(12)
`
`United States Patent
`Leung
`
`(10) Patent N0.:
`(45) Date of Patent:
`
`US 6,633,931 B2
`Oct. 14, 2003
`
`US006633931B2
`
`(54) CARD IDENTIFICATION SYSTEM AND
`METHOD FOR AN INPUT/OUTPUT
`INTERFACE
`
`(75) Inventor: Samuel C. Leung, Roseville, CA (US)
`
`(73) Assignee: Hewlett-Packard Development
`Company, L.P., Houston, TX (US)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`USC' 154(k)) by 385 days‘
`
`(21) Appl. N0.: 09/751,991
`
`(22) Filed:
`65
`(
`)
`
`58
`(
`)
`
`Dec. 29, 2000
`Pr, P bl,
`t, D t
`lor u lea Ion a a
`US 2002/0087762 A1 Jul. 4, 2002
`(51) Int C17
`G06F 13/10 G06F 13/14
`(52) Us‘ Ci """""""""""" "
`710/62 7’10/8_ 710/11_
`'
`'
`' """"""""""""""" "'710/14_ %10/64_’370/442’
`F, M f S
`h
`’
`710/2; 11 14
`1e
`0
`earc """""""""""
`64_ ’370’/442’
`’
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`’
`
`5,615,344 A * 3/1997 Corder ...................... .. 710/62
`5,712,472 A * 1/1998 Lee .......................... .. 235/486
`5,819,050 A * 10/1998 Boehling et a1. ......... .. 710/104
`6,009,486 A * 12/1999 Dayan et al. ............. .. 710/303
`6,059,583 A * 5/2000 Croft et a1. . . . . .
`. . . .. 439/131
`6,182,204 B1 * 1/2001 Nakashima ................ .. 712/38
`6,452,937 B1 * 9/2002 Borkovic et a1. ......... .. 370/442
`
`*
`
`.
`
`cued by exammer
`
`.
`
`Primary Examiner—Rehana Perveen
`
`(57)
`
`ABSTRACT
`
`A system and method for detecting the identi?cation of the
`type of card that is installed in an input/output interface for
`interconnecting ?rst and second electronic devices, such as
`a peripheral device and a peripheral control device is dis
`closed. The cards may be smart or peripheral dependent
`cards Which have different functionality and con?guration.
`Upon start-up, the peripheral device generates a reset signal
`Which causes the card to generate a digital identi?cation that
`is received by the peripheral device. If the identi?cation
`indicates that it is a type of card that the peripheral device
`supports, then the peripheral device operates in the manner
`speci?ed for that type of card.
`
`5,454,725 A * 10/1995 Speiser et a1. .............. .. 439/61
`
`17 Claims, 2 Drawing Sheets
`
`A
`_ B
`__13 C
`1L D
`3
`E
`
`— G
`
`—-;‘ F
`6
`H
`10
`
`CARD SIZE
`
`!
`|
`i
`28
`/ .
`9
`I
`I
`QH
`2 I
`7
`_
`QH —— 30
`I
`
`PERIPHERAL SIZE
`
`> CFG_DATA
`
`|
`
`i
`I [/16
`I/
`|
`|
`!
`|
`
`32
`/
`
`34/
`
`= CFG_CLK
`NRESET
`
`Cisco Systems, Inc., EX 1147 Page 1
`
`

`

`U.S. Patent
`
`0a. 14, 2003
`
`Sheet 1 of2
`
`US 6,633,931 B2
`
`0 % é ////%o
`
`FIG. 2
`
`Cisco Systems, Inc., EX 1147 Page 2
`
`

`

`U.S. Patent
`
`0a. 14, 2003
`
`Sheet 2 of2
`
`US 6,633,931 B2
`
`CARD SIZE
`
`!
`
`PERIPHERAL SIZE
`
`7
`
`l
`
`
`28 / .
`9
`I
`2 I
`30
`I
`i
`i
`I I/16
`l/
`!
`!
`!
`|
`
`QH
`(3H
`
`L A
`.12_ B
`_13_ C
`& D
`3__ E
`—;‘-F
`i- H
`L
`
`_ G
`
`32
`/
`
`34/
`
`> CFG_DATA
`
`4 CFG_CLK
`
`< NRESET
`
`FIG. 4
`
`NPRSNT
`
`NRESET
`
`CFG_CLK
`
`CFG_DATA
`
`|—>fmax<—l
`+Tsu —>|Tpw |<—
`l.
`|
`I m |
`|
`I
`'
`+ + Td + <_ Td
`CARD IDSBIT7 \CARD ID BITO
`\
`_-.;;
`( ;._-.
`\
`\
`<7L CARD ID FRAME O
`CARD ID FRAME 1
`CARD ID BIT 0
`CARD ID BIT 1
`
`FIG. 5
`
`Cisco Systems, Inc., EX 1147 Page 3
`
`

`

`US 6,633,931 B2
`
`1
`CARD IDENTIFICATION SYSTEM AND
`METHOD FOR AN INPUT/OUTPUT
`INTERFACE
`
`BACKGROUND OF THE INVENTION
`
`The present invention is directed to a system for detecting
`the identi?cation of a card that is installed in an input/output
`interface, and more particularly to a system for identifying
`the type of card that may be installed in an input/output
`interface betWeen tWo electronic components, such as a
`peripheral device and a peripheral control device, for
`example.
`As the functional capabilities of electronic products con
`tinue to expand, neW products continue to be developed
`Which must be compatible across manufacturers’ product
`lines. This is particularly evident in the areas of personal
`computers that are used in the home and in large and small
`business environments, Which may or may not be connected
`in a netWork or the Internet. Such personal computers are
`usually operationally connected to peripheral devices such
`as printers of various kinds, plotters, scanners, fax machines,
`copiers and the like, including multi-function peripherals
`Which can perform the more than one task of those men
`tioned above.
`One of the relatively recent advancements in the design of
`peripheral devices is the expansion of their operational
`capabilities through the use of cartridges or cards that can be
`plugged into a shared input/output interface of the peripheral
`device that is intended to operate in conjunction With a
`control device. Such cards can be so-called peripheral
`dependent cards Which can implement basic functionality, or
`they can be smart cards Which typically includes operational
`protocol that can increase the functional capability of the
`peripheral in conjunction With a control device, such as a
`print server, for example.
`Because different types of cards may be plugged into the
`interface, it is necessary to knoW the identity of the type of
`card that is plugged into the interface of a peripheral device
`so that the functionality and con?guration are supported in
`the system. Since the peripheral device is the device that is
`generally considered to be the master device in a system that
`Wishes to perform the peripheral device function, i.e., a
`printer, for example, must have the necessary input control
`commands to operate properly. It is the peripheral device
`that must support the cards that may be plugged into the
`peripheral interface.
`If the peripheral device does not support a particular card,
`then damage to the card and/or the peripheral device can
`easily occur if output signals are not applied to output lines,
`and input signals are not applied to input lines. It is therefore
`extremely important that the system be appropriately con
`?gured so that damage resulting from device interconnection
`incompatibility does not occur.
`
`SUMMARY OF THE INVENTION
`
`The present invention embodies a system and a method
`for detecting the identi?cation of the type of card or car
`tridge that may be plugged into an electrical interface that
`interconnects tWo electronic devices, such as a peripheral
`device and a peripheral control device. Because the cards
`may have different functionality and utiliZe different
`con?gurations, it is important that the peripheral device
`support the functionality of the card that is plugged into the
`interface. Upon start-up, the peripheral device generates a
`signal Which causes the card to generate a digital identi?
`
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`cation that is received by the peripheral device. If the
`identi?cation indicates that it is a type of card that the
`peripheral device supports, then the peripheral device oper
`ates in the manner speci?ed for that type of card. The
`preferred embodiment of the card is an implementation that
`requires only a single pin to reset a chip and generate the
`digital identi?cation, and therefore requires only minimal
`overhead in the design and operation of the input/output
`interface.
`
`DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a perspective vieW of a front portion of a printer
`peripheral device of the type Which has a slot in Which a card
`(i.e., a cartridge) is inserted, With the card controlling at least
`some of the functionality of the device.
`FIG. 2 is a perspective vieW of a printed circuit board
`having an interface attached thereto, including a metallic
`“garage” in Which a card can be inserted, and shoWn
`together With a generally back vieW of a card.
`FIG. 3 is another perspective vieW (similar to FIG. 2) of
`the printed circuit board having the interface attached
`thereto, including a front vieW of the metallic garage, shoWn
`together With a generally front vieW of the card.
`FIG. 4 is a schematic circuit diagram of a preferred
`embodiment of the present invention.
`FIG. 5 is a timing diagram of the operation of preferred
`embodiment shoWn in FIG. 4.
`
`DETAILED DESCRIPTION
`
`Broadly stated, the present invention is directed to a
`system for detecting or determining the identi?cation of the
`type of card that is installed in an input/output interface
`electrically interconnecting tWo electronic devices, such as
`a peripheral device and a peripheral control device. The
`identi?cation enables the devices to determine if they are
`compatible With one another and prevents generation of
`signals by each to the other that may be incorrect and could
`therefore cause damage to one or both. The reason that
`incorrect signals could be generated is that cards are being
`developed that have different functionality and con?gura
`tions.
`In this regard, an interface may have a relatively large
`number of electrical conductors or lines, for example, sev
`eral doZen in some instances, and some of the lines have
`dedicated functions While others are general input/output
`lines. Some of the cards may be so-called peripheral depen
`dent cards that have basic functionality, While other cards
`may be smart cards that have a speci?c protocol that
`overlays the interface. The use of a digital identi?cation
`enables the card’s functionality to be speci?cally de?ned,
`Which among other things, speci?es Which of the general
`input/output lines are input lines and Which are output lines.
`HoWever, the con?guration of a card must be predeter
`mined as to Whether it is Within the manufacturer’s product
`line or is supplied by third party manufacturers. If a par
`ticular card is compatible With the peripheral and can be
`con?gured for use With a peripheral device, then its con
`?guration can be speci?ed and a digital identi?cation can be
`de?ned and a library of such identi?cations and associated
`con?gurations can be loaded into a suitable memory in the
`peripheral device (typically burned in ROM or a ?ash
`memory or the like). When the peripheral device receives a
`digital identi?cation, it can compare the same With digital
`identi?cations Within the library and con?gure itself in
`accordance With its speci?cations. If there is no positive
`
`Cisco Systems, Inc., EX 1147 Page 4
`
`

`

`US 6,633,931 B2
`
`10
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`comparison, the particular card is not supported by the
`peripheral device and it Will generate a ?ag or other error
`message and not permit itself to generate or receive signals
`from the card. This Will prevent incorrect signals from
`crossing the interface Which could damage either the card or
`the peripheral device.
`Turning noW to the draWings and particularly FIG. 1, a
`printer 10 is shoWn With a card 12 plugged into a slot 14. As
`should be evident from the previous discussion, the card 12
`may be a peripheral dependent or smart card and may be
`manufactured by the printer manufacturer or a third party.
`Referring to FIGS. 2 and 3, the card 12 ?ts Within an
`interface, indicated generally at 16, that is attached to a
`printed circuit board 18 that is installed Within the printer 10
`or other peripheral device, such as a scanner, plotter, faX
`machine, copier, multi-function device or the like. The
`interface 16 shoWn has a metal enclosure or garage 20 Which
`has an opening 22 at the front through Which the card can be
`inserted. The opening is coextensive With the slot 14 in the
`printer 10. The card 12 has a multi-pinned connector 24 that
`is aligned to engage another multi-pinned connector 26 in
`the interface When the card is inserted into the interface 16.
`The connector 26 has a right angle connection to the printed
`circuit board 18 Although not shoWn in detail, the connec
`tors illustrated have 40 pins (and therefore 40 electrical
`conductors or lines) that interconnect the card 12 With the
`printer 10.
`To generate the digital identi?cation, the card 12 prefer
`ably has an 8-bit parallel input, serial output shift register,
`indicated generally at 28 in FIG. 4, preferably a high
`performance silicon-gate CMOS integrated circuit, such as
`Model MC74HC165A sold by Motorola. It should be under
`stood hoWever, that other devices could be used, including
`devices made by vendors other than Motorola, and Which
`could have a greater or lesser number of bits. By utiliZing 8
`bits, 256 different card identi?cations could be accommo
`dated. It should be understood that a larger or smaller
`number of bits may be utiliZed if a larger or smaller number
`of different card identi?cations are desired. The shift register
`28 is part of the card 12 and has a serial input SA and 8
`parallel inputs A—H, With input H being the least signi?cant
`bit. Aserial output line 30 eXtends to the peripheral side and
`carries the 8-bit serial digital identi?cation signal CFGi
`DATA to the peripheral, When it is outputted. Aclock signal
`from the peripheral is applied on line 32 and a reset signal
`(NRESET) is applied on line 34 to the card 28 by the
`peripheral.
`The unique digital identi?cation is produced by applying
`the appropriate logic levels to the inputs A—H. For eXample,
`if the digital ID is 2, that Would be generated by having
`inputs A—G and H at logic 0 and input G at logic 1. Similarly,
`card ID 0 Would be generated When all inputs A—H are at
`logic 0, and ID 255 Would be generated When all inputs are
`at logic 1. These logic values are constantly applied to the
`parallel inputs for each type of card as previously described.
`In accordance With an important aspect of the present
`invention, and referring to the timing diagram of FIG. 5, the
`generation of the digital identi?cation is commenced as soon
`as the reset signal is applied on line 34. Importantly, the
`digital identi?cation is only requested When the peripheral
`device is poWered-up or When a card is inserted into the
`interface 16. Once the peripheral detects the insertion of a
`card, it holds NRESET loW for an additional 100 millisec
`ond Minimum. The additional time for the assertion of
`NRESET alloWs the card enough time to reset properly and
`to load the 8-bit card identi?cation value into the shift
`register. The clock signal CFGiCLK must be loW prior to
`
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`
`4
`the deassertion of NRESET. After the deassertion of
`NRESET, the identi?cation bit 0 (input H) is outputted on
`CFGiDATA after Td time. On each rising edge of CFGi
`CLK, the neXt least signi?cant bit is outputted on CFGi
`DATA line 30. After seven successive clock cycles applied
`on line 32 by the peripheral, the complete 8-bit digital
`identi?cation is clocked out on line 30.
`An important aspect of the present invention is that the
`application of the reset signal causes the ?rst bit to be loaded
`into the shift register. This is in contrast to the usual
`convention of a reset signal resetting an integrated circuit
`and a separate signal on another line to load the inputs into
`the shift register. The importance of simultaneously begin
`ning to load the shift register upon application of the resent
`signal is to utiliZe a single line rather than tWo. This
`signi?cantly reduces the overhead required to generate the
`digital ID. Since the clock signal is required for operation of
`the card, a total of three lines are required for requesting and
`receiving the digital identi?cation signal.
`From the foregoing, it should be appreciated that a system
`for detecting a digital identi?cation of a card used in an
`input/output interface has been described Which has many
`desirable advantages and attributes. The invention utiliZes
`inexpensive components in a unique manner to request and
`communicate the digital identi?cation from a card to a
`peripheral device With little overhead in terms of utiliZing
`valuable electrical lines and connector pins, and is very
`reliable.
`While various embodiments of the present invention have
`been shoWn and described, it should be understood that other
`modi?cations, substitutions and alternatives are apparent to
`one of ordinary skill in the art. Such modi?cations, substi
`tutions and alternatives can be made Without departing from
`the spirit and scope of the invention, Which should be
`determined from the appended claims.
`Various features of the invention are set forth in the
`appended claims.
`What is claimed is:
`1. A system for detecting the identi?cation of the type of
`card means installed in an input/output interface that elec
`trically interconnects ?rst and second electronic devices, the
`type of card means de?ning its predetermined functionality
`and con?guration, said system comprising:
`an interface for electrically interconnecting the ?rst and
`second electronic devices;
`a card means for generating a digital identi?cation that
`identi?es the type of card means and therefore its
`predetermined functionality and con?guration and
`applying said digital identi?cation to the ?rst electronic
`device in response to a ?rst signal being applied
`thereto;
`the ?rst electronic device initially generating a ?rst signal
`that is received by said card means;
`the ?rst electronic device comparing said digital identi
`?cation to a library of one or more digital identi?ca
`tions and con?guring itself to operate in accordance
`With the predetermined functionality and con?guration
`in response to a positive comparison to said applied
`digital identi?cation;
`the ?rst and second electronic devices selectively sending
`and receiving signals in accordance With the type of
`card means identi?ed.
`2. Asystem as de?ned in claim 1 Wherein said ?rst signal
`is a reset signal that is generated When the ?rst electronic
`device is initially poWered up.
`3. A system as de?ned in claim 1 Wherein the ?rst
`electronic device is a peripheral device and the second
`electronic device is a peripheral control device.
`
`Cisco Systems, Inc., EX 1147 Page 5
`
`

`

`US 6,633,931 B2
`
`5
`4. A system as de?ned in claim 3 Wherein the ?rst
`electronic device is a peripheral device that performs at least
`one of the functions of a scanner, a plotter, a printer, a faX
`machine and a copier.
`5. A system as de?ned in claim 3 Wherein the second
`electronic device is a peripheral control device that com
`prises one of a personal computer, a print server, a
`microprocessor, an ASIC and a processing means.
`6. A system as de?ned in claim 1 Wherein said interface
`includes a plurality of separate electrical conductors, the
`functionality and con?guration that is speci?ed by the type
`of said card means including the designation of selected
`ones of said plurality of conductors as input or output
`conductors to the ?rst electronic device.
`7. Asystem as de?ned in claim 1 Wherein said card means
`comprises a shift register of the type Which has a plurality of
`parallel inputs, a reset input, a clock input and a serial
`output, said shift register generating said digital identi?ca
`tion signal in response to said ?rst signal being received and
`clock signals being applied.
`8. A system as de?ned in claim 7 Wherein said shift
`register has 8 parallel inputs, and said serial output is
`capable of generating 256 different digital identi?cation
`signals.
`9. A system as de?ned in claim 1 Wherein said ?rst
`electronic device generates said ?rst signal When said ?rst
`electronic device is poWered up.
`10. Asystem for detecting the identi?cation of the type of
`card means installed in an input/output interface that elec
`trically interconnects a peripheral device and a peripheral
`control device, the card means identi?cation specifying of
`the type of card means, the type of card means de?ning
`predetermined functionality and con?guration, said system
`comprising:
`an interface for electrically interconnecting the peripheral
`device and the peripheral control device;
`a card means for generating a digital identi?cation that
`identi?es the type of card means and therefore its
`predetermined functionality and con?guration and
`applying said digital identi?cation to the peripheral
`device in response to a reset signal being applied
`thereto;
`the peripheral device initially generating a reset signal
`that is received by said card means;
`the peripheral device comparing said digital identi?cation
`to a library of one or more digital identi?cations and
`con?guring itself to operate in accordance With the
`predetermined functionality and con?guration in
`response to a positive comparison to said applied
`digital identi?cation;
`the peripheral device and peripheral control device selec
`tively sending and receiving signals in accordance With
`the type of card means identi?ed.
`11. A system as de?ned in claim 10 Wherein said periph
`eral device generates said reset signal When said peripheral
`device is poWered up.
`12. Amethod of detecting the identi?cation of the type of
`card means that is installed in an input/output interface that
`electrically interconnects ?rst and second electronic devices,
`the type of card means de?ning its predetermined function
`
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`ality and con?guration, the ?rst device being capable of
`operating With one or more types of card means in response
`to the ?rst device recogniZing the identi?cation as specifying
`a type of card means that the ?rst device supports, said
`method comprising the steps of:
`the ?rst electronic device initially generating a ?rst signal
`that is received by said card means;
`the card means generating a digital identi?cation that
`identi?es the type of card means and therefore its
`predetermined functionality and con?guration and
`applying said digital identi?cation to the ?rst electronic
`device in response to the ?rst signal being applied
`thereto;
`the ?rst electronic device comparing said digital identi
`?cation to a library of one or more digital identi?ca
`tions and con?guring itself to operate in accordance
`With the predetermined functionality and con?guration
`in response to a positive comparison to said applied
`digital identi?cation; and,
`the ?rst and second electronic devices selectively sending
`and receiving signals in accordance With the type of
`card means identi?ed.
`13. A method as de?ned in claim 12 Wherein said ?rst
`electronic device generates said ?rst signal When it is
`poWered up.
`14. A method as de?ned in claim 12 Wherein the card
`means comprises a shift register of the type Which has a
`plurality of parallel inputs, a reset input, a clock input and a
`serial output, shift register generating said digital identi?
`cation signal in response to said ?rst signal being received
`and clock signals being applied.
`15. A method as de?ned in claim 14 Wherein said digital
`identi?cation comprises a multi-bit digital Word that is
`serially clocked out of the output by successive clock signals
`being applied.
`16. A card means for use With an input/output interface
`that electrically interconnects a peripheral device and a
`peripheral control device, said card means controlling the
`functionality and con?guration of the peripheral device and
`the peripheral control device, provided that the peripheral
`device is capable of supporting said card means, said card
`means comprising:
`means for generating a multiple bit digital identi?cation
`signal that identi?es the type of card means and there
`fore its predetermined functionality and con?guration
`for application to the peripheral device in response to a
`?rst signal being applied thereto, said means for gen
`erating beginning the generation of said multiple bit
`digital identi?cation signal serially on a single output
`line responsive to said ?rst signal being applied on a
`single input line.
`17. A card means as de?ned in claim 16 Wherein said
`means for generating comprises a shift register of the type
`Which has a plurality of parallel inputs, a reset input, a clock
`input and a serial output, shift register generating said digital
`identi?cation signal in response to said ?rst signal being
`received and clock signals being applied.
`
`*
`
`*
`
`*
`
`*
`
`*
`
`Cisco Systems, Inc., EX 1147 Page 6
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`