect time TA. The application software then has the time,
until the device voltage is no longer in valid operating
In many applications, the ability to determine if the range, to shut down the system. Voltage point VB is the
device voltage (VDD) is below a specified voltage level minimum valid operating voltage specification. This
is a desirable feature. A window of operation for the occurs at time TB. The difference, TB – TA, is the total
application can be created, where the application soft- time for shutdown.
ware can do “housekeeping tasks” before the device
voltage exits the valid operating range. This can be The block diagram for the LVD module is shown in
done using the Low-Voltage Detect module. Figure 15-4. A comparator uses an internally gener-
ated reference voltage as the set point. When the
This module is a software programmable circuitry, selected tap output of the device voltage crosses the
where a device voltage trip point can be specified. set point (is lower than), the LVDIF bit is set.
When the voltage of the device becomes lower then the
specified point, an interrupt flag is set. If the interrupt is Each node in the resistor divider represents a “trip
enabled, the program execution will branch to the inter- point” voltage. The “trip point” voltage is the minimum
rupt vector address and the software can then respond supply voltage level at which the device can operate
to that interrupt source. before the LVD module asserts an interrupt. When the
supply voltage is equal to the trip point, the voltage
The Low-Voltage Detect circuitry is completely under tapped off of the resistor array is equal to the 1.2V
software control. This allows the circuitry to be turned internal reference voltage generated by the voltage ref-
off by the software which minimizes the current erence module. The comparator then generates an
consumption for the device. interrupt signal setting the LVDIF bit. This voltage is
Figure 15-3 shows a possible application voltage curve software programmable to any one of 16 values (see
(typically for batteries). Over time, the device voltage Figure 15-4). The trip point is selected by programming
decreases. When the device voltage equals voltage VA, the LVDL3:LVDL0 bits (LVDCON<3:0>).
the LVD logic generates an interrupt. This occurs at

FIGURE 15-3: TYPICAL LOW-VOLTAGE DETECT APPLICATION

VA
VB
Voltage

Legend:
VA = LVD trip point
VB = Minimum valid device
operating voltage

TA TB
Time

DS30498B-page 174 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 15-4: LOW-VOLTAGE DETECT (LVD) BLOCK DIAGRAM

VDD LVDIN
LVD Control
Register

16 to 1 MUX
LVDIF

LVDEN Internally Generated

Reference Voltage
1.2V

The LVD module has an additional feature that allows pin, LVDIN (Figure 15-5). This gives users flexibility
the user to supply the sense voltage to the module because it allows them to configure the Low-Voltage
from an external source. This mode is enabled when Detect interrupt to occur at any voltage in the valid
bits LVDL3:LVDL0 are set to ‘1111’. In this state, the operating range.
comparator input is multiplexed from the external input

FIGURE 15-5: LOW-VOLTAGE DETECT (LVD) WITH EXTERNAL INPUT BLOCK DIAGRAM
VDD
VDD
LVD Control
Register
16 to 1 MUX

LVDIN LVDEN
Externally Generated
Trip Point
LVD

VxEN

BODEN

EN
BGAP

 2003 Microchip Technology Inc. Preliminary DS30498B-page 175

PIC16F7X7
15.9 Control Register
The Low-Voltage Detect Control register controls the
operation of the Low-Voltage Detect circuitry.

REGISTER 15-3: LVDCON REGISTER

U-0 U-0 R-0 R/W-0 R/W-0 R/W-1 R/W-0 R/W-1
— — IRVST LVDEN LVDL3 LVDL2 LVDL1 LVDL0
bit 7 bit 0

bit 7-6 Unimplemented: Read as ‘0’

bit 5 IRVST: Internal Reference Voltage Stable Flag bit
1 = Indicates that the Low-Voltage Detect logic will generate the interrupt flag at the specified
voltage range
0 = Indicates that the Low-Voltage Detect logic will not generate the interrupt flag at the
specified voltage range and the LVD interrupt should not be enabled
bit 4 LVDEN: Low-Voltage Detect Power Enable bit
1 = Enables LVD, powers up LVD circuit
0 = Disables LVD, powers down LVD circuit
bit 3-0 LVDL3:LVDL0: Low-Voltage Detection Limit bits
1111 = External analog input is used (input comes from the LVDIN pin)
1110 = 4.50V-4.78V
1101 = 4.20V-4.46V
1100 = 4.00V-4.26V
1011 = 3.80V-4.04V
1010 = 3.60V-3.84V
1001 = 3.50V-3.72V
1000 = 3.30V-3.52V
0111 = 3.00V-3.20V
0110 = 2.80V-2.98V
0101 = 2.70V-2.86V
0100 = 2.50V-2.66V
0011 = 2.40V-2.55V
0010 = 2.20V-2.34V
0001 = Reserved
0000 = Reserved
Note: LVDL3:LVDL0 modes which result in a trip point below the valid operating voltage
of the device are not tested.

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

DS30498B-page 176 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
15.10 Operation The following steps are needed to set up the LVD
module:
Depending on the power source for the device voltage,
the voltage normally decreases relatively slowly. This 1. Write the value to the LVDL3:LVDL0 bits
means that the LVD module does not need to be con- (LVDCON register) which selects the desired
stantly operating. To decrease the current require- LVD trip point.
ments, the LVD circuitry only needs to be enabled for 2. Ensure that LVD interrupts are disabled (the
short periods where the voltage is checked. After doing LVDIE bit is cleared or the GIE bit is cleared).
the check, the LVD module may be disabled. 3. Enable the LVD module (set the LVDEN bit in
Each time that the LVD module is enabled, the circuitry the LVDCON register).
requires some time to stabilize. After the circuitry has 4. Wait for the LVD module to stabilize (the IRVST
stabilized, all status flags may be cleared. The module bit to become set).
will then indicate the proper state of the system. 5. Clear the LVD interrupt flag, which may have
falsely become set, until the LVD module has
stabilized (clear the LVDIF bit).
6. Enable the LVD interrupt (set the LVDIE and the
GIE bits).
Figure 15-6 shows typical waveforms that the LVD
module may be used to detect.

FIGURE 15-6: LOW-VOLTAGE DETECT WAVEFORMS

CASE 1:
LVDIF may not be set

VDD

VLVD

LVDIF

Enable LVD

Internally Generated TIVRST

Reference Stable
LVDIF cleared in software

CASE 2:

VDD
VLVD

LVDIF

Enable LVD

Internally Generated TIVRST

Reference Stable

LVDIF cleared in software

LVDIF cleared in software,

LVDIF remains set since LVD condition still exists

 2003 Microchip Technology Inc. Preliminary DS30498B-page 177

PIC16F7X7
15.10.1 REFERENCE VOLTAGE SET POINT 15.13 Time-out Sequence
The internal reference voltage of the LVD module may On power-up, the time-out sequence is as follows: the
be used by other internal circuitry (the Programmable PWRT delay starts (if enabled) when a POR occurs.
Brown-out Reset). If these circuits are disabled (lower Then, OST starts counting 1024 oscillator cycles when
current consumption), the reference voltage circuit PWRT ends (LP, XT, HS). When the OST ends, the
requires a time to become stable before a low-voltage device comes out of Reset.
condition can be reliably detected. This time is invariant
of system clock speed. This start-up time is specified in If MCLR is kept low long enough, all delays will expire.
electrical specification parameter #36. The low-voltage Bringing MCLR high will begin execution immediately.
interrupt flag will not be enabled until a stable reference This is useful for testing purposes or to synchronize
voltage is reached. Refer to the waveform in Figure 15-6. more than one PIC16F7X7 device operating in parallel.
Table 15-3 shows the Reset conditions for the Status,
15.10.2 CURRENT CONSUMPTION PCON and PC registers, while Table 15-4 shows the
When the module is enabled, the LVD comparator and Reset conditions for all the registers.
voltage divider are enabled and will consume static cur-
rent. The voltage divider can be tapped from multiple 15.14 Power Control/Status Register
places in the resistor array. Total current consumption, (PCON)
when enabled, is specified in electrical specification
parameter #D022B. The Power Control/Status register, PCON, has two bits
to indicate the type of Reset that last occurred.
15.11 Operation During Sleep Bit 0 is Brown-out Reset Status bit, BOR. Bit BOR is
unknown on a Power-on Reset. It must then be set by
When enabled, the LVD circuitry continues to operate the user and checked on subsequent Resets to see if
during Sleep. If the device voltage crosses the trip bit BOR cleared, indicating a Brown-out Reset
point, the LVDIF bit will be set and the device will wake- occurred. When the Brown-out Reset is disabled, the
up from Sleep. Device execution will continue from the state of the BOR bit is unpredictable.
interrupt vector address if interrupts have been globally
enabled. Bit 1 is Power-on Reset Status bit, POR. It is cleared on
a Power-on Reset and unaffected otherwise. The user
must set this bit following a Power-on Reset.
15.12 Effects of a Reset
A device Reset forces all registers to their Reset state.
This forces the LVD module to be turned off.
Note: If the LVD is enabled and the BOR module
is not enabled, the band gap will require a
start-up time of no more than 50 µs before
the band gap reference is stable. Before
enabling the LVD interrupt, the user
should ensure that the band gap reference
voltage is stable by monitoring the IRVST
bit in the LVDCON register. The LVD could
cause erroneous interrupts before the
band gap is stable.

DS30498B-page 178 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
TABLE 15-1: TIME-OUT IN VARIOUS SITUATIONS
Power-up Brown-out Reset Wake-up from
Oscillator Configuration
PWRTE = 0 PWRTE = 1 PWRTE = 0 PWRTE = 1 Sleep
XT, HS, LP TPWRT + 1024 • TOSC TPWRT + 1024 • TOSC 1024 • TOSC
1024 • TOSC 1024 • TOSC
EXTRC, INTRC TPWRT 5-10 µs(1) TPWRT 5-10 µs(1) 5-10 µs(1)
T1OSC — — — — 5-10 µs(1)
Note 1: CPU start-up is always invoked on POR, BOR and wake-up from Sleep. The 5 µs-10 µs delay is based on
a 1 MHz system clock.

TABLE 15-2: STATUS BITS AND THEIR SIGNIFICANCE

POR BOR TO PD
0 x 1 1 Power-on Reset
0 x 0 x Illegal, TO is set on POR
0 x x 0 Illegal, PD is set on POR
1 0 1 1 Brown-out Reset
1 1 0 1 WDT Reset
1 1 0 0 WDT Wake-up
1 1 u u MCLR Reset during normal operation
1 1 1 0 MCLR Reset during Sleep or Interrupt Wake-up from Sleep
Legend: u = unchanged, x = unknown

TABLE 15-3: RESET CONDITION FOR SPECIAL REGISTERS

Program Status PCON
Condition
Counter Register Register
Power-on Reset 000h 0001 1xxx ---- --0x
MCLR Reset during normal operation 000h 000u uuuu ---- --uu
MCLR Reset during Sleep 000h 0001 0uuu ---- --uu
WDT Reset 000h 0000 1uuu ---- --uu
WDT Wake-up PC + 1 uuu0 0uuu ---- --uu
Brown-out Reset 000h 0001 1uuu ---- --u0
Interrupt Wake-up from Sleep PC + 1(1) uuu1 0uuu ---- --uu
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’
Note 1: When the wake-up is due to an interrupt and the GIE bit is set, the PC is loaded with the interrupt vector
(0004h).

 2003 Microchip Technology Inc. Preliminary DS30498B-page 179

PIC16F7X7
TABLE 15-4: INITIALIZATION CONDITIONS FOR ALL REGISTERS
Power-on Reset, MCLR Reset, Wake-up via WDT or
Register
Brown-out Reset WDT Reset Interrupt
W xxxx xxxx uuuu uuuu uuuu uuuu
INDF N/A N/A N/A
TMR0 xxxx xxxx uuuu uuuu uuuu uuuu
PCL 0000h 0000h PC + 1(2)
(3)
STATUS 0001 1xxx 000q quuu uuuq quuu(3)
FSR xxxx xxxx uuuu uuuu uuuu uuuu
PORTA xx0x 0000 uu0u 0000 uuuu uuuu
PORTB xx00 0000 uu00 0000 uuuu uuuu
PORTC xxxx xxxx uuuu uuuu uuuu uuuu
PORTD xxxx xxxx uuuu uuuu uuuu uuuu
PORTE (PIC16F737/767) ---- x--- ---- u--- ---- u---
PORTE (PIC16F747/777) ---- x000 ---- u000 ---- uuuu
PCLATH ---0 0000 ---0 0000 ---u uuuu
INTCON 0000 000x 0000 000u uuuu uuuu(1)
PIR1 0000 0000 0000 0000 uuuu uuuu(1)
PIR2 000- 0-00 000- 0-00 uuu- u-uu
TMR1L xxxx xxxx uuuu uuuu uuuu uuuu
TMR1H xxxx xxxx uuuu uuuu uuuu uuuu
T1CON -000 0000 -uuu uuuu -uuu uuuu
TMR2 0000 0000 0000 0000 uuuu uuuu
T2CON -000 0000 -000 0000 -uuu uuuu
SSPBUF xxxx xxxx uuuu uuuu uuuu uuuu
SSPCON 0000 0000 0000 0000 uuuu uuuu
SSPCON2 0000 0000 0000 0000 uuuu uuuu
CCPR1L xxxx xxxx uuuu uuuu uuuu uuuu
CCPR1H xxxx xxxx uuuu uuuu uuuu uuuu
CCP1CON --00 0000 --00 0000 --uu uuuu
CCP2CON --00 0000 --00 0000 --uu uuuu
CCP3CON --00 0000 --00 0000 uuuu uuuu
CCPR2L xxxx xxxx uuuu uuuu uuuu uuuu
CCPR2H xxxx xxxx uuuu uuuu uuuu uuuu
CCPR3L xxxx xxxx uuuu uuuu uuuu uuuu
CCPR3H xxxx xxxx uuuu uuuu uuuu uuuu
RCSTA 0000 000x 0000 000x uuuu uuuu
TXREG 0000 0000 0000 0000 uuuu uuuu
RCREG 0000 0000 0000 0000 uuuu uuuu
ADRESH xxxx xxxx uuuu uuuu uuuu uuuu
ADCON0 0000 0000 0000 0000 uuuu uuuu
OPTION 1111 1111 1111 1111 uuuu uuuu
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition,
r = reserved, maintain clear
Note 1: One or more bits in INTCON, PIR1 and PR2 will be affected (to cause wake-up).
2: When the wake-up is due to an interrupt and the GIE bit is set, the PC is loaded with the interrupt vector
(0004h).
3: See Table 15-3 for Reset value for specific condition.

DS30498B-page 180 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
TABLE 15-4: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Power-on Reset, MCLR Reset, Wake-up via WDT or
Register
Brown-out Reset WDT Reset Interrupt
TRISA 1111 1111 1111 1111 uuuu uuuu
TRISB 1111 1111 1111 1111 uuuu uuuu
TRISC 1111 1111 1111 1111 uuuu uuuu
TRISD 1111 1111 1111 1111 uuuu uuuu
TRISE (PIC16F737/767) ---- 1--- ---- u--- ---- 1---
TRISE (PIC16F747/777) 0000 1111 0000 1111 uuuu uuuu
PIE1 0000 0000 0000 0000 -uuu uuuu
PIE2 000- 0-00 000- 0-00 uuu- u-uu
PCON ---- -1qq ---- -uuu ---- -uuu
OSCCON -000 1000 -000 1000 -uuu uuuu
OSCTUNE --00 0000 --00 0000 --uu uuuu
PR2 1111 1111 1111 1111 1111 1111
SSPADD 0000 0000 0000 0000 uuuu uuuu
SSPSTAT 0000 0000 0000 0000 uuuu uuuu
TXSTA 0000 -010 0000 -010 uuuu -u1u
SPBRG 0000 0000 0000 0000 uuuu uuuu
CMCON 0000 0111 0000 0111 uuuu uuuu
CVRCON 000- 0000 000- 0000 uuu- uuuu
WDTCON ---0 1000 ---0 1000 ---u uuuu
ADRESL xxxx xxxx uuuu uuuu uuuu uuuu
ADCON1 0000 0000 0000 0000 uuuu uuuu
ADCON2 --00 0--- --00 0--- uuuu uuuu
PMDATA xxxx xxxx uuuu uuuu uuuu uuuu
PMADR xxxx xxxx uuuu uuuu uuuu uuuu
PMDATH --xx xxxx --uu uuuu --uu uuuu
PMADRH ---- xxxx ---- uuuu ---- uuuu
PMCON1 ---- ---0 ---- ---u ---- ---u
LVDCON --00 0101 --00 0101 --uu uuuu
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition,
r = reserved, maintain clear
Note 1: One or more bits in INTCON, PIR1 and PR2 will be affected (to cause wake-up).
2: When the wake-up is due to an interrupt and the GIE bit is set, the PC is loaded with the interrupt vector
(0004h).
3: See Table 15-3 for Reset value for specific condition.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 181

PIC16F7X7
FIGURE 15-7: TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD THROUGH
PULL-UP RESISTOR)

VDD

MCLR

Internal POR

TPWRT

PWRT Time-out TOST

OST Time-out

Internal Reset

FIGURE 15-8: TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD THROUGH

RC NETWORK): CASE 1

VDD

MCLR

Internal POR

TPWRT

PWRT Time-out TOST

OST Time-out

Internal Reset

FIGURE 15-9: TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD THROUGH

RC NETWORK): CASE 2

VDD

MCLR

Internal POR

TPWRT

PWRT Time-out TOST

OST Time-out

Internal Reset

DS30498B-page 182 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 15-10: SLOW RISE TIME (MCLR TIED TO VDD THROUGH RC NETWORK)

5V
VDD 0V 1V

MCLR

Internal POR

TPWRT

PWRT Time-out
TOST

OST Time-out

Internal Reset

 2003 Microchip Technology Inc. Preliminary DS30498B-page 183

PIC16F7X7
15.15 Interrupts The peripheral interrupt flags are contained in the
Special Function Register, PIR1. The corresponding
The PIC16F7X7 has up to 17 sources of interrupt. The interrupt enable bits are contained in Special Function
Interrupt Control register (INTCON) records individual Register, PIE1 and the peripheral interrupt enable bit is
interrupt requests in flag bits. It also has individual and contained in Special Function Register, INTCON.
global interrupt enable bits.
When an interrupt is serviced, the GIE bit is cleared to
Note: Individual interrupt flag bits are set regard- disable any further interrupt, the return address is
less of the status of their corresponding pushed onto the stack and the PC is loaded with 0004h.
mask bit or the GIE bit. Once in the Interrupt Service Routine, the source(s) of
A global interrupt enable bit, GIE (INTCON<7>), the interrupt can be determined by polling the interrupt
enables (if set) all unmasked interrupts or disables (if flag bits. The interrupt flag bit(s) must be cleared in soft-
cleared) all interrupts. When bit GIE is enabled and an ware before re-enabling interrupts to avoid recursive
interrupt’s flag bit and mask bit are set, the interrupt will interrupts.
vector immediately. Individual interrupts can be For external interrupt events, such as the INT pin or
disabled through their corresponding enable bits in PORTB change interrupt, the interrupt latency will be
various registers. Individual interrupt bits are set three or four instruction cycles. The exact latency
regardless of the status of the GIE bit. The GIE bit is depends on when the interrupt event occurs relative to
cleared on Reset. the current Q cycle. The latency is the same for one or
The “return from interrupt” instruction, RETFIE, exits two-cycle instructions. Individual interrupt flag bits are
the interrupt routine, as well as sets the GIE bit which set regardless of the status of their corresponding
re-enables interrupts. mask bit, PEIE bit or the GIE bit.
The RB0/INT pin interrupt, the RB port change interrupt
and the TMR0 overflow interrupt flags are contained in
the INTCON register.

FIGURE 15-11: INTERRUPT LOGIC

PSPIF(1)
PSPIE(1)
OSFIF
OSFIE
BCLIF
BCLIE
ADIF
ADIE Wake-up (If in Sleep mode)
RCIF TMR0IF
RCIE TMR0IE
INTF
TXIF
INTE
TXIE Interrupt to CPU
RBIF
SSPIF RBIE
SSPIE

PEIE
CCP1IF
CCP1IE
GIE
CCP2IF
CCP2IE
CCP3IF
CCP3IE
TMR2IF
TMR2IE
TMR1IF
TMR1IE
CMIF
CMIE

Note 1: PSP interrupt is implemented only on PIC16F747/777 devices.

DS30498B-page 184 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
15.15.1 INT INTERRUPT 15.15.3 PORTB INTCON CHANGE
External interrupt on the RB0/INT pin is edge-triggered, An input change on PORTB<7:4> sets flag bit, RBIF
either rising if bit INTEDG (OPTION<6>) is set or falling (INTCON<0>). The interrupt can be enabled/disabled
if the INTEDG bit is clear. When a valid edge appears by setting/clearing enable bit, RBIE (INTCON<4>), see
on the RB0/INT pin, flag bit INTF (INTCON<1>) is set. Section 2.2 “Data Memory Organization”.
This interrupt can be disabled by clearing enable bit,
INTE (INTCON<4>). Flag bit INTF must be cleared in 15.16 Context Saving During Interrupts
software in the Interrupt Service Routine before re-
enabling this interrupt. The INT interrupt can wake-up During an interrupt, only the return PC value is saved
the processor from Sleep if bit INTE was set prior to on the stack. Typically, users may wish to save key
going into Sleep. The status of global interrupt enable registers during an interrupt (i.e., W, Status registers).
bit, GIE, decides whether or not the processor Since the upper 16 bytes of each bank are common in
branches to the interrupt vector following wake-up. See the PIC16F7X7 devices, temporary holding registers
Section 15.18 “Power-down Mode (Sleep)” for W_TEMP, STATUS_TEMP and PCLATH_TEMP
details on Sleep mode. should be placed in here. These 16 locations don’t
require banking and therefore, make it easier for con-
15.15.2 TMR0 INTERRUPT text save and restore. The same code shown in
An overflow (FFh → 00h) in the TMR0 register will set Example 15-1 can be used.
flag bit, TMR0IF (INTCON<2>). The interrupt can be
enabled/disabled by setting/clearing enable bit,
TMR0IE (INTCON<5>), see Section 6.0 “Timer0
Module”.

EXAMPLE 15-1: SAVING STATUS AND W REGISTERS IN RAM

MOVWF W_TEMP ;Copy W to TEMP register
SWAPF STATUS, W ;Swap status to be saved into W
CLRF STATUS ;bank 0, regardless of current bank, Clears IRP,RP1,RP0
MOVWF STATUS_TEMP ;Save status to bank zero STATUS_TEMP register
:
:(ISR) ;Insert user code here
:
SWAPF STATUS_TEMP, W ;Swap STATUS_TEMP register into W
;(sets bank to original state)
MOVWF STATUS ;Move W into STATUS register
SWAPF W_TEMP, F ;Swap W_TEMP
SWAPF W_TEMP, W ;Swap W_TEMP into W

 2003 Microchip Technology Inc. Preliminary DS30498B-page 185

PIC16F7X7
15.17 Watchdog Timer (WDT) A new prescaler has been added to the path between
the internal RC and the multiplexors used to select the
For PIC16F7X7 devices, the WDT has been modified path for the WDT. This prescaler is 16 bits and can be
from previous PIC16 devices. The new WDT is code programmed to divide the internal RC by 128 to 65536,
and functionally backward compatible with previous giving the time base used for the WDT a nominal range
PIC16 WDT modules, and allows the user to have a of 1 ms to 2.097s.
scaler value for the WDT and TMR0 at the same time.
In addition, the WDT time-out value can be extended to 15.17.2 WDT CONTROL
268 seconds, using the prescaler with the postscaler
The WDTEN bit is located in Configuration Word
when PSA is set to ‘1’.
Register 1 and when this bit is set, the WDT runs
15.17.1 WDT OSCILLATOR continuously.

The WDT derives its time base from the 31.25 kHz The SWDTEN bit is in the WDTCON register. When the
INTRC; therefore, the accuracy of the 31.25 kHz will be WDTEN bit in the Configuration Word Register 1 is set,
the same accuracy for the WDT time-out period. the SWDTEN bit has no effect. If WDTEN is clear, then
the SWDTEN bit can be used to enable and disable the
The value of WDTCON is ‘---0 1000’ on all Resets. WDT. Setting the bit will enable it and clearing the bit
This gives a nominal time base of 16.38 ms, which is will disable it.
compatible with the time base generated with previous
PIC16 microcontroller versions. The PSA and PS<2:0> bits (OPTION_REG) have the
same function as in previous versions of the PIC16
Note: When the OST is invoked, the WDT is held family of microcontrollers.
in Reset because the WDT ripple counter
is used by the OST to perform the oscilla-
tor delay count. When the OST count has
expired, the WDT will begin counting (if
enabled).

FIGURE 15-12: WATCHDOG TIMER BLOCK DIAGRAM

From TMR0 Clock Source

Postscaler
1
16-bit Programmable Prescaler WDT

PSA
PS<2:0>

31.25 kHz WDTPS<3:0> TO TMR0

INTRC Clock
0 1
PSA

WDTEN from Configuration Word

SWDTEN from WDTCON
WDT Time-out

TABLE 15-5: PRESCALER/POSTSCALER BIT STATUS

Conditions Prescaler Postscaler (PSA = 1)
WDTEN = 0
CLRWDT command
Cleared Cleared
Osc Fail detected
Exit Sleep + System Clock = T1OSC, EXTRC, INTRC, EXTCLK
Exit Sleep + System Clock = XT, HS, LP Cleared at end of OST Cleared at end of OST

DS30498B-page 186 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
REGISTER 15-4: WDTCON REGISTER
U-0 U-0 U-0 R/W-0 R/W-1 R/W-0 R/W-0 R/W-0
— — — WDTPS3 WDTPS2 WDTPS1 WDTPS0 SWDTEN
bit 7 bit 0

bit 7-5 Unimplemented: Read as ‘0’

bit 4-1 WDTPS<3:0>: Watchdog Timer Period Select bits
0000 = 1:32 prescale rate
0001 = 1:64 prescale rate
0010 = 1:128 prescale rate
0011 = 1:256 prescale rate
0100 = 1:512 prescale rate
0101 = 1:1024 prescale rate
0110 = 1:2048 prescale rate
0111 = 1:4096 prescale rate
1000 = 1:8192 prescale rate
1001 = 1:16394 prescale rate
1010 = 1:32768 prescale rate
1011 = 1:65536 prescale rate
1100 = 1:1 prescale rate
bit 0 SWDTEN: Software Enable/Disable for Watchdog Timer bit(1)
1 = WDT is turned on
0 = WDT is turned off
Note 1: If WDTEN configuration bit = 1, then WDT is always enabled irrespective of this
control bit. If WDTEN configuration bit = 0, then it is possible to turn WDT on/off with
this control bit.

Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

TABLE 15-6: SUMMARY OF WATCHDOG TIMER REGISTERS

Value on
Value on
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 all other
POR, BOR
Resets

81h, 181h OPTION_REG RBPU INTEDG T0CS T0SE PSA PS2 PS1 PS0 1111 1111 1111 1111
2007h Configuration BORV0 BOREN MCLRE FOSC2 PWRTEN WDTEN FOSC1 FOSC0 uuuu uuuu uuuu uuuu
bits
105h WDTCON — — — WDTPS3 WDTPS2 WSTPS1 WDTPS0 SWDTEN ---0 1000 ---0 1000
Legend: Shaded cells are not used by the Watchdog Timer.
Note 1: See Register 15-1 for operation of these bits.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 187

PIC16F7X7
15.17.3 TWO-SPEED CLOCK START-UP Checking the state of the OSTS bit will confirm
MODE whether the primary clock configuration is engaged. If
not, the OSTS bit will remain clear.
Two-Speed Start-up minimizes the latency between
oscillator start-up and code execution that may be When the device is auto-configured in INTRC mode
selected with the IESO (Internal/External Switch Over) following a POR or wake-up from Sleep, the rules for
bit in Configuration Word Register 2. This mode is entering other oscillator modes still apply, meaning the
achieved by initially using the INTRC for code SCS<1:0> bits in OSCCON can be modified before the
execution until the primary oscillator is stable. OST time-out has occurred. This would allow the
application to wake-up from Sleep, perform a few
If this mode is enabled and any of the following condi-
instructions using the INTRC as the clock source and
tions exist, the system will begin execution with the
go back to Sleep without waiting for the primary
INTRC oscillator. This results in almost immediate
oscillator to become stable.
code execution with a minimum of delay.
• POR and after the Power-up Timer has expired (if Note: Executing a SLEEP instruction will abort
PWRTEN = 0) the oscillator start-up time and will cause
the OSTS bit to remain clear.
• or following a wake-up from Sleep
• or a Reset, when running from T1OSC or INTRC 15.17.3.1 Two-Speed Start-up Sequence
(after a Reset, SCS<1:0> are always set to ‘00’).
1. Wake-up from Sleep, Reset or POR.
Note: Following any Reset, the IRCF bits are 2. OSCON bits configured to run from INTRC
zeroed and the frequency selection is (31.25 kHz).
forced to 31.25 kHz. The user can modify
3. Instructions begin execution by INTRC
the IRCF bits to select a higher internal
(31.25 kHz).
oscillator frequency.
4. OST enabled to count 1024 clock cycles.
If the primary oscillator is configured to be anything
5. OST timed out, wait for falling edge of INTRC.
other than XT, LP or HS, then Two-Speed Start-up is
disabled because the primary oscillator will not require 6. OSTS is set.
any time to become stable after POR or an exit from 7. System clock held low for eight falling edges of
Sleep. new clock (LP, XT or HS).
If the IRCF bits of the OSCCON register are configured 8. System clock is switched to primary source (LP,
to a non-zero value prior to entering Sleep mode, the XT or HS).
secondary system clock frequency will come from the The software may read the OSTS bit to determine
output of the INTOSC. The IOFS bit in the OSCCON when the switch over takes place so that any software
register will be clear until the INTOSC is stable. This timing edges can be adjusted.
will allow the user to determine when the internal
oscillator can be used for time critical applications.

FIGURE 15-13: TWO-SPEED START-UP

CPU Start-up

Q1 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

INTRC
OSC1
TOST
OSC2

System Clock
Sleep

OSTS
Program PC 0000h 0001h 0003h 0004h 0005h
Counter

DS30498B-page 188 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
15.17.4 FAIL-SAFE OPTION The FSCM sample clock is generated by dividing the
INTRC clock by 64. This will allow enough time
The Fail-Safe Clock Monitor (FSCM) is designed to
between FSCM sample clocks for a system clock edge
allow the device to continue to operate even in the
to occur.
event of an oscillator failure.
On the rising edge of the postscaled clock, the
FIGURE 15-14: FSCM BLOCK DIAGRAM monitoring latch (CM = 0) will be cleared. On a falling
edge of the primary or secondary system clock, the
Clock Monitor
Latch (CM) monitoring latch will be set (CM = 1). In the event that
(edge-triggered) a falling edge of the postscaled clock occurs and the
Peripheral monitoring latch is not set, a clock failure has been
S Q
Clock detected.
While in Fail-Safe mode, a Reset will exit the Fail-Safe
condition. If the primary clock source is configured for
INTRC
Oscillator
÷ 64 C Q a crystal, the OST timer will wait for the 1024 clock
cycles for the OST time-out and the device will con-
31.25 kHz 488 Hz tinue running from the internal oscillator until the OST
(32 µs) (2.048 ms) is complete. A SLEEP instruction, or a write to the SCS
bits (where SCS bits do not = 00), can be performed to
Clock put the device into a low-power mode.
Failure
Detected If Reset occurs while in Fail-Safe mode and the
primary clock source is EC or RC, then the device will
The FSCM function is enabled by setting the FCMEN immediately switch back to EC or RC mode.
bit in Configuration Word Register 2. Note: Two-Speed Start-up is automatically
In the event of an oscillator failure, the FSCM will enabled when the Fail-Safe option is
generate an oscillator fail interrupt and will switch the enabled.
system clock over to the internal oscillator. The system
will continue to come from the internal oscillator until 15.17.4.1 Fail-Safe in Low-Power Mode
the Fail-Safe condition is exited. The Fail-Safe A change of SCS<1:0> or the SLEEP instruction will
condition is exited with either a Reset, the execution of end the Fail-Safe condition. The system clock will
a SLEEP instruction or a write to the SCS bits of a default to the source selected by the SCS bits, which
different value. is either T1OSC, INTRC or none (Sleep mode). How-
The frequency of the internal oscillator will depend ever, the FSCM will continue to monitor the system
upon the value contained in the IRCF bits. Another clock. If the secondary clock fails, the device will
clock source can be selected via the IRCF and the immediately switch to the internal oscillator clock. If
SCS bits of the OSCCON register. OSFIE is set, an interrupt will be generated.

FIGURE 15-15: FSCM TIMING DIAGRAM

Sample Clock

System Oscillator
Clock Failure
Output

CM Output
(Q)
Failure
Detected
OSCFIF

CM Test CM Test CM Test

Note: The system clock is normally at a much higher frequency than the sample clock. The relative frequencies in
this example have been chosen for clarity.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 189

PIC16F7X7
15.17.4.2 FSCM and the Watchdog Timer 15.18.1 WAKE-UP FROM SLEEP
When a clock failure is detected, SCS<1:0> will be The device can wake-up from Sleep through one of the
forced to ‘10’ which will reset the WDT (if enabled). following events:
1. External Reset input on MCLR pin.
15.17.4.3 POR or Wake from Sleep
2. Watchdog Timer wake-up (if WDT was
The FSCM is designed to detect oscillator failure at any enabled).
point after the device has exited Power-on Reset
3. Interrupt from INT pin, RB port change or a
(POR) or low-power Sleep mode. When the primary
peripheral interrupt.
system clock is EC, RC or INTRC modes, monitoring
can begin immediately following these events. External MCLR Reset will cause a device Reset. All
other events are considered a continuation of program
For oscillator modes involving a crystal or resonator
execution and cause a “wake-up”. The TO and PD bits
(HS, LP or XT), the situation is somewhat different.
in the Status register can be used to determine the
Since the oscillator may require a start-up time consid-
cause of the device Reset. The PD bit, which is set on
erably longer than the FSCM sample clock time, a false
power-up, is cleared when Sleep is invoked. The TO bit
clock failure may be detected. To prevent this, the inter-
is cleared if a WDT time-out occurred and caused
nal oscillator block is automatically configured as the
wake-up.
system clock and functions until the primary clock is
stable (the OST and PLL timers have timed out). This The following peripheral interrupts can wake the device
is identical to Two-Speed Start-up mode. Once the from Sleep:
primary clock is stable, the INTR returns to its role as 1. TMR1 interrupt. Timer1 must be operating as an
the FSCM source. asynchronous counter.
Note: The same logic that prevents false oscilla- 2. CCP Capture mode interrupt.
tor failure interrupts on POR or wake from 3. Special event trigger (Timer1 in Asynchronous
Sleep, will also prevent the detection of mode using an external clock).
the oscillator’s failure to start at all follow- 4. SSP (Start/Stop) bit detect interrupt.
ing these events. This can be avoided by 5. SSP transmit or receive in Slave mode (SPI/I2C).
monitoring the OSTS bit and using a
6. A/D conversion (when A/D clock source is RC).
timing routine to determine if the oscillator
is taking too long to start. Even so, no 7. EEPROM write operation completion.
oscillator failure interrupt will be flagged. 8. Comparator output changes state.
9. USART RX or TX (Synchronous Slave mode).
15.18 Power-down Mode (Sleep) Other peripherals cannot generate interrupts since
Power-down mode is entered by executing a SLEEP during Sleep, no on-chip clocks are present.
instruction. When the SLEEP instruction is being executed, the next
If enabled, the Watchdog Timer will be cleared but instruction (PC + 1) is prefetched. For the device to
keeps running, the PD bit (Status<3>) is cleared, the wake-up through an interrupt event, the corresponding
TO (Status<4>) bit is set and the oscillator driver is interrupt enable bit must be set (enabled). Wake-up
turned off. The I/O ports maintain the status they had occurs regardless of the state of the GIE bit. If the GIE
before the SLEEP instruction was executed (driving bit is clear (disabled), the device continues execution at
high, low or high-impedance). the instruction after the SLEEP instruction. If the GIE bit
is set (enabled), the device executes the instruction
For lowest current consumption in this mode, place all after the SLEEP instruction and then branches to the
I/O pins at either VDD or VSS, ensure no external cir- interrupt address (0004h). In cases where the execu-
cuitry is drawing current from the I/O pin, power-down tion of the instruction following SLEEP is not desirable,
the A/D and disable external clocks. Pull all I/O pins the user should have a NOP after the SLEEP instruction.
that are high-impedance inputs, high or low externally,
to avoid switching currents caused by floating inputs.
The T0CKI input should also be at VDD or VSS for low-
est current consumption. The contribution from on-chip
pull-ups on PORTB should also be considered.
The MCLR pin must be at a logic high level (VIHMC).

DS30498B-page 190 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
15.18.2 WAKE-UP USING INTERRUPTS Even if the flag bits were checked before executing a
SLEEP instruction, it may be possible for flag bits to
When global interrupts are disabled (GIE cleared) and
become set before the SLEEP instruction completes. To
any interrupt source has both its interrupt enable bit
determine whether a SLEEP instruction executed, test
and interrupt flag bit set, one of the following will occur:
the PD bit. If the PD bit is set, the SLEEP instruction
• If the interrupt occurs before the execution of a was executed as a NOP.
SLEEP instruction, the SLEEP instruction will com-
To ensure that the WDT is cleared, a CLRWDT instruction
plete as a NOP. Therefore, the WDT and WDT
should be executed before a SLEEP instruction.
prescaler and postscaler (if enabled) will not be
cleared, the TO bit will not be set and the PD bit
will not be cleared.
• If the interrupt occurs during or after the
execution of a SLEEP instruction, the device will
immediately wake-up from Sleep. The SLEEP
instruction will be completely executed before the
wake-up. Therefore, the WDT and WDT prescaler
and postscaler (if enabled) will be cleared, the TO
bit will be set and the PD bit will be cleared.

FIGURE 15-16: WAKE-UP FROM SLEEP THROUGH INTERRUPT

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
OSC1
CLKO(4) TOST(2)

INT pin
INTF Flag
(INTCON<1>) Interrupt Latency
(Note 2)
GIE bit
(INTCON<7>) Processor in
Sleep
INSTRUCTION FLOW
PC PC PC+1 PC+2 PC+2 PC + 2 0004h 0005h
Instruction
Fetched Inst(PC) = Sleep Inst(PC + 1) Inst(PC + 2) Inst(0004h) Inst(0005h)
Instruction Dummy Cycle Dummy Cycle
Executed Inst(PC - 1) Sleep Inst(PC + 1) Inst(0004h)

Note 1: XT, HS or LP Oscillator mode assumed.

2: TOST = 1024 TOSC (drawing not to scale). This delay will not be there for RC Osc mode.
3: GIE = 1 assumed. In this case, after wake-up, the processor jumps to the interrupt routine.
If GIE = 0, execution will continue in-line.
4: CLKO is not available in these osc modes but shown here for timing reference.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 191

PIC16F7X7
15.19 In-Circuit Debugger 15.22 In-Circuit Serial Programming
When the DEBUG bit in the Configuration Word is pro- PIC16F7X7 microcontrollers can be serially
grammed to a ‘0’, the in-circuit debugger functionality is programmed while in the end application circuit. This is
enabled. This function allows simple debugging simply done with two lines for clock and data and three
functions when used with MPLAB® ICD. When the other lines for power, ground and the programming
microcontroller has this feature enabled, some of the voltage (see Figure 15-17 for an example). This allows
resources are not available for general use. Table 15-7 customers to manufacture boards with unprogrammed
shows which features are consumed by the background devices and then program the microcontroller just
debugger. before shipping the product. This also allows the most
recent firmware or a custom firmware to be
TABLE 15-7: DEBUGGER RESOURCES programmed.
I/O pins RB6, RB7 For general information of serial programming, please
Stack 1 level refer to the In-Circuit Serial Programming™ (ICSP™)
Guide (DS30277).
Program Memory Address 0000h must be NOP
Last 100h words FIGURE 15-17: TYPICAL IN-CIRCUIT
Data Memory 0x070 (0x0F0, 0x170, 0x1F0) SERIAL PROGRAMMING
0x1EB-0x1EF CONNECTION
To use the in-circuit debugger function of the micro- To Normal
controller, the design must implement In-Circuit Serial Connections
Programming connections to MCLR/VPP, VDD, GND, External
RB7 and RB6. This will interface to the in-circuit Connector *
Signals PIC16F7X7
debugger module available from Microchip, or one of
the third party development tool companies. +5V VDD
0V VSS
15.20 Program Verification/Code VPP MCLR/VPP/RE3
Protection CLK RB6
If the code protection bit(s) have not been Data I/O RB7
programmed, the on-chip program memory can be
read out for verification purposes.

15.21 ID Locations
* * *
Four memory locations (2000h-2003h) are designated
as ID locations, where the user can store checksum or VDD
other code identification numbers. These locations are To Normal
Connections
not accessible during normal execution, but are
readable and writable during program/verify. It is * Isolation devices (as required).
recommended that only the four Least Significant bits
of the ID location are used.

DS30498B-page 192 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
16.0 INSTRUCTION SET SUMMARY For example, a “CLRF PORTB” instruction will read
PORTB, clear all the data bits, then write the result
The PIC16 instruction set is highly orthogonal and is back to PORTB. This example would have the unin-
comprised of three basic categories: tended result that the condition that sets the RBIF flag
• Byte-oriented operations would be cleared for pins configured as inputs and
• Bit-oriented operations using the PORTB interrupt-on-change feature.
• Literal and control operations
TABLE 16-1: OPCODE FIELD
Each PIC16 instruction is a 14-bit word divided into an DESCRIPTIONS
opcode, which specifies the instruction type and one or
more operands, which further specify the operation of Field Description
the instruction. The formats for each of the categories f Register file address (0x00 to 0x7F)
are presented in Figure 16-1, while the various opcode
W Working register (accumulator)
fields are summarized in Table 16-1.
b Bit address within an 8-bit file register
Table 13-2 lists the instructions recognized by the
MPASMTM Assembler. A complete description of each k Literal field, constant data or label
instruction is also available in the PICmicro® Mid-Range x Don’t care location (= 0 or 1).
MCU Family Reference Manual (DS33023). The assembler will generate code with x = 0.
For byte-oriented instructions, ‘f’ represents a file It is the recommended form of use for
register designator and ‘d’ represents a destination compatibility with all Microchip software tools.
designator. The file register designator specifies which d Destination select; d = 0: store result in W,
file register is to be used by the instruction. d = 1: store result in file register f.
Default is d = 1.
The destination designator specifies where the result of
the operation is to be placed. If ‘d’ is zero, the result is PC Program Counter
placed in the W register. If ‘d’ is one, the result is placed TO Time-out bit
in the file register specified in the instruction. PD Power-down bit
For bit-oriented instructions, ‘b’ represents a bit field
designator which selects the bit affected by the opera-
tion, while ‘f’ represents the address of the file in which FIGURE 16-1: GENERAL FORMAT FOR
the bit is located. INSTRUCTIONS
For literal and control operations, ‘k’ represents an Byte-oriented file register operations
eight or eleven-bit constant or literal value 13 8 7 6 0
One instruction cycle consists of four oscillator periods; OPCODE d f (FILE #)
for an oscillator frequency of 4 MHz, this gives a normal d = 0 for destination W
instruction execution time of 1 µs. All instructions are d = 1 for destination f
executed within a single instruction cycle, unless a f = 7-bit file register address
conditional test is true, or the program counter is
changed as a result of an instruction. When this occurs, Bit-oriented file register operations
the execution takes two instruction cycles, with the 13 10 9 7 6 0
second cycle executed as a NOP. OPCODE b (BIT #) f (FILE #)

Note: To maintain upward compatibility with b = 3-bit bit address

future PIC16F7X7 products, do not use f = 7-bit file register address
the OPTION and TRIS instructions.
All instruction examples use the format ‘0xhh’ to Literal and control operations
represent a hexadecimal number, where ‘h’ signifies a General
hexadecimal digit. 13 8 7 0
OPCODE k (literal)
16.1 Read-Modify-Write Operations
k = 8-bit immediate value
Any instruction that specifies a file register as part of
the instruction performs a Read-Modify-Write (R-M-W) CALL and GOTO instructions only
operation. The register is read, the data is modified, 13 11 10 0
and the result is stored according to either the instruc-
OPCODE k (literal)
tion, or the destination designator ‘d’. A read operation
is performed on a register even if the instruction writes k = 11-bit immediate value
to that register.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 193

PIC16F7X7
TABLE 16-2: PIC16F7X7 INSTRUCTION SET
Mnemonic, 14-Bit Opcode Status
Description Cycles Notes
Operands MSb LSb Affected

BYTE-ORIENTED FILE REGISTER OPERATIONS

ADDWF f, d Add W and f 1 00 0111 dfff ffff C, DC, Z 1, 2
ANDWF f, d AND W with f 1 00 0101 dfff ffff Z 1, 2
CLRF f Clear f 1 00 0001 lfff ffff Z 2
CLRW - Clear W 1 00 0001 0xxx xxxx Z
COMF f, d Complement f 1 00 1001 dfff ffff Z 1, 2
DECF f, d Decrement f 1 00 0011 dfff ffff Z 1, 2
DECFSZ f, d Decrement f, Skip if 0 1(2) 00 1011 dfff ffff 1, 2, 3
INCF f, d Increment f 1 00 1010 dfff ffff Z 1, 2
INCFSZ f, d Increment f, Skip if 0 1(2) 00 1111 dfff ffff 1, 2, 3
IORWF f, d Inclusive OR W with f 1 00 0100 dfff ffff Z 1, 2
MOVF f, d Move f 1 00 1000 dfff ffff Z 1, 2
MOVWF f Move W to f 1 00 0000 lfff ffff
NOP - No Operation 1 00 0000 0xx0 0000
RLF f, d Rotate Left f through Carry 1 00 1101 dfff ffff C 1,2
RRF f, d Rotate Right f through Carry 1 00 1100 dfff ffff C 1, 2
SUBWF f, d Subtract W from f 1 00 0010 dfff ffff C, DC, Z 1, 2
SWAPF f, d Swap nibbles in f 1 00 1110 dfff ffff 1, 2
XORWF f, d Exclusive OR W with f 1 00 0110 dfff ffff Z 1, 2
BIT-ORIENTED FILE REGISTER OPERATIONS
BCF f, b Bit Clear f 1 01 00bb bfff ffff 1, 2
BSF f, b Bit Set f 1 01 01bb bfff ffff 1, 2
BTFSC f, b Bit Test f, Skip if Clear 1 (2) 01 10bb bfff ffff 3
BTFSS f, b Bit Test f, Skip if Set 1 (2) 01 11bb bfff ffff 3
LITERAL AND CONTROL OPERATIONS
ADDLW k Add literal and W 1 11 111x kkkk kkkk C, DC, Z
ANDLW k AND literal with W 1 11 1001 kkkk kkkk Z
CALL k Call subroutine 2 10 0kkk kkkk kkkk
CLRWDT - Clear Watchdog Timer 1 00 0000 0110 0100 TO, PD
GOTO k Go to address 2 10 1kkk kkkk kkkk
IORLW k Inclusive OR literal with W 1 11 1000 kkkk kkkk Z
MOVLW k Move literal to W 1 11 00xx kkkk kkkk
RETFIE - Return from interrupt 2 00 0000 0000 1001
RETLW k Return with literal in W 2 11 01xx kkkk kkkk
RETURN - Return from Subroutine 2 00 0000 0000 1000
SLEEP - Go into Standby mode 1 00 0000 0110 0011 TO, PD
SUBLW k Subtract W from literal 1 11 110x kkkk kkkk C, DC, Z
XORLW k Exclusive OR literal with W 1 11 1010 kkkk kkkk Z
Note 1: When an I/O register is modified as a function of itself ( e.g., MOVF PORTB, 1), the value used will be that value
present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input and is driven low by an
external device, the data will be written back with a ‘0’.
2: If this instruction is executed on the TMR0 register (and where applicable, d = 1), the prescaler will be cleared if
assigned to the Timer0 module.
3: If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is
executed as a NOP.

Note: Additional information on the mid-range instruction set is available in the PICmicro® Mid-Range MCU
Family Reference Manual (DS33023).

DS30498B-page 194 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
16.2 Instruction Descriptions
ADDLW Add Literal and W BCF Bit Clear f
Syntax: [ label ] ADDLW k Syntax: [ label ] BCF f,b
Operands: 0 ≤ k ≤ 255 Operands: 0 ≤ f ≤ 127
Operation: (W) + k → (W) 0≤b≤7

Status Affected: C, DC, Z Operation: 0 → (f<b>)

Description: The contents of the W register Status Affected: None

are added to the eight-bit literal ‘k’ Description: Bit ‘b’ in register ‘f’ is cleared.
and the result is placed in the W
register.

ADDWF Add W and f BSF Bit Set f

Syntax: [ label ] ADDWF f,d Syntax: [ label ] BSF f,b
Operands: 0 ≤ f ≤ 127 Operands: 0 ≤ f ≤ 127
d ∈ [0,1] 0≤b≤7
Operation: (W) + (f) → (destination) Operation: 1 → (f<b>)
Status Affected: C, DC, Z Status Affected: None
Description: Add the contents of the W register Description: Bit ‘b’ in register ‘f’ is set.
with register ‘f’. If ‘d’ is ‘0’, the
result is stored in the W register. If
‘d’ is ‘1’, the result is stored back
in register ‘f’.

ANDLW AND Literal with W BTFSS Bit Test f, Skip if Set

Syntax: [ label ] ANDLW k Syntax: [ label ] BTFSS f,b

Operands: 0 ≤ k ≤ 255 Operands: 0 ≤ f ≤ 127
0≤b<7
Operation: (W) .AND. (k) → (W)
Operation: skip if (f<b>) = 1
Status Affected: Z
Status Affected: None
Description: The contents of W register are
AND’ed with the eight-bit literal Description: If bit ‘b’ in register ‘f’ is ‘0’, the next
‘k’. The result is placed in the W instruction is executed.
register. If bit ‘b’ is ‘1’, then the next
instruction is discarded and a NOP
is executed instead, making this a
2 TCY instruction.

ANDWF AND W with f BTFSC Bit Test, Skip if Clear

Syntax: [ label ] ANDWF f,d Syntax: [ label ] BTFSC f,b

Operands: 0 ≤ f ≤ 127 Operands: 0 ≤ f ≤ 127
d ∈ [0,1] 0≤b≤7
Operation: (W) .AND. (f) → (destination) Operation: skip if (f<b>) = 0
Status Affected: Z Status Affected: None
Description: AND the W register with register Description: If bit ‘b’ in register ‘f’ is ‘1’, the next
‘f’. If ‘d’ is ‘0’, the result is stored in instruction is executed.
the W register. If ‘d’ is ‘1’, the If bit ‘b’ in register ‘f’ is ‘0’, the next
result is stored back in register ‘f’. instruction is discarded and a NOP
is executed instead, making this a
2 TCY instruction.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 195

PIC16F7X7

CALL Call Subroutine CLRWDT Clear Watchdog Timer

Syntax: [ label ] CALL k Syntax: [ label ] CLRWDT
Operands: 0 ≤ k ≤ 2047 Operands: None
Operation: (PC)+ 1→ TOS, Operation: 00h → WDT
k → PC<10:0>, 0 → WDT prescaler,
(PCLATH<4:3>) → PC<12:11> 1 → TO
Status Affected: None 1 → PD

Description: Call Subroutine. First, return Status Affected: TO, PD

address (PC+1) is pushed onto Description: CLRWDT instruction resets the
the stack. The eleven-bit Watchdog Timer. It also resets the
immediate address is loaded into prescaler of the WDT. Status bits,
PC bits<10:0>. The upper bits of TO and PD, are set.
the PC are loaded from PCLATH.
CALL is a two-cycle instruction.

CLRF Clear f COMF Complement f

Syntax: [ label ] CLRF f Syntax: [ label ] COMF f,d
Operands: 0 ≤ f ≤ 127 Operands: 0 ≤ f ≤ 127
Operation: 00h → (f) d ∈ [0,1]
1→Z Operation: (f) → (destination)
Status Affected: Z Status Affected: Z
Description: The contents of register ‘f’ are Description: The contents of register ‘f’ are
cleared and the Z bit is set. complemented. If ‘d’ is ‘0’, the
result is stored in W. If ‘d’ is ‘1’, the
result is stored back in register ‘f’.

CLRW Clear W DECF Decrement f

Syntax: [ label ] CLRW Syntax: [ label ] DECF f,d
Operands: None Operands: 0 ≤ f ≤ 127
Operation: 00h → (W) d ∈ [0,1]
1→Z Operation: (f) - 1 → (destination)
Status Affected: Z Status Affected: Z
Description: W register is cleared. Zero bit (Z) Description: Decrement register ‘f’. If ‘d’ is ‘0’,
is set. the result is stored in the W
register. If ‘d’ is ‘1’, the result is
stored back in register ‘f’.

DS30498B-page 196 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7

DECFSZ Decrement f, Skip if 0 INCFSZ Increment f, Skip if 0

Syntax: [ label ] DECFSZ f,d Syntax: [ label ] INCFSZ f,d
Operands: 0 ≤ f ≤ 127 Operands: 0 ≤ f ≤ 127
d ∈ [0,1] d ∈ [0,1]
Operation: (f) - 1 → (destination); Operation: (f) + 1 → (destination),
skip if result = 0 skip if result = 0
Status Affected: None Status Affected: None
Description: The contents of register ‘f’ are Description: The contents of register ‘f’ are
decremented. If ‘d’ is ‘0’, the result incremented. If ‘d’ is ‘0’, the result
is placed in the W register. If ‘d’ is is placed in the W register. If ‘d’ is
‘1’, the result is placed back in ‘1’, the result is placed back in
register ‘f’. register ‘f’.
If the result is ‘1’, the next If the result is ‘1’, the next
instruction is executed. If the instruction is executed. If the
result is ‘0’, then a NOP is result is ‘0’, a NOP is executed
executed instead, making it a instead, making it a 2 TCY
2 TCY instruction. instruction.

GOTO Unconditional Branch IORLW Inclusive OR Literal with W

Syntax: [ label ] GOTO k Syntax: [ label ] IORLW k
Operands: 0 ≤ k ≤ 2047 Operands: 0 ≤ k ≤ 255
Operation: k → PC<10:0> Operation: (W) .OR. k → (W)
PCLATH<4:3> → PC<12:11> Status Affected: Z
Status Affected: None Description: The contents of the W register are
Description: GOTO is an unconditional branch. OR’ed with the eight-bit literal ‘k’.
The eleven-bit immediate value is The result is placed in the W
loaded into PC bits<10:0>. The register.
upper bits of PC are loaded from
PCLATH<4:3>. GOTO is a
two-cycle instruction.

INCF Increment f IORWF Inclusive OR W with f

Syntax: [ label ] INCF f,d Syntax: [ label ] IORWF f,d

Operands: 0 ≤ f ≤ 127 Operands: 0 ≤ f ≤ 127
d ∈ [0,1] d ∈ [0,1]
Operation: (f) + 1 → (destination) Operation: (W) .OR. (f) → (destination)
Status Affected: Z Status Affected: Z
Description: The contents of register ‘f’ are Description: Inclusive OR the W register with
incremented. If ‘d’ is ‘0’, the result register ‘f’. If ‘d’ is ‘0’, the result is
is placed in the W register. If ‘d’ is placed in the W register. If ‘d’ is
‘1’, the result is placed back in ‘1’, the result is placed back in
register ‘f’. register ‘f’.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 197

PIC16F7X7

MOVF Move f NOP No Operation

Syntax: [ label ] MOVF f,d Syntax: [ label ] NOP
Operands: 0 ≤ f ≤ 127 Operands: None
d ∈ [0,1] Operation: No operation
Operation: (f) → (destination) Status Affected: None
Status Affected: Z Description: No operation.
Description: The contents of register ‘f’ are
moved to a destination dependant
upon the status of ‘d’. If d = 0,
the destination is W register. If
d = 1, the destination is file register
‘f’ itself. d = 1 is useful to test a file
register since status flag Z is
affected.

MOVLW Move Literal to W RETFIE Return from Interrupt

Syntax: [ label ] MOVLW k Syntax: [ label ] RETFIE
Operands: 0 ≤ k ≤ 255 Operands: None
Operation: k → (W) Operation: TOS → PC,
Status Affected: None 1 → GIE

Description: The eight-bit literal ‘k’ is loaded Status Affected: None

into W register. The don’t cares
will assemble as ‘0’s.

MOVWF Move W to f RETLW Return with Literal in W

Syntax: [ label ] MOVWF f Syntax: [ label ] RETLW k
Operands: 0 ≤ f ≤ 127 Operands: 0 ≤ k ≤ 255
Operation: (W) → (f) Operation: k → (W);
Status Affected: None TOS → PC

Description: Move data from W register to Status Affected: None

register ‘f’. Description: The W register is loaded with the
eight-bit literal ‘k’. The program
counter is loaded from the top of
the stack (the return address).
This is a two-cycle instruction.

DS30498B-page 198 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7

RLF Rotate Left f through Carry SLEEP

Syntax: [ label ] RLF f,d Syntax: [ label ] SLEEP
Operands: 0 ≤ f ≤ 127 Operands: None
d ∈ [0,1] Operation: 00h → WDT,
Operation: See description below 0 → WDT prescaler,
Status Affected: C 1 → TO,
0 → PD
Description: The contents of register ‘f’ are
rotated one bit to the left through the Status Affected: TO, PD
Carry flag. If ‘d’ is ‘0’, the result is Description: The power-down status bit, PD,
placed in the W register. If ‘d’ is ‘1’, is cleared. Time-out status bit,
the result is stored back in register ‘f’. TO, is set. Watchdog Timer and
C Register f its prescaler are cleared.
The processor is put into Sleep
mode with the oscillator stopped.

RETURN Return from Subroutine SUBLW Subtract W from Literal

Syntax: [ label ] RETURN Syntax: [ label ] SUBLW k
Operands: None Operands: 0 ≤ k ≤ 255
Operation: TOS → PC Operation: k - (W) → (W)
Status Affected: None Status Affected: C, DC, Z
Description: Return from subroutine. The stack Description: The W register is subtracted (2’s
is POPed and the top of the stack complement method) from the
(TOS) is loaded into the program eight-bit literal ‘k’. The result is
counter. This is a two-cycle placed in the W register.
instruction.

RRF Rotate Right f through Carry SUBWF Subtract W from f

Syntax: [ label ] RRF f,d Syntax: [ label ] SUBWF f,d
Operands: 0 ≤ f ≤ 127 Operands: 0 ≤ f ≤ 127
d ∈ [0,1] d ∈ [0,1]
Operation: See description below Operation: (f) - (W) → (destination)
Status Affected: C Status Affected: C, DC, Z
Description: The contents of register ‘f’ are Description: Subtract (2’s complement method)
rotated one bit to the right through W register from register ‘f’. If ‘d’ is
the Carry flag. If ‘d’ is ‘0’, the ‘0’, the result is stored in the W
result is placed in the W register. register. If ‘d’ is ‘1’, the result is
If ‘d’ is ‘1’, the result is placed stored back in register ‘f’.
back in register ‘f’.
C Register f

 2003 Microchip Technology Inc. Preliminary DS30498B-page 199

PIC16F7X7

SWAPF Swap Nibbles in f XORWF Exclusive OR W with f

Syntax: [ label ] SWAPF f,d Syntax: [ label ] XORWF f,d
Operands: 0 ≤ f ≤ 127 Operands: 0 ≤ f ≤ 127
d ∈ [0,1] d ∈ [0,1]
Operation: (f<3:0>) → (destination<7:4>), Operation: (W) .XOR. (f) → (destination)
(f<7:4>) → (destination<3:0>) Status Affected: Z
Status Affected: None Description: Exclusive OR the contents of the
Description: The upper and lower nibbles of W register with register ‘f’. If ‘d’ is
register ‘f’ are exchanged. If ‘d’ is ‘0’, the result is stored in the W
‘0’, the result is placed in the W register. If ‘d’ is ‘1’, the result is
register. If ‘d’ is ‘1’, the result is stored back in register ‘f’.
placed in register ‘f’.

XORLW Exclusive OR Literal with W

Syntax: [ label ] XORLW k
Operands: 0 ≤ k ≤ 255
Operation: (W) .XOR. k → (W)
Status Affected: Z
Description: The contents of the W register
are XOR’ed with the eight-bit
literal ‘k’. The result is placed in
the W register.

DS30498B-page 200 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
17.0 DEVELOPMENT SUPPORT 17.1 MPLAB Integrated Development
Environment Software
The PICmicro® microcontrollers are supported with a
full range of hardware and software development tools: The MPLAB IDE software brings an ease of software
• Integrated Development Environment development previously unseen in the 8/16-bit micro-
controller market. The MPLAB IDE is a Windows®
- MPLAB® IDE Software
based application that contains:
• Assemblers/Compilers/Linkers
• An interface to debugging tools
- MPASMTM Assembler
- simulator
- MPLAB C17 and MPLAB C18 C Compilers
- programmer (sold separately)
- MPLINKTM Object Linker/
MPLIBTM Object Librarian - emulator (sold separately)
- MPLAB C30 C Compiler - in-circuit debugger (sold separately)
- MPLAB ASM30 Assembler/Linker/Library • A full-featured editor with color coded context
• Simulators • A multiple project manager
- MPLAB SIM Software Simulator • Customizable data windows with direct edit of
contents
- MPLAB dsPIC30 Software Simulator
• High-level source code debugging
• Emulators
• Mouse over variable inspection
- MPLAB ICE 2000 In-Circuit Emulator
• Extensive on-line help
- MPLAB ICE 4000 In-Circuit Emulator
• In-Circuit Debugger The MPLAB IDE allows you to:
- MPLAB ICD 2 • Edit your source files (either assembly or C)
• Device Programmers • One touch assemble (or compile) and download
- PRO MATE® II Universal Device Programmer to PICmicro emulator and simulator tools
(automatically updates all project information)
- PICSTART® Plus Development Programmer
• Debug using:
• Low-Cost Demonstration Boards
- source files (assembly or C)
- PICDEMTM 1 Demonstration Board
- absolute listing file (mixed assembly and C)
- PICDEM.netTM Demonstration Board
- machine code
- PICDEM 2 Plus Demonstration Board
- PICDEM 3 Demonstration Board MPLAB IDE supports multiple debugging tools in a
single development paradigm, from the cost effective
- PICDEM 4 Demonstration Board
simulators, through low-cost in-circuit debuggers, to
- PICDEM 17 Demonstration Board full-featured emulators. This eliminates the learning
- PICDEM 18R Demonstration Board curve when upgrading to tools with increasing flexibility
- PICDEM LIN Demonstration Board and power.
- PICDEM USB Demonstration Board
• Evaluation Kits
17.2 MPASM Assembler
- KEELOQ® The MPASM assembler is a full-featured, universal
- PICDEM MSC macro assembler for all PICmicro MCUs.
- microID® The MPASM assembler generates relocatable object
- CAN files for the MPLINK object linker, Intel® standard HEX
- PowerSmart® files, MAP files to detail memory usage and symbol ref-
erence, absolute LST files that contain source lines and
- Analog
generated machine code and COFF files for
debugging.
The MPASM assembler features include:
• Integration into MPLAB IDE projects
• User defined macros to streamline assembly code
• Conditional assembly for multi-purpose source
files
• Directives that allow complete control over the
assembly process

 2003 Microchip Technology Inc. Preliminary DS30498B-page201

PIC16F7X7
17.3 MPLAB C17 and MPLAB C18 17.6 MPLAB ASM30 Assembler, Linker
C Compilers and Librarian
The MPLAB C17 and MPLAB C18 Code Development MPLAB ASM30 assembler produces relocatable
Systems are complete ANSI C compilers for machine code from symbolic assembly language for
Microchip’s PIC17CXXX and PIC18CXXX family of dsPIC30F devices. MPLAB C30 compiler uses the
microcontrollers. These compilers provide powerful assembler to produce it’s object file. The assembler
integration capabilities, superior code optimization and generates relocatable object files that can then be
ease of use not found with other compilers. archived or linked with other relocatable object files and
For easy source level debugging, the compilers provide archives to create an executable file. Notable features
symbol information that is optimized to the MPLAB IDE of the assembler include:
debugger. • Support for the entire dsPIC30F instruction set
• Support for fixed-point and floating-point data
17.4 MPLINK Object Linker/ • Command line interface
MPLIB Object Librarian • Rich directive set
The MPLINK object linker combines relocatable • Flexible macro language
objects created by the MPASM assembler and the • MPLAB IDE compatibility
MPLAB C17 and MPLAB C18 C compilers. It can link
relocatable objects from precompiled libraries, using 17.7 MPLAB SIM Software Simulator
directives from a linker script.
The MPLAB SIM software simulator allows code devel-
The MPLIB object librarian manages the creation and opment in a PC hosted environment by simulating the
modification of library files of precompiled code. When PICmicro series microcontrollers on an instruction
a routine from a library is called from a source file, only level. On any given instruction, the data areas can be
the modules that contain that routine will be linked in examined or modified and stimuli can be applied from
with the application. This allows large libraries to be a file, or user defined key press, to any pin. The execu-
used efficiently in many different applications. tion can be performed in Single-Step, Execute Until
The object linker/library features include: Break or Trace mode.
• Efficient linking of single libraries instead of many The MPLAB SIM simulator fully supports symbolic
smaller files debugging using the MPLAB C17 and MPLAB C18
• Enhanced code maintainability by grouping C Compilers, as well as the MPASM assembler. The
related modules together software simulator offers the flexibility to develop and
• Flexible creation of libraries with easy module debug code outside of the laboratory environment,
listing, replacement, deletion and extraction making it an excellent, economical software
development tool.
17.5 MPLAB C30 C Compiler
17.8 MPLAB SIM30 Software Simulator
The MPLAB C30 C compiler is a full-featured, ANSI
compliant, optimizing compiler that translates standard The MPLAB SIM30 software simulator allows code
ANSI C programs into dsPIC30F assembly language development in a PC hosted environment by simulating
source. The compiler also supports many command- the dsPIC30F series microcontrollers on an instruction
line options and language extensions to take full level. On any given instruction, the data areas can be
advantage of the dsPIC30F device hardware capabili- examined or modified and stimuli can be applied from
ties and afford fine control of the compiler code a file, or user defined key press, to any of the pins.
generator. The MPLAB SIM30 simulator fully supports symbolic
MPLAB C30 is distributed with a complete ANSI C debugging using the MPLAB C30 C Compiler and
standard library. All library functions have been vali- MPLAB ASM30 assembler. The simulator runs in either
dated and conform to the ANSI C library standard. The a Command Line mode for automated tasks, or from
library includes functions for string manipulation, MPLAB IDE. This high-speed simulator is designed to
dynamic memory allocation, data conversion, time- debug, analyze and optimize time intensive DSP
keeping and math functions (trigonometric, exponential routines.
and hyperbolic). The compiler provides symbolic
information for high-level source debugging with the
MPLAB IDE.

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 PIC16F7X7
17.9 MPLAB ICE 2000 17.11 MPLAB ICD 2 In-Circuit Debugger
High-Performance Universal Microchip’s In-Circuit Debugger, MPLAB ICD 2, is a
In-Circuit Emulator powerful, low-cost, run-time development tool,
The MPLAB ICE 2000 universal in-circuit emulator is connecting to the host PC via an RS-232 or high-speed
intended to provide the product development engineer USB interface. This tool is based on the Flash
with a complete microcontroller design tool set for PICmicro MCUs and can be used to develop for these
PICmicro microcontrollers. Software control of the and other PICmicro microcontrollers. The MPLAB
MPLAB ICE 2000 in-circuit emulator is advanced by ICD 2 utilizes the in-circuit debugging capability built
the MPLAB Integrated Development Environment, into the Flash devices. This feature, along with
which allows editing, building, downloading and source Microchip’s In-Circuit Serial ProgrammingTM (ICSPTM)
debugging from a single environment. protocol, offers cost effective in-circuit Flash debugging
from the graphical user interface of the MPLAB Inte-
The MPLAB ICE 2000 is a full-featured emulator sys- grated Development Environment. This enables a
tem with enhanced trace, trigger and data monitoring designer to develop and debug source code by setting
features. Interchangeable processor modules allow the breakpoints, single-stepping and watching variables,
system to be easily reconfigured for emulation of differ- CPU status and peripheral registers. Running at full
ent processors. The universal architecture of the speed enables testing hardware and applications in
MPLAB ICE in-circuit emulator allows expansion to real-time. MPLAB ICD 2 also serves as a development
support new PICmicro microcontrollers. programmer for selected PICmicro devices.
The MPLAB ICE 2000 in-circuit emulator system has
been designed as a real-time emulation system with 17.12 PRO MATE II Universal Device
advanced features that are typically found on more Programmer
expensive development tools. The PC platform and
Microsoft® Windows 32-bit operating system were The PRO MATE II is a universal, CE compliant device
chosen to best make these features available in a programmer with programmable voltage verification at
simple, unified application. VDDMIN and VDDMAX for maximum reliability. It features
an LCD display for instructions and error messages
17.10 MPLAB ICE 4000 and a modular detachable socket assembly to support
various package types. In Stand-Alone mode, the
High-Performance Universal
PRO MATE II device programmer can read, verify and
In-Circuit Emulator program PICmicro devices without a PC connection. It
The MPLAB ICE 4000 universal in-circuit emulator is can also set code protection in this mode.
intended to provide the product development engineer
with a complete microcontroller design tool set for high- 17.13 PICSTART Plus Development
end PICmicro microcontrollers. Software control of the Programmer
MPLAB ICE in-circuit emulator is provided by the
The PICSTART Plus development programmer is an
MPLAB Integrated Development Environment, which
easy-to-use, low-cost, prototype programmer. It con-
allows editing, building, downloading and source
nects to the PC via a COM (RS-232) port. MPLAB
debugging from a single environment.
Integrated Development Environment software makes
The MPLAB ICD 4000 is a premium emulator system, using the programmer simple and efficient. The
providing the features of MPLAB ICE 2000, but with PICSTART Plus development programmer supports
increased emulation memory and high-speed perfor- most PICmicro devices up to 40 pins. Larger pin count
mance for dsPIC30F and PIC18XXXX devices. Its devices, such as the PIC16C92X and PIC17C76X,
advanced emulator features include complex triggering may be supported with an adapter socket. The
and timing, up to 2 Mb of emulation memory and the PICSTART Plus development programmer is CE
ability to view variables in real-time. compliant.
The MPLAB ICE 4000 in-circuit emulator system has
been designed as a real-time emulation system with
advanced features that are typically found on more
expensive development tools. The PC platform and
Microsoft Windows 32-bit operating system were
chosen to best make these features available in a
simple, unified application.

 2003 Microchip Technology Inc. Preliminary DS30498B-page203

PIC16F7X7
17.14 PICDEM 1 PICmicro 17.17 PICDEM 3 PIC16C92X
Demonstration Board Demonstration Board
The PICDEM 1 demonstration board demonstrates the The PICDEM 3 demonstration board supports the
capabilities of the PIC16C5X (PIC16C54 to PIC16C923 and PIC16C924 in the PLCC package. All
PIC16C58A), PIC16C61, PIC16C62X, PIC16C71, the necessary hardware and software is included to run
PIC16C8X, PIC17C42, PIC17C43 and PIC17C44. All the demonstration programs.
necessary hardware and software is included to run
basic demo programs. The sample microcontrollers 17.18 PICDEM 4 8/14/18-Pin
provided with the PICDEM 1 demonstration board can Demonstration Board
be programmed with a PRO MATE II device program-
mer or a PICSTART Plus development programmer. The PICDEM 4 can be used to demonstrate the capa-
The PICDEM 1 demonstration board can be connected bilities of the 8, 14 and 18-pin PIC16XXXX and
to the MPLAB ICE in-circuit emulator for testing. A PIC18XXXX MCUs, including the PIC16F818/819,
prototype area extends the circuitry for additional appli- PIC16F87/88, PIC16F62XA and the PIC18F1320 fam-
cation components. Features include an RS-232 ily of microcontrollers. PICDEM 4 is intended to show-
interface, a potentiometer for simulated analog input, case the many features of these low pin count parts,
push button switches and eight LEDs. including LIN and Motor Control using ECCP. Special
provisions are made for low-power operation with the
17.15 PICDEM.net Internet/Ethernet supercapacitor circuit and jumpers allow on-board
Demonstration Board hardware to be disabled to eliminate current draw in
this mode. Included on the demo board are provisions
The PICDEM.net demonstration board is an Internet/ for Crystal, RC or Canned Oscillator modes, a five volt
Ethernet demonstration board using the PIC18F452 regulator for use with a nine volt wall adapter or battery,
microcontroller and TCP/IP firmware. The board DB-9 RS-232 interface, ICD connector for program-
supports any 40-pin DIP device that conforms to the ming via ICSP and development with MPLAB ICD 2,
standard pinout used by the PIC16F877 or 2x16 liquid crystal display, PCB footprints for H-Bridge
PIC18C452. This kit features a user friendly TCP/IP motor driver, LIN transceiver and EEPROM. Also
stack, web server with HTML, a 24L256 Serial included are: header for expansion, eight LEDs, four
EEPROM for Xmodem download to web pages into potentiometers, three push buttons and a prototyping
Serial EEPROM, ICSP/MPLAB ICD 2 interface con- area. Included with the kit is a PIC16F627A and a
nector, an Ethernet interface, RS-232 interface and a PIC18F1320. Tutorial firmware is included along with
16 x 2 LCD display. Also included is the book and the User’s Guide.
CD-ROM “TCP/IP Lean, Web Servers for Embedded
Systems,” by Jeremy Bentham 17.19 PICDEM 17 Demonstration Board

17.16 PICDEM 2 Plus The PICDEM 17 demonstration board is an evaluation

board that demonstrates the capabilities of several
Demonstration Board Microchip microcontrollers, including PIC17C752,
The PICDEM 2 Plus demonstration board supports PIC17C756A, PIC17C762 and PIC17C766. A pro-
many 18, 28 and 40-pin microcontrollers, including grammed sample is included. The PRO MATE II device
PIC16F87X and PIC18FXX2 devices. All the neces- programmer, or the PICSTART Plus development pro-
sary hardware and software is included to run the dem- grammer, can be used to reprogram the device for user
onstration programs. The sample microcontrollers tailored application development. The PICDEM 17
provided with the PICDEM 2 demonstration board can demonstration board supports program download and
be programmed with a PRO MATE II device program- execution from external on-board Flash memory. A
mer, PICSTART Plus development programmer, or generous prototype area is available for user hardware
MPLAB ICD 2 with a Universal Programmer Adapter. expansion.
The MPLAB ICD 2 and MPLAB ICE in-circuit emulators
may also be used with the PICDEM 2 demonstration
board to test firmware. A prototype area extends the
circuitry for additional application components. Some
of the features include an RS-232 interface, a 2 x 16
LCD display, a piezo speaker, an on-board temperature
sensor, four LEDs and sample PIC18F452 and
PIC16F877 Flash microcontrollers.

DS30498B-page 204 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
17.20 PICDEM 18R PIC18C601/801 17.23 PICDEM USB PIC16C7X5
Demonstration Board Demonstration Board
The PICDEM 18R demonstration board serves to assist The PICDEM USB Demonstration Board shows off the
development of the PIC18C601/801 family of Microchip capabilities of the PIC16C745 and PIC16C765 USB
microcontrollers. It provides hardware implementation microcontrollers. This board provides the basis for
of both 8-bit Multiplexed/Demultiplexed and 16-bit future USB products.
Memory modes. The board includes 2 Mb external
Flash memory and 128 Kb SRAM memory, as well as 17.24 Evaluation and
serial EEPROM, allowing access to the wide range of Programming Tools
memory types supported by the PIC18C601/801.
In addition to the PICDEM series of circuits, Microchip
17.21 PICDEM LIN PIC16C43X has a line of evaluation kits and demonstration software
Demonstration Board for these products.
• KEELOQ evaluation and programming tools for
The powerful LIN hardware and software kit includes a Microchip’s HCS Secure Data Products
series of boards and three PICmicro microcontrollers.
• CAN developers kit for automotive network
The small footprint PIC16C432 and PIC16C433 are
applications
used as slaves in the LIN communication and feature
on-board LIN transceivers. A PIC16F874 Flash • Analog design boards and filter design software
microcontroller serves as the master. All three micro- • PowerSmart battery charging evaluation/
controllers are programmed with firmware to provide calibration kits
LIN bus communication. • IrDA® development kit
• microID development and rfLabTM development
17.22 PICkitTM 1 Flash Starter Kit software
A complete “development system in a box”, the PICkit • SEEVAL® designer kit for memory evaluation and
Flash Starter Kit includes a convenient multi-section endurance calculations
board for programming, evaluation and development of • PICDEM MSC demo boards for Switching mode
8/14-pin Flash PIC® microcontrollers. Powered via power supply, high-power IR driver, delta sigma
USB, the board operates under a simple Windows GUI. ADC and flow rate sensor
The PICkit 1 Starter Kit includes the user's guide (on
Check the Microchip web page and the latest Product
CD ROM), PICkit 1 tutorial software and code for vari-
Line Card for the complete list of demonstration and
ous applications. Also included are MPLAB® IDE (Inte-
evaluation kits.
grated Development Environment) software, software
and hardware “Tips 'n Tricks for 8-pin Flash PIC®
Microcontrollers” Handbook and a USB Interface
Cable. Supports all current 8/14-pin Flash PIC
microcontrollers, as well as many future planned
devices.

 2003 Microchip Technology Inc. Preliminary DS30498B-page205

PIC16F7X7
NOTES:

DS30498B-page 206 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
18.0 ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings †
Ambient temperature under bias................................................................................................................ .-55 to +125°C
Storage temperature .............................................................................................................................. -65°C to +150°C
Voltage on any pin with respect to VSS (except VDD, MCLR. and RA4) ......................................... -0.3V to (VDD + 0.3V)
Voltage on VDD with respect to VSS ............................................................................................................ -0.3 to +6.5V
Voltage on MCLR with respect to VSS (Note 2) ..............................................................................................0 to +13.5V
Voltage on RA4 with respect to Vss ...................................................................................................................0 to +12V
Total power dissipation (Note 1) ...............................................................................................................................1.0W
Maximum current out of VSS pin ...........................................................................................................................300 mA
Maximum current into VDD pin ..............................................................................................................................250 mA
Input clamp current, IIK (VI < 0 or VI > VDD)..................................................................................................................... ± 20 mA
Output clamp current, IOK (VO < 0 or VO > VDD) ............................................................................................................. ± 20 mA
Maximum output current sunk by any I/O pin..........................................................................................................25 mA
Maximum output current sourced by any I/O pin ....................................................................................................25 mA
Maximum current sunk by PORTA, PORTB and PORTE (combined) (Note 3) ....................................................200 mA
Maximum current sourced by PORTA, PORTB and PORTE (combined) (Note 3)...............................................200 mA
Maximum current sunk by PORTC and PORTD (combined) (Note 3) .................................................................200 mA
Maximum current sourced by PORTC and PORTD (combined) (Note 3) ............................................................200 mA
Note 1: Power dissipation is calculated as follows: Pdis = VDD x {IDD - ∑ IOH} + ∑ {(VDD - VOH) x IOH} + ∑(VOl x IOL)
2: Voltage spikes at the MCLR pin may cause latchup. A series resistor of greater than 1 kΩ should be used
to pull MCLR to VDD, rather than tying the pin directly to VDD.
3: PORTD and PORTE are not implemented on the PIC16F737/767 devices.

† NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the
device. This is a stress rating only and functional operation of the device at those or any other conditions above those
indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for
extended periods may affect device reliability.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 207

PIC16F7X7
FIGURE 18-1: PIC16F7X7 VOLTAGE-FREQUENCY GRAPH

6.0V
5.5V
5.0V
4.5V
Voltage

4.0V
3.5V
3.0V
2.5V
2.0V

16 MHz 20 MHz

Frequency

FIGURE 18-2: PIC16LF7X7 VOLTAGE-FREQUENCY GRAPH

6.0V
5.5V
5.0V
4.5V
Voltage

4.0V
3.5V
3.0V
2.5V
2.0V

4 MHz 10 MHz

Frequency
FMAX = (12 MHz/V) (VDDAPPMIN - 2.5V) + 4 MHz
Note 1: VDDAPPMIN is the minimum voltage of the PICmicro® device in the application.
Note 2: FMAX has a maximum frequency of 10 MHz.

DS30498B-page 208 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
18.1 DC Characteristics: PIC16F737/747/767/777 (Industrial, Extended)
PIC16LF737/747/767/777 (Industrial)
PIC16LF737/747/767/777 Standard Operating Conditions (unless otherwise stated)
(Industrial) Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC16F737/747/767/777 Standard Operating Conditions (unless otherwise stated)

(Industrial, Extended) Operating temperature -40°C ≤ TA ≤ +85°C for industrial
Param
Sym Characteristic Min Typ† Max Units Conditions
No.
VDD Supply Voltage
D001 PIC16LF7X7 2.5 — 5.5 V A/D in use, -40°C to +85°C
2.2 — 5.5 V A/D in use, 0°C to +85°C
2.0 — 5.5 V A/D not used, -40°C to +85°C
D001 PIC16F7X7 4.0 — 5.5 V All configurations
D001A VBOR* — 5.5 V BOR enabled (Note 7)
D002* VDR RAM Data Retention — 1.5 — V
Voltage (Note 1)
D003 VPOR VDD Start Voltage to — VSS — V See section on Power-on Reset for details
ensure internal Power-on
Reset signal
D004* SVDD VDD Rise Rate to ensure 0.05 — — V/ms See section on Power-on Reset for details
internal Power-on Reset signal
VBOR Brown-out Reset Voltage
PIC16LF7X7 Industrial Low Voltage
D005 BORV1:BORV0 = 11 NA — NA V Reserved
BORV1:BORV0 = 10 2.50 2.72 2.94 V
BORV1:BORV0 = 01 3.88 4.22 4.56 V
BORV1:BORV0 = 00 4.18 4.54 4.90 V
D005 PIC16F7X7 Industrial
BORV1:BORV0 = 1x NA — NA V Not in operating voltage range of device
BORV1:BORV0 = 01 3.88 4.22 4.56 V
BORV1:BORV0 = 00 4.18 4.54 4.90 V
Legend: Shading of rows is to assist in readability of of the table.
* These parameters are characterized but not tested.
† Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only
and are not tested.
Note 1: This is the limit to which VDD can be lowered without losing RAM data.
2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O
pin loading and switching rate, oscillator type, internal code execution pattern and temperature also have an
impact on the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from-rail to-rail; all I/O pins tri-stated, pulled to VDD
MCLR = VDD; WDT enabled/disabled as specified.
3: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is
measured with the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD and VSS.
4: For RC osc configuration, current through REXT is not included. The current through the resistor can be
estimated by the formula Ir = VDD/2REXT (mA) with REXT in kΩ.
5: Timer1 oscillator (when enabled) adds approximately 20 µA to the specification. This value is from
characterization and is for design guidance only. This is not tested.
6: The ∆ current is the additional current consumed when this peripheral is enabled. This current should be
added to the base IDD or IPD measurement.
7: When BOR is enabled, the device will operate correctly until the VBOR voltage trip point is reached.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 209

PIC16F7X7
18.2 DC Characteristics: Power-down and Supply Current
PIC16F7X7 (Industrial)
PIC16LF7X7 (Industrial)
PIC16LF7X7 Standard Operating Conditions (unless otherwise stated)
(Industrial) Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC16F7X7 Standard Operating Conditions (unless otherwise stated)

(Industrial) Operating temperature -40°C ≤ TA ≤ +85°C for industrial

Param
Device Typ Max Units Conditions
No.

Power-down Current (IPD)(1)

PIC16LF7X7 0.1 0.4 µA -40°C
0.1 0.4 µA +25°C VDD = 2.0V
0.4 1.5 µA +85°C
PIC16LF7X7 0.3 0.5 µA -40°C
0.3 0.5 µA +25°C VDD = 3.0V
0.7 1.7 µA +85°C
All devices 0.6 1.0 µA -40°C
0.6 1.0 µA +25°C VDD = 5.0V
1.2 5.0 µA +85°C
Legend: Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD;
MCLR = VDD; WDT enabled/disabled as specified.
3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be estimated
by the formula Ir = VDD/2REXT (mA) with REXT in kΩ.

DS30498B-page 210 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
18.2 DC Characteristics: Power-down and Supply Current
PIC16F7X7 (Industrial)
PIC16LF7X7 (Industrial) (Continued)
PIC16LF7X7 Standard Operating Conditions (unless otherwise stated)
(Industrial) Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC16F7X7 Standard Operating Conditions (unless otherwise stated)

(Industrial) Operating temperature -40°C ≤ TA ≤ +85°C for industrial

Param
Device Typ Max Units Conditions
No.

Supply Current (IDD)(2,3)

PIC16LF7X7 9 20 µA -40°C
7 15 µA +25°C VDD = 2.0V
7 15 µA +85°C
PIC16LF7X7 16 30 µA -40°C
FOSC = 32 kHZ
14 25 µA +25°C VDD = 3.0V
(LP Oscillator)
14 25 µA +85°C
All devices 32 40 µA -40°C
26 35 µA +25°C VDD = 5.0V
26 35 µA +85°C
PIC16LF7X7 72 95 µA -40°C
76 90 µA +25°C VDD = 2.0V
76 90 µA +85°C
PIC16LF7X7 138 175 µA -40°C
FOSC = 1 MHZ
136 170 µA +25°C VDD = 3.0V
(RC Oscillator)(3)
136 170 µA +85°C
All devices 310 380 µA -40°C
290 360 µA +25°C VDD = 5.0V
280 360 µA +85°C
PIC16LF7X7 270 315 µA -40°C
280 310 µA +25°C VDD = 2.0V
285 310 µA +85°C
PIC16LF7X7 460 610 µA -40°C
FOSC = 4 MHz
450 600 µA +25°C VDD = 3.0V
(RC Oscillator)(3)
450 600 µA +85°C
All devices 900 1060 µA -40°C
890 1050 µA +25°C VDD = 5.0V
890 1050 µA +85°C
Legend: Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD;
MCLR = VDD; WDT enabled/disabled as specified.
3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be estimated
by the formula Ir = VDD/2REXT (mA) with REXT in kΩ.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 211

PIC16F7X7
18.2 DC Characteristics: Power-down and Supply Current
PIC16F7X7 (Industrial)
PIC16LF7X7 (Industrial) (Continued)
PIC16LF7X7 Standard Operating Conditions (unless otherwise stated)
(Industrial) Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC16F7X7 Standard Operating Conditions (unless otherwise stated)

(Industrial) Operating temperature -40°C ≤ TA ≤ +85°C for industrial

Param
Device Typ Max Units Conditions
No.

Supply Current (IDD)(2,3)

All devices 1.8 2.3 mA -40°C
1.6 2.2 mA +25°C VDD = 4.0V
1.3 2.2 mA +85°C FOSC = 20 MHZ
All devices 3.0 4.2 mA -40°C (HS Oscillator)
2.5 4.0 mA +25°C VDD = 5.0V
2.5 4.0 mA +85°C
Legend: Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD;
MCLR = VDD; WDT enabled/disabled as specified.
3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be estimated
by the formula Ir = VDD/2REXT (mA) with REXT in kΩ.

DS30498B-page 212 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
18.2 DC Characteristics: Power-down and Supply Current
PIC16F7X7 (Industrial)
PIC16LF7X7 (Industrial) (Continued)
PIC16LF7X7 Standard Operating Conditions (unless otherwise stated)
(Industrial) Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC16F7X7 Standard Operating Conditions (unless otherwise stated)

(Industrial) Operating temperature -40°C ≤ TA ≤ +85°C for industrial

Param
Device Typ Max Units Conditions
No.

Supply Current (IDD)(2,3)

PIC16LF7X7 8 20 µA -40°C
7 15 µA +25°C VDD = 2.0V
7 15 µA +85°C
PIC16LF7X7 16 30 µA -40°C FOSC = 31.25 kHz
14 25 µA +25°C VDD = 3.0V (RC_RUN mode,
14 25 µA +85°C Internal RC Oscillator)

All devices 32 40 µA -40°C

29 35 µA +25°C VDD = 5.0V
29 35 µA +85°C
PIC16LF7X7 132 160 µA -40°C
126 155 µA +25°C VDD = 2.0V
126 155 µA +85°C
PIC16LF7X7 260 310 µA -40°C FOSC = 1 MHz
230 300 µA +25°C VDD = 3.0V (RC_RUN mode,
230 300 µA +85°C Internal RC Oscillator)

All devices 560 690 µA -40°C

500 650 µA +25°C VDD = 5.0V
500 650 µA +85°C
PIC16LF7X7 310 420 µA -40°C
300 410 µA +25°C VDD = 2.0V
300 410 µA +85°C
PIC16LF7X7 550 650 µA -40°C FOSC = 4 MHz
530 620 µA +25°C VDD = 3.0V (RC_RUN mode,
530 620 µA +85°C Internal RC Oscillator)

All devices 1.2 1.5 mA -40°C

1.1 1.4 mA +25°C VDD = 5.0V
1.1 1.4 mA +85°C
Legend: Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD;
MCLR = VDD; WDT enabled/disabled as specified.
3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be estimated
by the formula Ir = VDD/2REXT (mA) with REXT in kΩ.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 213

PIC16F7X7
18.2 DC Characteristics: Power-down and Supply Current
PIC16F7X7 (Industrial)
PIC16LF7X7 (Industrial) (Continued)
PIC16LF7X7 Standard Operating Conditions (unless otherwise stated)
(Industrial) Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC16F7X7 Standard Operating Conditions (unless otherwise stated)

(Industrial) Operating temperature -40°C ≤ TA ≤ +85°C for industrial

Param
Device Typ Max Units Conditions
No.

Supply Current (IDD)(2,3)

PIC16LF7X7 .950 1.3 mA -40°C
.930 1.2 mA +25°C VDD = 3.0V
.930 1.2 mA +85°C FOSC = 8 MHz
(RC_RUN mode,
All devices 1.8 3.0 mA -40°C Internal RC Oscillator)
1.7 2.8 mA +25°C VDD = 5.0V
1.7 2.8 mA +85°C
PIC16LF7X7 9 13 µA -10°C
9 14 µA +25°C VDD = 2.0V
11 16 µA +70°C
PIC16LF7X7 12 34 µA -10°C FOSC = 32 kHz
12 31 µA +25°C VDD = 3.0V (SEC_RUN mode,
14 28 µA +70°C Timer1 as Clock)

All devices 20 72 µA -10°C

20 65 µA +25°C VDD = 5.0V
25 59 µA +70°C
Legend: Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD;
MCLR = VDD; WDT enabled/disabled as specified.
3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be estimated
by the formula Ir = VDD/2REXT (mA) with REXT in kΩ.

DS30498B-page 214 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
18.2 DC Characteristics: Power-down and Supply Current
PIC16F7X7 (Industrial)
PIC16LF7X7 (Industrial) (Continued)
PIC16LF7X7 Standard Operating Conditions (unless otherwise stated)
(Industrial) Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC16F7X7 Standard Operating Conditions (unless otherwise stated)

(Industrial) Operating temperature -40°C ≤ TA ≤ +85°C for industrial

Param
Device Typ Max Units Conditions
No.

Module Differential Currents (∆IWDT, ∆IBOR, ∆ILVD, ∆IOSCB, ∆IAD)

D022 Watchdog Timer 1.5 3.8 µA -40°C
(∆IWDT) 2.2 3.8 µA +25°C VDD = 2.0V
2.7 4.0 µA +85°C
2.3 4.6 µA -40°C
2.7 4.6 µA +25°C VDD = 3.0V
3.1 4.8 µA +85°C
3.0 10.0 µA -40°C
3.3 10.0 µA +25°C VDD = 5.0V
3.9 13.0 µA +85°C
D022A Brown-out Reset 17 35 µA -40°C to +85°C VDD = 3.0V
(∆IBOR) 47 45 µA -40°C to +85°C VDD = 5.0V
0 0 µA -40°C to +85°C VDD = 2.0V
BOREN:BORSEN = 10
VDD = 3.0V
in Sleep mode
VDD = 5.0V
D022B Low-Voltage Detect 14 25 µA -40°C to +85°C VDD = 2.0V
(∆ILVD) 18 35 µA -40°C to +85°C VDD = 3.0V
21 45 µA -40°C to +85°C VDD = 5.0V
D025 Timer1 Oscillator 1.7 2.3 µA -40°C
(∆IOSCB) 1.8 2.3 µA +25°C VDD = 2.0V
2.0 2.3 µA +85°C
2.2 3.8 µA -40°C
2.6 3.8 µA +25°C VDD = 3.0V 32 kHz on Timer1
2.9 3.8 µA +85°C
3.0 6.0 µA -40°C
3.2 6.0 µA +25°C VDD = 5.0V
3.4 7.0 µA +85°C
D026 A/D Converter 0.001 2.0 µA -40°C to +85°C VDD = 2.0V
(∆IAD) 0.001 2.0 µA -40°C to +85°C VDD = 3.0V A/D on, not converting
0.003 2.0 µA -40°C to +85°C VDD = 5.0V
Legend: Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD;
MCLR = VDD; WDT enabled/disabled as specified.
3: For RC oscillator configurations, current through REXT is not included. The current through the resistor can be estimated
by the formula Ir = VDD/2REXT (mA) with REXT in kΩ.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 215

PIC16F7X7
18.3 DC Characteristics: Internal RC Accuracy
PIC16F7X7 (Industrial, Extended)
PIC16LF7X7 (Industrial)
PIC16LF7X7 Standard Operating Conditions (unless otherwise stated)
(Industrial) Operating temperature -40°C ≤ TA ≤ +85°C for industrial

PIC16F7X7 Standard Operating Conditions (unless otherwise stated)

(Industrial, Extended) Operating temperature -40°C ≤ TA ≤ +85°C for industrial

Param
Device Min Typ Max Units Conditions
No.

INTOSC Accuracy @ Freq = 8 MHz, 4 MHz, 2 MHz, 1 MHz, 500 kHz, 250 kHz, 125 kHz(1)
PIC16LF7X7 -2 ±1 2 % +25°C VDD = 2.7V-3.3V
-5 — 5 % -10°C to +85°C VDD = 2.7V-3.3V
-10 — 10 % -40°C to +85°C VDD = 2.7V-3.3V
PIC16F7X7 -2 ±1 2 % +25°C VDD = 4.5V-5.5V
-5 — 5 % -10°C to +85°C VDD = 4.5V-5.5V
-10 — 10 % -40°C to +85°C VDD = 4.5V-5.5V
INTRC Accuracy @ Freq = 31 kHz(2)
PIC16LF7X7 26.562 — 35.938 kHz -40°C to +85°C VDD = 2.7V-3.3V
PIC16F7X7 26.562 — 35.938 kHz -40°C to +85°C VDD = 4.5V-5.5V
Legend: Shading of rows is to assist in readability of the table.
Note 1: Frequency calibrated at 25°C. OSCTUNE register can be used to compensate for temperature drift.
2: INTRC is used to calibrate INTOSC.

DS30498B-page 216 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
18.4 DC Characteristics: PIC16F737/747/767/777 (Industrial, Extended)
PIC16LF737/747/767/777 (Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C ≤ TA ≤ +85°C for industrial
DC CHARACTERISTICS -40°C ≤ TA ≤ +125°C for extended
Operating voltage VDD range as described in
Section 18.1 “DC Characteristics”.
Param
Sym Characteristic Min Typ† Max Units Conditions
No.
VIL Input Low Voltage
I/O ports:
D030 with TTL buffer VSS — 0.15 VDD V For entire VDD range
D030A VSS — 0.8V V 4.5V ≤ VDD ≤ 5.5V
D031 with Schmitt Trigger buffer VSS — 0.2 VDD V
D032 MCLR, OSC1 (in RC mode) VSS — 0.2 VDD V (Note 1)
D033 OSC1 (in XT and LP mode) VSS — 0.3V V
OSC1 (in HS mode) VSS — 0.3 VDD V
VIH Input High Voltage
I/O ports:
D040 with TTL buffer 2.0 — VDD V 4.5V ≤ VDD ≤ 5.5V
D040A 0.25 VDD + 0.8 V — VDD V For entire VDD range
D041 with Schmitt Trigger buffer 0.8 VDD — VDD V For entire VDD range
D042 MCLR 0.8 VDD — VDD V
D042A OSC1 (in XT and LP mode) 1.6V — VDD V
OSC1 (in HS mode) 0.7 VDD — VDD V
D043 OSC1 (in RC mode) 0.9 VDD — VDD V (Note 1)
D070 IPURB PORTB Weak Pull-up Current 50 250 400 µA VDD = 5V, VPIN = VSS
IIL Input Leakage Current (Notes 2, 3)
D060 I/O ports — — ±1 µA VSS ≤ VPIN ≤ VDD, pin at
high-impedance
D061 MCLR, RE3/T0CKI — — ±5 µA VSS ≤ VPIN ≤ VDD
D063 OSC1 — — ±5 µA VSS ≤ VPIN ≤ VDD, XT, HS
and LP osc configuration
* These parameters are characterized but not tested.
† Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.
Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the
PIC16F7X7 be driven with external clock in RC mode.
2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified
levels represent normal operating conditions. Higher leakage current may be measured at different input
voltages.
3: Negative current is defined as current sourced by the pin.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 217

PIC16F7X7
18.4 DC Characteristics: PIC16F737/747/767/777 (Industrial, Extended)
PIC16LF737/747/767/777 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C ≤ TA ≤ +85°C for industrial
DC CHARACTERISTICS -40°C ≤ TA ≤ +125°C for extended
Operating voltage VDD range as described in
Section 18.1 “DC Characteristics”.
Param
Sym Characteristic Min Typ† Max Units Conditions
No.
VOL Output Low Voltage
D080 I/O ports — — 0.6 V IOL = 8.5 mA, VDD = 4.5V,
-40°C to +125°C
D083 OSC2/CLKO (RC osc config) — — 0.6 V IOL = 1.6 mA, VDD = 4.5V,
-40°C to +125°C
— — 0.6 V IOL = 1.2 mA, VDD = 4.5V,
-40°C to +125°C
VOH Output High Voltage
D090 I/O ports (Note 3) VDD – 0.7 — — V IOH = -3.0 mA, VDD = 4.5V,
-40°C to +125°C
D092 OSC2/CLKO (RC osc config) VDD – 0.7 — — V IOH = -1.3 mA, VDD = 4.5V,
-40°C to +125°C
VDD – 0.7 — — V IOH = -1.0 mA, VDD = 4.5V,
-40°C to +125°C
D150* VOD Open-Drain High Voltage — — 12 V RA4 pin
Capacitive Loading Specs on Output Pins
D100 COSC2 OSC2 pin — — 15 pF In XT, HS and LP modes
when external clock is used
to drive OSC1
D101 CIO All I/O pins and OSC2 — — 50 pF
(in RC mode)
D102 CB SCL, SDA in I2C mode — — 400 pF
Program Flash Memory
D130 EP Endurance 100 1000 — E/W 25°C at 5V
D131 VPR VDD for Read 2.0 — 5.5 V
* These parameters are characterized but not tested.
† Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.
Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the
PIC16F7X7 be driven with external clock in RC mode.
2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified
levels represent normal operating conditions. Higher leakage current may be measured at different input
voltages.
3: Negative current is defined as current sourced by the pin.

DS30498B-page 218 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
TABLE 18-1: COMPARATOR SPECIFICATIONS
Operating Conditions: 3.0V < VDD < 5.5V, -40°C < TA < +85°C (unless otherwise stated).

Param
Sym Characteristics Min Typ Max Units Comments
No.
D300 VIOFF Input Offset Voltage — ± 5.0 ± 10 mV
D301 VICM Input Common Mode Voltage* 0 - VDD – 1.5 V
D302 CMRR Common Mode Rejection Ratio* 55 - — dB
300 TRESP Response Time(1)* — 150 400 ns PIC16F7X7
300A 600 ns PIC16LF7X7
301 TMC2OV Comparator Mode Change to — — 10 µs
Output Valid*
* These parameters are characterized but not tested.
Note 1: Response time measured with one comparator input at (VDD – 1.5)/2, while the other input transitions from
VSS to VDD.

TABLE 18-2: VOLTAGE REFERENCE SPECIFICATIONS

Operating Conditions: 3.0V < VDD < 5.5V, -40°C < TA < +85°C (unless otherwise stated).

Param
Sym Characteristics Min Typ Max Units Comments
No.
D310 VRES Resolution VDD/24 — VDD/32 LSb
D311 VRAA Absolute Accuracy — — 1/4 LSb Low Range (VRR = 1)
— — 1/2 LSb High Range (VRR = 0)
D312 VRUR Unit Resistor Value (R)* — 2k — Ω
310 TSET Settling Time(1)* — — 10 µs
* These parameters are characterized but not tested.
Note 1: Settling time measured while VRR = 1 and VR<3:0> transitions from ‘0000’ to ‘1111’.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 219

PIC16F7X7
FIGURE 18-3: LOW-VOLTAGE DETECT CHARACTERISTICS

VDD

(LVDIF can be
VLVD cleared in software)
(LVDIF set by hardware)

LVDIF

TABLE 18-3: LOW-VOLTAGE DETECT CHARACTERISTICS

PIC16LF7X7 Standard Operating Conditions (unless otherwise stated)
(Industrial) Operating temperature -40°C ≤ TA ≤ +85°C for industrial

Standard Operating Conditions (unless otherwise stated)

PIC16F7X7
Operating temperature -40°C ≤ TA ≤ +85°C for industrial
(Industrial, Extended)
-40°C ≤ TA ≤ +125°C for extended

Param
Symbol Characteristic Min Typ† Max Units Conditions
No.
D420 LVD Voltage on VDD Transition High to Low Industrial
PIC16LF7X7 LVDL<3:0> = 0000 N/A N/A N/A V Reserved
LVDL<3:0> = 0001 N/A N/A N/A V Reserved
LVDL<3:0> = 0010 2.15 2.26 2.37 V
LVDL<3:0> = 0011 2.33 2.45 2.58 V
LVDL<3:0> = 0100 2.43 2.55 2.68 V
LVDL<3:0> = 0101 2.63 2.77 2.91 V
LVDL<3:0> = 0110 2.73 2.87 3.01 V
LVDL<3:0> = 0111 2.91 3.07 3.22 V
LVDL<3:0> = 1000 3.20 3.36 3.53 V
LVDL<3:0> = 1001 3.39 3.57 3.75 V
LVDL<3:0> = 1010 3.49 3.67 3.85 V
LVDL<3:0> = 1011 3.68 3.87 4.07 V
LVDL<3:0> = 1100 3.87 4.07 4.28 V
LVDL<3:0> = 1101 4.06 4.28 4.49 V
LVDL<3:0> = 1110 4.37 4.60 4.82 V
D420 LVD Voltage on VDD Transition High to Low Industrial
PIC16F7X7 LVDL<3:0> = 1011 3.68 3.87 4.07 V
LVDL<3:0> = 1100 3.87 4.07 4.28 V
LVDL<3:0> = 1101 4.06 4.28 4.49 V
LVDL<3:0> = 1110 4.37 4.60 4.82 V
Legend: Shading of rows is to assist in readability of the table.
† Production tested at TAMB = 25°C. Specifications over temperature limits ensured by characterization.

DS30498B-page 220 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
18.5 Timing Parameter Symbology
The timing parameter symbols have been created
using one of the following formats:

1. TppS2ppS 3. TCC:ST (I2C specifications only)

2. TppS 4. Ts (I2C specifications only)
T
F Frequency T Time
Lowercase letters (pp) and their meanings:
pp
cc CCP1 osc OSC1
ck CLKO rd RD
cs CS rw RD or WR
di SDI sc SCK
do SDO ss SS
dt Data in t0 T0CKI
io I/O port t1 T1CKI
mc MCLR wr WR
Uppercase letters and their meanings:
S
F Fall P Period
H High R Rise
I Invalid (Hi-impedance) V Valid
L Low Z High-impedance
I2C only
AA output access High High
BUF Bus free Low Low
TCC:ST (I2C specifications only)
CC
HD Hold SU Setup
ST
DAT DATA input hold STO Stop condition
STA Start condition

FIGURE 18-4: LOAD CONDITIONS

Load Condition 1 Load Condition 2
VDD/2

RL

CL CL
pin pin

VSS VSS
RL = 464Ω
CL = 50 pF for all pins except OSC2, but including PORTD and PORTE outputs as ports
15 pF for OSC2 output
Note: PORTD and PORTE are not implemented on the PIC16F737/767 devices.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 221

PIC16F7X7
FIGURE 18-5: EXTERNAL CLOCK TIMING
Q4 Q1 Q2 Q3 Q4 Q1

OSC1
1 3 3 4 4
2
CLKO

TABLE 18-4: EXTERNAL CLOCK TIMING REQUIREMENTS

Param
Symbol Characteristic Min Typ† Max Units Conditions
No.
FOSC External CLKI Frequency DC — 1 MHz XT Osc mode
(Note 1) DC — 20 MHz HS Osc mode
DC — 32 kHz LP Osc mode
Oscillator Frequency DC — 4 MHz RC Osc mode
(Note 1) 0.1 — 4 MHz XT Osc mode
4 — 20 MHz HS Osc mode
5 — 200 kHz LP Osc mode
1 TOSC External CLKI Period 1000 — — ns XT Osc mode
(Note 1) 50 — — ns HS Osc mode
5 — — ms LP Osc mode
Oscillator Period 250 — — ns RC Osc mode
(Note 1) 250 — 10,000 ns XT Osc mode
50 — 250 ns HS Osc mode
5 — — ms LP Osc mode
2 TCY Instruction Cycle Time 200 TCY DC ns TCY = 4/FOSC
(Note 1)
3 TOSL, External Clock in (OSC1) 500 — — ns XT oscillator
TOSH High or Low Time 2.5 — — ms LP oscillator
15 — — ns HS oscillator
4 TOSR, External Clock in (OSC1) — — 25 ns XT oscillator
TOSF Rise or Fall Time — — 50 ns LP oscillator
— — 15 ns HS oscillator
† Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.
Note 1: Instruction cycle period (TCY) equals four times the input oscillator time base period. All specified values are
based on characterization data for that particular oscillator type, under standard operating conditions, with
the device executing code. Exceeding these specified limits may result in an unstable oscillator operation
and/or higher than expected current consumption. All devices are tested to operate at “min.” values with an
external clock applied to the OSC1/CLKI pin. When an external clock input is used, the “max.” cycle time
limit is “DC” (no clock) for all devices.

DS30498B-page 222 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 18-6: CLKO AND I/O TIMING

Q4 Q1 Q2 Q3

OSC1

10 11

CLKO

13 12
19 18
14 16

I/O pin
(Input)

17 15

I/O pin Old Value New Value

(Output)

20, 21
Note: Refer to Figure 18-4 for load conditions.

TABLE 18-5: CLKO AND I/O TIMING REQUIREMENTS

Param
Symbol Characteristic Min Typ† Max Units Conditions
No.

10* TOSH2CKL OSC1 ↑ to CLKO ↓ — 75 200 ns (Note 1)

11* TOSH2CKH OSC1 ↑ to CLKO ↑ — 75 200 ns (Note 1)
12* TCKR CLKO Rise Time — 35 100 ns (Note 1)
13* TCKF CLKO Fall Time — 35 100 ns (Note 1)
14* TCKL2IOV CLKO ↓ to Port Out Valid — — 0.5 TCY + 20 ns (Note 1)
15* TIOV2CKH Port In Valid before CLKO ↑ TOSC + 200 — — ns (Note 1)
16* TCKH2IOI Port In Hold after CLKO ↑ 0 — — ns (Note 1)
17* TOSH2IOV OSC1 ↑ (Q1 cycle) to Port Out Valid — 100 255 ns
18* TOSH2IOI OSC1 ↑ (Q2 cycle) to PIC16F7X7 100 — — ns
Port Input Invalid (I/O in PIC16LF7X7 200 — — ns
hold time)
19* TIOV2OSH Port Input Valid to OSC1 ↑ (I/O in setup time) 0 — — ns
20* TIOR Port Output Rise Time PIC16F7X7 — 10 40 ns
PIC16LF7X7 — — 145 ns
21* TIOF Port Output Fall Time PIC16F7X7 — 10 40 ns
PIC16LF7X7 — — 145 ns
22††* TINP INT pin High or Low Time TCY — — ns
23††* TRBP RB7:RB4 Change INT High or Low Time TCY — — ns
* These parameters are characterized but not tested.
† Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
†† These parameters are asynchronous events not related to any internal clock edges.
Note 1: Measurements are taken in RC mode, where CLKO output is 4 x TOSC.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 223

PIC16F7X7
FIGURE 18-7: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND
POWER-UP TIMER TIMING

VDD

MCLR

30
Internal
POR

33
PWRT
Time-out
32

OSC
Time-out

Internal
Reset

Watchdog
Timer
Reset
31
34
34

I/O pins

Note: Refer to Figure 18-4 for load conditions.

FIGURE 18-8: BROWN-OUT RESET TIMING

VDD VBOR

35

TABLE 18-6: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER
AND BROWN-OUT RESET REQUIREMENTS
Param
Sym Characteristic Min Typ† Max Units Conditions
No.

30 TMCL MCLR Pulse Width (low) 2 — — µs VDD = 5V, -40°C to +85°C

31* TWDT Watchdog Timer Time-out Period 7 18 33 ms VDD = 5V, -40°C to +85°C
(no prescaler)
32 TOST Oscillation Start-up Timer Period — 1024 TOSC — — TOSC = OSC1 period
33* TPWRT Power-up Timer Period 28 72 132 ms VDD = 5V, -40°C to +85°C
34 TIOZ I/O High-Impedance from MCLR Low or — — 2.1 µs
Watchdog Timer Reset
35 TBOR Brown-out Reset Pulse Width 100 — — µs VDD ≤ VBOR (D005)
* These parameters are characterized but not tested.
† Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.

DS30498B-page 224 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 18-9: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS

RA4/T0CKI/C1OUT

40 41

42

RC0/T1OSO/T1CKI

45 46

47 48

TMR0 or TMR1

Note: Refer to Figure 18-4 for load conditions.

TABLE 18-7: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS

Param
Symbol Characteristic Min Typ† Max Units Conditions
No.
40* TT0H T0CKI High Pulse Width No Prescaler 0.5 TCY + 20 — — ns Must also meet
With Prescaler 10 — — ns parameter 42

41* TT0L T0CKI Low Pulse Width No Prescaler 0.5 TCY + 20 — — ns Must also meet
With Prescaler 10 — — ns parameter 42

42* TT0P T0CKI Period No Prescaler TCY + 40 — — ns

With Prescaler Greater of: — — ns N = prescale
20 or TCY + 40 value (2, 4, ...,
N 256)
45* TT1H T1CKI High Time Synchronous, Prescaler = 1 0.5 TCY + 20 — — ns Must also meet
Synchronous, PIC16F7X7 15 — — ns parameter 47
Prescaler = 2, 4, 8 PIC16LF7X7 25 — — ns
Asynchronous PIC16F7X7 30 — — ns
PIC16LF7X7 50 — — ns
46* TT1L T1CKI Low Time Synchronous, Prescaler = 1 0.5 TCY + 20 — — ns Must also meet
Synchronous, PIC16F7X7 15 — — ns parameter 47
Prescaler = 2, 4, 8 PIC16LF7X7 25 — — ns
Asynchronous PIC16F7X7 30 — — ns
PIC16LF7X7 50 — — ns
47* TT1P T1CKI Input Synchronous PIC16F7X7 Greater of: — — ns N = prescale
Period 30 or TCY + 40 value (1, 2, 4, 8)
N
PIC16LF7X7 Greater of: N = prescale
50 or TCY + 40 value (1, 2, 4, 8)
N
Asynchronous PIC16F7X7 60 — — ns
PIC16LF7X7 100 — — ns
FT1 Timer1 Oscillator Input Frequency Range DC — 200 kHz
(oscillator enabled by setting bit T1OSCEN)
48 TCKEZTMR1 Delay from External Clock Edge to Timer Increment 2 TOSC — 7 TOSC —
* These parameters are characterized but not tested.
† Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are
not tested.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 225

PIC16F7X7
FIGURE 18-10: CAPTURE/COMPARE/PWM TIMINGS (CCP1 AND CCP2)

RC1/T1OSI/CCP2
and RC2/CCP1
(Capture Mode)

50 51

52

RC1/T1OSI/CCP2
and RC2/CCP1
(Compare or PWM Mode)

53 54

Note: Refer to Figure 18-4 for load conditions.

TABLE 18-8: CAPTURE/COMPARE/PWM REQUIREMENTS (CCP1 AND CCP2)

Param
Symbol Characteristic Min Typ† Max Units Conditions
No.
50* TCCL CCP1, CCP2 and No Prescaler 0.5 TCY + 20 — — ns
CCP3 Input Low PIC16F7X7 10 — — ns
Time With Prescaler PIC16LF7X7 20 — — ns
51* TCCH CCP1, CCP2 and No Prescaler 0.5 TCY + 20 — — ns
CCP3 Input High PIC16F7X7 10 — — ns
Time With Prescaler PIC16LF7X7 20 — — ns
52* TCCP CCP1, CCP2 and CCP3 Input Period 3 TCY + 40 — — ns N = prescale
N value (1,4 or 16)
53* TCCR CCP1, CCP2 and CCP3 Output PIC16F7X7 — 10 25 ns
Rise Time PIC16LF7X7 — 25 50 ns
54* TCCF CCP1, CCP2 and CCP3 Output PIC16F7X7 — 10 25 ns
Fall Time PIC16LF7X7 — 25 45 ns
* These parameters are characterized but not tested.
† Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and
are not tested.

DS30498B-page 226 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 18-11: PARALLEL SLAVE PORT TIMING (PIC16F747/777 DEVICES ONLY)

RE2/CS/AN7

RE0/RD/AN5

RE1/WR/AN6

65

RD7/PSP7:RD0/PSP0

62
64

63
Note: Refer to Figure 18-4 for load conditions.

TABLE 18-9: PARALLEL SLAVE PORT REQUIREMENTS (PIC16F747/777 DEVICES ONLY)

Param
Symbol Characteristic Min Typ† Max Units Conditions
No.

62 TDTV2WRH Data In Valid before WR ↑ or CS ↑ (setup time) 20 — — ns

25 — — ns Extended range only
63* TWRH2DTI WR ↑ or CS ↑ to Data In Invalid PIC16F7X7 20 — — ns
(hold time) PIC16LF7X7 35 — — ns
64 TRDL2DTV RD ↓ and CS ↓ to Data Out Valid — — 80 ns
— — 90 ns Extended range only
65 TRDH2DTI RD ↑ or CS ↓ to Data Out Invalid 10 — 30 ns
* These parameters are characterized but not tested.
† Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 227

PIC16F7X7
FIGURE 18-12: SPI MASTER MODE TIMING (CKE = 0, SMP = 0)

SS

70
SCK
(CKP = 0)

71 72
78 79

SCK
(CKP = 1)

79 78
80

SDO MSb bit 6 - - - - - -1 LSb

75, 76

SDI MSb In bit 6 - - - -1 LSb In

74
73

Note: Refer to Figure 18-4 for load conditions.

FIGURE 18-13: SPI MASTER MODE TIMING (CKE = 1, SMP = 1)

SS

81
SCK
(CKP = 0)

71 72
79
73
SCK
(CKP = 1)
80
78

SDO MSb bit 6 - - - - - -1 LSb

75, 76

SDI MSb In bit 6 - - - -1 LSb In

74

Note: Refer to Figure 18-4 for load conditions.

DS30498B-page 228 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 18-14: SPI SLAVE MODE TIMING (CKE = 0)

SS

70
SCK
(CKP = 0) 83

71 72
78 79

SCK
(CKP = 1)

79 78
80

SDO MSb bit 6 - - - - - -1 LSb

75, 76 77

SDI MSb In bit 6 - - - -1 LSb In

74
73

Note: Refer to Figure 18-4 for load conditions.

FIGURE 18-15: SPI SLAVE MODE TIMING (CKE = 1)

82
SS

70
SCK
83
(CKP = 0)

71 72

SCK
(CKP = 1)
80

SDO MSb bit 6 - - - - - -1 LSb

75, 76 77

SDI
MSb In bit 6 - - - -1 LSb In

74

Note: Refer to Figure 18-4 for load conditions.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 229

PIC16F7X7
TABLE 18-10: SPI MODE REQUIREMENTS
Param
Symbol Characteristic Min Typ† Max Units Conditions
No.

70* TSSL2SCH, SS ↓ to SCK ↓ or SCK ↑ Input TCY — — ns

TSSL2SCL
71* TSCH SCK Input High Time (Slave mode) TCY + 20 — — ns
72* TSCL SCK Input Low Time (Slave mode) TCY + 20 — — ns
73* TDIV2SCH, Setup Time of SDI Data Input to SCK Edge 100 — — ns
TDIV2SCL
74* TSCH2DIL, Hold Time of SDI Data Input to SCK Edge 100 — — ns
TSCL2DIL
75* TDOR SDO Data Output Rise Time PIC16F7X7 — 10 25 ns
PIC16LF7X7 — 25 50 ns
76* TDOF SDO Data Output Fall Time — 10 25 ns
77* TSSH2DOZ SS ↑ to SDO Output High-Impedance 10 — 50 ns
78* TSCR SCK Output Rise Time PIC16F7X7 — 10 25 ns
(Master mode) PIC16LF7X7 — 25 50 ns
79* TSCF SCK Output Fall Time (Master mode) — 10 25 ns
80* TSCH2DOV, SDO Data Output Valid after PIC16F7X7 — — 50 ns
TSCL2DOV SCK Edge PIC16LF7X7 — — 145 ns
81* TDOV2SCH, SDO Data Output Setup to SCK Edge TCY — — ns
TDOV2SCL
82* TSSL2DOV SDO Data Output Valid after SS ↓ Edge — — 50 ns
83* TSCH2SSH, SS ↑ after SCK Edge 1.5 TCY + 40 — — ns
TSCL2SSH
* These parameters are characterized but not tested.
† Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.

FIGURE 18-16: I2C BUS START/STOP BITS TIMING

SCL
91 93
90 92

SDA

Start Stop
Condition Condition

Note: Refer to Figure 18-4 for load conditions.

DS30498B-page 230 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
TABLE 18-11: I2C BUS START/STOP BITS REQUIREMENTS
Param
Symbol Characteristic Min Typ Max Units Conditions
No.
90* TSU:STA Start condition 100 kHz mode 4700 — — ns Only relevant for Repeated
Setup time 400 kHz mode 600 — — Start condition
91* THD:STA Start condition 100 kHz mode 4000 — — ns After this period, the first clock
Hold time 400 kHz mode 600 — — pulse is generated
92* TSU:STO Stop condition 100 kHz mode 4700 — — ns
Setup time 400 kHz mode 600 — —
93 THD:STO Stop condition 100 kHz mode 4000 — — ns
Hold time 400 kHz mode 600 — —
* These parameters are characterized but not tested.

FIGURE 18-17: I2C BUS DATA TIMING

103 100 102

101
SCL
90
106 107
91 92
SDA
In
110
109 109

SDA
Out

Note: Refer to Figure 18-4 for load conditions.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 231

PIC16F7X7
TABLE 18-12: I2C BUS DATA REQUIREMENTS
Param.
Symbol Characteristic Min Max Units Conditions
No.
100* THIGH Clock High Time 100 kHz mode 4.0 — µs Device must operate at a
minimum of 1.5 MHz
400 kHz mode 0.6 — µs Device must operate at a
minimum of 10 MHz
SSP module 1.5 TCY —
101* TLOW Clock Low Time 100 kHz mode 4.7 — µs Device must operate at a
minimum of 1.5 MHz
400 kHz mode 1.3 — µs Device must operate at a
minimum of 10 MHz
SSP module 1.5 TCY —
102* TR SDA and SCL Rise 100 kHz mode — 1000 ns
Time 400 kHz mode 20 + 0.1 CB 300 ns CB is specified to be from
10-400 pF
103* TF SDA and SCL Fall 100 kHz mode — 300 ns
Time 400 kHz mode 20 + 0.1 CB 300 ns CB is specified to be from
10-400 pF
90* TSU:STA Start Condition 100 kHz mode 4.7 — µs Only relevant for Repeated
Setup Time 400 kHz mode 0.6 — µs Start
condition
91* THD:STA Start Condition Hold 100 kHz mode 4.0 — µs After this period, the first
Time 400 kHz mode 0.6 — µs clock pulse is generated
106* THD:DAT Data Input Hold 100 kHz mode 0 — ns
Time 400 kHz mode 0 0.9 µs
107* TSU:DAT Data Input Setup 100 kHz mode 250 — ns (Note 2)
Time 400 kHz mode 100 — ns
92* TSU:STO Stop Condition 100 kHz mode 4.7 — µs
Setup Time 400 kHz mode 0.6 — µs
109* TAA Output Valid from 100 kHz mode — 3500 ns (Note 1)
Clock 400 kHz mode — — ns
110* TBUF Bus Free Time 100 kHz mode 4.7 — µs Time the bus must be free
400 kHz mode 1.3 — µs before a new transmission
can start
CB Bus Capacitive Loading — 400 pF
* These parameters are characterized but not tested.
Note 1: As a transmitter, the device must provide this internal minimum delay time to bridge the undefined region
(min. 300 ns) of the falling edge of SCL to avoid unintended generation of Start or Stop conditions.
2: A fast mode (400 kHz) I2C bus device can be used in a standard mode (100 kHz) I2C bus system, but the
requirement, TSU:DAT ≥ 250 ns, must then be met. This will automatically be the case if the device does not
stretch the LOW period of the SCL signal. If such a device does stretch the LOW period of the SCL signal,
it must output the next data bit to the SDA line, TR max. + TSU:DAT = 1000 + 250 = 1250 ns (according to
the standard mode I2C bus specification), before the SCL line is released.

DS30498B-page 232 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 18-18: USART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING

RC6/TX/CK
pin 121
121
RC7/RX/DT
pin

120
122

Note: Refer to Figure 18-4 for load conditions.

TABLE 18-13: USART SYNCHRONOUS TRANSMISSION REQUIREMENTS

Param
Symbol Characteristic Min Typ† Max Units Conditions
No.
120 TCKH2DTV SYNC XMIT (MASTER & PIC16F7X7
SLAVE) — — 80 ns
Clock High to Data Out Valid PIC16LF7X7 — — 100 ns
121 TCKRF Clock Out Rise Time and Fall Time PIC16F7X7 — — 45 ns
(Master mode) PIC16LF7X7 — — 50 ns
122 TDTRF Data Out Rise Time and Fall Time PIC16F7X7 — — 45 ns
PIC16LF7X7 — — 50 ns
† Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.

FIGURE 18-19: USART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING

RC6/TX/CK
pin 125
RC7/RX/DT
pin

126

Note: Refer to Figure 18-4 for load conditions.

TABLE 18-14: USART SYNCHRONOUS RECEIVE REQUIREMENTS

Param
Symbol Characteristic Min Typ† Max Units Conditions
No.
125 TDTV2CKL SYNC RCV (MASTER & SLAVE)
Data Setup before CK ↓ (DT setup time) 15 — — ns
126 TCKL2DTL Data Hold after CK ↓ (DT hold time) 15 — — ns
† Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 233

PIC16F7X7
TABLE 18-15: A/D CONVERTER CHARACTERISTICS: PIC16F7X7 (INDUSTRIAL, EXTENDED)
PIC16LF7X7 (INDUSTRIAL)
Param
Sym Characteristic Min Typ† Max Units Conditions
No.
A01 NR Resolution PIC16F7X7 — — 8 bits bit VREF = VDD = 5.12V,
VSS ≤ VAIN ≤ VREF
PIC16LF7X7 — — 8 bits bit VREF = VDD = 2.2V
A02 EABS Total Absolute Error — — < ±1 LSb VREF = VDD = 5.12V,
VSS ≤ VAIN ≤ VREF
A03 EIL Integral Linearity Error — — < ±1 LSb VREF = VDD = 5.12V,
VSS ≤ VAIN ≤ VREF
A04 EDL Differential Linearity Error — — < ±1 LSb VREF = VDD = 5.12V,
VSS ≤ VAIN ≤ VREF
A05 EFS Full-Scale Error — — < ±1 LSb VREF = VDD = 5.12V,
VSS ≤ VAIN ≤ VREF
A06 EOFF Offset Error — — < ±1 LSb VREF = VDD = 5.12V,
VSS ≤ VAIN ≤ VREF
A10 — Monotonicity (Note 3) — guaranteed — — VSS ≤ VAIN ≤ VREF
A20 VREF Reference Voltage 2.5 — 5.5 V -40°C to +125°C
2.2 — 5.5 V 0°C to +125°C
A25 VAIN Analog Input Voltage VSS – 0.3 — VREF + 0.3 V
A30 ZAIN Recommended Impedance of — — 10.0 kΩ
Analog Voltage Source
A40 IAD A/D Conversion PIC16F7X7 — 180 — µA Average current
Current (VDD) PIC16LF7X7 — 90 — µA consumption when A/D
is on (Note 1)
A50 IREF VREF Input Current (Note 2) N/A — ±5 µA During VAIN acquisition.
— — 500 µA During A/D conversion
cycle.
* These parameters are characterized but not tested.
† Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.
Note 1: When A/D is off, it will not consume any current other than minor leakage current. The power-down current
spec includes any such leakage from the A/D module.
2: VREF current is from the RA3 pin or the VDD pin, whichever is selected as a reference input.
3: The A/D conversion result never decreases with an increase in the input voltage and has no missing
codes.

DS30498B-page 234 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
FIGURE 18-20: A/D CONVERSION TIMING

BSF ADCON0, GO 1 TCY

134 (TOSC/2)(1)
131
Q4
130

A/D CLK 132

A/D DATA 7 6 5 4 3 2 1 0

ADRES OLD_DATA NEW_DATA

ADIF

GO DONE

SAMPLE SAMPLING STOPPED

Note 1: If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts. This allows the SLEEP instruction
to be executed.

TABLE 18-16: A/D CONVERSION REQUIREMENTS

Param
Sym Characteristic Min Typ† Max Units Conditions
No.
130 TAD A/D Clock Period PIC16F7X7 1.6 — — µs TOSC based, VREF ≥ 3.0V
PIC16LF7X7 2.0 — — µs TOSC based,
2.0V ≤ VREF ≤ 5.5V
PIC16F7X7 2.0 4.0 6.0 µs A/D RC mode
PIC16LF7X7 3.0 6.0 9.0 µs A/D RC mode
131 TCNV Conversion Time (not including 9 — 9 TAD
S/H time) (Note 1)
132 TACQ Acquisition Time 5* — — µs The minimum time is the
amplifier settling time. This
may be used if the “new” input
voltage has not changed by
more than 1 LSb (i.e.,
20.0 mV @ 5.12V) from the
last sampled voltage (as
stated on CHOLD).
134 TGO Q4 to A/D Clock Start — TOSC/2 — — If the A/D clock source is
selected as RC, a time of TCY
is added before the A/D clock
starts. This allows the SLEEP
instruction to be executed.
* These parameters are characterized but not tested.
† Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.
Note 1: ADRES register may be read on the following TCY cycle.
2: See Section 12.1 “A/D Acquisition Requirements” for minimum conditions.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 235

PIC16F7X7
NOTES:

DS30498B-page 236 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
19.0 DC AND AC
CHARACTERISTICS GRAPHS
AND TABLES
Graphs and tables are not available at this time.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 237

PIC16F7X7
NOTES:

DS30498B-page 238 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
20.0 PACKAGING INFORMATION

20.1 Package Marking Information

28-Lead PDIP (Skinny DIP) Example

XXXXXXXXXXXXXXXXX PIC16F737-I/SP
XXXXXXXXXXXXXXXXX 0310017
YYWWNNN

28-Lead SOIC Example

XXXXXXXXXXXXXXXXXXXX PIC16F767-I/SO
XXXXXXXXXXXXXXXXXXXX 0310017
XXXXXXXXXXXXXXXXXXXX
YYWWNNN

28-Lead SSOP Example

XXXXXXXXXXXX PIC16F737
XXXXXXXXXXXX -I/SS
YYWWNNN 0310017

28-Lead QFN Example

XXXXXXXX 16F737
XXXXXXXX -I/ML
YYWWNNN 0310017

Legend: XX...X Customer specific information*

Y Year code (last digit of calendar year)
YY Year code (last 2 digits of calendar year)
WW Week code (week of January 1 is week ‘01’)
NNN Alphanumeric traceability code

Note: In the event the full Microchip part number cannot be marked on one line, it will
be carried over to the next line thus limiting the number of available characters
for customer specific information.

* Standard PICmicro device marking consists of Microchip part number, year code, week code, and
traceability code. For PICmicro device marking beyond this, certain price adders apply. Please check
with your Microchip Sales Office. For QTP devices, any special marking adders are included in QTP
price.

 2003 Microchip Technology Inc. Preliminary DS30498B-page 239

PIC16F7X7
Package Marking Information (Cont’d)

40-Lead PDIP Example

XXXXXXXXXXXXXXXXXX PIC16F777-I/P
XXXXXXXXXXXXXXXXXX 0310017
XXXXXXXXXXXXXXXXXX
YYWWNNN

44-Lead TQFP Example

XXXXXXXXXX PIC16F777
XXXXXXXXXX -I/PT
XXXXXXXXXX 0310017
YYWWNNN

44-Lead QFN Example

XXXXXXXXXX PIC16F777
XXXXXXXXXX -I/ML
XXXXXXXXXX 0310017
YYWWNNN

DS30498B-page 240 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
20.2 Package Details
The following sections give the technical details of the
packages.

28-Lead Skinny Plastic Dual In-line (SP) – 300 mil (PDIP)

E1

2
n 1 α

E
A2

L
c

β A1 B1

eB B p

Units INCHES* MILLIMETERS

Dimension Limits MIN NOM MAX MIN NOM MAX
Number of Pins n 28 28
Pitch p .100 2.54
Top to Seating Plane A .140 .150 .160 3.56 3.81 4.06
Molded Package Thickness A2 .125 .130 .135 3.18 3.30 3.43
Base to Seating Plane A1 .015 0.38
Shoulder to Shoulder Width E .300 .310 .325 7.62 7.87 8.26
Molded Package Width E1 .275 .285 .295 6.99 7.24 7.49
Overall Length D 1.345 1.365 1.385 34.16 34.67 35.18
Tip to Seating Plane L .125 .130 .135 3.18 3.30 3.43
Lead Thickness c .008 .012 .015 0.20 0.29 0.38
Upper Lead Width B1 .040 .053 .065 1.02 1.33 1.65
Lower Lead Width B .016 .019 .022 0.41 0.48 0.56
Overall Row Spacing § eB .320 .350 .430 8.13 8.89 10.92
Mold Draft Angle Top α 5 10 15 5 10 15
Mold Draft Angle Bottom β 5 10 15 5 10 15
* Controlling Parameter
§ Significant Characteristic
Notes:
Dimension D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed
.010” (0.254mm) per side.
JEDEC Equivalent: MO-095
Drawing No. C04-070

 2003 Microchip Technology Inc. Preliminary DS30498B-page 241

PIC16F7X7
28-Lead Plastic Small Outline (SO) – Wide, 300 mil (SOIC)

E
E1
p

B
2
n 1

h
α

45°

c
A A2

φ
β L A1

Units INCHES* MILLIMETERS

Dimension Limits MIN NOM MAX MIN NOM MAX
Number of Pins n 28 28
Pitch p .050 1.27
Overall Height A .093 .099 .104 2.36 2.50 2.64
Molded Package Thickness A2 .088 .091 .094 2.24 2.31 2.39
Standoff § A1 .004 .008 .012 0.10 0.20 0.30
Overall Width E .394 .407 .420 10.01 10.34 10.67
Molded Package Width E1 .288 .295 .299 7.32 7.49 7.59
Overall Length D .695 .704 .712 17.65 17.87 18.08
Chamfer Distance h .010 .020 .029 0.25 0.50 0.74
Foot Length L .016 .033 .050 0.41 0.84 1.27
Foot Angle Top φ 0 4 8 0 4 8
Lead Thickness c .009 .011 .013 0.23 0.28 0.33
Lead Width B .014 .017 .020 0.36 0.42 0.51
Mold Draft Angle Top α 0 12 15 0 12 15
Mold Draft Angle Bottom β 0 12 15 0 12 15
* Controlling Parameter
§ Significant Characteristic
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed
.010” (0.254mm) per side.
JEDEC Equivalent: MS-013
Drawing No. C04-052

DS30498B-page 242 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
28-Lead Plastic Shrink Small Outline (SS) – 209 mil, 5.30 mm (SSOP)

E1
p

B
2
n 1

α
A
c
A2

φ A1

L
β

Units INCHES MILLIMETERS*

Dimension Limits MIN NOM MAX MIN NOM MAX
Number of Pins n 28 28
Pitch p .026 0.65
Overall Height A .068 .073 .078 1.73 1.85 1.98
Molded Package Thickness A2 .064 .068 .072 1.63 1.73 1.83
Standoff § A1 .002 .006 .010 0.05 0.15 0.25
Overall Width E .299 .309 .319 7.59 7.85 8.10
Molded Package Width E1 .201 .207 .212 5.11 5.25 5.38
Overall Length D .396 .402 .407 10.06 10.20 10.34
Foot Length L .022 .030 .037 0.56 0.75 0.94
Lead Thickness c .004 .007 .010 0.10 0.18 0.25
Foot Angle φ 0 4 8 0.00 101.60 203.20
Lead Width B .010 .013 .015 0.25 0.32 0.38
Mold Draft Angle Top α 0 5 10 0 5 10
Mold Draft Angle Bottom β 0 5 10 0 5 10
* Controlling Parameter
§ Significant Characteristic
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed
.010” (0.254mm) per side.
JEDEC Equivalent: MS-150
Drawing No. C04-073

 2003 Microchip Technology Inc. Preliminary DS30498B-page 243

PIC16F7X7
28-Lead Plastic Quad Flat No Lead Package (ML) 6x6 mm Body, Punch Singulated (QFN)

E EXPOSED
METAL
E1 PADS

D1 D D2
p

2
1 B

n
R
E2
CH X 45° L
TOP VIEW BOTTOM VIEW
α

A2 A
A1

A3

Units INCHES MILLIMETERS*

Dimension Limits MIN NOM MAX MIN NOM MAX
Number of Pins n 28 28
Pitch p .026 BSC 0.65 BSC
Overall Height A .033 .039 0.85 1.00
Molded Package Thickness A2 .026 .031 0.65 0.80
Standoff A1 .000 .0004 .002 0.00 0.01 0.05
Base Thickness A3 .008 REF 0.20 REF
Overall Width E .236 BSC 6.00 BSC
Molded Package Width E1 .226 BSC 5.75 BSC
Exposed Pad Width E2 .140 .146 .152 3.55 3.70 3.85
Overall Length D .236 BSC 6.00 BSC
Molded Package Length D1 .226 BSC 5.75 BSC
Exposed Pad Length D2 .140 .146 .152 3.55 3.70 3.85
Lead Width B .009 .011 .014 0.23 0.28 0.35
Lead Length L .020 .024 .030 0.50 0.60 0.75
Tie Bar Width R .005 .007 .010 0.13 0.17 0.23
Tie Bar Length Q .012 .016 .026 0.30 0.40 0.65
Chamfer CH .009 .017 .024 0.24 0.42 0.60
Mold Draft Angle Top α 12° 12°
*Controlling Parameter
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not
exceed .010" (0.254mm) per side.
JEDEC equivalent: mMO-220
Drawing No. C04-114

DS30498B-page 244 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
40-Lead Plastic Dual In-line (P) – 600 mil (PDIP)

E1

2 α
n 1

A A2

L
c

β B1
A1
eB B p

Units INCHES* MILLIMETERS

Dimension Limits MIN NOM MAX MIN NOM MAX
Number of Pins n 40 40
Pitch p .100 2.54
Top to Seating Plane A .160 .175 .190 4.06 4.45 4.83
Molded Package Thickness A2 .140 .150 .160 3.56 3.81 4.06
Base to Seating Plane A1 .015 0.38
Shoulder to Shoulder Width E .595 .600 .625 15.11 15.24 15.88
Molded Package Width E1 .530 .545 .560 13.46 13.84 14.22
Overall Length D 2.045 2.058 2.065 51.94 52.26 52.45
Tip to Seating Plane L .120 .130 .135 3.05 3.30 3.43
Lead Thickness c .008 .012 .015 0.20 0.29 0.38
Upper Lead Width B1 .030 .050 .070 0.76 1.27 1.78
Lower Lead Width B .014 .018 .022 0.36 0.46 0.56
Overall Row Spacing § eB .620 .650 .680 15.75 16.51 17.27
Mold Draft Angle Top α 5 10 15 5 10 15
Mold Draft Angle Bottom β 5 10 15 5 10 15
* Controlling Parameter
§ Significant Characteristic
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed
.010” (0.254mm) per side.
JEDEC Equivalent: MO-011
Drawing No. C04-016

 2003 Microchip Technology Inc. Preliminary DS30498B-page 245

PIC16F7X7
44-Lead Plastic Thin Quad Flatpack (PT) 10x10x1 mm Body, 1.0/0.10 mm Lead Form (TQFP)

E
E1
#leads=n1

D1 D

2
1
B

n
CH x 45 °
α
A

φ
β A1 A2
L
(F)

Units INCHES MILLIMETERS*

Dimension Limits MIN NOM MAX MIN NOM MAX
Number of Pins n 44 44
Pitch p .031 0.80
Pins per Side n1 11 11
Overall Height A .039 .043 .047 1.00 1.10 1.20
Molded Package Thickness A2 .037 .039 .041 0.95 1.00 1.05
Standoff § A1 .002 .004 .006 0.05 0.10 0.15
Foot Length L .018 .024 .030 0.45 0.60 0.75
Footprint (Reference) (F) .039 1.00
Foot Angle φ 0 3.5 7 0 3.5 7
Overall Width E .463 .472 .482 11.75 12.00 12.25
Overall Length D .463 .472 .482 11.75 12.00 12.25
Molded Package Width E1 .390 .394 .398 9.90 10.00 10.10
Molded Package Length D1 .390 .394 .398 9.90 10.00 10.10
Lead Thickness c .004 .006 .008 0.09 0.15 0.20
Lead Width B .012 .015 .017 0.30 0.38 0.44
Pin 1 Corner Chamfer CH .025 .035 .045 0.64 0.89 1.14
Mold Draft Angle Top α 5 10 15 5 10 15
Mold Draft Angle Bottom β 5 10 15 5 10 15
* Controlling Parameter
§ Significant Characteristic
Notes:
Dimensions D1 and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed
.010” (0.254mm) per side.
JEDEC Equivalent: MS-026
Drawing No. C04-076

DS30498B-page 246 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
44-Lead Plastic Quad Flat No Lead Package (ML) 8x8 mm Body (QFN)

E EXPOSED
METAL
PAD

D D2

2 B
1
n PIN 1
OPTIONAL PIN 1
INDEX ON E2
INDEX ON
EXPOSED PAD L
TOP MARKING
(PROFILE MAY VARY)
TOP VIEW BOTTOM VIEW

DETAIL: CONTACT VARIANTS

A
A1

(A3)

Units INCHES MILLIMETERS*

Dimension Limits MIN NOM MAX MIN NOM MAX
Number of Contacts n 44 44
Pitch p .026 BSC 1 0.65 BSC 1
Overall Height A .031 .035 .039 0.80 0.90 1.00
Standoff A1 .000 .001 .002 0 0.02 0.05
Base Thickness (A3) .010 REF 2 0.25 REF 2
Overall Width E .309 .315 .321 7.85 8.00 8.15
Exposed Pad Width E2 .246 .268 .274 6.25 6.80 6.95
Overall Length D .309 .315 .321 7.85 8.00 8.15
Exposed Pad Length D2 .246 .268 .274 6.25 6.80 6.95
Contact Width B .008 .013 .013 0.20 0.33 0.35
Contact Length L .014 .016 .019 0.35 0.40 0.48
*Controlling Parameter
Notes:
1. BSC: Basic Dimension. Theoretically exact value shown without tolerances.
See ASME Y14.5M
2. REF: Reference Dimension, usually without tolerance, for information purposes only.
See ASME Y14.5M
3. Contact profiles may vary.
4. JEDEC equivalent: M0-220
Drawing No. C04-103

 2003 Microchip Technology Inc. Preliminary DS30498B-page 247

PIC16F7X7
NOTES:

DS30498B-page 248 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
APPENDIX A: REVISION HISTORY APPENDIX B: DEVICE
DIFFERENCES
Revision A (June 2003)
The differences between the devices in this data sheet
This is a new data sheet. However, these devices are are listed in Table B-1.
similar to the PIC16C7X devices found in the
PIC16C7X Data Sheet (DS30390) or the PIC16F87X
devices (DS30292).

Revision B (November 2003)

This revision includes updates to the Electrical Specifi-
cations in Section 18.0 “Electrical Characteristics”
and minor corrections to the data sheet text.

TABLE B-1: DEVICE DIFFERENCES

Difference PIC16F737 PIC16F747 PIC16F767 PIC16F777
Flash Program Memory 4K 4K 8K 8K
(14-bit words)
Data Memory (bytes) 368 368 368 368
I/O Ports 3 5 3 5
A/D 11 channels, 14 channels, 11 channels, 14 channels,
10 bits 10 bits 10 bits 10 bits
Parallel Slave Port no yes no yes
Interrupt Sources 16 17 16 17
Packages 28-pin PDIP 40-pin PDIP 28-pin PDIP 40-pin PDIP
28-pin SOIC 44-pin QFN 28-pin SOIC 44-pin QFN
28-pin SSOP 44-pin TQFP 28-pin SSOP 44-pin TQFP
28-pin QFN 28-pin QFN

 2003 Microchip Technology Inc. Preliminary DS30498B-page 249

PIC16F7X7
APPENDIX C: CONVERSION
CONSIDERATIONS
Considerations for converting from previous versions
of devices to the ones listed in this data sheet are listed
in Table C-1.

TABLE C-1: CONVERSION CONSIDERATIONS

Characteristic PIC16C7X PIC16F87X PIC16F7X7
Pins 28/40 28/40 28/40
Timers 3 3 3
Interrupts 11 or 12 13 or 14 16 or 17
Communication PSP, USART, SSP PSP, USART, SSP PSP, AUSART, MSSP
(SPI, I2C Slave) (SPI, I2C Master/Slave) (SPI, I2C Slave)
Frequency 20 MHz 20 MHz 20 MHz
A/D 8-bit 10-bit 10-bit
CCP 2 2 3
Program Memory 4K, 8K EPROM 4K, 8K Flash 4K, 8K Flash
(1,000 E/W cycles) (100 E/W cycles)
RAM 192, 368 bytes 192, 368 bytes 368 bytes
EEPROM Data None 128, 256 bytes None
Other — In-Circuit Debugger, —
Low-Voltage Programming

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 PIC16F7X7
INDEX
A MSSP (SPI Mode) ...................................................... 93
On-Chip Reset Circuit............................................... 172
A/D
OSC1/CLKI/RA7 Pin................................................... 54
A/D Converter Interrupt, Configuring ........................ 155
OSC2/CLKO/RA6 Pin................................................. 53
Acquisition Requirements ......................................... 156
PIC16F737 and PIC16F767 ......................................... 6
ADRESH Register..................................................... 154
PIC16F747 and PIC16F777 ......................................... 7
Analog Port Pins ......................................................... 68
PORTC (Peripheral Output Override)
Analog-to-Digital Converter....................................... 151
RC<2:0>, RC<7:5> Pins..................................... 65
Associated Registers ................................................ 160
PORTC (Peripheral Output Override)
Automatic Acquisition Time....................................... 157
RC<4:3> Pins ..................................................... 65
Calculating Acquisition Time..................................... 156
PORTD (In I/O Port Mode) ......................................... 67
Configuring Analog Port Pins.................................... 158
PORTD and PORTE (Parallel Slave Port).................. 70
Configuring the Module............................................. 155
PORTE (In I/O Port Mode) ......................................... 68
Conversion Clock...................................................... 157
PWM Mode................................................................. 91
Conversion Requirements ........................................ 235
RA0/AN0:RA1/AN1 Pins............................................. 50
Conversion Status (GO/DONE Bit) ........................... 154
Conversions .............................................................. 159 RA2/AN2/VREF-/CVREF Pin ........................................ 51
RA3/AN3/VREF+ Pin ................................................... 50
Converter Characteristics ......................................... 234
RA4/T0CKI/C1OUT Pin .............................................. 51
Delays ....................................................................... 156
RA5/AN4/LVDIN/SS/C2OUT Pin................................ 52
Effects of a Reset...................................................... 160
RB0/INT/AN12 Pin...................................................... 57
Internal Sampling Switch (Rss) Impedance .............. 156
RB1/AN10 Pin ............................................................ 57
Operation During Sleep ............................................ 160
RB2/AN8 Pin .............................................................. 58
Operation in Power Managed Modes ....................... 158
RB3/CCP2/AN9 Pin.................................................... 59
Source Impedance.................................................... 156
RB4/AN11 Pin ............................................................ 60
Time Delays .............................................................. 156
RB5/AN13/CCP3 Pin.................................................. 61
Using the CCP Trigger.............................................. 160
RB6/PGC Pin.............................................................. 62
Absolute Maximum Ratings .............................................. 207
RB7/PGD Pin.............................................................. 63
ACKSTAT ......................................................................... 123
Recommended MCLR Circuit................................... 173
ADCON0 Register
System Clock.............................................................. 39
GO/DONE Bit............................................................ 154
Timer0/WDT Prescaler ............................................... 73
Addressable Universal Synchronous Asynchronous
Timer1 ........................................................................ 79
Receiver Transmitter. See USART.
Timer2 ........................................................................ 85
ADRESL Register ............................................................. 154
USART Receive ............................................... 140, 142
Application Notes
USART Transmit ...................................................... 138
AN552 (Implementing Wake-up on Key Stroke) ......... 56
Watchdog Timer (WDT)............................................ 186
AN556 (Implementing a Table Read) ......................... 29
BOR. See Brown-out Reset.
AN607 (Power-up Trouble Shooting)........................ 173
BRG. See Baud Rate Generator.
Assembler
BRGH Bit .......................................................................... 135
MPASM Assembler................................................... 201
Brown-out Reset (BOR).................... 169, 172, 173, 179, 180
Asynchronous Reception
Bus Collision During a Repeated Start Condition ............. 130
Associated Registers ........................................ 141, 143
Bus Collision During a Start Condition.............................. 128
Asynchronous Transmission
Bus Collision During a Stop Condition.............................. 131
Associated Registers ................................................ 139

B C
C Compilers
Banking, Data Memory ....................................................... 15
MPLAB C17.............................................................. 202
Baud Rate Generator ........................................................ 119
MPLAB C18.............................................................. 202
BF ..................................................................................... 123
MPLAB C30.............................................................. 202
Block Diagrams
Capture/Compare/PWM (CCP) .......................................... 87
A/D ............................................................................ 155
Capture Mode............................................................. 89
Analog Input Model ........................................... 156, 165
Prescaler ............................................................ 89
Baud Rate Generator................................................ 119
CCP Pin Configuration ......................................... 89, 90
Capture Mode Operation ............................................ 89
Compare Mode........................................................... 89
Comparator I/O Operating Modes............................. 162
Software Interrupt Mode ..................................... 90
Comparator Output ................................................... 164
Special Event Trigger Output ............................. 90
Comparator Voltage Reference ................................ 168
Timer1 Mode Selection....................................... 90
Compare ..................................................................... 89
Example PWM Frequencies and Resolutions ............ 92
Fail-Safe Clock Monitor............................................. 189
Interaction of Two CCP Modules................................ 87
In-Circuit Serial Programming Connections.............. 192
PWM Duty Cycle ........................................................ 91
Interrupt Logic ........................................................... 184
PWM Mode................................................................. 91
Low-Voltage Detect (LVD) ........................................ 175
PWM Period ............................................................... 91
Low-Voltage Detect (LVD) with External Input.......... 175
Registers Associated with Capture,
MSSP (I2C Master Mode) ......................................... 117
MSSP (I2C Mode) ..................................................... 102 Compare and Timer1.......................................... 90
Registers Associated with PWM and Timer2 ............. 92

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PIC16F7X7
Setup for PWM Operation ........................................... 92 Demonstration Boards
Special Event Trigger.................................................. 90 PICDEM 1................................................................. 204
Timer Resources......................................................... 87 PICDEM 17............................................................... 204
CCP1 Module...................................................................... 87 PICDEM 18R PIC18C601/801.................................. 205
CCP2 Module...................................................................... 87 PICDEM 2 Plus......................................................... 204
CCP3 Module...................................................................... 87 PICDEM 3 PIC16C92X............................................. 204
CCPR1H Register ............................................................... 87 PICDEM 4................................................................. 204
CCPR1L Register................................................................ 87 PICDEM LIN PIC16C43X ......................................... 205
CCPxM<3:0> Bits................................................................ 88 PICDEM USB PIC16C7X5 ....................................... 205
CCPxX and CCPxY Bits...................................................... 88 PICDEM.net Internet/Ethernet .................................. 204
Clock Sources ..................................................................... 37 Development Support ....................................................... 201
Selection Using OSCCON Register ............................ 37 Device Differences............................................................ 249
Clock Switching................................................................... 37 Device Overview................................................................... 5
Modes (table) .............................................................. 47 Features ....................................................................... 5
Transition and the Watchdog Timer ............................ 38 Direct Addressing ............................................................... 30
Code Examples
Call of a Subroutine in Page 1 from Page 0................ 29 E
Changing Between Capture Prescalers ...................... 89 Electrical Characteristics .................................................. 207
Changing Prescaler Assignment from Errata .................................................................................... 4
WDT to Timer0.................................................... 76 Evaluation and Programming Tools.................................. 205
Flash Program Read ................................................... 32 External Clock Input............................................................ 34
Implementing a Real-Time Clock Using a External Reference Signal ................................................ 163
Timer1 Interrupt Service ..................................... 82
Indirect Addressing ..................................................... 30
F
Initializing PORTA ....................................................... 49 Fail-Safe Clock Monitor ............................................ 169, 189
Loading the SSPBUF (SSPSR) Register .................... 96 Firmware Instructions ....................................................... 193
Reading a 16-bit Free Running Timer......................... 80 FSR Register ...................................................................... 30
Saving Status and W Registers in RAM ................... 185
G
Writing a 16-bit Free Running Timer ........................... 80
Code Protection ........................................................ 169, 192 General Call Address Support .......................................... 116
Comparator Module .......................................................... 161 I
Analog Input Connection Considerations.................. 165
I/O Ports.............................................................................. 49
Associated Registers ................................................ 165
I2C Mode
Configuration............................................................. 162
Registers .................................................................. 102
Effects of a Reset...................................................... 165
I2C Mode........................................................................... 102
Interrupts ................................................................... 164
ACK Pulse ........................................................ 106, 107
Operation .................................................................. 163
Acknowledge Sequence Timing ............................... 126
Operation During Sleep ............................................ 165
Baud Rate Generator ............................................... 119
Outputs ..................................................................... 163
Bus Collision
Reference ................................................................. 163
Repeated Start Condition ................................. 130
Response Time ......................................................... 163
Start Condition.................................................. 128
Comparator Specifications ................................................ 219
Stop Condition .................................................. 131
Comparator Voltage Reference ........................................ 167
Clock Arbitration ....................................................... 120
Associated Registers ................................................ 168
Effect of a Reset ....................................................... 127
Computed GOTO ................................................................ 29
General Call Address Support .................................. 116
Configuration Bits.............................................................. 169
Master Mode............................................................. 117
Conversion Considerations ............................................... 250
Operation.......................................................... 118
Crystal and Ceramic Resonators ........................................ 33
Repeated Start Condition Timing ..................... 122
D Master Mode Reception............................................ 123
Data Memory....................................................................... 15 Master Mode Start Condition .................................... 121
Bank Select (RP1:RP0 Bits) ....................................... 15 Master Mode Transmission ...................................... 123
General Purpose Registers......................................... 15 Multi-Master Communication, Bus Collision
Map for PIC16F737 and PIC16F767 .......................... 16 and Arbitration .................................................. 127
Map for PIC16F747 and PIC16F777 .......................... 17 Multi-Master Mode .................................................... 127
Special Function Registers ......................................... 18 Read/Write Bit Information (R/W Bit) ................ 106, 107
DC and AC Characteristics Serial Clock (RC3/SCK/SCL).................................... 107
Graphs and Tables ................................................... 237 Slave Mode............................................................... 106
DC Characteristics .................................................... 209, 217 Addressing........................................................ 106
Internal RC Accuracy ................................................ 216 Reception ......................................................... 107
Power-down and Supply Current .............................. 210 Transmission .................................................... 107
Sleep Operation........................................................ 127
Stop Condition Timing .............................................. 126

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 PIC16F7X7
ID Locations .............................................................. 169, 192 Interrupts
In-Circuit Debugger ........................................................... 192 Exiting Sleep with ....................................................... 48
In-Circuit Serial Programming ........................................... 169 Synchronous Serial Port Interrupt .............................. 25
In-Circuit Serial Programming (ICSP) ............................... 192 Interrupts, Context Saving During..................................... 185
INDF Register ..................................................................... 30 Interrupts, Enable Bits
Indirect Addressing ............................................................. 30 Global Interrupt Enable (GIE Bit)........................ 23, 184
FSR Register .............................................................. 15 Interrupt-on-Change (RB7:RB4) Enable
Instruction Format ............................................................. 193 (RBIE Bit).......................................................... 185
Instruction Set ................................................................... 193 Peripheral Interrupt Enable (PEIE Bit)........................ 23
ADDLW ..................................................................... 195 RB0/INT Enable (INT0IE Bit)...................................... 23
ADDWF..................................................................... 195 TMR0 Overflow Enable (TMR0IE Bit)......................... 23
ANDLW ..................................................................... 195 Interrupts, Flag Bits
ANDWF..................................................................... 195 Interrupt-on Change (RB7:RB4) Flag
BCF........................................................................... 195 (RBIF Bit)............................................................ 23
BSF ........................................................................... 195 Interrupt-on-Change (RB7:RB4) Flag
BTFSC ...................................................................... 195 (RBIF Bit).............................................. 23, 56, 185
BTFSS ...................................................................... 195 RB0/INT Flag (INT0IF Bit) .......................................... 23
CALL ......................................................................... 196 TMR0 Overflow Flag (TMR0IF Bit) ........................... 185
CLRF......................................................................... 196 INTRC Modes
CLRW ....................................................................... 196 Adjustment.................................................................. 36
CLRWDT................................................................... 196
COMF ....................................................................... 196 L
DECF ........................................................................ 196 Load Conditions................................................................ 221
DECFSZ.................................................................... 197 Loading of PC ..................................................................... 29
GOTO ....................................................................... 197 Low-Voltage Detect .......................................................... 174
INCF.......................................................................... 197 Characteristics.......................................................... 220
INCFSZ ..................................................................... 197 Effects of a Reset ..................................................... 178
IORLW ...................................................................... 197 Operation.................................................................. 177
IORWF ...................................................................... 197 Current Consumption ....................................... 178
MOVF........................................................................ 198 Reference Voltage Set Point ............................ 178
MOVLW .................................................................... 198 Operation During Sleep ............................................ 178
MOVWF .................................................................... 198 Low-Voltage Detect (LVD) ................................................ 169
NOP .......................................................................... 198 LVD. See Low-Voltage Detect.
RETFIE ..................................................................... 198
RETLW ..................................................................... 198
M
RETURN ................................................................... 199 Master Clear (MCLR)
RLF ........................................................................... 199 MCLR Reset, Normal Operation............... 172, 179, 180
RRF........................................................................... 199 MCLR Reset, Sleep.................................. 172, 179, 180
SLEEP ...................................................................... 199 Operation and ESD Protection ................................. 173
SUBLW ..................................................................... 199 Master Synchronous Serial Port (MSSP). See MSSP.
SUBWF ..................................................................... 199 MCLR/VPP/RE3 Pin .............................................................. 8
SWAPF ..................................................................... 200 MCLR/VPP/RE3 Pin ............................................................ 11
XORLW..................................................................... 200 Memory Organization ......................................................... 15
XORWF..................................................................... 200 Data Memory .............................................................. 15
Summary Table......................................................... 194 Program Memory........................................................ 15
INT Interrupt (RB0/INT). See Interrupt Sources. Program Memory and Stack Maps ............................. 15
INTCON Register MPLAB ASM30 Assembler, Linker, Librarian ................... 202
GIE Bit......................................................................... 23 MPLAB ICD 2 In-Circuit Debugger ................................... 203
INT0IE Bit.................................................................... 23 MPLAB ICE 2000 High-Performance
INT0IF Bit.................................................................... 23 Universal In-Circuit Emulator.................................... 203
PEIE Bit....................................................................... 23 MPLAB ICE 4000 High-Performance
RBIF Bit................................................................. 23, 56 Universal In-Circuit Emulator.................................... 203
TMR0IE Bit.................................................................. 23 MPLAB Integrated Development
Inter-Integrated Circuit. See I2C. Environment Software .............................................. 201
Internal Oscillator Block ...................................................... 35 MPLINK Object Linker/MPLIB Object Librarian ................ 202
INTRC Modes ............................................................. 36 MSSP ................................................................................. 93
Internal Reference Signal ................................................. 163 I2C Mode. See I2C.
Interrupt Sources ...................................................... 169, 184 SPI Mode.................................................................... 93
A/D Conversion Complete ........................................ 155 SPI Mode. See SPI.
Interrupt-on-Change (RB7:RB4) ................................. 56 MSSP Mode
RB0/INT Pin, External............................................... 185 SPI Slave Mode.......................................................... 99
TMR0 Overflow ......................................................... 185
USART Receive/Transmit Complete ........................ 133

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PIC16F7X7
MSSP Module Pinout Descriptions
Clock Stretching ........................................................ 112 PIC16F737/PIC16F767 .......................................... 8–10
10-bit Slave Receive Mode (SEN = 1) .............. 112 PIC16F747/PIC16F777 ........................................ 11–14
10-bit Slave Transmit Mode .............................. 112 PMADR Register ................................................................ 31
7-bit Slave Receive Mode (SEN = 1) ................ 112 POP .................................................................................... 29
7-bit Slave Transmit Mode ................................ 112 POR. See Power-on Reset.
Clock Synchronization and the CKP Bit .................... 113 PORTA ........................................................................... 8, 11
Control Registers (General) ........................................ 93 Associated Registers .................................................. 55
Operation .................................................................. 106 PORTA Register ......................................................... 49
Overview ..................................................................... 93 TRISA Register........................................................... 49
SPI Master Mode ........................................................ 98 PORTA Register ................................................................. 49
SSPBUF...................................................................... 98 PORTB ........................................................................... 9, 12
SSPSR ........................................................................ 98 Associated Registers .................................................. 64
Multi-Master Mode ............................................................ 127 PORTB Register ......................................................... 56
Pull-up Enable (RBPU Bit).......................................... 22
O RB0/INT Edge Select (INTEDG Bit) ........................... 22
Opcode Field Descriptions ................................................ 193 RB0/INT Pin, External............................................... 185
OPTION_REG Register RB7:RB4 Interrupt-on-Change ................................. 185
INTEDG Bit ................................................................. 22 RB7:RB4 Interrupt-on-Change Enable
PS2:PS0 Bits .............................................................. 22 (RBIE Bit).......................................................... 185
PSA Bit........................................................................ 22 RB7:RB4 Interrupt-on-Change Flag
RBPU Bit ..................................................................... 22 (RBIF Bit).............................................. 23, 56, 185
T0CS Bit...................................................................... 22 TRISB Register........................................................... 56
T0SE Bit ...................................................................... 22 PORTB Register ................................................................. 56
OSC1/CLKI/RA7 Pin ....................................................... 8, 11 PORTC ......................................................................... 10, 13
OSC2/CLKO/RA6 Pin ..................................................... 8, 11 Associated Registers .................................................. 66
Oscillator Configuration....................................................... 33 PORTC Register......................................................... 65
ECIO ........................................................................... 33 RC3/SCK/SCL Pin .................................................... 107
EXTRC ...................................................................... 179 RC6/TX/CK Pin......................................................... 134
HS ....................................................................... 33, 179 RC7/RX/DT Pin................................................. 134, 135
INTIO1 ........................................................................ 33 TRISC Register................................................... 65, 133
INTIO2 ........................................................................ 33 PORTC Register................................................................. 65
INTRC ....................................................................... 179 PORTD ............................................................................... 14
LP........................................................................ 33, 179 Associated Registers .................................................. 67
RC ......................................................................... 33, 35 Parallel Slave Port (PSP) Function............................. 67
RCIO ........................................................................... 33 PORTD Register......................................................... 67
XT ....................................................................... 33, 179 TRISD Register........................................................... 67
Oscillator Control Register PORTD Register................................................................. 67
Modifying IRCF Bits .................................................... 39 PORTE ............................................................................... 14
Clock Transition Sequence ................................. 40 Analog Port Pins ......................................................... 68
Oscillator Delay upon Power-up, Wake-up Associated Registers .................................................. 68
and Clock Switching.................................................... 40 Input Buffer Full Status (IBF Bit) ................................. 69
Oscillator Start-up Timer (OST) ................................ 169, 173 Input Buffer Overflow (IBOV Bit)................................. 69
Oscillator Switching............................................................. 37 PORTE Register ......................................................... 68
PSP Mode Select (PSPMODE Bit) ....................... 67, 68
P RE0/RD/AN5 Pin ........................................................ 68
Packaging ......................................................................... 239 RE1/WR/AN6 Pin........................................................ 68
Marking ..................................................................... 239 RE2/CS/AN7 Pin......................................................... 68
Paging, Program Memory ................................................... 29 TRISE Register........................................................... 68
Parallel Slave Port PORTE Register ................................................................. 68
Associated Registers .................................................. 71 Postscaler, WDT
Parallel Slave Port (PSP) .............................................. 67, 70 Assignment (PSA Bit) ................................................. 22
RE0/RD/AN5 Pin......................................................... 68 Rate Select (PS2:PS0 Bits) ........................................ 22
RE1/WR/AN6 Pin ........................................................ 68 Power Managed Modes...................................................... 41
RE2/CS/AN7 Pin......................................................... 68 RC_RUN..................................................................... 41
Select (PSPMODE Bit) ......................................... 67, 68 SEC_RUN................................................................... 42
PCL Register....................................................................... 29 SEC_RUN/RC_RUN to Primary Clock Source........... 43
PCLATH Register................................................................ 29 Power-down Mode. See Sleep.
PCON Register ................................................................. 178 Power-on Reset (POR)..................... 169, 172, 173, 179, 180
POR Bit ....................................................................... 28 POR Status (POR Bit) ................................................ 28
Peripheral Interrupt (PEIE Bit)............................................. 23 Power Control (PCON) Register............................... 178
PICkit 1 Flash Starter Kit................................................... 205 Power-down (PD Bit) ................................................ 172
PICSTART Plus Development Programmer ..................... 203 Time-out (TO Bit) ................................................ 21, 172

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 PIC16F7X7
Power-up Timer (PWRT) .......................................... 169, 173 RD1/PSP1 Pin .................................................................... 14
PR2 Register....................................................................... 85 RD2/PSP2 Pin .................................................................... 14
Prescaler, Timer0 RD3/PSP3 Pin .................................................................... 14
Assignment (PSA Bit) ................................................. 22 RD4/PSP4 Pin .................................................................... 14
Rate Select (PS2:PS0 Bits) ........................................ 22 RD5/PSP5 Pin .................................................................... 14
PRO MATE II Universal Device Programmer ................... 203 RD6/PSP6 Pin .................................................................... 14
Program Counter RD7/PSP7 Pin .................................................................... 14
Reset Conditions....................................................... 179 RE0/RD/AN5 Pin ................................................................ 14
Program Memory RE1/WR/AN6 Pin................................................................ 14
Flash RE2/CS/AN7 Pin................................................................. 14
Associated Registers .......................................... 32 Read-Modify-Write Operations ......................................... 193
Interrupt Vector ........................................................... 15 Register File........................................................................ 15
Memory and Stack Maps ............................................ 15 Registers
Operation During Code-Protect .................................. 32 ADCON0 (A/D Control 0).......................................... 152
Organization................................................................ 15 ADCON1 (A/D Control 1).......................................... 153
Paging......................................................................... 29 CCPxCON (CCPx Control)......................................... 88
PMADR Register......................................................... 31 CMCON (Comparator Control) ................................. 161
PMADRH Register ...................................................... 31 CVRCON (Voltage Reference Control) .................... 167
Reading....................................................................... 31 Initialization Conditions (table).......................... 180–181
Reading Flash............................................................. 32 INTCON (Interrupt Control) ........................................ 23
Reading, PMADR Register ......................................... 31 LVDCON (LVD Control)............................................ 176
Reading, PMADRH Register....................................... 31 OPTION_REG ...................................................... 22, 75
Reading, PMCON1 Register....................................... 31 OSCCON (Oscillator Control)..................................... 38
Reading, PMDATA Register ....................................... 31 OSCTUNE (Oscillator Tuning).................................... 36
Reading, PMDATH Register ....................................... 31 PCON (Power Control) ............................................... 28
Reset Vector ............................................................... 15 PIE1 (Peripheral Interrupt Enable 1) .......................... 24
Program Verification ......................................................... 192 PIE2 (Peripheral Interrupt Enable 2) .......................... 26
Programming, Device Instructions .................................... 193 PIR1 (Peripheral Interrupt Request 1) ........................ 25
PUSH .................................................................................. 29 PIR2 (Peripheral Interrupt Request 2) ........................ 27
PMCON1 (Program Memory Control 1) ..................... 31
R RCSTA (Receive Status and Control) ...................... 134
RA0/AN0 Pin ................................................................... 8, 11 Special Function, Summary.................................. 18–20
RA1/AN1 Pin ................................................................... 8, 11 SSPCON (MSSP Control) Register 1
RA2/AN2/VREF-/CVREF Pin............................................. 8, 11 (I2C Mode) ........................................................ 104
RA3/AN3/VREF+ Pin........................................................ 8, 11 SSPCON (MSSP Control) Register 1
RA4/T0CKI/C1OUT Pin .................................................. 8, 11 (SPI Mode) ......................................................... 95
RA5/AN4/LVDIN/SS/C2OUT Pin .................................... 8, 11 SSPCON2 (MSSP Control) Register 2
RAM. See Data Memory. (I2C Mode) ........................................................ 105
RB0/INT/AN12 Pin .......................................................... 9, 12 SSPSTAT (MSSP Status), I2C Mode ....................... 103
RB1/AN10 Pin ................................................................. 9, 12 SSPSTAT (MSSP Status), SPI Mode......................... 94
RB2/AN8 Pin ................................................................... 9, 12 Status ......................................................................... 21
RB3/CCP2/AN9 Pin ........................................................ 9, 12 T1CON (Timer1 Control) ............................................ 78
RB4/AN11 Pin ................................................................. 9, 12 T2CON (Timer2 Control) ............................................ 86
RB5/AN13/CCP3 Pin ...................................................... 9, 12 TRISE ......................................................................... 69
RB6/PGC Pin .................................................................. 9, 12 TXSTA (Transmit Status and Control)...................... 133
RB7/PGD Pin .................................................................. 9, 12 WDTCON (WDT Control) ......................................... 187
RC0/T1OSO/T1CKI Pin ................................................ 10, 13 Reset ........................................................................ 169, 172
RC1/T1OSI/CCP2 Pin................................................... 10, 13 Brown-out Reset (BOR). See Brown-out Reset (BOR).
RC2/CCP1 Pin .............................................................. 10, 13 MCLR Reset. See MCLR.
RC3/SCK/SCL Pin ........................................................ 10, 13 Power-on Reset (POR). See Power-on Reset (POR).
RC4/SDI/SDA Pin ......................................................... 10, 13 Reset Conditions for All Registers.................... 180, 181
RC5/SDO Pin ................................................................ 10, 13 Reset Conditions for PCON Register ....................... 179
RC6/TX/CK Pin ............................................................. 10, 13 Reset Conditions for Program Counter .................... 179
RC7/RX/DT Pin ............................................................. 10, 13 Reset Conditions for Status Register ....................... 179
RCIO Oscillator ................................................................... 35 WDT Reset. See Watchdog Timer (WDT).
RCSTA Register Revision History................................................................ 249
ADDEN Bit ................................................................ 134
CREN Bit................................................................... 134 S
FERR Bit ................................................................... 134 SCI. See USART.
OERR Bit .................................................................. 134 SCK .................................................................................... 93
RX9 Bit...................................................................... 134 SDI...................................................................................... 93
RX9D Bit ................................................................... 134 SDO .................................................................................... 93
SPEN Bit ........................................................... 133, 134 Serial Clock, SCK ............................................................... 93
SREN Bit................................................................... 134 Serial Communication Interface. See USART.
RD0/PSP0 Pin .................................................................... 14

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PIC16F7X7
Serial Data In, SDI .............................................................. 93 Timer0................................................................................. 73
Serial Data Out, SDO.......................................................... 93 Associated Registers .................................................. 76
Serial Peripheral Interface. See SPI. Clock Source Edge Select (T0SE Bit) ........................ 22
Slave Select Synchronization.............................................. 99 Clock Source Select (T0CS Bit).................................. 22
Slave Select, SS ................................................................. 93 External Clock............................................................. 74
Sleep ................................................................. 169, 172, 190 Interrupt ...................................................................... 73
Software Simulator (MPLAB SIM)..................................... 202 Operation .................................................................... 73
Software Simulator (MPLAB SIM30)................................. 202 Overflow Enable (TMR0IE Bit).................................... 23
Special Features of the CPU............................................. 169 Overflow Flag (TMR0IF Bit) ...................................... 185
Special Function Registers ..................................... 18, 18–20 Overflow Interrupt ..................................................... 185
SPI Mode ...................................................................... 93, 99 Prescaler .................................................................... 74
Associated Registers ................................................ 101 T0CKI ......................................................................... 74
Bus Mode Compatibility ............................................ 101 Timer1................................................................................. 77
Effects of a Reset...................................................... 101 Associated Registers .................................................. 83
Enabling SPI I/O ......................................................... 97 Asynchronous Counter Mode ..................................... 80
Master Mode ............................................................... 98 Reading and Writing ........................................... 80
Master/Slave Connection ............................................ 97 Capacitor Selection..................................................... 81
Serial Clock ................................................................. 93 Counter Operation ...................................................... 79
Serial Data In .............................................................. 93 Operation .................................................................... 77
Serial Data Out ........................................................... 93 Operation in Synchronized Counter Mode.................. 79
Slave Select ................................................................ 93 Operation in Timer Mode ............................................ 79
Slave Select Synchronization ..................................... 99 Oscillator..................................................................... 81
Sleep Operation ........................................................ 101 Oscillator Layout Considerations ................................ 81
SPI Clock .................................................................... 98 Prescaler .................................................................... 82
Typical Connection ..................................................... 97 Resetting Timer1 Register Pair................................... 82
SS ....................................................................................... 93 Resetting Timer1 Using a CCP Trigger Output .......... 81
SSP Use as a Real-Time Clock .......................................... 82
SPI Master/Slave Connection ..................................... 97 Timer2................................................................................. 85
SSPIF Bit............................................................................. 25 Associated Registers .................................................. 86
SSPOV.............................................................................. 123 Output ......................................................................... 85
SSPSTAT Register Postscaler ................................................................... 85
R/W Bit .............................................................. 106, 107 Prescaler .................................................................... 85
Stack ................................................................................... 29 Prescaler and Postscaler............................................ 85
Overflows .................................................................... 29 Timing Diagrams
Underflow .................................................................... 29 A/D Conversion......................................................... 235
Status Register Acknowledge Sequence ........................................... 126
C Bit ............................................................................ 21 Asynchronous Master Transmission......................... 139
DC Bit.......................................................................... 21 Asynchronous Master Transmission
IRP Bit ......................................................................... 21 (Back to Back) .................................................. 139
PD Bit .................................................................. 21, 172 Asynchronous Reception.......................................... 140
TO Bit .................................................................. 21, 172 Asynchronous Reception with
Z Bit............................................................................. 21 Address Byte First ............................................ 143
Synchronous Master Reception Asynchronous Reception with
Associated Registers ................................................ 146 Address Detect ................................................. 143
Synchronous Master Transmission Baud Rate Generator with Clock Arbitration............. 120
Associated Registers ................................................ 145 BRG Reset Due to SDA Arbitration During
Synchronous Serial Port Interrupt Flag Bit (SSPIF) ............ 25 Start Condition.................................................. 129
Synchronous Slave Reception Brown-out Reset ....................................................... 224
Associated Registers ................................................ 149 Bus Collision During a Repeated Start
Synchronous Slave Transmission Condition (Case 1)............................................ 130
Associated Registers ................................................ 148 Bus Collision During a Repeated Start
Condition (Case 2)............................................ 130
T Bus Collision During a Stop Condition
T1CKPS0 Bit ....................................................................... 78 (Case 1)............................................................ 131
T1CKPS1 Bit ....................................................................... 78 Bus Collision During a Stop Condition
T1OSCEN Bit ...................................................................... 78 (Case 2)............................................................ 131
T1SYNC Bit......................................................................... 78 Bus Collision During Start Condition
T2CKPS0 Bit ....................................................................... 86 (SCL = 0) .......................................................... 129
T2CKPS1 Bit ....................................................................... 86 Bus Collision During Start Condition
TAD .................................................................................... 157 (SDA Only) ....................................................... 128
Time-out Sequence........................................................... 178 Bus Collision for Transmit and Acknowledge ........... 127
Capture/Compare/PWM (CCP1 and CCP2)............. 226

DS30498B-page 256 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
CLKO and I/O ........................................................... 223 Timer0 ...................................................................... 225
Clock Synchronization .............................................. 113 Timer1 ...................................................................... 225
External Clock........................................................... 222 Timer1 Incrementing Edge ......................................... 79
Fail-Safe Clock Monitor............................................. 189 Transition Between SEC_RUN/RC_RUN
First Start Bit ............................................................. 121 and Primary Clock .............................................. 44
I2C Bus Data ............................................................. 231 Two-Speed Start-up ................................................. 188
I2C Bus Start/Stop Bits.............................................. 230 USART Synchronous Receive
I2C Master Mode (Reception, (Master/Slave) .................................................. 233
7-bit Address) ................................................... 125 USART Synchronous Transmission
I2C Master Mode (Transmission, (Master/Slave) .................................................. 233
7 or 10-bit Address) .......................................... 124 Wake-up from Sleep via Interrupt............................. 191
I2C Slave Mode (Transmission, Watchdog Timer ....................................................... 224
10-bit Address) ................................................. 111 XT, HS, LP, EC, EXTRC to RC_RUN Mode .............. 41
I2C Slave Mode (Transmission, Timing Parameter Symbology .......................................... 221
7-bit Address) ................................................... 109 Timing Requirements
I2C Slave Mode with SEN = 0 (Reception, Capture/Compare/PWM (CCP1 and CCP2)............. 226
10-bit Address) ................................................. 110 CLKO and I/O ........................................................... 223
I2C Slave Mode with SEN = 0 (Reception, External Clock .......................................................... 222
7-bit Address) ................................................... 108 I2C Bus Data............................................................. 232
I2C Slave Mode with SEN = 1 (Reception, I2C Bus Start/Stop Bits ............................................. 231
10-bit Address) ................................................. 115 Parallel Slave Port .................................................... 227
I2C Slave Mode with SEN = 1 (Reception, Reset, Watchdog Timer, Oscillator
7-bit Address) ................................................... 114 Start-up Timer, Power-up Timer
Low-Voltage Detect................................................... 177 and Brown-out Reset........................................ 224
LP Clock to Primary System Clock after SPI Mode.................................................................. 230
Reset (EC, RC, INTRC) ...................................... 46 Timer0 and Timer1 External Clock ........................... 225
LP Clock to Primary System Clock after USART Synchronous Receive ................................. 233
Reset (HS, XT, LP) ............................................. 45 USART Synchronous Transmission ......................... 233
Parallel Slave Port .................................................... 227 TMR1CS Bit........................................................................ 78
Parallel Slave Port Read............................................. 71 TMR1ON Bit ....................................................................... 78
Parallel Slave Port Write ............................................. 71 TMR2ON Bit ....................................................................... 86
Power-up Timer ........................................................ 224 TOUTPS<3:0> Bits ............................................................. 86
PWM Output ............................................................... 91 TRISA Register................................................................... 49
Repeat Start Condition.............................................. 122 TRISB Register................................................................... 56
Reset......................................................................... 224 TRISC Register................................................................... 65
Slave Mode General Call Address Sequence TRISD Register................................................................... 67
(7 or 10-bit Address Mode) ............................... 116 TRISE Register................................................................... 68
Slave Synchronization ................................................ 99 IBF Bit......................................................................... 69
Slow Rise Time (MCLR Tied to VDD IBOV Bit...................................................................... 69
Through RC Network) ....................................... 183 PSPMODE Bit ...................................................... 67, 68
SPI Master Mode (CKE = 0, SMP = 0) ..................... 228 Two-Speed Clock Start-up Mode...................................... 188
SPI Master Mode (CKE = 1, SMP = 1) ..................... 228 Two-Speed Start-up.......................................................... 169
SPI Mode (Master Mode)............................................ 98 TXSTA Register
SPI Mode (Slave Mode with CKE = 0) ...................... 100 BRGH Bit .................................................................. 133
SPI Mode (Slave Mode with CKE = 1) ...................... 100 CSRC Bit .................................................................. 133
SPI Slave Mode (CKE = 0) ....................................... 229 TRMT Bit .................................................................. 133
SPI Slave Mode (CKE = 1) ....................................... 229 TX9 Bit...................................................................... 133
Start-up Timer ........................................................... 224 TX9D Bit ................................................................... 133
Stop Condition Receive or Transmit Mode ............... 126 TXEN Bit ................................................................... 133
Switching to SEC_RUN Mode .................................... 42
Synchronous Reception U
(Master Mode, SREN) ...................................... 147 USART ............................................................................. 133
Synchronous Transmission....................................... 145 Address Detect Enable (ADDEN Bit)........................ 134
Synchronous Transmission (Through TXEN) ........... 145 Asynchronous Mode................................................. 138
Time-out Sequence on Power-up (MCLR Asynchronous Receive (9-bit Mode) ........................ 142
Tied to VDD Through Pull-up Resistor) ............. 182 Asynchronous Receive with Address Detect.
Time-out Sequence on Power-up (MCLR See Asynchronous Receive (9-bit Mode).
Tied to VDD Through RC Network): Case 1 ...... 182 Asynchronous Receiver............................................ 140
Time-out Sequence on Power-up (MCLR Asynchronous Reception.......................................... 141
Tied to VDD Through RC Network): Case 2 ...... 182 Asynchronous Transmitter........................................ 138

 2003 Microchip Technology Inc. Preliminary DS30498B-page 257

PIC16F7X7
Baud Rate Generator (BRG)..................................... 135 V
Associated Registers ........................................ 135
Voltage Reference Specifications..................................... 219
Baud Rate Formula........................................... 135
Baud Rates, Asynchronous Mode W
(BRGH = 0) ............................................... 136 Wake-up from Sleep ................................................. 169, 190
Baud Rates, Asynchronous Mode Interrupts .......................................................... 179, 180
(BRGH = 1) ............................................... 136 MCLR Reset ............................................................. 180
High Baud Rate Select (BRGH Bit)................... 133 WDT Reset ............................................................... 180
INTRC Baud Rates, Asynchronous Mode Wake-up Using Interrupts ................................................. 191
(BRGH = 0) ............................................... 137 Watchdog Timer (WDT)............................................ 169, 186
INTRC Baud Rates, Asynchronous Mode Associated Registers ................................................ 187
(BRGH = 1) ............................................... 137 WDT Reset, Normal Operation................. 172, 179, 180
Sampling ........................................................... 135 WDT Reset, Sleep .................................... 172, 179, 180
Clock Source Select (CSRC Bit) ............................... 133 WCOL ............................................................... 121, 123, 126
Continuous Receive Enable (CREN Bit) ................... 134 WCOL Status Flag............................................................ 121
Framing Error (FERR Bit) ......................................... 134 WWW, On-Line Support ....................................................... 4
Overrun Error (OERR Bit) ......................................... 134
Receive Data, 9th bit (RX9D Bit) .............................. 134
Receive Enable, 9-bit (RX9 Bit) ................................ 134
Serial Port Enable (SPEN Bit)........................... 133, 134
Single Receive Enable (SREN Bit) ........................... 134
Synchronous Master Mode ....................................... 144
Synchronous Master Reception ................................ 146
Synchronous Master Transmission........................... 144
Synchronous Slave Mode ......................................... 148
Synchronous Slave Reception .................................. 149
Synchronous Slave Transmit .................................... 148
Transmit Data, 9th Bit (TX9D)................................... 133
Transmit Enable (TXEN Bit)...................................... 133
Transmit Enable, Nine-bit (TX9 Bit) .......................... 133
Transmit Shift Register Status (TRMT Bit)................ 133

DS30498B-page 258 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
ON-LINE SUPPORT SYSTEMS INFORMATION AND
Microchip provides on-line support on the Microchip UPGRADE HOT LINE
World Wide Web site. The Systems Information and Upgrade Line provides
The web site is used by Microchip as a means to make system users a listing of the latest versions of all of
files and information easily available to customers. To Microchip's development systems software products.
view the site, the user must have access to the Internet Plus, this line provides information on how customers
and a web browser, such as Netscape® or Microsoft® can receive the most current upgrade kits. The Hot Line
Internet Explorer. Files are also available for FTP Numbers are:
download from our FTP site. 1-800-755-2345 for U.S. and most of Canada, and
1-480-792-7302 for the rest of the world.
Connecting to the Microchip Internet
Web Site 042003
The Microchip web site is available at the following
URL:
www.microchip.com
The file transfer site is available by using an FTP
service to connect to:
ftp://ftp.microchip.com
The web site and file transfer site provide a variety of
services. Users may download files for the latest
Development Tools, Data Sheets, Application Notes,
User's Guides, Articles and Sample Programs. A vari-
ety of Microchip specific business information is also
available, including listings of Microchip sales offices,
distributors and factory representatives. Other data
available for consideration is:
• Latest Microchip Press Releases
• Technical Support Section with Frequently Asked
Questions
• Design Tips
• Device Errata
• Job Postings
• Microchip Consultant Program Member Listing
• Links to other useful web sites related to
Microchip Products
• Conferences for products, Development Systems,
technical information and more
• Listing of seminars and events

 2003 Microchip Technology Inc. Preliminary DS30498B-page 259

PIC16F7X7
READER RESPONSE
It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip prod-
uct. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation
can better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-4150.
Please list the following information, and use this outline to provide us with your comments about this document.

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Device: PIC16F7X7 Literature Number: DS30498B

Questions:

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2. How does this document meet your hardware and software development needs?

3. Do you find the organization of this document easy to follow? If not, why?

4. What additions to the document do you think would enhance the structure and subject?

5. What deletions from the document could be made without affecting the overall usefulness?

6. Is there any incorrect or misleading information (what and where)?

7. How would you improve this document?

DS30498B-page 260 Preliminary  2003 Microchip Technology Inc.

 PIC16F7X7
PIC16F7X7 PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
PART NO. X /XX XXX
Examples:
Device Temperature Package Pattern a) PIC16F777-I/P 301 = Industrial temp., PDIP
Range package, normal VDD limits, QTP pattern #301.
b) PIC16LF767-I/SO = Industrial temp., SOIC
package, extended VDD limits.
c) PIC16F747-E/P = Extended temp., PDIP
Device PIC16F7X7(1), PIC16F7X7T(1); VDD range 4.0V to 5.5V package, normal VDD limits.
PIC16LF7X7(1), PIC16LF7X7T(1); VDD range 2.0V to 5.5V

Temperature Range I = -40°C to +85°C (Industrial)

E = -40°C to +125°C (Extended)
Note 1: F = CMOS Flash
LF = Low-Power CMOS Flash
Package ML = QFN (Micro Lead Frame) 2: T = in tape and reel – SOIC, SSOP,
PT = TQFP (Thin Quad Flatpack) TQFP packages only.
SO = SOIC
SP = Skinny Plastic DIP
P = PDIP
SS = SSOP

Pattern QTP, SQTP, Code or Special Requirements

(blank otherwise)

 2003 Microchip Technology Inc. Preliminary DS30498B-page 261

 WORLDWIDE SALES AND SERVICE
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Tel: 81-45-471- 6166 Fax: 81-45-471-6122 07/28/03

DS30498B-page 262 Preliminary  2003 Microchip Technology Inc.

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