USOO83 01822B2

(12) United States Patent (10) Patent No.: US 8,301,822 B2

(54) MULTI-PROTOCOL STORAGE DEVICE 6,839,864 B2 * 1/2005 Mambakkam et al. ...... T14? 5.11
BRIDGE 6,880,024 B2 * 4/2005 Chen et al. ...................... T10.62
6,895,447 B2 * 5/2005 Brewer et al. ................... T10, 11
7,047.450 B2 * 5/2006 I itsu et al. ............... T14? 43
(75) Inventors: Yosi Pinto, Kfar-Vradim (IL); Yacov contine SU a
DuZly, Ra-Anana (IL); Amir Fridman,
Tel Aviv (IL); Eyal Hakoun, Kibbutz FOREIGN PATENT DOCUMENTS
Matzuba (IL) DE 102006059 109 A1 6, 2008
(73) Assignee: Sandisk IL Ltd., Kfar Saba (IL) (Continued)
(*) Notice: Subject to any disclaimer, the term of this OTHER PUBLICATIONS
patent is extended or adjusted under 35 McLean, Peter. Information Technology—AT Attachment with
U.S.C. 154(b) by 515 days. Packet Interface–6. Working Draft. Feb. 26, 2002.*
(21) Appl. No.: 12/565,685 (Continued)
(22) Filed: Sep. 23, 2009 Primary Examiner — Matthew D Spittle
(74) Attorney, Agent, or Firm — Toler Law Group, PC
(65) Prior Publication Data
57 ABSTRACT
US 2011 FOOT2185 A1 Mar. 24, 2011 (
A bridge includes a host interface via which data/commands
(51) Int. Cl. are received from and transferred to a host, and a storage
G06F I3/36 (2006.01) device interface via which data/commands are received from
(52) U.S. Cl. ......... 710/315: 710/305: 710/311: 710,313 and transferred to a storage device. The bridge also includes
(58) Field of Classification search. 740. one SDPC, a controller and a switching system that is con
710/65, 301, 305,36, 311, 313, 315: 714/43, figurable by the controller to connect the protocol converter to
71.4744 the host interface and the storage device interface if the stor
See annlication file for complete search historv. age device protocol used by the host device differs from the
pp p ry storage device protocol used by the storage device, and to
(56) References Cited connect the host device interface to the storage device inter
face, not via the bi-directional protocol converter, if the two
U.S. PATENT DOCUMENTS storage device protocols are the same. The bridge may
5,151,898 A 9, 1992 Kondo include two SDPCs, each for converting a different protocol
5.832,244. A 11/1998 Jolley et al. ................... T10,305 to the host protocol and vice versa, with the Switching system
5,928,347 A * 7/1999 Jones ........... 710,305 being configurable to switch between the two SDPCs. The
6,038,618 A 3/2000 Beer et al....... ... 710, 18 bridge may omit the SDPC altogether, with the switching
E. A : 38 Sayashi et al. . 2839.
6.3341 60 B1 12/2001 Emmert et al. ................. T10/11
system being configurable to switch between connecting (1)
the host device interface to the storage device interface, and
6,502,159 B1 12/2002 Chuang et al. (2) bypassing the storage device interface.
6,718.274 B2 * 4/2004 Huang et al. .................... TO2/64
6,832,281 B2 * 12/2004 Jones et al. ................... T10,301 34 Claims, 18 Drawing Sheets

A 200

210 Removable
Storage Device

Embedded (Legacy SD
Memory Card or UFS
(UFS)
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U.S. PATENT DOCUMENTS 2005/0097263 A1* 5/2005 Wurzburg ................ T11 103
2006, O161716 A1* 7, 2006 Lin .......... ... 710,313
7,069,369 6, 2006 Chou et al. .................... T10,301 2009/02701 17 A1* 10/2009 Buckley ........................ 455,515
7,076,580 T/2006 Nakano ........................... T10/65
7,120,713 10, 2006 Kinstler FOREIGN PATENT DOCUMENTS
7,162,549 1/2007 Mambakkam et al. ......... T10/16 WO 2006101057 A1 9, 2006
7,222,205 5/2007 Jones et al. 710,301
OTHER PUBLICATIONS
7,237,049 6, 2007 Kang et al. .................... T10/104
7,254,650 8, 2007 Lin et al. ......................... T10/11 Compaq et al. Universal Serial Bus Specification. Revision 2.0. Apr.
7,263,476 8, 2007 Dellacona .......... TO3/13 27, 2000.*
7,278,051 10, 2007 Mambakkam et al. ...... 714f6.12 Venkatesan, Vandana. Mobile Storage: Trends for Tomorrow. The
7,376,773 5/2008 Kim et al. ....................... 71 Of74 Advent of UFS (Universal Flash Storage). Aug. 2011.*
7,412,628 8, 2008 Shikada ......... ... 714.f43 JEDEC. Universal Flash Storage (UFS 1.1). JESD220A. Jun. 2012.*
7,624,216 11/2009 Yoshikawa et al. 710,301 Vuong, Hung. Flash Storage Trends & Ecosystem. Qualcomm Inc.
7,664,902 2, 2010 Chow et al. .... 710,301 2010.*
7,827,337 11, 2010 Jeong ............................ T10/113 JEDEC. Universal Flash Storage (UFS) Host Controller Interface.
7,848,160 12, 2010 Kuriyama ................ 365,189.15 JESD223. Aug. 2011.*
7,925,812 4, 2011 Konno et al. ................. T10,301 International Search Report and Written Opinion issued in Interna
2003/0066087 4, 2003 Sawyer et al. tional Application No. PCT/IB2010/002191 dated Feb. 7, 2011, 12
pageS.
2004/OO27879 2, 2004 Chang ........................... 365,200
2004/OO70952 4, 2004 Higuchi et al. ............... 361/737 * cited by examiner
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1. 2
MULTI-PROTOCOL STORAGE DEVICE device uses to convert and transfer data and commands to the
BRIDGE storage device through the storage device interface. The
bridge also includes a controller and a Switching system. The
FIELD OF THE INVENTION switching system may be configurable by the controller to be
in one of a number of states. For example, in state (1), the
The present invention generally relates to storage systems Switching system connects the host interface to the storage
and more specifically to a method for connecting a host device interface via an SDPC if the storage device protocol
device to a storage device using a communication protocol used by the host device and the storage device protocol used
the same as or different from the communication protocol the by a storage device engaged by the host are different, in State
host device is using, and to an apparatus that enables the 10
(2), the Switching system connects the host device interface to
connection method. the storage device interface directly or through other means,
BACKGROUND bypassing the SDPC, if the two storage device protocols are
the same, and in State (3), the Switching system bypasses the
Use of flash storage devices has been rapidly increasing 15 storage device interface if the storage device is not connected
over the years because they are portable and they have small to the bridge.
physical size and large storage capacity. Flash storage devices Not all of the three switch states described above are nec
come in a variety of designs. Some storage devices are essarily implemented in or used by a bridge. The number and
regarded as “removable', which means that a user can move types of Switch states that a bridge uses may depend on the
them from one host device (e.g., cellular phone) to another or circumstances (e.g., type of required conversion(s), type of
use multiple storage devices with one host device by Swap used network topology, etc.). For example, state (1) and State
ping storage devices engaged by Such host device. Other (2) referred to above are applicable, for example, if the host
storage devices are regarded as “embedded, meaning that device and the storage device are functionally connected via
they are built into and not intended to be removed by the user a chain topology. In another example, state (1) and state (3)
from the host device. 25 referred to above are applicable, for example, if the host
A host may need to operate with various kinds of remov device and the storage device are functionally connected via
able storage devices, be it presently existing or future storage a ring topology and no protocol conversion is involved, and
devices (e.g., SD cards, UFS cards, UHS-II cards, etc.). Vari all of the states mentioned above are applicable for a ring
ous storage devices use or may be designed to use different topology system where protocol conversion is required. By
kinds of protocols. To this end, the host device would have to 30 manipulating the Switching system, devices that use a low
accommodate different protocols, and this has typically speed storage device protocol and devices that use a high
required separate interfaces for the different cards and proto speed storage device protocol can both communicate with a
cols. Also, the host may have to accommodate different Stor host device through the bridge using a single, common high
age device communication topologies. speed storage device protocol.
Providing a host with large number of interfaces that Sup 35 Alternatively, the bridge may include two SDPCs, each for
port different protocols and topologies for communicating converting a different protocol to the host protocol and vice
with various storage devices is not always practical and effec Versa, with the Switching system being configurable by the
tive. Hence, there is a need to address this problem with a controller to switch merely between the two SDPCs. Then
better approach. again, the bridge may omit the SDPC altogether, with the
40 Switching system being configurable by the controller to
SUMMARY switch merely between connecting (1) the host device inter
face to the storage device interface, and (2) bypassing the
In view of the foregoing, it would be beneficial to have, for storage device interface. In another implementation, the
example, a host device that can communicate with storage bridge may be connected directly to the host device or to a
devices of various types via a single, common interface. 45 communication hub. These and other, embodiments, features,
Among the various storage devices there are slower cards, aspects and advantages thereof will become better under
such as legacy SD cards, and faster cards, such as UHS-II stood from the description herein, appended claims, and
cards or UFS cards, and accommodating all of them with a accompanying drawings as hereafter described.
single, common interface is advantageous. To carry out the
communications in different protocols, the single, common 50 BRIEF DESCRIPTION OF THE DRAWINGS
interface is adapted as a versatile interface (which is referred
to hereinafter as a “bridge'). Various embodiments of a bridge The accompanying drawings, which are incorporated in
designed to accommodate such communications are provided and constitute part of this specification, illustrate various
herein. embodiments with the intent that these examples not be
In one implementation, a bridge is placed along a serial 55 restrictive. It will be appreciated that for simplicity and clarity
communication path so as to interface, communication-wise, of the illustration, elements shown in the figures referenced
between a host device and a removable storage device. The below are not necessarily drawn to Scale. Also, where con
bridge includes two interfaces for conveying data and com sidered appropriate, reference numerals may be repeated
mands between the host device and storage device. One of the among the figures to indicate like, corresponding or analo
two interfaces is on the host side, a host interface, and the 60 gous elements. Of the accompanying figures:
other is on the storage device side, a storage device interface. FIG. 1 is a diagram of an example conventional network
The bridge may include one or more bi-directional storage architecture in which a host device communicates with a
device protocol converters (“SDPCs”). An SDPC may be faster storage device (e.g., UFS card) or a slower storage
adapted to use a storage device protocol that the host device device (e.g., legacy SD card) using chain topology;
uses to convert and transfer data and commands to the host 65 FIG. 2 is a diagramofa storage device network architecture
device through the host interface. Such SDPC is further using a chain topology and including a bridge according to an
adapted to use a storage device protocol that the storage embodiment;
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3 4
FIG. 3 is a diagram of a network architecture using a chain that facilitates relatively slow data communication. Host
topology and including a bridge according to an embodiment; devices are designed to communicate with UFS cards and
FIG. 4 shows a bridge according to an embodiment; UHS-II cards by using a UFS protocol and a UHS-II protocol,
FIG. 5 shows a bridge according to an embodiment; respectively, that facilitates faster data communication. The
FIG. 6 shows a bridge according to an embodiment; 5 UHS-II and UFS protocols are defined for significantly
FIG. 7 shows a method for operating a bridge according to higher data transferrates than the legacy SD protocol. In order
an embodiment; to support such high speed data transfer both protocols (UHS
FIG. 8 schematically illustrates communication between a II and UFS) use a differential signaling physical interface as
host device and a storage device via a bridge where storage opposed to the single ended physical interface that legacy SD
device interface commands are transferred transparently both 10 interfaces and eMMC interfaces use. The high speed proto
ways by using the SCSI over UFS protocol; cols and the low speed protocols also differ in that they use
FIG.9 schematically illustrates communication between a one or more layers (e.g., link layer, transport layer) in a
host device and a storage device via a bridge where Storage different way. The terms “high speed protocol/device/inter
Device interface commands are transferred transparently face' and “fast protocol/device/interface' are used herein
both ways using the SD over UFS protocol; 15 interchangeably. Likewise, the terms “low speed protocol/
FIG. 10 schematically illustrates communication between device/interface' and “slow protocol/device/interface' are
a host device using the SCSI over UFS protocol and a storage also used herein interchangeably.
device using the legacy SD protocol via a bridge; The host device traditionally communicates with legacy
FIG. 11 shows a bridge functional layout according to an SD cards directly, by using a "point-to-point’ communication
embodiment; 2O scheme. UFS devices, on the other hand, are planned to com
FIG. 12 schematically illustrates communication between municate with their host devices through a data network of a
a host device using SD-over-UFS and a storage device using chain topology type. In the chain topology, devices commu
legacy SD protocol via a bridge; nicate with each other by using high-speed two-wire differ
FIG. 13 shows a bridge functional layout according to an ential buses. Consequently, a host device that can Support
embodiment; 25 faster standards (i.e., UFS and/or UHS-II) and is also slow
FIG. 14 shows a host device with a UHS-II interface for standard (e.g., SD) backward-compatible would be required
embedded storage devices connected in a Ring topology, a to have two separate communication interfaces: a slow inter
storage device interface for legacy SD cards, and a storage face (e.g., an SD interface) and a faster interface (e.g., a UFS
device interface for UHS-II cards; interface and a UHS-II interface). This means that such host
FIG. 15 shows a host device with one legacy SD interface, 30 device would have to deal with different communication pro
one UHS-II interface connected in a ring topology, and a tocols and topologies, which is costly in terms of number of
bypass socket in a “non-bypass' state; input-output (“I/O”) count, processor complexity, circuit
FIG.16 shows the data storage system of FIG. 15 with the board wiring, computer resources, host gate count, testing
bypass socket in a "bypass' state; procedures, etc.
FIG. 17 shows a host device with one UHS-II interface and 35 AUHS-II storage device can be designed to communicate
the bridge of FIG. 6 connected in a ring topology; and with a host device by using a network topology known as
FIG. 18 shows a connection analyzer according to an “ring”. “Ring' topology is a network setup in which multiple
embodiment. devices are connected in series, and the first device and the
last device are connected directly to the host device). Because
DETAILED DESCRIPTION 40 a ring topology provides one-way communication path
between each pair of interconnected devices, ring networks
The description that follows provides various details of may be disrupted by the failure of a single link. A cable break
example embodiments. However, this description is not might isolate the other devices that are attached to the ring.
intended to limit the scope of the claims but instead to explain Therefore, a host device using a UHS-II type storage device
various principles of the invention and the manner of practic- 45 would require a special communication interface. Using the
ing it. ring topology in host-storage device environment is problem
Universal Flash Storage (UFS) is a proposed common flash atic because, typically, this type of environment includes a
storage specification for digital cameras, mobile phones and removable storage device, and removal of a storage device
consumer electronic devices. UFS is designed to provide would break the communication path. This means that a
higher data transfer speed and increased reliability in flash 50 UHS-II based host device would be required to have three
memory storage. Ultra-High-Speed type II (UHS-II) is a new types of interfaces (as demonstrated by FIG.14): (1) a UHS-II
specification that defines a new generation of SD cards. UFS interface for the embedded devices that are connected
and UHS-II protocols are also referred to herein as “high through the ring topology, (2) a UHS-II interface for remov
speed protocols. A current generation (i.e., non-UHS-II) SD able storage devices that support the UHS-II standard, and (3)
card/protocol is referred to herein as a “legacy SD card/ 55 a legacy SD interface to facilitate SD backward compatibility.
protocol or “low speed card/protocol. FIG. 1 is an example of conventional storage system archi
Secure digital (“SD) memory cards and embedded multi tecture 100. As explained above, new data storage device
media-card (“eMMC) storage devices are examples of rela protocols are designed to facilitate faster transfer of data and
tively slow flash storage devices. Examples of faster flash commands, for example relative to the legacy SD protocol. A
storage devices include ultra high speed type II (“UHS-II) 60 conventional solution to cope with the two types of Storage
memory cards and universal flash storage (“UFS) storage device protocols (i.e., slow protocol; e.g., legacy SD protocol,
devices. “UFS is a standard developed by UFS task force and fast protocol; e.g., UFS and UHS-II) allows a host pro
working for the Joint Electron Device Engineering Council cessor (i.e., host processor 110) to handle them separately, as
(s) (“JEDEC) Solid State Technology Association, and demonstrated by FIG.1. Hereinafter, “legacy SD is referred
“UHS-II is a standard developed by the SD Association 65 to as “SD for short.
(“SDA) for the next generation of SD storage device. Host Assume that host processor 110 is designed to operate
devices communicate with SD cards by using an SD protocol using both the UFS protocol and SD protocol, in order to
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5 6
make it SD backward compatible. In order to cope with the host CPU 210 and removable storage device 260, whether
UFS protocol and SD protocol, host processor 110 is pro storage device 260 be a slow card (e.g., legacy SD card) or
vided with two separate interfaces: interface 112 and inter a fast card (e.g., UFS card, SD-over-UFS compatible SD
face 114. Interface 112 is use for communicating with a card).
removable SD card 120 directly (i.e., via SD bus 130). Inter Bridge 250 can be either in a “transparent state or in a
face 114 is used for communicating UFS data/commands “conversion' State, depending on the type of protocol that
with external devices such as UFS input/output device 150, host processor 210 uses and on the type of protocol that
UFS input/output device 160, UFS-type memory device 170, removable storage device 260 uses. That is, bridge 250 iden
and also with removable storage device 120; i.e., if removable tifies these types of protocols, for example by using a con
storage device 120 is a UFS card or an SD-UFS card that is 10
nection analyzer Such as connection analyzer 442 of FIG. 4),
capable of communicating with host processor 110 by encap and acts accordingly: it transitions to (or remains in) the
sulating SD data/commands within the UFS protocol. (Note: “conversion' state if removable storage device 260 uses the
encapsulation of SD data/commands within the UFS protocol legacy SD protocol, to thereby bridge between the UFS stor
is referred to hereinafter as “SD-over-UFS'.) age device protocol used by UFS-type host CPU 210 and the
Because of the way the UFS protocol is designed, host 15
device 110 can communicate with its peripherals via a bus legacy storage device protocol used by legacy SD card 260,
that has a chain topology. Chain Topology is a wiring scheme and it transitions to (or remains in) the “transparent state if
in which device A is wired to device B, device B is wired to removable storage device 260 and host CPU 210 use the same
device C, device C is wired to device D, etc., and the last protocol which, in this example, is the UFS protocol. (Note:
device in the chain is not looped back to device A but rather it regarding the present disclosure, a UFS card and a SD-over
communicates with device A through the other devices. With UFS type card are collectively referred to herein as UFS
reference to FIG. 1, host processor 110 is communicating card.)
with device 150 via UFS bus 140, device 150 is communicat While in the “conversion' state, bridge 250 receives data/
ing with device 160 via UFS bus 142, device 160 is commu commands from host CPU 210 (via devices 220, 230, and
nicating with UFS embedded memory 170 via UFS bus 144, 25 240) in the UFS storage device protocol and sends them to
and UFS embedded memory 170 is communicating with legacy SD card 260, via legacy SD connection 252, by using
removable storage device 120 via UFS bus 146. The circuit the legacy SD storage device protocol, and receives data/
configuration of FIG. 1 has the drawbacks of using two sepa commands from legacy SD card 260, via legacy SD connec
rate interfaces, an SD interface (i.e., interface 112) and a UFS tion 252, in the legacy SD storage device protocol and sends
interface (i.e., interface 114), and of requiring host CPU 110 30 them to host processor 210 (via devices 240,230, and 220) by
to allocate space and resources, and dedicate circuits for both using UFS storage device protocol. As explained above, no
types of storage device protocols and topologies. protocol change is required if host CPU 210 and removable
FIG. 2 is a diagram of a storage system architecture 200 storage device 260 use the same storage device protocol (in
with a bridge 250 according to an example embodiment. Host this example the UFS protocol). If host CPU 210 and storage
CPU 210 has one communication interface (i.e., communi 35 device 260 are UFS devices, bridge 250 and storage device
cation interface 212) via which it communicates with external 260 are connected via UFS connection 254. SD connection
devices (e.g., removable storage device 260). In this architec 252 and UFS connection 254 are shown logically as separate
ture, which uses a chain topology, both the slow storage connections. However, physically, they may have terminals in
device interface (e.g., legacy SD interface) and the high speed common. A bridge (e.g., bridge 250) in the transparent state is
interface (e.g., UFS interface) will communicate with the host 40 transparent to communications between host CPU 210 and
through the bridge by using the high speed storage device removable storage device 260. Storage system architecture
protocol. This way, a system that includes a host device that 200 includes a bridge as a separate device (i.e., bridge 250).
uses a high speed protocol and a bridge such as bridge 250 is However, the bridge functionality may be incorporated into
backward compatible, which means that it can operate with the embedded memory (e.g., embedded memory 240), as
devices that use low speed protocols (Note: in this example, 45 exemplified by FIG. 3, which is described below.
the faster storage device protocol is the UFS protocol and the There may be SD-UFS combined cards that include two
slow storage device protocol is the legacy SD protocol.) logically separate sets of host interface terminals, which may
In the example of FIG. 2, host CPU 210, UHS-II type have common connection terminals; i.e., one set which con
input/output module 220 (e.g., an execute in place (XIP) forms to legacy SD card and another set which conforms to
device), UHS-II type input/output module 230 (e.g., WiFi 50 UFS card, and two sets of storage device interfaces; i.e., one
device), and embedded memory 240 are designed to receive set of storage device interface for operating the card as a
and transmit data and commands by using the UFS protocol. legacy SD and another set of storage device interface for
This means that communication between each pair of inter operating the card as a UFS card. Having two sets of terminals
connected devices, via the corresponding UFS bus, is straight and front-ends allows SD-UFS cards to be used either as a
forward; namely, no changes are required to be made in the 55 legacy SD card or as a UFS card, depending on the type of
storage device protocol as the data and commands propagate interface and socket accommodating the SD-UFS card.
along the chain (chain topology) network from host CPU 210 Bridge 250 may have only one storage device interface (not
to input/output module 220 (via UFS bus 270), from input/ shown in FIG. 2) that can accommodate both types of remov
output module 220 to input/output module 230 (via a UFS bus able storage device 260. Alternatively, bridge 250 may have
that connects them), and from input/output module 230 to 60 separate storage device interfaces (also not shown in FIG. 2):
embedded memory 240 (via a UFS bus that connects them). one storage device interface which is dedicated for a legacy
Even though host CPU 210 does not have an interface SD cards, and another storage device interface which is dedi
dedicated to legacy SD cards (note: it has only one high-speed cated for UFS cards.
interface; i.e., interface 212, which, in this example, is In one implementation, bridge 250 may be connected to
designed for UFS communication), it uses high-speed inter 65 host CPU 210 as shown in FIG. 2 (i.e., via one or more
face 212 to communicate with legacy SD cards by using intermediate devices). In another implementation, bridge 250
bridge 250. Bridge 250 facilitates communication between may be connected directly to host CPU 250. In another imple
 US 8,301,822 B2
7 8
mentation, bridge 250 may be connected directly to a com If the first storage device protocol differs from the second
munication hub that is connected, directly or via one or more storage device protocol, this means that the data and com
devices, to host CPU 250. mands, which host CPU 410 propagates through bridge 400
FIG. 3 is a diagram of a storage system architecture 300 to SD card 420 by using a certain storage device protocol
with a device 350 that is a combination of a bridge and an (e.g., UFS protocol), has to be sent to card 420 by using a
embedded memory according to an example embodiment. different storage device protocol (i.e., legacy SD protocol)
Storage system architecture 300 is identical to storage system that SD card 420 “understands’. In this case, controller 440
architecture 200 of FIG. 2 in all respects, except that in sends a control signal 444 to Switching system 460 to connect
storage system architecture 300 the bridge and the embedded contact “(0) to contact "(1), to thereby connect protocol
memory are combined in one device, as shown at 350. Using 10 converter 450 to host device interface 402 (note: in the
one device (i.e., device 350) that combines the functionalities example shown in FIG. 4, protocol converter 450 is perma
of the embedded memory and bridge is beneficial as it saves nently connected to storage device interface 406). This way,
space, internal wiring, input/output interfaces, etc. host CPU 410 communicates data/commands to storage
FIG. 4 shows a bridge 400 according to an example device 420 by using the first storage device protocol, which is
embodiment. Bridge 400 includes a host device interface 402. 15 USF protocol in this example, and UFS/SD converter 450
Host device interface 402 is connected to a communication converts the UFS protocol to a second storage device protocol
bus 404 that is connected (possibly via other devices 412 that which, in this example is the legacy SD protocol, which is
are part of the chain) to a host CPU that uses a first storage usable by legacy SD card 420. The procedure of receiving
device protocol (e.g., UFS). Bridge 400 also includes a first data, commands and signaling from a first device in a first
storage device interface 406 for interfacing with a removable storage device protocol, translating the data/commands/sig
storage device 420 that uses a second storage device protocol naling, and transmitting the translated data/commands/sig
(e.g., legacy SD), and a bi-directional storage device protocol naling to a second device by using another storage device
converter (SDPC) 450 for converting the first storage device protocol is referred to herein as “protocol conversion’, or
protocol to the second storage device protocol and vice versa. “conversion' for short, hence using the term “converter and
Bridge 400 also includes a controller 440 and a switching 25 lingual derivatives thereof. Such a conversion typically
system 460. Switching system 460 is configurable by con includes encapsulating a slow protocol (e.g., legacy SD pro
troller 440 to connect protocol converter (SDPC) 450 tocol) within a fast protocol (e.g., UFS protocol, UHS-II
between host device interface 402 and first storage device protocol), and de-capsulating the slow protocol from the fast
interface 406 if the first storage device protocol (i.e., the protocol. While “encapsulation” means embedding a proto
storage device protocol used by host CPU 410) differs from 30 col within another protocol, "de-capsulation” means the
the second storage device protocol (i.e., the storage device opposite operation. A SCSI from/to SD conversion also
protocol used by the removable storage device), and to dis includes basic SD-to-SCSI and SCSI-to-SD commands
connect protocol converter 450 and to connect host device translation (and the translation is performed, e.g., by a trans
interface 402 to second storage device interface 408 if the first lator such as commands translator 1130 of FIG. 11). Proto
storage device protocol and the second storage device proto 35 cols conversion also includes signaling translations (e.g.,
col are the same. “busy signaling translations) in the link layer level (and the
Controller 440 may know in advance the type of host CPU translation is performed e.g., by a translator Such as link
and/or the type of storage device protocol it uses. If controller signaling translator 1185 of FIG. 11).
440 does not know the type of host CPU and/or the type of If the storage device protocol used by host CPU 410 is the
storage protocol the host device uses in advance, then con 40 same as the storage device protocol used by the removable
troller 440, in conjunction with a connection analyzer 442, storage device that is connected bridge 400 (in this case UFS
monitors host device interface 402, to infer the type of host card 430), controller 440 sends a control signal 444 to switch
CPU and/or the type of storage device protocol that host CPU ing system 460 to connect contact “(0) to contact “(2), to
uses from information originating from host CPU 410. Con thereby connect host device interface 402 to storage device
troller 440 also uses connection analyzer 442 to monitor 45 interface 408 directly 464, that is, without going through
storage device interfaces 406 and 408 to detect which storage converter 450 (it is possible that other components could be
device is connected to bridge 400 and/or which storage device connected between 402 and 408).
protocol is used by a storage device that is connected to As explained in connection with FIG. 2, if host CPU 210 is
storage device interfaces 406 or to storage device interface of the UFS type, bridge 250 can have one storage device
408. Controller 440, then, determines whether storage device 50 interface that is configured to accommodate one storage
420 uses a first storage device protocol which is also used by device that can be a legacy SD card, SD-UFS card or UFS
host CPU 410, or a second storage device protocol that is not card, or two storage device interfaces: one for legacy SD cards
used by host CPU410. Controller 440 may determine the type and another for SD-UFS cards or UFS cards.
of the storage device protocol used by the two sides (i.e., host FIG. 5 shows a bridge 500 according to an additional
CPU 410 and storage device 420), and compare them to 55 example embodiment. Bridge 500 is similar to bridge 400
determine whether a protocol conversion is required. Alter except that bridge 500 includes two protocol converters: one
natively, controller 440 may determine that the two sides use (i.e., protocol converter 450) that converts from UFS protocol
the same storage device protocol or different storage device to legacy SD protocol and vice versa, as shown also in FIG. 4.
protocols without determining the type of each used storage and another (i.e., protocol converter 510) that converts from
device protocol. Typically, a device such as host CPU 410 and 60 UFS protocol to UHS-II protocol and vice versa. (Note: only
storage device 420 communicates an explicit message regard one removable storage device; i.e., card 420 or card 530, can
ing the type and/or version of the storage device protocol it be connected to bridge 500 at a time.)
uses to the other side with which it communicates. There If connection analyzer 542 notifies controller 540 that
fore, controller 440 may determine the storage device proto legacy SD card 420 is currently connected to bridge 500,
cols based on Such communication. Alternatively, controller 65 controller 540 sends a control signal 544 to switching system
440 may infer the type of storage device protocols from 560 to connect contact"(0) to contact "(1), as also shown in
monitored communications. and described in connection with FIG. 4. If connection ana
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lyzer 542 notifies controller 540 that UHS-II card 530 (or information (“ID) of the removable storage device. Such an
SD-UHS-II card which uses UHS-II protocol) is currently ID would allow controller 660 to know whether the com
connected to bridge 500, controller 540 sends a control signal mand/data is intended for the removable storage device (e.g.,
544 to switching system 560 to connect contact “(0) to card 630 or 640) or not.
contact “(2), to enable conversion of the UFS protocol, If the storage device connected to bridge 600 is a UHS-II
which is used by host PCU410, to the UHS-II protocol, which compatible card 640 (i.e., UHS-II card or SD-UHS-II card),
is use by UHS-II card (or SD-UHS card) 530 and vice versa. controller 660 sets switches 680 and 690 to position “(2)”
As host CPU 410 uses the UFS protocol, bridge 500, like because no protocol conversion is required (i.e., both host
bridge 400, is configured in a chain topology. In the case of a CPU 610 and card 640 are genuine UHS-II devices). In posi
host CPU using the UHS-II protocol, the bridge may be 10 tion “(2), data/command originating from host CPU 610
configured in a ring topology, as demonstrated by FIG. 6. propagate through UHS-II device 620, are received at bridge
FIG. 6 shows a bridge 600 according to yet another 600, and forwarded to UHS-II card 640 directly (i.e., without
example embodiment. Host CPU 610 uses the UHS-II proto undergoing protocol conversion), via storage device interface
col to communicate with external devices (e.g., UHS-II 606A. If the data/command is not intended for UHS-II card
device 620, legacy SD card 630 or UHS-II card 640 (or 15 640, UHS-II card 640 forwards them, via storage device
SD-UHS-II card 640), and UHS-II Input/Output device 650) interface 606B and contact “(2)” of switch 690, to the next
through a bus having a ring topology. (Note: only one of device in the ring which, in this example, is UHS-II Input/
legacy SD card 630 and UHS-II card 640 is connected to Output device 650. If one of the devices in a ring type data
bridge 600 at a time.) Bridge 600 includes host device inter network is removed and no measure is taken to bridge the gap
face 602 for receiving data and commands from UHS-II created by the removal of the device, the communication loop
device 620, storage device interface 604 for transferring the is disconnected. Turning again to FIG. 6, a connection ana
data and command to, and receiving them back from, legacy lyzer 662, which is similar to connection analyzer 442 of FIG.
SD card 630, storage device interface 606 for transferring the 4 (for example), monitors host device interface 602, and
data and command to, and receiving them back from UHS-II storage device interfaces 604, 606, and 608, to detect devices
card 640, and storage device interface 608 for transferring the 25 that are connected to them and to determine the storage device
data and command to UHS-II device 650 that may be a protocol that each device uses. Connection analyzer 662 noti
UHS-II type embedded memory or a UHS-II type Input/ fies controller 660 of the status of the monitored interfaces
Output device or any other device that uses the UHS-II pro (i.e., a device is connected to interface X or not, a device
tocol. connected to interface X is using protocol y, etc.) If con
Bridge 600 also includes a controller 660 that functions in 30 nection analyzer 662 notifies controller 660 that neither a
a similar way as controller 440 of FIG. 4 and controller 540 of legacy SD card is connected to storage device interface 604
FIG. 5, a bi-directional SDPC 670 for converting the UHS-II nor a UHS-II compatible card is connected to storage device
protocol used by host CPU 610 to the legacy SD protocol used interface 606, controller 660 sets switch 680 and switch 690
by legacy SD card 630 (and vice versa), and a switching to position “(3)'.
system 682 that includes a three-position switch 680 and a 35 If switches 680 and 690 are in position (1), bridge 600 is in
three-position switch 690. Switch 680 and switch 690 are a “conversion' state. If switches 680 and 690 are in position
designed and controlled in Such a way that they are always in (2), bridge 600 is in a “transparent state. If switches 680 and
the same position and always move together from one posi 690 are in position (3), bridge 600 is in a “bypass' state. By
tion to another position. For example, if switch 680 is, say, in setting switches 680 AND 690 to position “(3), both storage
position "(1), switch 690 is also in position "(1), and if 40 device interfaces 604 and 606 are bypassed. That is, the
controller 660 transitions one of them (e.g., switch 680) to bridge's ring input (i.e., host device interface 602) is inter
position “(3)' (for example), the other switch (e.g., switch nally connected to the bridge's ring output (i.e., storage
690) also transitions to the same position. device interface 608), thereby closing the ring loop via bridge
If the storage device connected to bridge 600 is a legacy SD 600. (Note: if a removable storage device; e.g., legacy SD
card such as legacy SD card 630, controller 660 sets switches 45 card 630 or UHS-II card 640, is connected to bridge 600, the
680 and 690 to position “(1), which state is shown in FIG. 6. ring loop is closed via the UHS-II/SD converter or via UHS-II
In position "(1), data and commands originating from host device 640, respectively.)
CPU 610 propagate through UHS-II device 620, are received FIG. 7 is a method for operating a bridge according to an
at bridge 600, and forwarded to bi-directional UHS-II/SD example embodiment. Assume that a bridge, which may be
converter 670. UHS-II/SD converter 670 converts the UHS-II 50 similar to bridge 400 or 500, is permanently connected, indi
protocol to the legacy SD protocol and forwards the data/ rectly or directly, to a host CPU as the two devices are embed
command to legacy SD card 630, via storage device interface ded in the same host device. At step 710, a connection ana
604, using the legacy SD protocol. (Note: the term “converts' lyZer, Such as connection analyzer 542, checks whether a
is to be construed in the way explained above). Legacy SD removable storage device (e.g., legacy SD card 420 or UHS-II
card 630 transfers data or a response to UHS-II/SD converter 55 compatible card 530) is connected to the bridge, and if such a
670 by using the legacy SD protocol, and UHS-II/SD con device is connected to the bridge, it detects 730 the type of the
verter 670 sends the data or the response to the next device in storage device protocol used by the connected device. If no
the ring (i.e., UHS-II Input/Output device 650) by using the removable storage device is connected to the bridge (shown
UHS-II protocol. Then, the data/command continues to as “Nat step 710), the bridge remains, or enters, an idle state
propagate through the ring by using the UHS-II protocol. If 60 and waits, at step 720, until a removable storage device is
the data/command sent by host CPU 610 is not intended for connected to it. If a removable storage device is connected to
legacy SD card 630, the requirement to convert command/ the bridge (shown as “Y” at step 710), the connection ana
data to/from the legacy SD protocol can be avoided by trans lyzer identifies, at step 730, for the controller the storage
ferring the command/data to the next device in the ring (i.e., device protocol used by the host CPU and the storage device
UHS-II Input/Output device 650) through storage device 65 protocol used by the removable storage device. (As noted, the
interface 608 without using protocol conversion. One way to controller may already know the protocol used by the host
enable this feature is to store in the bridge identification CPU, in which case it does not need to “determine' the
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11 12
storage device protocol used by the host CPU.) At step 740, a device protocol used by a host device and the storage device
controller similar to controller 540 (for example) checks protocol used by a storage device are the same, for which the
whether the two storage device protocols are the same, and, in bridge is communication-wise transparent; i.e., no storage
the case of the embodiment shown in FIG. 5, if the protocols device protocol conversion is exercised. Host device 910
are not the same, controller 540 determines what type of 5 sends and receives SD data/commands to/from storage device
protocol conversion should be used. If the two storage device 920 by using UFS-configured physical layer and UFS-con
protocols are the same (shown as “Y” at step 740), controller figured link layer (the two layers are shown at 940), and by
540 connects host CPU410 and the removable storage device using SD-over-UFS transport layer and SD-configured appli
directly, at step 750, as demonstrated in FIG. 4 (i.e., contact cation layer (the two layers are shown at 950). Storage device
"(2) is connected to interface 406 or to interface 408) and in 10 920 is configured, communication layer wise, in the same
FIG. 6 (i.e., communication path established by using con way as host device 910. Therefore, bridge 830 is communi
tacts “(2)). If the two storage device protocols differ (shown cation-wise transparent to both devices; i.e., no protocol con
as “N” at step 740), the controller uses a suitable bi-direc version is required/used.
tional protocol converter to convert an incoming storage FIG. 10 schematically illustrates the conventional commu
device protocol to an outgoing storage device protocol. Data/ 15 nication layers as in FIG. 8, but in FIG. 10 they are used to
command communications from the host CPU to the bridge transfer data and commands between a host device 1010
and data/command communications from the removable Stor using SCSI-over-UFS protocol and a removable storage
age device to the bridge are regarded as “incoming commu device 1020, via bridge 1030, that is configured as legacy SD
nication', as the data/command enter the bridge. Data/com card. Host device 1010 uses a UFS physical layer and a UFS
mand communications from the bridge to the host CPU and link layer (both layers are shown at 1040), and a SCSI trans
data/command communications from the bridge to the port layer and a SCSI application layer (the latter two layers
removable storage device are regarded as “outgoing commu are shown at 1050). Legacy SD card 1020 uses an SD physical
nication', as the data/command exit the bridge. layer, an SD link layer, an SD transport layer and an SD
FIG. 8 schematically illustrates four conventional commu application layer. FIG. 10 refers to a scenario in which the
nication layers that are used to exchange data and commands 25 storage device protocol used by a host device differs from the
between a host device 810 and a removable storage device storage device protocol used by a storage device, for which a
820 via a bridge 830, where data and commands are trans storage device protocol conversion is exercised.
ferred both ways by using Small computer system interface FIG.11 schematically illustrates a conversion scheme used
(“SCSI) standards. FIG. 8 refers to a scenario in which the by a bridge such as bridge 1030 of FIG. 10, for converting a
storage device protocol used by a host device and the storage 30 high-speed protocol to a legacy (slow) SD protocol and visa
device protocol used by a storage device are the same, for verse. The bridge scheme applied by storage device protocol
which reason the bridge is communication-wise transparent; converter (SDPC) 1100 facilitates communication of data/
i.e., no storage device protocol conversion is exercised. FIG. commands between a host device and an SD card by using
8 is related to FIG.4, in which a UFS card oran SD-UFS card SCSI transport and application layer. SDPC 1100, which
430 is connected to bridge 400. Briefly, “SCSI is a set of 35 shows SDPC 450 and SDPC 670 in more details, receives
standards for physically connecting, and transferring data 1110 a SCSI command that is “riding over a high speed
between, computers and peripheral devices. The SCSI stan protocol (e.g., UFS or UHS-II). The SCSI basic commands
dards define commands, protocols, and electrical and optical (e.g., “Read/"Write') are translated 1130 into a correspond
interfaces. SCSI can be used to connect a wide range of ing SD command. The SD protocol specific commands (e.g.,
devices. For the UFS standard only a limited part of the SCSI 40 “Write Protect”, “SD Security”) are transferred from the host
protocol is used. device encapsulated inside the SCSI protocol. Such a com
The layers, which have been defined by the UFS task force mand shall undergo a de-capsulation process (1120). The SD
working for JEDEC, are “physical connection' layer, “link command (i.e., either the outcome of SD/SCSI translator
commands' layer, “transport layer and “application layer. 1130 or SD/SCSI protocol encapsulator 1120) is held in reg
Host device 810 sends and receives data/commands to/from 45 isters 1140 which are common to the legacy SD Common/
storage device 820 by using UFS-configured physical layer Status/Data registers. The legacy SD card protocol transfers
and UFS-configured link layer (the two layers are shown at the commands to the legacy SD card through memory device
840), and by using SCSI-configured transport layer and interface 1150 (the SD card is not shown in FIG. 11) by using
SCSI-configured application layer (the two layers are shown SD transport and link layer 1160 and SD physical layer 1170.
at 850). (Note” “SOUP is an abbreviation of “SCSI-over 50 Link layer signaling used for command/data flow control
UFS protocol.) Storage device 820 is configured to use the (e.g., “Ready'7"Busy') are translated, by using link signaling
same communication layers as host device 810 uses. There translator 1185, from the high speed protocol link layer to the
fore, bridge 830 is communication-wise transparent to both legacy SD protocol link layer. Any Command-Response,
devices; i.e., no protocol conversion is required/used. Data and signaling sent from the storage device to the host
FIG.9 schematically illustrates the conventional commu 55 device undergo a similar process (i.e., command responses
nication layers as in FIG. 8, but now they are used to exchange and data are loaded through the legacy SD protocol to the
SD data and SD commands between a host device 910 and a common set of registers 1140. Basic information is translated
removable storage device 920 via a bridge 930. The SD data to SCSI by SD/SCSI translator 1130, and SD specific com
and SD commands are exchanged, through bridge 930, mands will be encapsulated within SCSI by SD/SCSI encap
between host device 910 and storage device 920 by using 60 sulator 1120. The generated SCSI command is transferred
SD-over-UFS configuration, as host device 910 and storage outside through high-speed memory interface 1110 using the
device 920 are UFS-configured devices, and the SD data and link layer 1180 and physical layer 1190 of the high speed
SD commands are communicated through UFS communica protocol. Link layer signaling will be translated by using link
tion. By “SD-over-UFS configuration” and “SD-over-UFS signaling translator 1185 to high speed link layer signaling).
communication' is meant that SD data and commands are 65 FIG. 12 schematically illustrates the conventional commu
encapsulated within (i.e., they are inserted as a payload of) the nication layers as in FIG. 8, but in FIG. 12 they are used to
UFS signal. FIG. 9 refers to a scenario in which the storage transfer data and command, via bridge 1230, between a host
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13 14
device 1210 using SD-over-UFS protocol and a removable is removed from bridge 1510, as shown in FIG. 16, which is
storage device 1220 such as legacy SD card. Host device 1210 described below. The networkscheme of FIG.15 saves one of
uses a UFS physical layer and a UFS link layer (both layers the two UHS-II interfaces shown in FIG. 14 (i.e., UHS-II
are shown at 1240), and an SD transport layer and an SD interface 1430). However, a separate SD interface (i.e., SD
application layer (the latter two layers are shown at 1250). interface 1440) is still required in FIG. 15 in order to make
FIG. 12 refers to a scenario in which the storage device host device 1500 an SD backward compatible device.
protocol used by a host device differs from the storage device FIG. 16 shows the data storage system of FIG. 15 with
protocol used by a storage device, for which a storage device removable UHS-II card 1432 disconnected from bridge
protocol conversion is exercised. 1510–card 1432 is shown connected to bridge 1510 in FIG.
FIG.13 schematically illustrates a conversion scheme used 10 15 and the consequent “bypass' state of bridge 1510. In the
by a bridge, such as bridge 1230 of FIG. 12, for converting "bypass' state, input terminal 1520 of bridge 1510 is inter
high speed protocol to legacy (slow) SD protocol. The bridge nally 1610 connected to output terminal 1530 of the bridge,
scheme applied by storage device protocol converter (SDPC) thereby bypassing a storage device interface in bridge 1510
1300 facilitates communication of data/commands between a while removable UHS-II card 1432 is removed or discon
host device and an SD card by using SD-over-UFS transport 15 nected from the storage device interface.
layer. SDPC 1300, which shows SDPC450 and SDPC 670 in FIG. 17 shows a bridge 1710 that is connected in a ring
more details, receives 1310 an SD command that is encapsu topology according to an example embodiment. The ring
lated within high speed protocol (e.g., UFS or UHS-II). The topology includes a host 1740. N embedded devices (i.e.,
SD command is de-capsulated 1320 and held in registers “Device 1”, which is shown at 1742, through “Device N”,
1330 and transferred 1340 to the SD card (the SD card is not which is shown at 1744, and bridge 1710, which corresponds
shown in FIG. 13) by using SD transmission and link layer to bridge 600 of FIG. 6. Bridge 1710 enables communication
1350 and SD physical layer 1360. Link layer signaling used between removable legacy SD card 1720, or removable UHS
for Command/DATA flow control (e.g., “Ready'7"Busy’) are II card 1730, and host device 1740 even though host device
translated using link signaling translator 1385 from the high 1740 has only one interface (i.e., UHS-II interface 1750).
speed protocol link layer to the legacy SD protocol link layer. 25 Host 1740 has only one storage device interface, which is
Any command-response, data and signaling sent from the shown at 1750, through which it communicates with each
storage device to the host device undergoes a similar process device in the ring topology by using the UHS-II protocol. If
(i.e., command responses, data, etc. are loaded through the removable UHS-II card 1730 is connected to bridge 1710,
legacy SD protocol to the common set of registers 1330. The switching system 1760 connects the card (i.e., card 1730) to
information is sent out in SD format through high speed 30 the ring's loop without using SDPC 1770. If removable
memory interface 1310 by using link layer 1380 and physical legacy SD card 1720 is connected to bridge 1710, switching
layers 1390 of the high speed protocol. Link layer signaling is system 1760 connects the card to the ring's loop through
translated, by using link signaling translator 1385, directly to SDPC 1770 in order to enable conversion of the UHS-II
the high speed link layer signaling). protocol to the legacy SD protocol and vice versa. Switching
FIG. 14 schematically illustrates a system that includes N 35 system 1760 is similar to switching system 682 of FIG. 6, and
embedded UHS-II cards/devices, designated as “Device 1 SDPC 1770 is Similar to SDPC 670 of FIG. 6.
(shown at 1402), “Device 2'' (shown at 1404), ..., “Device FIG. 18 shows a connection analyzer 1800 according to an
N” (shown at 1406), which N devices are functionally con embodiment. Connection analyzer 1800 includes a host pro
nected to a host device 1410 via a ring topology, and a remov tocol detector 1810, a card protocol detector 1820 and a card
able UHS-II storage device 1432 that is connected to device 40 insertion/removal detector 1830. As explained above, if the
1410 through UHS-II interface 1430, and a legacy SD remov host device does not know in advance the type of the storage
able card 1442 connected to host device 1410 through SD device protocol, the bridge may determine its type by moni
interface 1440. Host device 1410 has three types of interfaces: toring communication with the host device. Accordingly, host
(1) a UHS-II interface 1420 for the N embedded devices protocol detector 1810 monitors communication signals that
“Device 1 through “Device N that are connected through 45 originate from a host device to detect the type of the storage
the ring topology, (2) a UHS-II interface 1430 for removable device protocol that the host device uses. Connection ana
storage devices that support the UHS-II standard (e.g., UHS lyzer 1800 may include a configurable interface 1840 to sup
II card 1432), and (3) a legacy SD interface 1440 for legacy port one or more storage device protocols that a host device
SD card 1442. Removable UHS-II card 1432 can be function may use. In order to detect the type of protocol that a host
ally disconnected from host 1410 without affecting operation 50 device uses, host protocol detector 1810 initially configures
of the N embedded devices that are wired via the ring topol interface 1840 to operate using a high speed protocol of a first
ogy because of the separate communication paths. Neverthe type (e.g., UFS). Host protocol detector 1810 determines
less, a host device that includes three separate interfaces Such whether the initial interface configuration matches the stor
as interfaces 1420, 1430, and 1440 is problematic because of age device protocol that the host device uses based on com
the reasons explained above (i.e., extra input/output wiring, 55 munication signals that host protocol detector 1810 receives
etc.). from the host device through interface 1840. If the initial
FIG. 15 schematically illustrates a partial solution to the interface configuration does not match the protocol used by
problem posed by the system scheme shown in FIG. 14. the host device, host protocol detector 1810 configures inter
Removable UHS-II card 1432 is connected to the ring topol face 1840 to operate using a high speed protocol of a second
ogy via a bridge 1510 that includes a bypass switch 1540). 60 type (e.g., UHS-II). It is assumed that one interface configu
Bridge 1510 is provided with means for detecting whether ration matches one protocol that the host device uses. (Note:
removable UHS-II card 1432 is connected to it, and for con other fast storage device protocols than the UFS and/or UHS
necting an input terminal 1520 of bridge 1510 to the “D0” II may be used by a host device.) In other words, host protocol
terminal of removable UHS-II card 1432 and an output ter detector 1810 determines the type of storage device protocol
minal 1530 of bridge 1510 to the “D1' terminal of removable 65 that a host device uses from the association between the
UHS-II card 1432, and to internally connect input terminal operative configuration of interface 1840 and the correspond
1520 to output terminal 1530 if removable UHS-II card 1432 ing protocol. Host protocol detector 1810 may alternatively
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15 16
determine the type of the protocol that the host device uses by fails, card protocol detector 1820 determines that a storage
using information or protocol command(s) that the host device is not connected to socket 1880.
device transfers to the bridge by using an upper communica Controllers 440, 540, and 660 can be a standard off-the
tion layer (e.g., link layer, transport layer, application layer). shelf System-on-Chip (“SoC) device or a System-in-Pack
Alternatively, host protocol detector 1810 may communi age (SiP) device or general purpose processing unit with
cate with the host device by using one physical interface (e.g., specialized firmware, Software or application that, when
interface 1840) that is suitable for one or more fast protocols. executed by the controller, performs the configurations, steps,
Assume that the host device communicates a protocol com operations, determinations and evaluations described herein.
mand to the bridge by using a particular fast protocol. Host Alternatively, the controller can be an Application-Specific
protocol detector 1810 receives the protocol command, infers 10 Integrated Circuit (ASIC) that implements the configura
the type of the protocol that the host device uses from the tions, steps, operations, determination and evaluations
protocol command, and uses the corresponding storage described herein by using hardware.
The articles “a” and “an are used herein to refer to one or
device protocol. to more than one (i.e., to at least one) of the grammatical
In one implementation, card protocol detector 1820 com 15 object of the article, depending on the context. By way of
municates with storage devices (e.g., storage device 1860) example, depending on the context, “an element can mean
that use at least the slow storage device protocol (e.g., legacy one element or more than one element. The term “including
SD protocol). In this implementation, card protocol detector is used herein to mean, and is used interchangeably with, the
1820 initially communicates 1860 with storage device 1870 phrase “including but not limited to’. The terms 'or' and
by using the slow storage device protocol in order to read “and” are used herein to mean, and are used interchangeably
configuration information from storage device 1870. The with, the term “and/or unless context clearly indicates oth
configuration information includes information regarding the erwise. The term "such as is used hereinto mean, and is used
type of storage device protocol(s) that the storage device can interchangeably, with the phrase “such as but not limited to’.
use. Based on the read configuration information, card pro Having thus described exemplary embodiments of the
tocol detector 1820 determines whether storage device 1870 25 invention, it will be apparent to those skilled in the art that
can use the fast storage device protocol that the host device modifications of the disclosed embodiments will be within
uses. If storage device 1870 does not use the fast storage the scope of the invention. Alternative embodiments may,
device protocol that the host device uses, card protocol detec accordingly, include more modules, fewer modules and/or
tor 1820 determines that storage device 1870 is to be accessed functionally equivalent modules. The present disclosure is
using the slow protocol. If storage device 1870 can use the fast 30 relevant to various types of mass storage devices such as
storage device protocol that the host device uses, card proto memory cards, SD-driven flash memory cards, flash storage
col detector 1820 determines that storage device 1870 is to be devices, USB Flash Drives (“UFDs), MultiMedia Card
accessed using the fast protocol. (“MMC), Secure Digital (“SD), miniSD, and microSD, and
In another implementation, card protocol detector 1820 so on. Hence the scope of the claims that follow is not limited
initially communicates with storage devices (e.g., Storage 35 by the disclosure herein.
device 1860) by using the fast storage device protocol (e.g., What is claimed is:
UHS-II). In this implementation, card protocol detector 1820 1. A method of communication between a host device and
initially communicates 1860 with storage device 1870 by a storage device, the method comprising:
using the fast storage device protocol. If storage device 1870 in a bridge comprising a controller, a Switching system, a
does not respond to the communication, card protocol detec 40 bi-directional converter, a host interface configured to
tor 1820 determines that storage device 1870 is to be accessed interface with a host device that uses a first storage
using the slow protocol. If storage device 1870 responds to device protocol, and a storage device interface config
the communication, card protocol detector 1820 determines ured to interface with a storage device that uses the first
that storage device 1870 is to be accessed using the fast storage device protocol or that uses a second storage
protocol. 45 device protocol different from the first storage device
In order to initiate the process of protocol detection there is protocol, the controller performing:
a need to determine whether a storage device e is connected to determining, in response to the storage device being
the bridge. In another implementation, storage device 1870 is operatively connected to the bridge via the storage
connected to the bridge via a socket 1880. As explained above device interface, whether the storage device uses the
in connection with the ring topology, if a device is removed 50 first storage device protocol or whether the storage
from the ring's loop, it is imperative that the removed device device uses the second storage device protocol;
be bypassed in order not to break the loop. To this end, socket in response to the storage device using the second stor
1880 may include a mechanical switch 1890 that is in a first age device protocol, configuring the Switching system
state (e.g., “ON”) when socket 1890 and storage device 1870 such that the bi-directional converter is functionally
are physically and functionally engaged, and in a second state 55 connected between the host interface and the storage
(e.g., “OFF) when storage device 1870 is removed from device interface and converting communicated data
socket 1890. That being said, socket 1890 transfers a connec from either of the first storage device protocol and the
tion signal 1892 to card connection detector 1830, based on second storage device protocol to the other of the first
which card connection detector determines whether a storage storage device protocol and the second storage device
device is connected to socket 1890 (i.e., to the bridge). Alter 60 protocol, and
natively, card connection detector 1830 may use a polling in response to the storage device using the first storage
scheme to poll storage device 1870. Polling sessions would device protocol, configuring the Switching system to
be performed after the type of the protocol used by the storage bypass the bi-directional converter when connecting
device is determined. A determination that any protocol is the host interface to the storage device interface,
used by a storage device is also used as an indication that a 65 wherein one of the first storage device protocol and the
storage device is connected to the bridge. If an attempt to second storage device protocol is a secure digital (SD)
communicate with a presumably connected storage device over universal flash storage (UFS) protocol.
 US 8,301,822 B2
17 18
2. The method of claim 1, wherein the controller is prepro device interface and in response to detecting the discon
grammed to recall that the host device uses the first storage nection, to activate the bypass Switch so as to bypass the
device protocol. storage device interface.
3. The method of claim 1, wherein the controller further 11. The storage system bridge of claim 10, wherein the
performs determining a type of storage device protocol used 5 controller is preprogrammed to recall that the host device uses
by the host device through interaction between the controller the first storage device protocol.
and the host device. 12. The storage system bridge of claim 10, wherein the
4. The method of claim 1, wherein the first storage device controller is further configured to determine a type of storage
protocol facilitates faster data communication than the sec device protocol through interaction with the host device.
ond storage device protocol. 10
13. The storage system bridge of claim 10, wherein the first
5. The method of claim 1, wherein the first storage device storage device protocol facilitates faster data communication
protocol is one of a universal flash storage (UFS) protocol and than the second storage device protocol.
an ultra high speed (UHS-II) protocol.
6. The method of claim 1, wherein the second storage 14. The storage system bridge of claim 10, wherein the first
device protocol is one of a secure digital (SD) protocol, a 15 storage device protocol is one of a universal flash storage
universal flash storage (UFS) protocol, and an ultra high (UFS) protocol and an ultra high speed (UHS-II) protocol.
speed (UHS-II) protocol. 15. The storage system bridge of claim 10, wherein the
7. The method of claim 1, wherein the storage device is one second storage device protocol is one of a secure digital (SD)
of secure digital (SD) card, universal flash storage (UFS) protocol, a universal flash storage (UFS) protocol, and an
card, ultra high speed (UHS-II) card, SD-UFS card, and SD ultra high speed (UHS-II) protocol.
UHS-II card. 16. The storage system bridge of claim 10, wherein one of
8. The method of claim 1, wherein the bridge connects to a the first storage device protocol and the second storage device
host device and to a storage device via a data network, protocol is a small computer system interface (SCSI) over
wherein the data network has one of a chain topology and a universal flash storage (UFS) protocol.
ring topology. 25 17. The storage system bridge of claim 10, wherein one of
9. The method of claim 1, wherein the bridge is connected the first storage device protocol and the second storage device
directly to one of the host device and to a communication hub. protocol is a secure digital over universal flash storage (SD
10. A storage system bridge, the storage system bridge over-UFS) protocol.
comprising: 18. The storage system bridge of claim 10, wherein the
a host interface configured to interface with a host device 30
storage device is one of a secure digital (SD) memory card, a
that uses a first storage device protocol; universal flash storage (UFS) memory card, an ultra high
a storage device interface configured to interface with a speed (UHS-II) memory card, an SD-UFS card, and an SD
storage device that uses the first storage device protocol UHS-II card.
or that uses a second storage device protocol different 19. The storage system bridge of claim 10, further com
from the first storage device protocol; 35
a bi-directional converter configured to convert communi prising a connection analyzer configured to determine
cated data from either of the first storage device protocol whether a storage device is interfaced with the storage system
to and the second storage device protocol to the other of bridge and configured to determine a storage device protocol
the first storage device protocol and the second storage type that at least one of the host device and the storage device
device protocol; 40 USS.
a controller; and 20. The storage system bridge of claim 10, wherein the
a Switching system, storage system bridge is connected directly to one of the host
wherein, in response to the storage device being opera device and to a communication hub.
tively coupled to the storage device interface, the con 21. A storage system bridge, comprising:
troller is configured: 45 a host interface configured to interface with a host device
to determine whether the storage device uses the first that uses a first storage device protocol;
storage device protocol or whether the storage device a storage device interface configured to interface with a
uses the second storage device protocol; storage device that uses one of a second storage device
in response to the storage device using the second stor protocol and a third storage device protocol, wherein
age device protocol, to configure the Switching sys 50 each of the second storage device protocol and the third
tem such that the bi-directional converter is function storage device protocol differ from the first storage
ally connected between the host interface and the device protocol;
storage device interface and converting the commu a first bi-directional converter configured to convert com
nicated data from either of the first storage device municated data from either of the first storage device
protocol and the second storage device protocol to the 55 protocol and the second storage device protocol to the
other of the first storage device protocol and the sec other of the first storage device protocol and the second
ond storage device protocol, and storage device protocol;
in response to the storage device using the first storage a second bi-directional converter configured to convert the
device protocol; to configure the Switching system to communicated data from either of the first storage
bypass the bi-directional converter when connecting 60 device protocol and the third storage device protocol to
the host interface to the storage device interface, the other of the first storage device protocol and the third
wherein the storage system bridge connects to the host storage device protocol;
device and to the storage device via a bus, wherein the a controller; and
bus has one of a chain topology and a ring topology, a Switching system that includes a bypass Switch,
wherein the Switching system includes a bypass Switch, 65 wherein, in response to the storage device being opera
and wherein the controller is further configured to detect tively connected to the storage device interface, the con
a disconnection of the storage device from the storage troller is configured:
 US 8,301,822 B2
19 20
to determine whether the storage device uses the second 26. The storage system bridge of claim 25, wherein the
storage device protocol or whether the storage device controller is further configured to detect whether the storage
uses the third storage device protocol; device is using the second storage device protocol or a third
in response to the storage device using the second stor storage device protocol.
age device protocol, to configure the Switching sys 27. The storage system bridge of claim 26, further com
tem such that the first bi-directional converter is func prising a second bi-directional converter configured to con
tionally connected between the host interface and the vert the communicated data from either of the first storage
device protocol and the third storage device protocol to the
storage device interface and converting the commu other of the first storage device protocol and the third storage
nicated data from either of the first storage device 10 device protocol, wherein the controller is configured to func
protocol to and the second storage device protocol to tionally connect the second bi-directional converter between
the other of the first storage device protocol and the the host interface and the storage device interface in response
second storage device protocol, and to detecting that the storage device uses the third storage
in response to the storage device using the third storage device protocol.
device protocol, to configure the Switching system 15
28. The storage system bridge of claim 25, wherein the
such that the second bi-directional converter is func controller is further configured to detect whether the storage
tionally connected between the host interface and the device is using the first storage device protocol or the second
storage device interface and converting the commu storage device protocol.
nicated data from either of the first storage device 29. The storage system bridge of claim 25, wherein the first
protocol and the third storage device protocol to the storage device protocol facilitates faster data communication
other of the first storage device protocol and the third than the second storage device protocol.
storage device protocol, and 30. The storage system bridge of claim 25, wherein the
to detect a disconnection of the storage device from the controller is further configured to determine use of the first
storage device interface and to respond to the discon storage device protocol by the host device through interaction
between the controller and the host device.
nection by activating the bypass Switch so as to bypass 25
31. A storage system bridge, comprising:
the storage device interface. a host interface;
22. The storage system bridge of claim 21, wherein the a storage device interface;
controller is preprogrammed to recall that the host device uses a bi-directional converter configured to convert communi
the first storage device protocol without interaction with the cated data from either of a first storage device protocol
host device. 30
23. The storage system bridge of claim 21, wherein the and a second storage device protocol to the other of the
controller is further configured to detect a type of storage first storage device protocol and the second storage
device protocol through interaction with the host device. device protocol, wherein one of the first storage device
24. The storage system bridge of claim 21, further com protocol and the second storage device protocol is
prising a connection analyzer configured to detect whether 35 a small computer system interface (SCSI over universal
the storage device is interfaced with the storage system flash storage (UFS) protocol; and
bridge, and configured to detect a storage device protocol a controller;
type that at least one of the host device and the storage device wherein, in response to a storage device being operatively
USS.
coupled to the storage device interface while a host
25. A storage system bridge, comprising: 40
device that uses the first storage device protocol is opera
a host interface configured to interface with a host device tively coupled to the host device interface, the controller
via a bus having a ring topology, wherein the host inter is configured to functionally connect the bi-directional
face uses a first storage device protocol; converter between the host interface and the storage
a storage device interface configured to interface with a device interface in response to detecting that the storage
storage device via the bus having the ring topology, 45
device uses the second storage device protocol.
wherein the storage device interface uses the first storage 32. The storage system bridge of claim 31, wherein the
device protocol or a second storage device protocol dif controller is further configured to detect whether the storage
ferent from the first storage device protocol, wherein one device is using the first storage device protocol or the second
of the first storage device protocol and the second stor storage device protocol.
age device protocol is a secure digital (SD) over univer 50
33. The storage system bridge of claim 31, wherein the
sal flash storage (UFS) protocol; controller is further configured to detect whether the storage
a controller; and device is using the second storage device protocol or a third
a configurable bypass Switch, storage device protocol.
wherein the controller is configured: 34. The storage system bridge of claim 33, further com
to determine whether a the storage device is operatively 55
prising a second bi-directional converter configured to con
connected to the storage device interface; vert the communicated data from either of the first storage
in response to the storage device being operatively con device protocol and the third storage device protocol to the
nected to the storage device interface, to connect the other of the first storage device protocol and the third storage
host device interface to the storage device interface, device protocol, wherein the controller is configured to func
and 60 tionally connect the second bi-directional converter between
in response to the storage device not being connected to the host interface and the storage device interface in response
the storage device interface, to activate the config to detecting that the storage device uses the third storage
urable bypass Switch so as to bypass the storage device protocol.
device interface.
 UNITED STATES PATENT AND TRADEMARK OFFICE
CERTIFICATE OF CORRECTION
PATENT NO. : 8,301,822 B2 Page 1 of 1
APPLICATIONNO. : 12/565685
DATED : October 30, 2012
INVENTOR(S) : Yosi Pinto et al.

It is certified that error appears in the above-identified patent and that said Letters Patent is hereby corrected as shown below:

In the Claims section, Column 17, Claim 10, Line 38, “to and the second storage device protocol to the
other of should read-and the second storage device protocol to the other of -.
In the Claims section, Column 17, Claim 10, Line 59, “device protocol; to configure the switching
system to should read--device protocol, to configure the switching system to--.
In the Claims section, Column 19, Claim 21, Line 10, “protocol to and the second storage device
protocol to the other should read -protocol and the second storage device protocol to the other--.
In the Claims section, Column 19, Claim 25, Line 55, “to determine whether a the storage device is
operatively connected should read-to determine whether the storage device is operatively
connected--.

In the Claims section, Column 20, Claim 31, Line 35, “a small computer system interface (SCSI over
universal flash storage should read -a small computer system interface (SCSI) over universal flash
Storage--.

Signed and Sealed this

Teresa Stanek Rea