IDT723674_技术文档

CMOS SyncBiFIFO^TMWITH BUS-MATCHING

2,048 x 36 x 2

4,096 x 36 x 2

IDT723654

IDT723664

IDT723674

8,192 x 36 x 2

• Port B bus sizing of 36 bits (long word), 18 bits (word) and 9 bits

(byte)

• Big- or Little-Endian format for word and byte bus sizes

• Retransmit Capability

• Master Reset clears data and configures FIFO, Partial Reset

clears data but retains configuration settings

• Mailbox bypass registers for each FIFO

• Free-running CLKA and CLKB may be asynchronous or coincident

(simultaneous reading and writing of data on a single clock edge

is permitted)

• Auto power down minimizes power dissipation

• Available in space saving 128-pin Thin Quad Flatpack (TQFP)

• Pincompatibletothelowerdensityparts, IDT723624/723634/723644

• Industrial temperature range (–40°C to +85°C) is available

FEATURES

• Memory storage capacity:

IDT723654

IDT723664

IDT723674

–

2,048 x 36 x 2

4,096 x 36 x 2

8,192 x 36 x 2

• Clock frequencies up to 83 MHz (8ns access time)

• Two independent clocked FIFOs buffering data in opposite

directions

• Select IDT Standard timing (using EFA, EFB, FFA, and FFB flags

functions) or First Word Fall Through Timing (using ORA, ORB,

IRA, and IRB flag functions)

• Programmable Almost-Empty and Almost-Full flags; each has five

default offsets (8, 16, 64, 256 and 1,024 )

• Serial or parallel programming of partial flags

FUNCTIONAL BLOCK DIAGRAM

MBF1

Mail 1

Register

CLKA

Port-A

Control

Logic

CSA

W/RA

ENA

RAM ARRAY

2,048 x 36

4,096 x 36

8,192 x 36

36

MBA

36

FIFO1,

Mail1

Reset

Logic

MRS1

PRS1

Write

Pointer

Read

Pointer

36

Status Flag

Logic

EFB/ORB

AEB

FFA/IRA

AFA

FIFO1

FIFO2

FS2

FS0/SD

Programmable Flag

Offset Registers

Timing

Mode

FWFT

FS1/SEN

B0-B35

A0-A35

13

Status Flag

Logic

EFA/ORA

FFB/IRB

AFB

AEA

36

Read

Pointer

Write

Pointer

36

FIFO2,

Mail2

Reset

Logic

MRS2

PRS2

RT1

RTM

RT2

FIFO1 and

FIFO2

Retransmit

Logic

RAM ARRAY

2,048 x 36

4,096 x 36

8,192 x 36

36

CLKB

CSB

W/RB

ENB

MBB

BE

Port-B

Control

Logic

Mail 2

Register

BM

SIZE

MBF2

5608 drw01

IDTandtheIDTlogoareregisteredtrademarksofIntegratedDeviceTechnology,Inc.SyncBiFIFOisatrademarkofIntegratedDeviceTechnology,Inc.

NOVEMBER 2003

COMMERCIAL TEMPERATURE RANGE

1



DSC-5608/5

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

These devices are a synchronous (clocked) FIFO, meaning each port

DESCRIPTION

employsasynchronousinterface. Alldatatransfersthroughaportaregated

totheLOW-to-HIGHtransitionofaportclockbyenablesignals. Theclocksfor

each port are independent of one another and can be asynchronous or

coincident. The enables for each port are arranged to provide a simple

bidirectionalinterfacebetweenmicroprocessorsand/orbuseswithsynchro-

nouscontrol.

TheIDT723654/723664/723674isamonolithic,high-speed,low-power,

CMOS bidirectional synchronous (clocked) FIFO memory which supports

clockfrequenciesupto83MHzandhasreadaccesstimesasfastas8ns. Two

independent2,048/4,096/8,192 x 36dual-portSRAMFIFOsonboardeach

chipbufferdatainoppositedirections. FIFOdataonPortBcanbeinputand

outputin36-bit, 18-bit, or9-bitformats witha choice ofBig-orLittle-Endian

configurations.

PIN CONFIGURATION

INDEX

W/RA

ENA

CLKA

3

GND

A35

5

A34

A33

7

A32

Vcc

A31

A30

GND

A29

A28

A27

A26

A25

102

101

100

99

98

97

96

95

94

93

92

91

90

89

88

87

86

85

84

83

82

81

80

79

78

77

76

75

74

73

72

71

70

69

68

67

66

65

CLKB

PRS2/RT2

Vcc

1

2

B35

B34

B33

B32

RTM

GND

B31

B30

B29

B28

B27

B26

Vcc

4

6

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

B25

B24

BM

A24

A23

BE/FWFT

GND

A22

GND

B23

B22

B21

B20

B19

B18

GND

B17

B16

SIZE

Vcc

B15

B14

B13

B12

GND

B11

B10

Vcc

A21

A20

A19

A18

GND

A17

A16

A15

A14

A13

Vcc

A12

GND

A11

A10

5608 drw02

TQFP (PK128-1, order code: PF)

TOP VIEW

2

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

CommunicationbetweeneachportmaybypasstheFIFOsviatwomailbox necessitateaformalreadrequest).ThestateoftheBE/FWFTpinduringFIFO

registers.Themailboxregisters’widthmatchestheselectedPortBbuswidth. operationdeterminesthemodeinuse.

EachMailboxregisterhas a flag(MBF1 andMBF2)tosignalwhennewmail

has beenstored.

EachFIFOhasacombinedEmpty/OutputReadyFlag(EFA/ORAandEFB/

ORB) and a combined Full/Input Ready Flag (FFA/IRA and FFB/IRB). The

TwokindsofresetareavailableontheseFIFOs:MasterResetandPartial EF and FF functions are selected in the IDT Standard mode. EF indicates

Reset. MasterResetinitializesthereadandwritepointerstothefirstlocation whetherornottheFIFOmemoryisempty.FFshowswhetherthememoryis

of the memory array, configures the FIFO for Big- or Little-Endian byte fullornot.TheIRandORfunctionsareselectedintheFirstWordFallThrough

arrangementandselectsserialflagprogramming,parallelflagprogramming, mode.IRindicateswhetherornottheFIFOhasavailablememorylocations.

oroneoffivepossibledefaultflagoffsetsettings,8,16,64,256or1,024.There ORshowswhethertheFIFOhasdataavailableforreadingornot.Itmarksthe

are two Master Reset pins, MRS1 and MRS2.

PartialResetalsosetsthereadandwritepointerstothefirstlocationofthe

presenceofvaliddataontheoutputs.

EachFIFOhasaprogrammableAlmost-Emptyflag(AEAandAEB)anda

memory.UnlikeMasterReset,anysettingsexistingpriortoPartialReset(i.e., programmableAlmost-Fullflag(AFAandAFB). AEAandAEB indicatewhen

programmingmethodandpartialflagdefaultoffsets)areretained.PartialReset aselectednumberofwordsremainintheFIFOmemory.AFAandAFBindicate

is useful since it permits flushing of the FIFO memory without changing any whenthe FIFOcontains more thana selectednumberofwords.

configurationsettings.EachFIFOhasitsown,independentPartialResetpin,

PRS1 and PRS2.

FFA/IRA,FFB/IRB,AFAandAFB aretwo-stagesynchronizedtotheport

clockthatwrites dataintoits array.EFA/ORA,EFB/ORB,AEAandAEBare

BothFIFO'shaveRetransmitcapability,whenaRetransmitisperformedon two-stage synchronized to the port clock that reads data from its array.

arespectiveFIFOonlythereadpointerisresettothefirstmemorylocation.A ProgrammableoffsetsforAEA,AEB,AFAandAFBareloaded inparallelusing

RetransmitisperformedbyusingtheRetransmitMode,RTMpininconjunction PortAorinserialviatheSDinput.Fivedefaultoffsetsettingsarealsoprovided.

withtheRetransmitpinsRT1orRT2,foreachrespectiveFIFO.Notethatthe The AEA and AEB threshold can be set at 8, 16, 64, 256 or 1,024 locations

twoRetransmitpins RT1andRT2 are muxedwiththe PartialResetpins.

fromtheemptyboundaryandtheAFAandAFBthresholdcanbesetat8,16,

Thesedeviceshavetwomodesofoperation:IntheIDTStandardmode,the 64,256or1,024locationsfromthefullboundary.Allthesechoicesaremade

firstwordwrittentoanemptyFIFOisdepositedintothememoryarray. Aread using the FS0, FS1 and FS2 inputs during Master Reset.

operationisrequiredtoaccessthatword(alongwithallotherwordsresiding

InterspersedParitycanalsobeselectedduringaMasterResetoftheFIFO.

inmemory). IntheFirstWordFallThroughmode(FWFT),thefirstwordwritten IfInterspersedParityisselectedthenduringparallelprogrammingoftheflag

to an empty FIFO appears automatically on the outputs, no read operation offsetvalues,thedevicewillignoredatalineA8.IfNon-InterspersedParityis

required (Nevertheless, accessing subsequent words does necessitate a selectedthendatalineA8willbecomeavalidbit.

formal read request). The state of the BE/FWFT pin during Master Reset

determinesthemodeinuse.

Twoormoredevicesmaybeusedinparalleltocreatewiderdatapaths.If,

at any time, the FIFO is not actively performing a function, the chip will

Thesedeviceshavetwomodesofoperation:IntheIDTStandardmode,the automatically power down. During the power down state, supply current

firstwordwrittentoanemptyFIFOisdepositedintothememoryarray.Aread consumption(ICC)isataminimum.Initiatinganyoperation(byactivatingcontrol

operationisrequiredtoaccessthatword(alongwithallotherwordsresiding inputs)willimmediatelytakethedeviceoutofthepowerdownstate.

inmemory).IntheFirstWordFallThroughmode(FWFT),thefirstlong-word

(36-bitwide)writtentoanemptyFIFOappearsautomaticallyontheoutputs,no to70°C.Industrialtemperaturerange(-40°Cto+85°C)isavailable.Theyare

readoperationisrequired(Nevertheless,accessingsubsequentwordsdoes fabricatedusingIDT’shighspeed,submicronCMOStechnology.

TheIDT723654/723664/723674arecharacterizedforoperationfrom0°C

3

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

PINDESCRIPTIONS

Symbol

A0-A35

AEA

Name

I/O

O

Description

PortAData

36-bitbidirectionaldataportforsideA.

PortAAlmost-

EmptyFlag

ProgrammableAlmost-EmptyflagsynchronizedtoCLKA.ItisLOWwhenthenumberofwordsin

FIFO2islessthanorequaltothevalueintheAlmost-EmptyAOffsetregister,X2.

AEB

PortBAlmost-

EmptyFlag

O

ProgrammableAlmost-EmptyflagsynchronizedtoCLKB.ItisLOWwhenthenumberofwordsin

FIFO1islessthanorequaltothevalueintheAlmost-EmptyBOffsetregister,X1.

AFA

PortAAlmost-

Full Flag

ProgrammableAlmost-FullflagsynchronizedtoCLKA.ItisLOWwhenthenumberofempty

locationsinFIFO1islessthanorequaltothevalueintheAlmost-FullAOffsetregister,Y1.

AFB

PortBAlmost-

Full Flag

ProgrammableAlmost-FullflagsynchronizedtoCLKB.ItisLOWwhenthenumberofempty

locations inFIFO2is less thanorequaltothevalueintheAlmost-FullBOffsetregister,Y2.

B0-B35

PortAData

I/O

I

36-bitbidirectionaldataportforsideB.

BE/FWFT Big-Endian/

FirstWord

This is a dual purpose pin. During Master Reset, a HIGH on BE will select Big Endian operation.

Inthis case, dependingonthe bus size, the mostsignificantbyte orwordonPortAis readfrom

PortBfirst (A-to-Bdata flow)orwrittentoPortBfirst(B-to-Adata flow). ALOWonBEwillselect

Little-Endianoperation. Inthis case,theleastsignificantbyteorwordonPortAis readfromPortB

first(forA-to-Bdataflow)orwrittentoPortBfirst(B-to-Adata flow). After Master Reset, this pin

selects the timing mode. A HIGH on FWFT selects IDT Standard mode, a LOW selects First Word

FallThroughmode.Oncethetimingmodehas beenselected,thelevelonFWFTmustbestatic

throughoutdeviceoperation.

Fall Through

Select

(1)

BM

Bus-MatchSelect

(Port B)

I

A HIGH on this pin enables either byte or word bus width on Port B, depending on the state of

SIZE. A LOW selects long word operation. BM works with SIZE and BE to select the bus size and

endianarrangementforPortB.ThelevelofBMmustbestaticthroughoutdeviceoperation.

CLKA

CLKB

PortAClock

PortBClock

CLKAis acontinuous clockthatsynchronizes alldatatransfers throughPortAandcanbe

asynchronous or coincident to CLKB. FFA/IRA, EFA/ORA, AFA, and AEA are allsynchronized

totheLOW-to-HIGHtransitionofCLKA.

CLKBis acontinuous clockthatsynchronizes alldatatransfers throughPortBandcanbe

asynchronous orcoincidenttoCLKA. FFB/IRB, EFB/ORB, AFB, andAEB are synchronizedto

theLOW-to-HIGHtransitionofCLKB.

CSA

CSB

PortAChipSelect

PortBChipSelect

I

CSA mustbeLOWtoenabletoLOW-to-HIGHtransitionofCLKAtoreadorwriteonPortA.

The A0-A35outputs are inthe high-impedance state when CSAis HIGH.

CSB mustbe LOWtoenable a LOW-to-HIGHtransitionofCLKBtoreadorwrite data onPortB.

The B0-B35outputs are inthe high-impedance state when CSBis HIGH.

EFA/ORA PortAEmpty/

OutputReadyFlag

O

This is a dualfunctionpin. Inthe IDTStandardmode, the EFA functionis selected. EFA

indicates whetherornotthe FIFO2memoryis empty. Inthe FWFTmode, the ORAfunctionis

selected. ORAindicates thepresenceofvaliddataonA0-A35outputs,availableforreading.

EFA/ORAissynchronizedtotheLOW-to-HIGHtransitionofCLKA.

EFB/ORB PortBEmpty/

OutputReadyFlag

O

This is adualfunctionpin.IntheIDTStandardmode,theEFBfunctionis selected. EFBindicates

whetherornotthe FIFO1memoryis empty. Inthe FWFTmode, the ORBfunctionis selected. ORB

indicates thepresenceofvaliddataontheB0-B35outputs,availableforreading. EFB/ORBis

synchronizedtotheLOW-to-HIGHtransitionofCLKB.

ENA

PortAEnable

I

ENAmustbe HIGHtoenable a LOW-to-HIGHtransitionofCLKAtoreadorwrite data onPortA.

ENBmustbe HIGHtoenable a LOW-to-HIGHtransitionofCLKBtoreadorwrite data onPortB.

ENB

PortBEnable

FFA/IRA

PortAFull/

Input Ready Flag

O

This is a dualfunctionpin. Inthe IDTStandardmode, the FFA functionis selected. FFA indicates

whetherornotthe FIFO1memoryis full. Inthe FWFTmode, the IRAfunctionis selected. IRA

indicates whetherornotthere is space available forwritingtothe FIFO1memory. FFA/IRAis

synchronizedtotheLOW-to-HIGHtransitionofCLKA.

FFB/IRB

PortBFull/

Input Ready Flag

O

This is adualfunctionpin.IntheIDTStandardmode,the FFB functionis selected. FFB indicates

whether or not the FIFO2 memory is full. In the FWFT mode, the IRB function is selected. IRB

indicates whether or not there is space available for writing to the FIFO2 memory. FFB/IRB is

synchronized to the LOW-to-HIGH transition of CLKB.

4

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

PINDESCRIPTIONS(CONTINUED)

Symbol

Name

I/O

Description

FS0/SD

FlagOffsetSelect0/

SerialData

I

FS1/SEN andFS0/SDaredual-purposeinputs usedforflagoffsetregisterprogramming. During

MasterReset,FS1/SENandFS0/SD,togetherwithFS2,selecttheflagoffsetprogrammingmethod.

Threeoffsetregisterprogrammingmethodsareavailable:automaticallyloadoneoffivepreset

values (8, 16, 64, 256 or 1,024), parallel load from Port A, and serial load.

FS1/SEN

FlagOffsetSelect1/

SerialEnable

Whenserialloadisselectedforflagoffsetregisterprogramming,FS1/SENisusedasanenable

synchronous totheLOW-to-HIGHtransitionofCLKA. WhenFS1/SENis LOW,arisingedgeon

CLKA load the bit present on FS0/SD into the X and Y registers. The number of bit writes required

to program the offset registers is 44 for the IDT723654, 48 for the IDT723664, and 52 for the

IDT723674.Thefirstbitwritestores theY-register(Y1)MSBandthelastbitwritestores the

X-register (X2) LSB.

FS2⁽¹⁾

FlagOffsetSelect2

I

MBA

MBB

MBF1

Port A Mailbox

Select

A HIGH level on MBA chooses a mailbox register for a Port A read or write operation. When

theA0-A35outputsareactive,aHIGHlevelonMBAselectsdatafromthemail2registerforoutput

andaLOWlevelselectsFIFO2outputregisterdataforoutput.

Port B Mailbox

Select

I

A HIGH level on MBB chooses a mailbox register for a Port B read or write operation. When the

B0-B35outputs areactive,aHIGHlevelonMBBselects datafromthemail1registerforoutputand

aLOWlevelselectsFIFO1outputregisterdataforoutput.

Mail1Register

Flag

O

MBF1 is set LOW by a LOW-to-HIGH transition of CLKA that writes data to the mail1 register.

Writes tothe mail1registerare inhibitedwhile MBF1 is LOW. MBF1 is setHIGHbya LOW-to-

HIGH transition of CLKB when a Port B read is selected and MBB is HIGH. MBF1 is set HIGH

followingeitheraMasterorPartialResetofFIFO1.

MBF2

MRS1

Mail2Register

Flag

O

I

MBF2issetLOWbyaLOW-to-HIGHtransitionofCLKBthatwritesdatatothemail2register.

Writes tothemail2registerareinhibitedwhileMBF2 is LOW.MBF2 is setHIGHbyaLOW-to-HIGH

transition of CLKA when a Port A read is selected and MBA is HIGH. MBF2 is set HIGH

followingeitheraMasterorPartialResetofFIFO2.

FIFO1Master

Reset

ALOWonthis pin initializes the FIFO1readandwrite pointers tothe firstlocationofmemoryand

setsthePortBoutputregistertoallzeroes. ALOW-to-HIGHtransitiononMRS1selectstheprogramming

method(serialorparallel)andoneoffiveprogrammableflagdefaultoffsets forFIFO1andFIFO2.It

also configuresPortBforbussizeandendianarrangement. FourLOW-to-HIGHtransitionsofCLKA

andfourLOW-to-HIGHtransitionsofCLKBmustoccurwhileMRS1isLOW.

MRS2

FIFO2Master

Reset

I

ALOWonthispininitializestheFIFO2readandwritepointerstothefirstlocationofmemoryandsets

thePortAoutputregistertoallzeroes.ALOW-to-HIGHtransitiononMRS2,toggledsimultaneously

withMRS1,selectstheprogrammingmethod(serialorparallel)andoneoftheprogrammableflagdefault

offsets for FIFO2. Four LOW-to-HIGH transitions of CLKA and four LOW-to-HIGH transitions of CLKB

mustoccurwhileMRS2isLOW.

PRS1/

RT1

PartialReset/

RetransmitFIFO1

ThispinismuxedforbothPartialReset andRetransmitoperations,itisusedinconjunctionwiththeRTM

pin. IfRTMisinaLOWcondition,aLOWonthispinperformsaPartialResetonFIFO1andinitializes

theFIFO1readandwritepointerstothefirstlocationofmemoryandsetsthePortBoutputregisterto

allzeroes.DuringPartialReset,thecurrentlyselectedbussize,endianarrangement,programming

method(serialorparallel),andprogrammableflagsettingsareallretained.IfRTMisHIGH,aLOWon

thispinperformsaRetransmitandinitializestheFIFO1readpointeronlytothefirstmemorylocation.

PRS2/

RT2

PartialReset/

RetransmitFIFO2

I

ThispinismuxedforbothPartialReset andRetransmitoperations,itisusedinconjunctionwiththeRTM

pin. IfRTMisinaLOWcondition,aLOWonthispinperformsaPartialResetonFIFO2andinitializes

theFIFO2readandwriteselectedbus size,endianarrangement,programmingmethod(serialor

parallel),andprogrammableflagsettingsareallretained.IfRTMisHIGH,aLOWonthispinperforms

aRetransmitandinitializestheFIFO2readpointeronlytothefirstmemorylocation.

RTM

RetransmitMode

BusSizeSelect

I

ThispinisusedinconjunctionwiththeRT1andRT2pins.WhenRTMisHIGHaRetransmitisperformed

on FIFO1 or FIFO2 respectively.

(1)

SIZE

AHIGHonthis pinwhenBMis HIGHselects byte bus (9-bit)size onPortB. ALOWonthis pinwhen

BMisHIGHselectsword(18-bit)bussize.SIZEworkswithBMandBEtoselectthebussizeandendian

arrangementforPortB.ThelevelofSIZEmustbestaticthroughoutdeviceoperation

NOTE:

1. FS2, BM and SIZE inputs are not TTL compatible. These inputs should be tied to GND or V^CC.

5

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

PINDESCRIPTIONS(CONTINUED)

Symbol

Name

I/O

Description

W/RA

Port-AWrite/

ReadSelect

I

A HIGHselects a write operationanda LOWselects a readoperationonPortAfora LOW-to-HIGH

transitionofCLKA.TheA0-A35outputs areintheHIGHimpedancestatewhenW/RAis HIGH.

W/RB

Port-BWrite/

ReadSelect

I

A LOWselects a write operationanda HIGHselects a readoperationonPortBfora LOW-to-HIGH

transitionofCLKB.TheB0-B35outputsareintheHIGHimpedancestatewhenW/RBisLOW.

6

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

ABSOLUTE MAXIMUM RATINGS OVER OPERATING FREE-AIR

TEMPERATURE RANGE (Unless otherwise noted)⁽¹⁾

Symbol

Rating

Commercial

–0.5to+7.0

–0.5 to VCC+0.5

±20

Unit

V

VCC

SupplyVoltageRange

InputVoltageRange

OutputVoltageRange

(2)

VI

V

(2)

VO

V

IIK

Input Clamp Current (VI < 0 or VI > VCC)

Output Clamp Current (VO = < 0 or VO > VCC)

Continuous Output Current (VO = 0 to VCC)

Continuous Current Through VCC or GND

StorageTemperatureRange

mA

°C

IOK

±50

IOUT

ICC

±50

±400

TSTG

–65 to 150

NOTES:

1. Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these

or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect

device reliability.

2. The input and output voltage ratings may be exceeded provided the input and output current ratings are observed.

RECOMMENDEDOPERATINGCONDITIONS

Symbol

VCC

VIH

Parameter

SupplyVoltage

Min.

4.5

2

Max.

5.5

–

Unit

V

HIGH Level Input Voltage

LOW-LevelInputVoltage

HIGH-Level Output Current

LOW-Level Output Current

OperatingFree-airTemperature

V

VIL

–

0.8

–4

V

IOH

–

mA

°C

IOL

–

8

TA

0

70

ELECTRICALCHARACTERISTICSOVERRECOMMENDEDOPERATING

FREE-AIRTEMPERATURERANGE(Unlessotherwisenoted)

IDT723654

IDT723664

IDT723674

Commercial

tCLK = 12, 15ns

Symbol

VOH

VOL

Parameter

OutputLogic"1"Voltage

OutputLogic"0"Voltage

InputLeakageCurrent(AnyInput)

OutputLeakageCurrent

Test Conditions

IOH = –4 mA

Min.

2.4

—

Typ.⁽¹⁾

—

4

Max.

—

0.5

±10

8

Unit

V

VCC = 4.5V,

VCC = 5.5V,

IOL = 8 mA

V

ILI

VI = VCC or 0

µ A

mA

pF

ILO

VO = VCC or 0

VI = VCC –0.2V or 0V

f = 1 MHz

ICC2⁽²⁾

ICC3⁽²⁾

Standby Current (with CLKA & CLKB running) VCC = 5.5V,

StandbyCurrent(noclocksrunning)

InputCapacitance

VCC = 5.5V,

VI = 0,

1

(3)

CIN

—

(3)

COUT

OutputCapacitance

VO = 0,

f = 1 MHZ

8

pF

NOTES:

1. All typical values are at V^CC= 5V, TA = 25°C.

2. For additional I^CCinformation, see Figure 1, Typical Characteristics: Supply Current (ICC) vs. Clock Frequency (fS).

3. Characterized values, not currently tested.

4. Industrial temperature range is available by special order.

7

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

DETERMINING ACTIVE CURRENT CONSUMPTION AND POWER DISSIPATION

The ICC(f) current for the graph in Figure 1 was taken while simultaneously reading and writing a FIFO on the IDT723654/723664/723674 with CLKA

andCLKBsettofS. Alldatainputsanddataoutputschangestateduringeachclockcycletoconsumethehighestsupplycurrent. Dataoutputsweredisconnected

tonormalizethegraphtoazerocapacitanceload. Oncethecapacitanceloadperdata-outputchannelandthenumberofthesedevice'sinputsdrivenbyTTL

HIGHlevels areknown,thepowerdissipationcanbecalculatedwiththeequationbelow.

CALCULATING POWER DISSIPATION

WithICC(f) takenfromFigure1,themaximumpowerdissipation(PT)oftheseFIFOs maybecalculatedby:

2

PT = VCC x ICC(f) + Σ(CL x VCC x fo)

N

where:

N

= number of used outputs (36-bit (long word), 18-bit (word) or 9-bit (byte) bus size)

CL = outputcapacitanceload

fo = switchingfrequencyofanoutput

300

fdata = 1/2 fS

TA = 25^oC

CL = 0 pF

250

200

150

VCC = 5.5V

VCC = 5.0V

VCC = 4.5V

100

50

0

10

20

30

40

50

60

70

80

90

5608drw03

fS  Clock Frequency  MHz

Figure 1. Typical Characteristics: Supply Current (ICC) vs. Clock Frequency (fS)

8

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

TIMING REQUIREMENTS OVER RECOMMENDED RANGES OF SUPPLY

VOLTAGE AND OPERATING FREE-AIR TEMPERATURE

(Commercial: VCC = 5V ± 10%, TA = 0°C to +70°C)

Commercial

IDT723654L12

IDT723664L12

IDT723674L12

IDT723654L15

IDT723664L15

IDT723674L15

Symbol

fS

Parameter

Min.

—

12

5

Max.

83

Min.

—

15

6

Max.

66.7

—

Unit

MHz

ns

Clock Frequency, CLKA or CLKB

tCLK

tCLKH

tCLKL

tDS

Clock Cycle Time, CLKA or CLKB

—

Pulse Duration, CLKA or CLKB HIGH

ns

PulseDuration, CLKAandCLKBLOW

5

6

ns

SetupTime, A0-A35before CLKA↑andB0-B35before CLKB↑

SetupTime,CSA andW/RAbefore CLKA↑;CSB andW/RBbefore CLKB↑

Setup Time, ENA, and MBA before CLKA↑;ENB, andMBBbefore CLKB↑

Setup Time, MRS1, MRS2, PRS1, or PRS2 LOW before CLKA↑or CLKB↑

Setup Time, FS0, FS1, FS2 before MRS1 and MRS2 HIGH

SetupTime, BE/FWFT beforeMRS1 andMRS2HIGH

SetupTime,FS0/SDbeforeCLKA↑

3

4

ns

tENS1

tENS2

tRSTS

tFSS

4

4.5

5

ns

3

ns

(1)

5

ns

7.5

3

7.5

4

ns

tBES

ns

tSDS

ns

tSENS

tFWS

tRTMS

tDH

SetupTime,FS1/SENbeforeCLKA↑

3

4

ns

SetupTime,BE/FWFTbeforeCLKA↑

0

ns

Setup Time, RTM before RT1; RTM before RT2

HoldTime,A0-A35afterCLKA↑andB0-B35afterCLKB↑

5

ns

0.5

1

ns

tENH

Hold Time, CSA, W/RA, ENA, and MBA after CLKA↑; CSB, W/RB, ENB, and

MBBafterCLKB↑

1

ns

(1)

tRSTH

tFSH

Hold Time, MRS1, MRS2, PRS1 or PRS2 LOW after CLKA↑ or CLKB↑

4

2

—

4

2

—

ns

Hold Time, FS0, FS1, FS2 after MRS1 and MRS2 HIGH

Hold Time, BE/FWFT after MRS1 and MRS2 HIGH

HoldTime, FS0/SDafterCLKA↑

tBEH

2

tSDH

0.5

2

1

tSENH

tSPH

HoldTime,FS1/SENHIGHafterCLKA↑

1

Hold Time, FS1/SEN HIGH after MRS1 and MRS2 HIGH

HoldTime, RTMafterRT1;RTMafterRT2

2

tRTMH

tSKEW1⁽²⁾

5

SkewTime betweenCLKA↑andCLKB↑ forEFA/ORA,EFB/ORB,FFA/IRA,

and FFB/IRB

5

7.5

tSKEW2^(2.3)Skew Time between CLKA↑ and CLKB↑ for AEA, AEB, AFA, and AFB

12

—

12

—

ns

NOTES:

1. Requirement to count the clock edge as one of at least four needed to reset a FIFO.

2. Skew time is not a timing constraint for proper device operation and is only included to illustrate the timing relationship between CLKA cycle and CLKB cycle.

3. Design simulated, not tested.

4. Industrial temperature range is available by special order.

9

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

SWITCHING CHARACTERISTICS OVER RECOMMENDED RANGES OF SUPPLY

VOLTAGE AND OPERATING FREE-AIR TEMPERATURE, C^L= 30pF

(Commercial: VCC = 5V ± 10%, TA = 0°C to +70°C)

Commercial

IDT723654L12 IDT723654L15

IDT723664L12 IDT723664L15

IDT723674L12 IDT723674L15

Symbol

tA

Parameter

Min. Max. Min Max. Unit

Access Time,CLKA↑toA0-A35andCLKB↑toB0-B35

Propagation Delay Time, CLKA↑ toFFA/IRAandCLKB↑ toFFB/IRB

PropagationDelayTime,CLKA↑toEFA/ORAandCLKB↑ toEFB/ORB

PropagationDelayTime, CLKA↑toAEAandCLKB↑toAEB

PropagationDelayTime, CLKA↑toAFAandCLKB↑toAFB

2

1

0

8

2

1

0

10

8

ns

tWFF

tREF

tPAE

tPAF

tPMF

8

Propagation Delay Time, CLKA↑ to MBF1 LOW or MBF2 HIGH and CLKB↑ to MBF2

LOW or MBF1 HIGH

8

tPMR

tMDV

tRSF

PropagationDelayTime, CLKA↑ toB0-B35⁽¹⁾andCLKB↑toA0-A35⁽²⁾

2

1

8

2

1

10

15

ns

Propagation Delay Time, MBA to A0-A35 valid and MBB to B0-B35 valid

Propagation Delay Time, MRS1 or PRS1 LOW to AEB LOW, AFA HIGH, and MBF1 HIGH

and MRS2 or PRS2 LOW to AEA LOW, AFB HIGH, and MBF2 HIGH

10

tEN

tDIS

Enable Time, CSA or W/RA LOW to A0-A35 Active and CSB LOW and W/RB

2

1

6

2

1

10

8

ns

HIGH to B0-B35 Active

Disable Time, CSA or W/RA HIGH to A0-A35 at high impedance and CSB HIGH

orW/RBLOWtoB0-B35athighimpedance.

NOTES:

1. Writing data to the mail1 register when the B0-B35 outputs are active and MBB is HIGH.

2. Writing data to the mail2 register when the A0-A35 outputs are active and MBA is HIGH.

3. Industrial temperature range is available by special order.

10

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

and four Port B Clock (CLKB) LOW-to-HIGH transitions. The Retransmit

initializesthereadpointerofFIFO1tothefirstmemorylocation.

The FIFO2 memory undergoes a Retransmit by taking its associated

Retransmit(RT2)inputLOWforatleastfourPortAClock(CLKA)andfourPort

CClock(CLKC)LOW-to-HIGHtransitions.TheRetransmitinitializestheread

pointerofFIFO2tothefirstmemorylocation.

TheRTMpinmustbeHIGHduringthetimeofRetransmit.Notethatthe RT1

inputismuxedwiththePRS1input,thestateoftheRTMpindeterminingwhether

thispinperformsaRetransmitorPartialReset.Also,theRT2inputismuxed

with the PRS2 input, the state of the RTM pin determining whether this pin

performsaRetransmitorPartialReset.

SIGNALDESCRIPTION

MASTER RESET (MRS1, MRS2)

Afterpowerup,aMasterReset operationmustbeperformedbyproviding

aLOWpulsetoMRS1andMRS2simultaneously. Afterwards,eachofthetwo

FIFO memories of the IDT723654/723664/723674 undergoes a complete

resetbytakingitsassociatedMasterReset(MRS1,MRS2)inputLOWforat

leastfourPortAClock(CLKA)andfourPortBClock(CLKB)LOW-to-HIGH

transitions. TheMasterResetinputscanswitchasynchronouslytotheclocks.

AMasterReset initializes the associatedwrite andreadpointers tothe first

locationofthememoryandforces theFull/InputReadyflag(FFA/IRA,FFB/

IRB) LOW, the Empty/Output Ready flag (EFA/ORA, EFB/ORB) LOW, the

Almost-Emptyflag(AEA,AEB)LOWandforcestheAlmost-Fullflag(AFA,AFB)

HIGH. AMasterResetalsoforcestheassociatedMailboxFlag(MBF1,MFB2)

oftheparallelmailboxregisterHIGH. AfteraMasterReset,theFIFO's Full/

InputReadyflagissetHIGHaftertwowriteclockcycles. ThentheFIFOisready

tobewrittento.

BIG-ENDIAN/FIRST WORD FALL THROUGH (BE/FWFT)

— ENDIAN SELECTION

Thisisadualpurposepin.AtthetimeofMasterReset,theBEselectfunction

isactive,permittingachoiceofBigorLittle-Endianbytearrangementfordata

writtentoorreadfromPortB.This selectiondetermines theorderbywhich

bytes (orwords)ofdata are transferredthroughthis port. Forthe following

illustrations,assumethatabyte(orword)bussizehasbeenselectedforPort

B.(NotethatwhenPortBis configuredforalongwordsize,theBig-Endian

ALOW-to-HIGHtransitionontheFIFO1MasterReset(MRS1)inputlatches

thevaluesoftheBig-Endian(BE)inputfordeterminingtheorderbywhichbytes

aretransferredthroughPortB. Italso latchesthevaluesoftheFlagSelect(FS0,

FS1andFS2)inputs forchoosingthe Almost-FullandAlmost-Emptyoffset

programmingmethod.

1

functionhas noapplicationandthe BEinputis a “don’tcare” .)

A HIGH on the BE/FWFT input when the Master Reset (MRS1, MRS2)

inputsgofromLOWtoHIGHwillselectaBig-Endianarrangement.Whendata

ismovinginthedirectionfromPortAtoPortB,themostsignificantbyte(word)

ofthelongwordwrittentoPortAwillbereadfromPortBfirst;theleastsignificant

byte(word)ofthelongwordwrittentoPortAwillbereadfromPortBlast.When

data is movinginthe directionfromPortBtoPortA, the byte (word)written

toPortBfirstwillbereadfromPortAasthemostsignificantbyte(word)ofthe

long word; the byte (word) written to Port B last will be read from Port A as

theleastsignificantbyte(word)ofthelongword.

ALOW-to-HIGHtransitionontheFIFO2MasterReset(MRS2)clearsthe

Flag Offset Registers of FIFO2 (X2, Y2). A LOW-to-HIGH transition on the

FIFO2MasterReset(MRS2)togetherwiththeFIFO1MasterReset(MRS1)

inputlatchesthevalueoftheBig-Endian(BE)inputforPortBandalsolatches

thevaluesoftheFlagSelect(FS0,FS1andFS2)inputsforchoosingtheAlmost-

FullandAlmost-Emptyoffsetprogrammingmethod. (FordetailsseeTable1,

FlagProgramming,andtheProgrammingtheAlmost-EmptyandAlmost-Full

Flagssection). TherelevantFIFOMasterResettimingdiagramcanbefound

in Figure 3.

A LOW on the BE/FWFT input when the Master Reset (MRS1, MRS2)

inputsgofromLOWtoHIGHwillselectaLittle-Endianarrangement.Whendata

ismovinginthedirectionfromPortAtoPortB,theleastsignificantbyte(word)

ofthelongwordwrittentoPortAwillbereadfromPortBfirst;themostsignificant

byte(word)ofthelongwordwrittentoPortAwillbereadfromPortBlast.When

data is movinginthe directionfromPortBtoPortA, the byte (word)written

toPortBfirstwillbereadfromPortAastheleastsignificantbyte(word)ofthe

long word; the byte (word) written to Port B last will be read from Port A as

the most significant byte (word) of the long word. Refer to Figure 2 for an

illustrationoftheBEfunction.SeeFigure3(MasterReset)fortheEndianselect

timingdiagram.

PARTIAL RESET (PRS1, PRS2)

EachofthetwoFIFOmemoriesofthesedevicesundergoesalimitedreset

bytakingitsassociatedPartialReset(PRS1,PRS2)inputLOWforatleastfour

PortAClock(CLKA)andfourPortBClock(CLKB)LOW-to-HIGHtransitions.

ThePartialResetinputs canswitchasynchronouslytotheclocks.APartial

ResetinitializestheinternalreadandwritepointersandforcestheFull/Input

Readyflag(FFA/IRA,FFB/IRB)LOW,theEmpty/OutputReadyflag(EFA/

ORA, EFB/ORB) LOW, the Almost-Empty flag (AEA, AEB) LOW, and the

Almost-Fullflag(AFA,AFB)HIGH.APartialResetalsoforcestheMailboxFlag

(MBF1,MBF2)oftheparallelmailboxregisterHIGH.AfteraPartialReset,the

FIFO’s Full/InputReadyflagis setHIGHaftertwowrite clockcycles. Then

the FIFO is ready to be written to.

— TIMING MODE SELECTION

AfterMasterReset,theFWFTselectfunctionisactive,permittingachoice

betweentwopossibletimingmodes:IDTStandardmodeorFirstWordFall

Through (FWFT) mode. Once the Master Reset (MRS1, MRS2) input is

HIGH,aHIGHontheBE/FWFTinputduringthenextLOW-to-HIGHtransition

ofCLKA(forFIFO1)andCLKB(forFIFO2)willselectIDTStandardmode.

This modeuses theEmptyFlagfunction(EFA,EFB)toindicatewhetheror

not there are any words present in the FIFO memory. It uses the Full Flag

function(FFA,FFB)toindicatewhetherornottheFIFOmemoryhasanyfree

space for writing. In IDT Standard mode, every word read from the FIFO,

includingthefirst,mustberequestedusingaformalreadoperation.

Whateverflagoffsets,programmingmethod(parallelorserial),andtiming

mode(FWFTorIDTStandardmode)arecurrentlyselectedatthetimeaPartial

Resetisinitiated,thosesettingswillberemainunchangeduponcompletionof

the reset operation. A Partial Reset may be useful in the case where

reprogrammingaFIFOfollowingaMasterResetwouldbeinconvenient.See

Figure4forthePartialResettimingdiagram.

RETRANSMIT (RT1, RT2)

TheFIFO1memoryofthesedevicesundergoesaRetransmitbytakingits

associatedRetransmit (RT1)inputLOWforatleastfourPortAClock(CLKA)

NOTE:

1. Either a HIGH or LOW can be applied to a "don't care" input with no change to the logical operation of the FIFO. Nevertheless, inputs that are temporarily "don't care" (along with

unused inputs) must not be left open, rather they must be either HIGH or LOW.

11

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

orLOWduringamasterreset.Forexample,toloadthepresetvalueof64into

X1 and Y1, FS0, FS1 and FS2 must be HIGH when FlFO1 reset (MRS1)

returnsHIGH.Flag-offsetregistersassociatedwithFIFO2areloadedwithone

ofthepresetvaluesinthesamewaywithFIFO2MasterReset(MRS2),toggled

simultaneously with FIFO1 Master Reset (MRS1). For relevant preset value

loading timing diagram, see Figure 3.

OncetheMasterReset(MRS1,MRS2)inputis HIGH,aLOWontheBE/

FWFTinputduringthenextLOW-to-HIGHtransitionofCLKA(forFIFO1)and

CLKB(forFIFO2)willselectFWFTmode.ThismodeusestheOutputReady

function(ORA,ORB)toindicatewhetherornotthereisvaliddataatthedata

outputs(A0-A35orB0-B35).ItalsousestheInputReadyfunction(IRA,IRB)

toindicate whetherornotthe FIFOmemoryhas anyfree space forwriting.

IntheFWFTmode,thefirstwordwrittentoanemptyFIFOgoesdirectlytodata

outputs,noreadrequestnecessary. Subsequentwordsmustbeaccessed

byperforminga formalreadoperation.

— PARALLEL LOAD FROM PORT A

ToprogramtheX1,X2,Y1,andY2registersfromPortA,performaMaster

ResetonbothFlFOs simultaneouslywithFS2HIGHorLOW, FS0andFS1

LOWduringtheLOW-to-HIGHtransitionofMRS1andMRS2.ThestateofFS2

atthispointofresetwilldeterminewhethertheparallelprogrammingmethod

hasInterspersedParityorNon-InterspersedParity.RefertoTable1forFlag

Programming Flag Offset setup . It is important to note that once parallel

programminghasbeenselectedduringaMasterResetbyholdingbothFS0

& FS1 LOW, these inputs must remain LOW during all subsequent FIFO

operation. They can only be toggled HIGH when future Master Resets are

performedandotherprogrammingmethodsaredesired.

Afterthisresetiscomplete,thefirstfourwritestoFIFO1donotstoredatain

RAM but load the Offset registers in the order Y1, X1, Y2, X2. For Non-

InterspersedParitymodethePortAdatainputsusedbytheOffsetregistersare

(A10-A0), (A11-A0), or (A12-A0) for the IDT723654, IDT723664, or

IDT723674,respectively.ForInterspersedParitymodethePortAdatainputs

usedbytheOffsetregistersare(A11-A9,A7-A0),(A12-A9,A7-A0),or(A13-

A9,A7-A0)fortheIDT723654,IDT723664,orIDT723674,respectively. The

highestnumberedinputisusedasthemostsignificantbitofthebinarynumber

ineachcase.Validprogrammingvaluesfortheregistersrangefrom1to2,044

for the IDT723654; 1 to 4,092 for the IDT723664; and 1 to 8,188 for the

IDT723674.AfteralltheoffsetregistersareprogrammedfromPortA,thePortB

FollowingMasterReset,thelevelappliedtotheBE/FWFTinputtochoose

thedesiredtimingmodemustremainstaticthroughoutFIFOoperation.Refer

toFigure3(MasterReset)foraFirstWordFallThroughselecttimingdiagram.

PROGRAMMINGTHEALMOST-EMPTYANDALMOST-FULLFLAGS

FourregistersintheIDT723654/723664/723674areusedtoholdtheoffset

valuesfortheAlmost-EmptyandAlmost-Fullflags.ThePortBAlmost-Empty

flag(AEB)OffsetregisterislabeledX1andthePortAAlmost-Emptyflag(AEA)

OffsetregisterislabeledX2.ThePortAAlmost-Fullflag(AFA)Offsetregister

islabeledY1andthePortBAlmost-Fullflag(AFB)OffsetregisterislabeledY2.

TheindexofeachregisternamecorrespondstoitsFIFOnumber.Theoffset

registers can be loaded with preset values during the reset of a FIFO,

programmedinparallelusingtheFIFO’sPortAdatainputs,orprogrammed

in serial using the Serial Data (SD) input (see Table 1).

FS0/SD,FS1/SENandFS2functionthesamewayinbothIDTStandard

andFWFTmodes.

— PRESET VALUES

ToloadaFIFO’sAlmost-EmptyflagandAlmost-FullflagOffsetregisterswith

oneofthefivepresetvalueslistedinTable1,theflagselectinputsmustbeHIGH

TABLE 1 — FLAG PROGRAMMING

FS2

FS1/SEN

FS0/SD

MRS1

MRS2

X1 AND Y1 REGlSTERS⁽¹⁾

X2 AND Y2 REGlSTERS⁽²⁾

H

L

H

L

H

L

H

L

H

L

H

L

↑

X

↑

X

↑

X

↑

X

↑

X

↑

X

↑

X

↑

X

↑

X

↑

X

↑

64

X

64

16

X

L

X

16

H

L

8

X

8

256

X

256

1,024

X

1,024

X

SerialprogrammingviaSD

(3,5)

L

ParallelprogrammingviaPortA

IP Mode^{(4, 5)}

L

IP Mode^{(4, 5)}

NOTES:

1. X1 register holds the offset for AEB; Y1 register holds the offset for AFA.

2. X2 register holds the offset for AEA; Y2 register holds the offset for AFB.

3. When this method of parallel programming is selected, Port A will assume Non-Interspersed Parity.

4. When IP Mode is selected, only parallel programming of the offset values via Port A, can be performed and Port A will assume Interspersed Parity.

5. IF parallel programming is selected during a Master Reset, then FS0 & FS1 must remain LOW during FIFO operation.

12

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

Full/Input Ready flag (FFB/IRB) is set HIGH, and both FIFOs begin normal

operation. Refer to Figure 5 for a timing diagram illustration of parallel

programmingoftheflagoffsetvalues.

offsetvalues,thedevicewillignoredatalineA8.IfNon-InterspersedParityis

selectedthendatalineA8willbecomeavalidbit.IfInterspersedParityisselected

serialprogrammingoftheoffsetvaluesisnotpermitted,onlyparallelprogram-

ming can be done.

INTERSPERSED PARITY

InterspersedParityisselectedduringaMasterResetoftheFIFO.Referto

Table1fortheset-upconfigurationofInterspersedParity.TheInterspersed

Parityfunctionallowstheusertoselectthelocationoftheparitybitsintheword

loadedintotheparallelport(A0-An)duringprogrammingoftheflagoffsetvalues.

IfInterspersedParityisselectedthenduringparallelprogrammingoftheflag

— SERIAL LOAD

ToprogramtheX1,X2,Y1,andY2registersserially,initiateaMasterReset

withFS2LOW,FS0/SDLOWandFS1/SENHIGHduringtheLOW-to-HIGH

transitionofMRS1andMRS2.Afterthisresetiscomplete,theXandYregister

valuesareloadedbit-wisethroughtheFS0/SDinputoneachLOW-to-HIGH

TABLE 2 — PORT A ENABLE FUNCTION TABLE

CSA

W/RA

ENA

MBA

CLKA

Data A (A0-A35) I/O

Port Function

H

L

X

H

L

X

H

L

X

L

X

↑

X

↑

X

↑

High-Impedance

Input

None

FIFO1 write

Mail1write

H

L

Input

Output

None

L

H

L

Output

FIFO2read

L

H

Output

None

L

H

Output

Mail2 read (set MBF2 HIGH)

TABLE 3 — PORT B ENABLE FUNCTION TABLE

CSB

W/RB

ENB

MBB

CLKB

Data B (B0-B35) I/O

Port Function

H

L

X

L

X

L

X

L

X

↑

High-Impedance

Input

None

L

H

L

Input

FIFO2 write

Mail2write

L

H

L

↑

Input

H

X

↑

Output

None

H

L

FIFO1read

None

H

X

↑

H

Mail1 read (set MBF1 HIGH)

FIFO WRITE/READ OPERATION

transitionofCLKAthattheFS1/SENinputisLOW.Thereare44-,48-,or52-

bitwritesneededtocompletetheprogrammingfortheIDT723654,IDT723664,

orIDT723674,respectively.ThefourregistersarewrittenintheorderY1,X1,

Y2,andfinally,X2. Thefirst-bitwritestoresthemostsignificantbitoftheY1register

andthelast-bitwritestorestheleastsignificantbitoftheX2register.Eachregister

valuecanbeprogrammedfrom1to2,044(IDT723654),1to4,092(IDT723664),

or 1 to 8,188 (IDT723674).

Whentheoptiontoprogramtheoffsetregistersseriallyischosen,thePortA

Full/InputReady(FFA/IRA)flagremainsLOWuntilallregisterbitsarewritten.

FFA/IRAissetHIGHbytheLOW-to-HIGHtransitionofCLKAafterthelastbit

isloadedtoallownormalFIFO1operation.ThePortBFull/InputReady(FFB/

IRB)flagalsoremainsLOWthroughouttheserialprogrammingprocess,until

allregisterbitsarewritten.FFB/IRBissetHIGHbytheLOW-to-HIGHtransition

ofCLKBafterthelastbitisloadedtoallownormalFIFO2operation. SeeFigure 6

forSerialProgrammingoftheAlmost-FullFlagandAlmost-EmptyFlagOffset

Values (IDT Standard and FWFT Modes) timing diagram.

ThestateofthePortAdata(A0-A35)linesiscontrolledbyPortAChipSelect

(CSA)andPortAWrite/Readselect(W/RA).TheA0-A35linesareintheHigh-

impedance state wheneitherCSA orW/RAis HIGH. The A0-A35lines are

active outputs whenbothCSA andW/RAare LOW.

Data is loaded into FIFO1 from the A0-A35 inputs on a LOW-to-HIGH

transitionofCLKAwhenCSAisLOW,W/RAisHIGH,ENAisHIGH,MBAis

LOW,andFFA/IRAisHIGH.DataisreadfromFIFO2totheA0-A35outputs

by a LOW-to-HIGH transition of CLKA when CSA is LOW, W/RA is LOW,

ENA is HIGH, MBA is LOW, and EFA/ORA is HIGH (see Table 2). FIFO

reads and writes on Port A are independent of any concurrent Port B

operation.

The Port B control signals are identical to those of Port A with the

exceptionthatthePortBWrite/Readselect(W/RB)istheinverseofthePort

A Write/Read select (W/RA). The state of the Port B data (B0-B35) lines is

controlledbythePortBChipSelect(CSB)andPortBWrite/Readselect(W/

13

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

TABLE 4 — FIFO1 FLAG OPERATION (IDT Standard and FWFT modes)

Synchronized

to CLKB

Synchronized

to CLKA

Number of Words in FIFO Memory^(1,2)

(3)

IDT723654

IDT723664

IDT723674

EFB/ORB

AEB

AFA

FFA/IRA

0

1toX1

0

1toX1

0

1toX1

L

H

L

H

L

H

L

(X1+1)to[2,048-(Y1+1)]

(2,048-Y1)to2,047

2,048

(X1+1)to[4,096-(Y1+1)]

(4,096-Y1)to4,095

4,096

(X1+1)to[8,192-(Y1+1)]

(8,192-Y1)to8,191

8,192

H

L

NOTES:

1. When a word loaded to an empty FIFO is shifted to the output register, its previous FIFO memory location is free.

2. Data in the output register does not count as a "word in FIFO memory". Since in FWFT mode, the first word written to an empty FIFO goes unrequested to the output register (no read

operation necessary), it is not included in the FIFO memory count.

3. X1 is the Almost-Empty offset for FIFO1 used by AEB. Y1 is the Almost-Full offset for FIFO1 used by AFA. Both X1 and Y1 are selected during a FIFO1 reset or port A programming.

4. The ORB and IRA functions are active during FWFT mode; the EFB and FFA functions are active in IDT Standard mode.

TABLE 5 — FIFO2 FLAG OPERATION (IDT Standard and FWFT modes)

Synchronized

to CLKA

Synchronized

to CLKB

Number of Words in FIFO Memory^(1,2)

(3)

IDT723654

IDT723664

IDT723674

EFA/ORA

AEA

AFB

H

FFB/IRB

0

1toX2

0

1toX2

0

1toX2

L

H

L

H

L

H

(X2+1)to[2,048-(Y2+1)]

(2,048-Y2)to2,047

2,048

(X2+1)to[4,096-(Y2+1)]

(4,096-Y2)to4,095

4,096

(X2+1)to[8,192-(Y2+1)]

(8,192-Y2)to8,191

8,192

H

L

NOTES:

1. When a word loaded to an empty FIFO is shifted to the output register, its previous FIFO memory location is free.

2. Data in the output register does not count as a "word in FIFO memory". Since in FWFT mode, the first word written to an empty FIFO goes unrequested to the output register (no read

operation necessary), it is not included in the FIFO memory count.

3. X2 is the Almost-Empty offset for FIFO2 used by AEA. Y2 is the Almost-Full offset for FIFO2 used by AFB. Both X2 and Y2 are selected during a FIFO2 reset or port A programming.

4. The ORA and IRB functions are active during FWFT mode; the EFA and FFB functions are active in IDT Standard mode.

RB).TheB0-B35lines areinthehigh-impedancestatewheneitherCSB is

HIGH or W/RB is LOW. The B0-B35 lines are active outputs when CSB is

LOW and W/RB is HIGH.

WhentheOutputReadyflagisHIGH,subsequentdataisclockedtotheoutput

registersonlywhenareadisselectedusingtheport’sChipSelect,Write/Read

select,Enable,andMailboxselect.

Data is loaded into FIFO2 from the B0-B35 inputs on a LOW-to-HIGH

transitionofCLKBwhenCSBisLOW,W/RBisLOW,ENBisHIGH,MBBis

LOW,andFFB/IRBisHIGH.DataisreadfromFIFO1totheB0-B35outputs

byaLOW-to-HIGHtransitionofCLKBwhenCSBisLOW,W/RBisHIGH,ENB

isHIGH,MBBisLOW,andEFB/ORBisHIGH(seeTable3).FIFOreadsand

writes on Port B are independent of any concurrent Port A operation.

ThesetupandholdtimeconstraintstotheportclocksfortheportChipSelects

andWrite/Readselectsareonlyforenablingwriteandreadoperationsand

arenotrelatedtohigh-impedancecontrolofthedataoutputs.Ifaportenable

isLOWduringaclockcycle,theport’sChipSelectandWrite/Readselectmay

changestates duringthesetupandholdtimewindowofthecycle.

WhenoperatingtheFIFOinFWFTmodeandtheOutputReadyflagisLOW,

thenextwordwrittenisautomaticallysenttotheFIFO’soutputregisterbythe

LOW-to-HIGHtransitionoftheportclockthatsetstheOutputReadyflagHIGH.

WhenoperatingtheFIFOinIDTStandardmode,thefirstwordwillcause

theEmptyFlagtochangestateonthesecondLOW-to-HIGHtransitionofthe

ReadClock. Thedatawordwillnotbeautomaticallysenttotheoutputregister.

Instead, data residing in the FIFO's memory array is clocked to the output

registeronlywhenareadisselectedusingtheport’sChipSelect,Write/Read

select,Enable,andMailboxselect.WriteandreadtimingdiagramsforPortA

canbefoundinFigure7and14. RelevantPortBwriteandreadcycle timing

diagrams togetherwithBus-MatchingandEndianselectoperations canbe

found in Figures 8 through 13.

SYNCHRONIZED FIFO FLAGS

Each FIFO is synchronized to its port clock through at least two flip-flop

stages.Thisisdonetoimproveflag-signalreliabilitybyreducingtheprobability

ofmetastableeventswhenCLKAandCLKBoperateasynchronouslytoone

14

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

twocyclesoftheFull/InputReadyflagsynchronizingclockhaveelapsedsince

the nextmemorywrite locationhas beenread. The secondLOW-to-HIGH

transitionontheFull/InputReadyflagsynchronizingclockafterthereadsets

the Full/InputReadyflagHIGH.

another. EFA/ORA, AEA, FFA/IRA, and AFA are synchronized to CLKA.

EFB/ORB,AEB,FFB/IRB,andAFBaresynchronizedtoCLKB.Tables4and

5 show the relationship of each port flag to FIFO1 and FIFO2.

EMPTY/OUTPUTREADYFLAGS(EFA/ORA,EFB/ORB)

ALOW-to-HIGHtransitiononaFull/InputReadyflagsynchronizingclock

beginsthefirstsynchronizationcycleofareadiftheclocktransitionoccursat

timetSKEW1orgreateraftertheread.Otherwise,thesubsequentclockcycle

can be the first synchronization cycle (see Figures 19, 20, 21, and 22).

Thesearedualpurposeflags. IntheFWFTmode,theOutputReady(ORA,

ORB)functionisselected.WhentheOutput-ReadyflagisHIGH,newdatais

presentintheFIFOoutputregister.WhentheOutputReadyflagisLOW,the

previousdatawordispresentintheFIFOoutputregisterandattemptedFIFO

reads are ignored.

ALMOST-EMPTYFLAGS(AEA,AEB)

IntheIDTStandardmode,theEmptyFlag(EFA,EFB)functionisselected.

WhentheEmptyFlagisHIGH,dataisavailableintheFIFO’sRAMmemory

forreadingtotheoutputregister.WhentheEmptyFlagisLOW,theprevious

datawordispresentintheFIFOoutputregisterandattemptedFIFOreadsare

ignored.

TheEmpty/OutputReadyflagofaFIFOis synchronizedtotheportclock

thatreadsdatafromitsarray.ForboththeFWFTandIDTStandardmodes,

theFIFOreadpointeris incrementedeachtimeanewwordis clockedtoits

outputregister.ThestatemachinethatcontrolsanOutputReadyflagmonitors

a write pointer and read pointer comparator that indicates when the FIFO

memorystatusisempty,empty+1,orempty+2.

TheAlmost-EmptyflagofaFIFOissynchronizedtotheportclockthatreads

data from its array. The state machine that controls an Almost-Empty flag

monitorsawritepointerandreadpointercomparatorthatindicateswhenthe

FIFOmemorystatusisalmost-empty,almost-empty+1,oralmost-empty+2.

Thealmost-emptystateisdefinedbythecontentsofregisterX1forAEBand

registerX2forAEA.Theseregistersareloadedwithpresetvaluesduringa

FIFOreset,programmedfromPortA,orprogrammedserially(seeAlmost-

Empty flag and Almost-Full flag offset programming section). An Almost-

EmptyflagisLOWwhenitsFIFOcontainsXorlesswordsandisHIGHwhen

itsFIFOcontains(X+1)ormorewords.AdatawordpresentintheFIFOoutput

registerhas beenreadfrommemory.

InFWFTmode,fromthetimeawordis writtentoaFIFO,itcanbeshifted

totheFIFOoutputregisterinaminimumofthreecyclesoftheOutputReady

flagsynchronizingclock. Therefore, anOutputReadyflagis LOWifa word

inmemoryisthenextdatatobesenttotheFlFOoutputregisterandthreecycles

oftheportClockthatreadsdatafromtheFIFOhavenotelapsedsincethetime

thewordwaswritten.TheOutputReadyflagoftheFIFOremainsLOWuntil

thethirdLOW-to-HIGHtransitionofthesynchronizingclockoccurs,simulta-

neouslyforcingtheOutputReadyflagHIGHandshiftingthewordtotheFIFO

outputregister.

InIDTStandardmode,fromthetimeawordiswrittentoaFIFO,theEmpty

Flagwillindicatethepresenceofdataavailableforreadinginaminimumof

twocyclesoftheEmptyFlagsynchronizingclock.Therefore,anEmptyFlag

isLOWifawordinmemoryisthenextdatatobesenttotheFlFOoutputregister

andtwocyclesoftheportClockthatreadsdatafromtheFIFOhavenotelapsed

sincethetimethewordwaswritten.TheEmptyFlagoftheFIFOremainsLOW

untilthesecondLOW-to-HIGHtransitionofthesynchronizingclockoccurs,

forcing the Empty Flag HIGH; only then can data be read.

TwoLOW-to-HIGHtransitionsoftheAlmost-Emptyflagsynchronizingclock

arerequiredafteraFIFOwriteforitsAlmost-Emptyflagtoreflectthenewlevel

offill.Therefore,theAlmost-FullflagofaFIFOcontaining(X+1)ormorewords

remainsLOWiftwocyclesofitssynchronizingclockhavenotelapsedsince

thewritethatfilledthememorytothe(X+1)level.AnAlmost-Emptyflagisset

HIGHbythesecondLOW-to-HIGHtransitionofitssynchronizingclockafter

theFIFOwritethatfillsmemorytothe(X+1)level.ALOW-to-HIGHtransition

ofanAlmost-Emptyflagsynchronizingclockbeginsthefirstsynchronization

cycleifitoccurs attimet^SKEW2orgreaterafterthewritethatfills theFIFOto

(X+1)words.Otherwise,thesubsequentsynchronizingclockcyclemaybe

the first synchronization cycle. (See Figure 23 and 24).

ALMOST-FULLFLAGS(AFA, AFB)

TheAlmost-FullflagofaFIFOissynchronizedtotheportclockthatwrites

datatoitsarray.ThestatemachinethatcontrolsanAlmost-Fullflagmonitors

a write pointer and read pointer comparator that indicates when the FIFO

memorystatusisalmost-full,almost-full-1,oralmost-full-2.Thealmost-fullstate

isdefinedbythecontentsofregisterY1forAFAandregisterY2forAFB.These

registersareloadedwithpresetvaluesduringaFlFOreset,programmedfrom

PortA,orprogrammedserially(seeAlmost-EmptyflagandAlmost-Fullflag

offsetprogrammingsection).AnAlmost-FullflagisLOWwhenthenumberof

wordsinitsFIFOisgreaterthanorequalto(2,048-Y),(4,096-Y),or(8,192-Y)

fortheIDT723654,IDT723664,orIDT723674respectively.AnAlmost-Full

flag is HIGH when the number of words in its FIFO is less than or equal to

[2,048-(Y+1)],[4,096-(Y+1)],or[8,192-(Y+1)]fortheIDT723654,IDT723664,

orIDT723674respectively.NotethatadatawordpresentintheFIFOoutput

registerhas beenreadfrommemory.

TwoLOW-to-HIGHtransitionsoftheAlmost-Fullflagsynchronizingclock

arerequiredafteraFIFOreadforitsAlmost-Fullflagtoreflectthenewlevel

offill.Therefore,theAlmost-FullflagofaFIFOcontaining[2,048/4,096/8,192-

(Y+1)]orlesswordsremainsLOWiftwocyclesofitssynchronizingclockhave

notelapsedsince the readthatreducedthe numberofwords inmemoryto

[2,048/4,096/8,192-(Y+1)]. An Almost-Full flag is set HIGH by the second

LOW-to-HIGHtransitionofits synchronizingclockafterthe FIFOreadthat

reduces the number of words in memory to [2,048/4,096/8,192-(Y+1)]. A

LOW-to-HIGHtransitionofanAlmost-Fullflagsynchronizingclockbeginsthe

firstsynchronizationcycleifitoccursattime tSKEW2 orgreateraftertheread

ALOW-to-HIGHtransitiononanEmpty/OutputReadyflagsynchronizing

clockbeginsthefirstsynchronizationcycleofawriteiftheclocktransitionoccurs

attimetSKEW1orgreaterafterthewrite.Otherwise,thesubsequentclockcycle

can be the first synchronization cycle (see Figures 15, 16, 17, and 18).

FULL/INPUT READY FLAGS (FFA/IRA, FFB/IRB)

Thisisadualpurposeflag.InFWFTmode,theInputReady(IRAandIRB)

function is selected. In IDT Standard mode, the Full Flag (FFA and FFB)

functionisselected.Forbothtimingmodes,whentheFull/InputReadyflagis

HIGH,amemorylocationisfreeintheFIFOtoreceivenewdata.Nomemory

locationsarefreewhentheFull/InputReadyflagisLOWandattemptedwrites

to the FIFO are ignored.

The Full/InputReadyflagofa FlFOis synchronizedtothe portclockthat

writesdatatoitsarray.ForbothFWFTandIDTStandardmodes,eachtime

awordiswrittentoaFIFO,itswritepointerisincremented.Thestatemachine

thatcontrolsaFull/InputReadyflagmonitorsawritepointerandreadpointer

comparatorthatindicateswhentheFlFOmemorystatusisfull,full-1,orfull-2.

FromthetimeawordisreadfromaFIFO,itspreviousmemorylocationisready

to be written to in a minimum of two cycles of the Full/Input Ready flag

synchronizingclock.Therefore,anFull/InputReadyflagisLOWiflessthan

15

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

thatreducesthenumberofwordsinmemoryto[2,048/4,096/8,192-(Y+1)]. BUS SIZING

Otherwise,thesubsequentsynchronizingclockcyclemaybethefirstsynchro-

nization cycle (see Figure 25 and 26).

The PortBbus canbe configuredina 36-bitlongword,18-bitword,or9-

bit byte format for data read from FIFO1 or written to FIFO2. The levels

appliedtothePortBBusSizeselect(SIZE)andtheBus-Matchselect(BM)

determinethePortBbussize.TheselevelsshouldbestaticthroughoutFIFO

MAILBOX REGISTERS

Each FIFO has a 36-bit bypass register to pass command and control operation. Both bus size selections are implemented at the completion of

informationbetweenPortAandPortBwithoutputtingitinqueue.TheMailbox MasterReset,bythetimetheFull/InputReadyflagissetHIGH,asshownin

select(MBA, MBB)inputs choose betweena mailregisteranda FIFOfora Figure 2.

port data transfer operation. The usable width of both the Mail1 and Mail2

registersmatchestheselectedbussizeforPortB.

TwodifferentmethodsforsequencingdatatransferareavailableforPort

Bwhenthebussizeselectioniseitherbyte-orword-size.Theyarereferred

ALOW-to-HIGHtransitiononCLKAwritesdatatotheMail1Registerwhen toasBig-Endian(mostsignificantbytefirst)andLittle-Endian(leastsignificant

a Port A write is selected by CSA, W/RA, and ENA with MBA HIGH. If the bytefirst).ThelevelappliedtotheBig-Endianselect(BE)inputduringtheLOW-

selectedPortBbussizeisalso36bits,thentheusablewidthoftheMail1register to-HIGHtransitionofMRS1andMRS2selectstheendianmethodthatwillbe

employsdatalinesA0-A35.IftheselectedPortBbussizeis18bits,thenthe active during FIFO operation. BE is a don’t care input when the bus size

usablewidthoftheMail1RegisteremploysdatalinesA0-A17.(Inthiscase, selected for Port B is long word. The endian method is implemented at the

A18-A35aredon’tcareinputs.)IftheselectedPortBbus sizeis 9bits,then completionofMasterReset,bythetimetheFull/InputReadyflagissetHIGH,

theusablewidthoftheMail1RegisteremploysdatalinesA0-A8.(Inthiscase, as shown in Figure 2.

A9-A35 are don’t care inputs.)

Only36-bitlongworddataiswrittentoorreadfromthetwoFIFOmemories

ALOW-to-HIGHtransitiononCLKBwritesB0-B35datatotheMail2Register ontheIDT723654/723664/723674.Bus-matchingoperationsaredoneafter

whena PortBwrite is selectedbyCSB, W/RB,andENBwithMBBHIGH.If dataisreadfromtheFIFO1RAMandbeforedataiswrittentotheFIFO2RAM.

theselectedPortBbussizeisalso36bits,thentheusablewidthoftheMail2 Thesebus-matchingoperationsarenotavailablewhentransferringdatavia

employsdatalinesB0-B35.IftheselectedPortBbussizeis18bits,thenthe mailboxregisters.Furthermore,boththeword-andbyte-sizebusselections

usablewidthoftheMail2RegisteremploysdatalinesB0-B17.(Inthiscase, limitthewidthofthedatabusthatcanbeusedformailregisteroperations.In

B18-B35aredon’tcareinputs.)IftheselectedPortBbus sizeis 9bits,then thiscase,onlythosebytelanesbelongingtotheselectedword-orbyte-size

theusablewidthoftheMail2RegisteremploysdatalinesB0-B8.(Inthiscase, buscancarrymailboxdata.Theremainingdataoutputswillbeindeterminate.

B9-B35 are don’t care inputs.)

Theremainingdatainputswillbedon’tcareinputs.Forexample,whenaword-

Writingdatatoamailregistersetsitscorrespondingflag(MBF1orMBF2) sizebusisselected,thenmailboxdatacanbetransmittedonlybetweenA0-

LOW.AttemptedwritestoamailregisterareignoredwhilethemailflagisLOW. A17andB0-B17.Whenabyte-sizebusisselected,thenmailboxdatacanbe

Whendataoutputsofaportareactive,thedataonthebuscomesfromthe transmitted only between A0-A8 and B0-B8. (See Figures 27 and 28).

FIFOoutputregisterwhentheportMailboxselectinputisLOWandfromthe

mailregisterwhenthe portMailboxselectinputis HIGH.

BUS-MATCHING FIFO1 READS

TheMail1RegisterFlag(MBF1)issetHIGHbyaLOW-to-HIGHtransition

DataisreadfromtheFIFO1RAMin36-bitlongwordincrements.Ifalong

onCLKBwhenaPortBreadisselectedbyCSB,W/RB,andENBwithMBB wordbus sizeis implemented,theentirelongwordimmediatelyshifts tothe

HIGH. For a 36-bit bus size, 36 bits of mailbox data are placed on B0-B35. FIFO1outputregister.IfbyteorwordsizeisimplementedonPortB,onlythe

Foran18-bitbussize,18bitsofmailboxdataareplacedonB0-B17.(Inthis firstoneortwobytesappearontheselectedportionoftheFIFO1outputregister,

case,B18-B35areindeterminate.)Fora9-bitbussize,9bitsofmailboxdata with the rest of the long word stored in auxiliary registers. In this case,

are placed on B0-B8. (In this case, B9-B35 are indeterminate.)

subsequentFIFO1readsoutputtherestofthelongwordtotheFIFO1output

TheMail2RegisterFlag(MBF2)issetHIGHbyaLOW-to-HIGHtransition register in the order shown by Figure 2.

onCLKAwhenaPortAreadisselectedbyCSA,W/RA,andENAwithMBA

HIGH.

WhenreadingdatafromFIFO1inbyteorwordformat,theunusedB0-B35

outputsareindeterminate.

For a 36-bit bus size, 36 bits of mailbox data are placed on A0-A35. For

an18-bitbussize,18bitsofmailboxdataareplacedonA0-A17.(Inthiscase, BUS-MATCHING FIFO2 WRITES

A18-A35are indeterminate.)Fora 9-bitbus size, 9bits ofmailboxdata are

placedonA0-A8. (Inthis case, A9-A35are indeterminate.)

DataiswrittentotheFIFO2RAMin36-bitlongwordincrements.Datawritten

toFIFO2withabyteorwordbussizestorestheinitialbytesorwordsinauxiliary

Thedatainamailregisterremainsintactafteritisreadandchangesonly registers.TheCLKBrisingedgethatwritesthefourthbyteorthesecondword

whennewdataiswrittentotheregister.TheEndianselectfeaturehasnoeffect oflongwordtoFIFO2alsostorestheentirelongwordintheFIFO2memory.

onmailboxdata.FormailregisterandMailRegisterFlagtimingdiagrams,see The bytes are arranged in the manner shown in Figure 2.

Figure 27 and 28.

WhenwritingdatatoFIFO2inbyteorwordformat,theunusedB0-B35inputs

aredon'tcareinputs.

16

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

A35  A27

A26  A18

A17  A9

A8  A0

BYTE ORDER ON PORT A:

Write to FIFO1/

Read from FIFO2

D

A

B

C

B35  B27

B26  B18

B17  9

B8  B0

BYTE ORDER ON PORT B:

BE BM SIZE

Read from FIFO1/

Write to FIFO2

A

B

D

C

X

L

X

(a) LONG WORD SIZE

B35  B27

B26  B18

B17  B9

B8  B0

1st: Read from FIFO1/

Write to FIFO2

BE BM SIZE

A

B

H

L

B17  B9

B8  B0

2nd: Read from FIFO1/

Write to FIFO2

C

D

(b) WORD SIZE



BIG ENDIAN

B17  B9

C

B35  B27

B26  B18

B8  B0

1st: Read from FIFO1/

Write to FIFO2

BE BM SIZE

D

L

H

L

B26  B18

B17  B9

B8  B0

2nd: Read from FIFO1/

Write to FIFO2

A

B

(c) WORD SIZE



LITTLE-ENDIAN

B35  B27

B26  B18

B17  B9

B8  B0

BE BM SIZE

1st: Read from FIFO1/

Write to FIFO2

A

H

B26  B18

B17  B9

B8  B0

2nd: Read from FIFO1/

Write to FIFO2

B

B8  B0

3rd: Read from FIFO1/

Write to FIFO2

C

B8  B0

4th: Read from FIFO1/

Write to FIFO2

D

(d) BYTE SIZE



BIG-ENDIAN

B35  B27

B26  B18

B17  B9

B8  B0

BE BM SIZE

1st: Read from FIFO1/

Write to FIFO2

D

L

H

B26  B18

B17  B9

B8  B0

2nd: Read from FIFO1/

Write to FIFO2

C

B8  B0

3rd: Read from FIFO1/

Write to FIFO2

B

B17  B9

B8  B0

4th: Read from FIFO1/

Write to FIFO2

A

5608 drw 04

(e) BYTE SIZE



LITTLE-ENDIAN

Figure 2. Bus Sizing

17

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

CLKA

CLKB

t

RSTS

tRSTH

MRS1

tBEH

t

BES

tFWS

BE

0,1

BE/FWFT

FWFT

t

FSS

tFSH

FS2,

FS1,FS0

t

WFF

t

WFF

FFA/IRA

EFB/ORB

AEB

(3)

REF

t

RSF

t

RSF

AFA

t

RSF

MBF1

LOW

RTM

5608 drw 05

NOTES:

1. FIFO2 Master Reset (MRS2) is performed in the same manner to load X2 and Y2 with a preset value. For FIFO2 Master Reset, MRS1 must toggle simultaneously with MRS2.

2. PRS1 must be HIGH during Master Reset.

3. If BE/FWFT is HIGH, then EFB/ORB will go LOW one CLKB cycle earlier than in this case where BE/FWFT is LOW.

Figure 3. FIFO1 Master Reset and Loading X1 and Y1 with a Preset Value of Eight⁽¹⁾(IDT Standard and FWFT Modes)

CLKA

CLKB

t

RSTS

tRSTH

PRS1

t

WFF

t

WFF

FFA/IRA

(3)

tREF

EFB/ORB

t

RSF

AEB

AFA

t

RSF

t

RSF

MBF1

RTM

LOW

5608 drw 06

NOTES:

1. Partial Reset is performed in the same manner for FIFO2.

2. MRS1 must be HIGH during Partial Reset.

3. If BE/FWFT is HIGH, then EFB/ORB will go LOW one CLKB cycle earlier than in this case where BE/FWFT is LOW.

Figure 4. FIFO1 Partial Reset⁽¹⁾(IDT Standard and FWFT Modes)

18

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

CLKA

2

1

4

MRS1,

MRS2

tFSS

tFSH

FS2

FS1,FS0

FFA/IRA

0,0

tWFF

tDS

(1)

tSKEW1

tENS2

tDH

tENH

ENA

A0-A35

AEB Offset

AFA Offset

AFB Offset

(Y 2)

AEA Offset

(X 2)

First Word to FIFO1

(X1)

(Y1)

CLKB

1

2

tWFF

FFB/IRB

5608 drw 07

NOTES:

1. t^SKEW1is the minimum time between the rising CLKA edge and a rising CLKB edge for FFB/IRB to transition HIGH in the next cycle. If the time between the rising edge of CLKA and rising

edge of CLKB is less than t^SKEW1, then FFB/IRB may transition HIGH one CLKB cycle later than shown.

2. CSA=LOW, W/RA=HIGH,MBA=LOW. It is not necessary to program offset register on consecutive clock cycles.

Figure 5. Parallel Programming of the Almost-Full Flag and Almost-Empty Flag Offset Values after Reset

(IDT Standard and FWFT Modes)

CLKA

4

MRS1,

MRS2

t

FSS

tFSH

FS2

t

WFF

(1)

tSKEW

FFA/IRA

t

SENS

t

FSS

t

SENH

SDH

t

SENS

t

SENH

tSPH

FS1/SEN

tSDS

t

tSDH

tSDS

FS0/SD⁽³⁾

AFA Offset (Y1) MSB

AEA Offset (X2) LSB

CLKB

4

t

WFF

5608 drw08

FFB/IRB

NOTES:

1. t^SKEW1is the minimum time between the rising CLKA edge and a rising CLKB edge for FFB/IRB to transition HIGH in the next cycle. If the time between the rising edge of CLKA and rising

edge of CLKB is less than t^SKEW1, then FFB/IRB may transition HIGH one CLKB cycle later than shown.

2. It is not necessary to program offset register bits on consecutive clock cycles. FIFO write attempts are ignored until FFA/IRA and FFB/IRB is set HIGH.

3. Programmable offsets are written serially to the SD input in the order AFA offset (Y1), AEB offset (X1), AFB offset (Y2), and AEA offset (X2).

Figure 6. Serial Programming of the Almost-Full Flag and Almost-Empty Flag Offset Values (IDT Standard and FWFT Modes)

19

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

tCLK

tCLKH

tCLKL

CLKA

FFA/IRA HIGH

t

ENH

t

ENS1

CSA

t

ENS1

t

W/RA

t

ENS2

t

ENH

MBA

ENA

tENS2

tENH

tENS2

tENH

t

tDS

tDH

W1⁽¹⁾

W2⁽¹⁾

A0 - A35

No Operation

5608 drw09

NOTE:

1. Written to FIFO1.

Figure 7. Port A Write Cycle Timing for FIFO1 (IDT Standard and FWFT Modes)

tCLK

tCLKH

tCLKL

CLKB

FFB/IRB HIGH

tENH

tENS1

CSB

tENH

tENS1

W/RB

tENH

tENS2

MBB

tENH

tENS2

ENB

tDH

t

DS

W1⁽¹⁾

W2⁽¹⁾

No Operation

B0-B35

5608 drw 10

NOTE:

1. Written to FIFO2.

DATA SIZE TABLE FOR LONG-WORD WRITES TO FIFO2

SIZE MODE⁽¹⁾

SIZE

DATA WRITTEN TO FIFO2

DATA READ FROM FIFO2

BM

BE

B35-B27

B26-B18

B17-B9

B8-B0

A35-A27

A26-A18

A17-A9

A8-A0

L

X

A

B

C

D

A

B

C

D

NOTE:

1. BE is selected at Master Reset: BM and SIZE must be static throughout device operation.

Figure 8. Port B Long-Word Write Cycle Timing for FIFO2 (IDT Standard and FWFT Modes)

20

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

CLKB

FFB/IRB HIGH

tENH

t

ENS1

CSB

t

W/RB

t

ENH

t

ENH

t

ENS2

t

ENS2

MBB

t

ENH

t

ENH

t

ENS2

t

ENB

tDH

tDS

B0-B17

5608 drw 11

DATA SIZE TABLE FOR WORD WRITES TO FIFO2

SIZE MODE⁽¹⁾

WRITE NO.

DATA WRITTEN

TO FIFO2

DATA READ FROM FIFO2

BM

SIZE

BE

B17-B9

B8-B0

A35-A27

A26-A18

A17-A9

A8-A0

1

2

1

2

A

B

H

L

H

A

B

C

D

C

A

D

B

H

L

A

B

C

D

NOTE:

1. BE is selected at Master Reset; BM and SIZE must be static throughout device operation.

Figure 9. Port B Word Write Cycle Timing for FIFO2 (IDT Standard and FWFT Modes)

CLKB

FFB/IRB HIGH

tENH

t

ENS1

CSB

t

W/RB

MBB

t

ENH

tENH

t

ENS2

t

tENH

tENS2

tENH

ENB

tDS

tDH

B0-B8

5608 drw 12

DATA SIZE TABLE FOR BYTE WRITES TO FIFO2

SIZE MODE⁽¹⁾

WRITE NO. DATA WRITTEN

TO FIFO2

DATA READ FROM FIFO2

BM

SIZE

BE

B8-B0

A35-A27

A26-A18

A17-A9

A8-A0

1

2

3

4

1

2

3

4

A

B

C

D

C

B

A

H

A

B

C

D

H

L

A

B

C

D

NOTE:

1. BE is selected at Master Reset; BM and SIZE must be static throughout device operation.

Figure 10. Port B Byte Write Cycle Timing for FIFO2 (IDT Standard and FWFT Modes)

21

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

tCLK

tCLKH

tCLKL

CLKB

EFB/ORB

HIGH

CSB

W/RB

MBB

tENH

tENS2

ENB

t

MDV

No Operation

W2⁽¹⁾

tDIS

t

A

t

A

t

EN

W1⁽¹⁾

W2⁽¹⁾

Previous Data

B0-B35

(Standard Mode)

t

MDV

tDIS

tA

t

A

OR

tEN

W3⁽¹⁾

W1⁽¹⁾

B0-B35

(FWFT Mode)

5608 drw 13

NOTE:

1. Read From FIFO1.

DATA SIZE TABLE FOR FIFO LONG-WORD READS FROM FIFO1

SIZE MODE⁽¹⁾

SIZE

DATA WRITTEN TO FIFO1

DATA READ FROM FIFO1

BM

BE

A35-A27

A26-A18

A17-A9

A8-A0

B35-B27

B26-B18

B17-B9

B8-B0

L

X

A

B

C

D

A

B

C

D

NOTE:

1. BE is selected at Master Reset; BM and SIZE must be static throughout device operation .

Figure 11. Port B Long-Word Read Cycle Timing for FIFO1 (IDT Standard and FWFT Modes)

CLKB

HIGH

EFB/ORB

CSB

W/RB

MBB

ENB

t

ENS2

tENH

No Operation

t

MDV

tDIS

t

A

tA

t

EN

B0-B17

Previous Data

(Standard Mode)

tDIS

t

MDV

OR

t

A

tA

t

EN

B0-B17

(FWFT Mode)

5608 drw 14

NOTE:

1. Unused word B18-B35 are indeterminate for word-size reads.

DATA SIZE TABLE FOR WORD READS FROM FIFO1

SIZE MODE⁽¹⁾

SIZE

DATA WRITTEN TO FIFO1

READ NO.

DATA READ FROM FIFO1

BM

BE

A35-A27

A26-A18

A17-A9

A8-A0

B17-B9

B8-B0

H

L

H

A

B

C

D

1

2

1

2

A

C

A

B

D

B

H

L

A

B

C

D

NOTE:

1. BE is selected at Master Reset; BM and SIZE must be static throughout device operation .

Figure 12. Port-B Word Read Cycle Timing for FIFO1 (IDT Standard and FWFT Modes)

22

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

CLKB

EFB/ORB HIGH

CSB

W/RB

MBB

tENS2

tENH

ENB

No Operation

t

DIS

t

MDV

t

A

t

A

t

A

t

A

t

EN

B0-B8

Previous Data

(Standard Mode)

t

MDV

t

OR

t

A

tA

t

A

t

EN

B0-B8

(FWFT Mode)

5608 drw 15

NOTE:

1. Unused bytes B9-B17, B18-B26, and B27-B35 are indeterminate for byte-size reads.

DATA SIZE TABLE FOR BYTE READS FROM FIFO1

SIZE MODE⁽¹⁾

DATA WRITTEN TO FIFO1

READ NO.

DATA READ

FROM FIFO1

B8-B0

BM

SIZE

BE

A35-A27

A26-A18

A17-A9

A8-A0

1

2

3

4

1

2

3

4

A

B

C

D

C

B

A

H

A

B

C

D

H

L

A

B

C

NOTE:

1. BE is selected at Master Reset; BM and SIZE must be static throughout device operation.

Figure 13. Port-B Byte Read Cycle Timing for FIFO1 (IDT Standard and FWFT Modes)

tCLK

tCLKL

tCLKH

CLKA

EFA/ORA HIGH

CSA

W/RA

MBA

tENH

tENS2

ENA

No Operation

W2⁽¹⁾

t

MDV

t

DIS

t

A

t

A

t

EN

A0-A35

Previous Data

W1⁽¹⁾

W2⁽¹⁾

(Standard Mode)

t

MDV

t

tA

t

A

OR

t

EN

A0-A35

W3⁽¹⁾

(1)

W1

(FWFT Mode)

5608 drw16

NOTE:

1. Read From FIFO2.

Figure 14. Port-A Read Cycle Timing for FIFO2 (IDT Standard and FWFT Modes)

23

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

tCLK

tCLKH

tCLKL

CLKA

CSA

LOW

WRA HIGH

t

ENS2

t

ENH

MBA

t

ENH

ENA

IRA HIGH

tDS

tDH

A0-A35

W1

t

^CLKtCLKL

(1)

tCLKH

tSKEW1

CLKB

ORB

1

2

3

t

REF

tREF

FIFO1 Empty

CSB LOW

W/RB HIGH

LOW

MBB

tENS2

tENH

ENB

tA

Old Data in FIFO1 Output Register

W1

B0-B35

5608 drw17

NOTES:

1. t^SKEW1is the minimum time between a rising CLKA edge and a rising CLKB edge for ORB to transition HIGH and to clock the next word to the FIFO1 output register in three CLKB cycles.

If the time between the rising CLKA edge and rising CLKB edge is less than t^SKEW1, then the transition of ORB HIGH and load of the first word to the output register may occur one CLKB

cycle later than shown.

2. If Port B size is word or byte, ORB is set LOW by the last word or byte read from FIFO1, respectively.

Figure 15. ORB Flag Timing and First Data Word Fall Through when FIFO1 is Empty (FWFT Mode)

24

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

t

CLK

t

CLKL

t

CLKH

CLKA

CSA

LOW

HIGH

WRA

t

ENS2

t

ENH

MBA

t

tENS2

ENA

FFA

HIGH

tDS

tDH

A0-A35

W1

t

CLK

(1)

SKEW1

t

CLKH

t

tCLKL

CLKB

1

2

t

REF

t

REF

FIFO1 Empty

LOW

EFB

CSB

W/RB HIGH

LOW

MBB

tENH

tENS2

ENB

tA

W1

B0-B35

5608 drw18

NOTES:

1. t^SKEW1is the minimum time between a rising CLKA edge and a rising CLKB edge for EFB to transition HIGH in the next CLKB cycle. If the time between the rising CLKA edge and rising

CLKB edge is less than t^SKEW1, then the transition of EFB HIGH may occur one CLKB cycle later than shown.

2. If Port B size is word or byte, EFB is set LOW by the last word or byte read from FIFO1, respectively.

Figure 16. EFB Flag Timing and First Data Read Fall Through when FIFO1 is Empty (IDT Standard Mode)

25

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

tCLK

tCLKH

tCLKL

CLKB

CSB

LOW

W/RB

tENS2

tENH

MBB

ENB

tENH

tENS2

IRB

HIGH

tDH

tDS

B0-B35

W1

t

CLK

(1)

SKEW1

tCLKH

t

CLKL

t

1

2

CLKA

ORA

3

t

REF

tREF

FIFO2 Empty

CSA

LOW

W/RA

LOW

MBA

ENA

tENS2

tENH

tA

Old Data in FIFO2 Output Register

W1

A0-A35

5608 drw19

NOTES:

1. t^SKEW1is the minimum time between a rising CLKB edge and a rising CLKA edge for ORA to transition HIGH and to clock the next word to the FIFO2 output register in three CLKA cycles.

If the time between the CLKB edge and the rising CLKA edge is less than t^SKEW1, then the transition of ORA HIGH and load of the first word to the output register may occur one CLKA

cycle later than shown.

2. If Port B size is word or byte, t^SKEW1is referenced to the rising CLKB edge that writes the last word or byte of the long word, respectively.

Figure 17. ORA Flag Timing and First Data Word Fall through when FIFO2 is Empty (FWFT Mode)

26

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

t

CLK

t

CLKL

t

CLKH

CLKB

CSB LOW

LOW

W/RB

tENS2

tENH

MBB

ENB

tENS2

tENH

FFB HIGH

B0-B35

tDH

tDS

W1

(1)

t

CLK

tSKEW1

t

CLKH

t

CLKL

1

2

CLKA

t

REF

t

REF

EFA

FIFO2 Empty

LOW

CSA

W/RA

MBA

tENS2

tENH

ENA

tA

W1

A0-A35

5608 drw20

NOTES:

1. t^SKEW1is the minimum time between a rising CLKB edge and a rising CLKA edge for EFA to transition HIGH in the next CLKA cycle. If the time between the rising CLKB edge and rising

CLKA edge is less than t^SKEW1, then the transition of EFA HIGH may occur one CLKA cycle later than shown.

2. If Port B size is word or byte, t^SKEW1is referenced to the rising CLKB edge that writes the last word or byte of the long word, respectively.

Figure 18. EFA Flag Timing and First Data Read when FIFO2 is Empty (IDT Standard Mode)

27

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

tCLK

tCLKH

tCLKL

CLKB

CSB

LOW

W/RB

HIGH

LOW

MBB

tENS2

tENH

ENB

ORB

HIGH

tA

Previous Word in FIFO1 Output Register

Next Word From FIFO1

B0-B35

(1)

tCLK

tSKEW1

tCLKH

tCLKL

1

2

CLKA

t

WFF

t

WFF

FIFO1 Full

LOW

IRA

CSA

HIGH

W/RA

tENH

tENS2

MBA

tENS2

tENH

ENA

tDS

tDH

Write

A0-A35

To FIFO1

5608 drw21

NOTES:

1. t^SKEW1is the minimum time between a rising CLKB edge and a rising CLKA edge for IRA to transition HIGH in the next CLKA cycle. If the time between the

rising CLKB edge and rising CLKA edge is less than tSKEW1, then IRA may transition HIGH one CLKA cycle later than shown.

2. If Port B size is word or byte, tSKEW1 is referenced to the rising CLKB edge that reads the last word or byte write of the long word, respectively.

Figure 19. IRA Flag Timing and First Available Write when FIFO1 is Full (FWFT Mode)

tCLK

tCLKH

tCLKL

CLKB

LOW

CSB

W/RB

MBB

HIGH

LOW

tENS2

tENH

ENB

HIGH

EFB

tA

Previous Word in FIFO1 Output Register

Next Word From FIFO1

B0-B35

(1)

t

^CLKtCLKL

tSKEW1

tCLKH

CLKA

1

2

t

WFF

t

WFF

FFA

FIFO1 Full

CSA LOW

W/RA HIGH

t

ENH

t

ENS2

MBA

t

tENH

ENA

tDH

tDS

Write

A0-A35

5608 drw22

To FIFO1

NOTES:

1. t^SKEW1is the minimum time between a rising CLKB edge and a rising CLKA edge for FFA to transition HIGH in the next CLKA cycle. If the time between the

rising CLKB edge and rising CLKA edge is less than tSKEW1, then FFA may transition HIGH one CLKA cycle later than shown.

2. If Port B size is word or byte, t^SKEW1is referenced from the rising CLKB edge that reads the last word or byte of the long word, respectively.

Figure 20. FFA Flag Timing and First Available Write when FIFO1 is Full (IDT Standard Mode)

28

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

tCLK

tCLKH

tCLKL

CLKA

CSA

LOW

W/RA

LOW

MBA

tENS2

tENH

ENA

ORA

HIGH

tA

Previous Word in FIFO2 Output Register

SKEW1

Next Word From FIFO2

A0-A35

(1)

tCLK

t

tCLKH

tCLKL

1

2

CLKB

t

WFF

t

WFF

IRB

CSB

FIFO2 FULL

LOW

W/RB

LOW

tENS2

tENH

MBB

ENB

tENS2

tENH

tDS

tDH

Write

B0-B35

5608 drw23

To FIFO2

NOTES:

1. t^SKEW1is the minimum time between a rising CLKA edge and a rising CLKB edge for IRB to transition HIGH in the next CLKB cycle. If the time between the rising CLKA edge and rising

CLKB edge is less than t^SKEW1, then IRB may transition HIGH one CLKB cycle later than shown.

2. If Port B size is word or byte, IRB is set LOW by the last word or byte write of the long word, respectively.

Figure 21. IRB Flag Timing and First Available Write when FIFO2 is Full (FWFT Mode)

29

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

tCLK

tCLKH

tCLKL

CLKA

LOW

CSA

W/RA

MBA

tENS2

tENH

ENA

EFA

HIGH

tA

Previous Word in FIFO2 Output Register

Next Word From FIFO2

A0-A35

(1)

tCLK

tSKEW1

tCLKH

tCLKL

CLKB

1

2

t

WFF

t

WFF

FIFO2 Full

LOW

FFB

CSB

LOW

W/RB

t

ENS2

t

ENH

MBB

ENB

t

ENH

tDS

tDH

Write

B0-B35

5608 drw24

To FIFO2

NOTES:

1. t^SKEW1is the minimum time between a rising CLKA edge and a rising CLKB edge for FFB to transition HIGH in the next CLKB cycle. If the time between the rising CLKA edge and rising

CLKB edge is less than t^SKEW1, then FFB may transition HIGH one CLKB cycle later than shown.

2. If Port B size is word or byte, FFB is set LOW by the last word or byte write of the long word, respectively.

Figure 22. FFB Flag Timing and First Available Write when FIFO2 is Full (IDT Standard Mode)

30

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

CLKA

tENS2

tENH

ENA

(1)

tSKEW2

1

2

CLKB

t

PAE

t

PAE

X1 Words in FIFO1

AEB

(X1+1) Words in FIFO1

ENS2

t

ENH

ENB

5608 drw 25

NOTES:

1. t^SKEW2is the minimum time between a rising CLKA edge and a rising CLKB edge for AEB to transition HIGH in the next CLKB cycle. If the time between the rising CLKA edge and rising

CLKB edge is less than t^SKEW2, then AEB may transition HIGH one CLKB cycle later than shown.

2. FIFO1 Write (CSA = LOW, W/RA = LOW, MBA = LOW), FIFO1 read (CSB = LOW, W/RB = HIGH, MBB = LOW). Data in the FIFO1 output register has been read from the FIFO.

3. If Port B size is word or byte, AEB is set LOW by the last word or byte read from FIFO1, respectively.

Figure 23. Timing for AEB when FIFO1 is Almost-Empty (IDT Standard and FWFT Modes)

CLKB

tENS2

tENH

ENB

(1)

tSKEW2

1

2

CLKA

t

PAE

t

PAE

AEA

X2 Words in FIFO2

(X2+1) Words in FIFO2

ENS2

t

tENH

ENA

5608 drw 26

NOTES:

1. t^SKEW2is the minimum time between a rising CLKB edge and a rising CLKA edge for AEA to transition HIGH in the next CLKA cycle. If the time between the rising CLKB edge and rising

CLKA edge is less than t^SKEW2, then AEA may transition HIGH one CLKA cycle later than shown.

2. FIFO2 Write (CSB = LOW, W/RB = LOW, MBB = LOW), FIFO2 read (CSA = LOW, W/RA = LOW, MBA = LOW). Data in the FIFO2 output register has been read from the FIFO.

3. If Port B size is word or byte, tSKEW2 is referenced to the rising CLKB edge that writes the last word or byte of the long word, respectively.

Figure 24. Timing for AEA when FIFO2 is Almost-Empty (IDT Standard and FWFT Modes)

(1)

tSKEW2

1

2

CLKA

ENA

tENH

tENS2

t

PAF

t

PAF

(D-Y1) Words in FIFO1

[D-(Y1+1)] Words in FIFO1

AFA

CLKB

tENS2

tENH

ENB

5608 drw 27

NOTES:

1. t^SKEW2is the minimum time between a rising CLKA edge and a rising CLKB edge for AFA to transition HIGH in the next CLKA cycle. If the time between the rising CLKA edge and rising

CLKB edge is less than t^SKEW2, then AFA may transition HIGH one CLKA cycle later than shown.

2. FIFO1 Write (CSA = LOW, W/RA = HIGH, MBA = LOW), FIFO1 read (CSB = LOW, W/RB = HIGH, MBB = LOW). Data in the FIFO1 output register has been read from the FIFO.

3. D = Maximum FIFO Depth = 2,048 for the IDT723654, 4,096 for the IDT723664, 8,192 for the IDT723674.

4. If Port B size is word or byte, t^SKEW2is referenced to the rising CLKB edge that reads the last word or byte of the long word, respectively.

Figure 25. Timing for AFA when FIFO1 is Almost-Full (IDT Standard and FWFT Modes)

31

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

(1)

tSKEW2

1

2

CLKB

ENB

tENH

tENS2

t

PAF

t

PAF

(D-Y2) Words in FIFO2

AFB

[D-(Y2+1)] Words in FIFO2

CLKA

tENH

tENS2

ENA

5608 drw 28

NOTES:

1. t^SKEW2is the minimum time between a rising CLKB edge and a rising CLKA edge for AFB to transition HIGH in the next CLKB cycle. If the time between the rising CLKB edge and rising

CLKA edge is less than t^SKEW2, then AFB may transition HIGH one CLKB cycle later than shown.

2. FIFO2 write (CSB = LOW, W/RB = LOW, MBB = LOW), FIFO2 read (CSA = LOW, W/RA = LOW, MBA = LOW). Data in the FIFO2 output register has been read from the FIFO.

3. D = Maximum FIFO Depth = 2,048 for the IDT723654, 4,096 for the IDT723664, 8,192 for the IDT723674.

4. If Port B size is word or byte, AFB is set LOW by the last word or byte write of the long word, respectively.

Figure 26. Timing for AFB when FIFO2 is Almost-Full (IDT Standard and FWFT Modes)

CLKA

t

ENH

t

ENS1

CSA

t

ENS1

W/RA

tENH

tENS2

MBA

tENH

tENS2

ENA

tDH

tDS

W1

A0-A35

CLKB

t

PMF

t

PMF

MBF1

CSB

W/RB

MBB

ENB

tENH

tENS2

t

PMR

tEN

t

MDV

tDIS

FIFO1 Output Register

W1 (Remains valid in Mail1 Register after read)

B0-B35

5608 drw29

NOTE:

1. If Port B is configured for word size, data can be written to the Mail1 register using A0-A17 (A18-A35 are don't care inputs). In this first case B0-B17 will have valid data (B18-B35

will be indeterminate). If Port B is configured for byte size, data can be written to the Mail1 Register using A0-A8 (A9-A35 are don't care inputs). In this second case, B0-B8 will

have valid data (B9-B35 will be indeterminate).

Figure 27. Timing for Mail1 Register and MBF1 Flag (IDT Standard and FWFT Modes)

32

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

CLKB

tENH

tENS1

CSB

W/RB

MBB

ENB

t

ENH

t

ENS1

t

ENH

t

ENS2

t

ENH

t

DH

tDS

W1

B0-B35

CLKA

t

PMF

tPMF

MBF2

CSA

W/RA

MBA

ENA

tENH

tENS2

t

PMR

tEN

tDIS

t

MDV

A0-A35

W1 (Remains valid in Mail 2 Register after read)

FIFO2 Output Register

5608 drw30

NOTE:

1. If Port B is configured for word size, data can be written to the Mail2 Register using B0-B17 (B18-B35 are don’t care inputs). In this first case A0-A17 will have valid data

(A18-A35 will be indeterminate). If Port B is configured for byte size, data can be written to the Mail2 Register using B0-B8 (B9-B35 are don’t care inputs). In this second

case, A0-A8 will have valid data (A9-A35 will be indeterminate).

Figure 28. Timing for Mail2 Register and MBF2 Flag (IDT Standard and FWFT Modes)

33

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

CLKA

CLKB

4

1

2

3

2

3

4

1

tENS2

tENH

ENB

RT1

t

RSTS

t

RSTH

t

RTMH

t

RTMS

RTM

(2)

REF

(2)

REF

t

EFB

tA

B0-Bn

Wx

W1

5608 drw 31

NOTES:

1. CSB = LOW

2. Retransmit setup is complete after EFB returns HIGH, only then can a read operation begin.

3. W1 = first word written to the FIFO1 after Master Reset on FIFO1.

4. No more than D-2 may be written to the FIFO1 between Reset of FIFO1 (Master or Partial) and Retransmit setup. Therefore, FFA will be LOW throughout the Retransmitsetup

procedure. D = 2,048, 4,096 and 8,192 for the IDT723654, IDT723664 and IDT723674 respectively.

Figure 29. Retransmit Timing for FIFO1 (IDT Standard Mode)

CLKB

CLKA

4

1

2

3

2

3

4

1

tENS2

tENH

ENA

RT2

t

RSTH

t

RSTS

t

RTMH

t

RTMS

RTM

(2)

REF

(2)

REF

t

EFA

tA

A0-An

Wx

W1

5608 drw 32

NOTES:

1. CSA = LOW

2. Retransmit setup is complete after EFA returns HIGH, only then can a read operation begin.

3. W1 = first word written to the FIFO1 after Master Reset on FIFO2.

4. No more than D-2 may be written to the FIFO1 between Reset of FIFO2 (Master or Partial) and Retransmit setup. Therefore, FFB will be LOW throughout the Retransmit

setup procedure. D = 2,048, 4,096 and 8,192 for the IDT723654, IDT723664 and IDT723674 respectively.

Figure 30. Retransmit Timing for FIFO2 (IDT Standard Mode)

34

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

CLKA

CLKB

4

1

2

3

2

3

4

1

ENB LOW

t

RSTS

tRSTH

RT1

RTM

ORB

t

RTMH

t

RTMS

(2)

REF

(2)

REF

t

tA

B0-Bn

Wx

W1

5608 drw 33

NOTES:

1. CSB = LOW

2. Retransmit setup is complete after ORB returns HIGH, only then can a read operation begin.

3. W1 = first word written to the FIFO1 after Master Reset on FIFO1.

4. No more than D-2 may be written to the FIFO1 between Reset of FIFO1 (Master or Partial) and Retransmit setup. Therefore, IRA will be LOW throughout the Retransmit

setup procedure. D = 2,049, 4,097 and 8,193 for the IDT723654, IDT723664 and IDT723674 respectively.

Figure 31. Retransmit Timing for FIFO1 (FWFT Mode)

CLKB

CLKA

4

1

2

3

2

3

4

1

LOW

ENA

RT2

tRSTH

t

RSTS

t

RTMH

t

RTMS

RTM

(2)

REF

(2)

REF

t

ORA

tA

A0-An

Wx

W1

5608 drw 34

NOTES:

1. CSA = LOW

2. Retransmit setup is complete after ORA returns HIGH, only then can a read operation begin.

3. W1 = first word written to the FIFO2 after Master Reset on FIFO2.

4. No more than D-2 may be written to the FIFO2 between Reset of FIFO2 (Master or Partial) and Retransmit setup. Therefore, IRB will be LOW throughout the Retransmit

setup procedure. D = 2,049, 4,097 and 8,193 for the IDT723654, IDT723664 and IDT723674 respectively.

Figure 32. Retransmit Timing for FIFO2 (FWFT Mode)

35

IDT723654/723664/723674CMOSSyncBiFIFO^TMWITHBUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

COMMERCIALTEMPERATURERANGE

PARAMETER MEASUREMENT INFORMATION

5V

1.1KΩ

From Output

Under Test

30 pF ⁽¹⁾

680Ω

PROPAGATION DELAY

LOAD CIRCUIT

3 V

Timing

Input

1.5 V

High-Level

1.5 V

Input

GND

1.5 V

GND

3 V

t

S

th

tW

3 V

Data,

Enable

Input

1.5 V

Low-Level

1.5 V

GND

Input

GND

VOLTAGE WAVEFORMS

SETUP AND HOLD TIMES

VOLTAGE WAVEFORMS

PULSE DURATIONS

3 V

Output

Enable

1.5 V

t

PZL

GND

tPLZ

3 V

≈3 V

Input

1.5 V

Low-Level

Output

GND

V

OL

tPD

t

PZH

tPD

V

OH

V

OH

≈O V

In-Phase

Output

1.5 V

High-Level

Output

1.5 V

V

t

PHZ

OL

VOLTAGE WAVEFORMS

ENABLE AND DISABLE TIMES

VOLTAGE WAVEFORMS

PROPAGATION DELAY TIMES

5608 drw35

NOTE:

1. Includes probe and jig capacitance.

Figure 33. Output Load and AC Test Conditions

36

ORDERINGINFORMATION

IDT

X

XX

X

XXXXXX

Device Type Power

Speed

Package

Process/

Temperature

Range

Commercial (0°C to +70°C)

BLANK

PF

Thin Quad Flat Pack (TQFP, PK128-1)

12

15

Clock Cycle Time (tCLK

)

Commercial Only

Speed in Nanoseconds

Low Power

L

723654

723664

723674

2,048 x 36 x 2  SyncBiFIFO

4,096 x 36 x 2  SyncBiFIFO

8,192 x 36 x 2  SyncBiFIFO



with Bus-Matching

5608 drw36

NOTE:

1. Industrial temperature range is available by special order.

DATASHEETDOCUMENTHISTORY

12/20/2000

02/09/2001

03/21/2001

08/01/2001

11/03/2003

pg. 13

pgs. 5 and 12.

pgs. 7 and 8.

pgs. 7, 9, 10 and 37.

pg. 1.

CORPORATE HEADQUARTERS

for SALES:

for TECH SUPPORT:

2975StenderWay

Santa Clara, CA 95054

800-345-7015 or 408-727-6116

fax: 408-492-8674

408-330-1753

e-mail: FIFOhelp@idt.com

www.idt.com

37


型号：	IDT723674
厂家：	INTEGRATED DEVICE TECHNOLOGY
描述：	CMOS SyncBiFIFO WITH BUS-MATCHING 具有总线匹配CMOS SyncBiFIFO 配套器件先进先出芯片
文件：	总37页 (文件大小：396K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

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