IDT72T2098/108/118/128 2.5V HIGH-SPEED TeraSync™ DDR/SDR FIFO 20-BIT/10-BIT CONFIGURATIONS
32K x 20/64K x 10, 64K x 20/128K x 10, 128K x 20/256K x 10, 256K x 20/512K x 10
COMMERCIAL AND INDUSTRIAL
TEMPERATURERANGES
PINDESCRIPTION(CONTINUED)
Symbol &
Pin No.
Name
I/OTYPE
Description
RCS
(F14)
Read Chip
Select
HSTL-LVTTL RCSprovidessynchronousenable/disablecontrolof thereadportandHigh-Impedancecontrolofthe
INPUT
Qndataoutputs,synchronoustoRCLK. WhenusingRCS theOEpinmustbetiedLOW. DuringMaster
orPartialResettheRCSinputisdon’tcare,ifOEisLOWthedataoutputswillbeLow-Impedanceregardless
ofRCS.
REN
(F16)
ReadEnable
HSTL-LVTTL WhenLOWandinDDRmode,RENalongwitharisingandfallingedgeofRCLKwillsenddatainFIFO
INPUT
memorytothe outputregisterandreadthe currentdata inoutputregister. InSDRmode data willonly
be read on the rising edge of RCLK only.
(1)
RSDR
(L2)
ReadSingle
DataRate
LVTTL
INPUT
WhenLOW,thisinputpinsetsthereadporttoSingleDataClockmode. WhenHIGH,thereadportwill
operateinDoubleDataClockmode.ThispinmustbetiedeitherHIGHorLOWandcannottoggleduring
operation.
RT
(F15)
Retransmit
HSTL-LVTTL RTassertedontherisingedgeofRCLKinitializesthereadpointertothefirstlocationinmemory.EFflag
INPUT
issettoLOW(ORtoHIGHinFWFTmode).Thewritepointer,offsetregisters,andflagsettingsarenot
affected.IfamarkhasbeensetviatheMARKinputpin,thenthereadpointerwillinitializetothemarklocation
when RT is asserted.
SCLK
(H15)
SerialClock
LVTTL
INPUT
ArisingedgeofSCLKwillclocktheserialdatapresentontheSIinputintotheoffsetregistersprovided
thatSENisenabled.ArisingedgeofSCLKwillalsoreaddataoutoftheoffsetregistersprovidedthatSREN
isenabled.
SEN
(J15)
SerialInput
Enable
HSTL-LVTTL SENusedinconjunctionwithSIandSCLKenablesserialloadingoftheprogrammableflagoffsets.
INPUT
SREN
(J16)
Serial Read
Enable
HSTL-LVTTL SRENusedinconjunctionwithSOandSCLKenablesserialreadingoftheprogrammableflagoffsets.
INPUT
SI
(H16)
SerialInput
SerialOutput
JTAGClock
HSTL-LVTTL Thisinputpinisusedtoloadserialdataintotheprogrammableflagoffsets.UsedinconjunctionwithSEN
INPUT
and SCLK.
SO
(K15)
HSTL-LVTTL Thisoutputpinisusedtoreaddatafromtheprogrammableflagoffsets.UsedinconjunctionwithSREN
OUTPUT and SCLK.
(2)
TCK
HSTL-LVTTL ClockinputforJTAGfunction.Oneoffourterminals requiredbyIEEEStandard1149.1-1990.Test
(F1)
INPUT
operationsofthedevicearesynchronoustoTCK.DatafromTMSandTDIaresampledontherisingedge
ofTCKandoutputschangeonthefallingedgeofTCK.IftheJTAGfunctionisnotusedthissignalneeds
tobe tiedtoGND.
(2)
TDI
JTAGTestData HSTL-LVTTL One of four terminals required by IEEE Standard 1149.1-1990. During the JTAG boundary scan
(E2)
Input
INPUT
operation,testdataseriallyloadedviatheTDIontherisingedgeofTCKtoeithertheInstructionRegister,
IDRegisterandBypass Register.Aninternalpull-upresistorforces TDIHIGHifleftunconnected.
(2)
TDO
JTAGTestData HSTL-LVTTL One of four terminals required by IEEE Standard 1149.1-1990. During the JTAG boundary scan
(F3)
Output
OUTPUT
operation,testdataseriallyloadedoutputviatheTDOonthefallingedgeofTCKfromeithertheInstruction
Register,IDRegisterandBypassRegister.Thisoutputishighimpedanceexceptwhenshifting,whilein
SHIFT-DR and SHIFT-IR controller states.
TMS(2)
(F2)
JTAGMode
Select
HSTL-LVTTL TMSisaserialinputpin.OneoffourterminalsrequiredbyIEEEStandard1149.1-1990.TMSdirectsthe
INPUT thedevicethroughitsTAPcontrollerstates.Aninternalpull-upresistorforcesTMSHIGHifleftunconnected.
HSTL-LVTTL TRST is an asynchronous reset pin for the JTAG controller. The JTAG TAP controller does not
(2)
TRST
JTAGReset
(E3)
INPUT
automaticallyresetuponpower-up,thusitmustberesetbyeitherthissignalorbysettingTMS=HIGH
forfiveTCKcycles.IftheTAPcontrollerisnotproperlyresetthentheFIFOoutputswillalwaysbeinhigh-
impedance.IftheJTAGfunctionisusedbuttheuserdoesnotwanttouseTRST,thenTRSTcanbetied
withMRStoensureproperFIFOoperation.IftheJTAGfunctionisnotusedthenthissignalneedstobe
tiedtoGND.Aninternalpull-upresistorforcesTRSTHIGHifleftunconnected.
WCLK
(G1)
WriteClock
HSTL-LVTTL InputclockwhenusedinconjunctionwithWENforwritingdataintotheFIFOmemory.
INPUT
WCS
(H2)
WriteChipSelect HSTL-LVTTL The WCS pin an be regarded as a second WEN input, enabling/disabling write operations.
INPUT
WEN
(H1)
WriteEnable
HSTL-LVTTL WhenLOWandinDDRmode,WENalongwitharisingandfallingedgeofWCLKwillwritedataintothe
INPUT
FIFO memory. In SDR mode data will only be read on the rising edge of RCLK only.
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