IDT72V36106L10PF [IDT]

3.3 VOLT CMOS TRIPLE BUS SyncFIFOTM WITH BUS-MATCHING; 3.3伏的CMOS三重总线SyncFIFOTM具有总线匹配
IDT72V36106L10PF
型号: IDT72V36106L10PF
厂家: INTEGRATED DEVICE TECHNOLOGY    INTEGRATED DEVICE TECHNOLOGY
描述:

3.3 VOLT CMOS TRIPLE BUS SyncFIFOTM WITH BUS-MATCHING
3.3伏的CMOS三重总线SyncFIFOTM具有总线匹配

存储 内存集成电路 配套器件 先进先出芯片 时钟
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中文:  中文翻译
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3.3 VOLT CMOS TRIPLE BUS SyncFIFOTM WITH BUS-MATCHING  
16,384 x 36 x 2  
32,768 x 36 x 2  
65,536 x 36 x 2  
IDT72V3686  
IDT72V3696  
IDT72V36106  
Serial or parallel programming of partial flags  
FEATURES  
Big- or Little-Endian format for word and byte bus sizes  
Loopback mode on Port A  
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, CLKB and CLKC 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 a space-saving 128-pin Thin Quad Flatpack (TQFP)  
Pin compatible to the lower density parts, IDT72V3626/72V3636/  
72V3646/72V3656/72V3666/72V3676  
Memory storage capacity:  
IDT72V3686 – 16,384 x 36 x 2  
IDT72V3696 – 32,768 x 36 x 2  
IDT72V36106 – 65,536 x 36 x 2  
Clock frequencies up to 100 MHz (6.5ns access time)  
Two independent FIFOs buffer data between one bidirectional  
36-bit port and two unidirectional 18-bit ports (Port C receives  
and Port B transmits)  
18-bit (word) and 9-bit (byte) bus sizing of 18 bits (word) on  
Ports B and C  
Select IDT Standard timing (using EFA , EFB , FFA , and FFC flag  
functions) or First Word Fall Through Timing (using ORA, ORB,  
IRA, and IRC flag functions)  
Programmable Almost-Empty and Almost-Full flags; each has  
five default offsets (8, 16, 64, 256 and 1024)  
Industrial temperature range (–40°C to +85°C) is available  
FUNCTIONAL BLOCK DIAGRAM  
MBF1  
Mail 1  
Register  
CLKA  
CSA  
Port-A  
Control  
Logic  
18  
W/RA  
ENA  
B0-B17  
RAM ARRAY  
16,384 x 36  
32,768 x 36  
65,536 x 36  
MBA  
36  
36  
LOOP  
CLKB  
RENB  
CSB  
Port-B  
Control  
Logic  
FIFO1,  
Mail1  
Reset  
Logic  
MRS1  
PRS1  
MBB  
Read  
Pointer  
Write  
Pointer  
SIZEB  
36  
Status Flag  
Logic  
FFA/IRA  
EFB/ORB  
AFA  
AEB  
FIFO1  
FIFO2  
Common  
Port  
FS2  
FS0/SD  
Control  
Logic  
Programmable Flag  
Offset Registers  
Timing  
Mode  
BE  
FS1/SEN  
(B and C)  
A0-A35  
16  
FWFT  
FFC/IRC  
AFC  
Status Flag  
Logic  
EFA/ORA  
AEA  
Read  
Pointer  
Write  
Pointer  
FIFO2,  
Mail2  
Reset  
Logic  
MRS2  
PRS2  
36  
RT1  
RTM  
RT2  
FIFO1 and  
FIFO2  
Retransmit  
Logic  
RAM ARRAY  
16,384 x 36  
32,768 x 36  
65,536 x 36  
18  
36  
36  
C0-C17  
CLKC  
WENC  
MBC  
Port-C  
Control  
Logic  
Mail 2  
Register  
SIZEC  
4676 drw01  
MBF2  
IDTandtheIDTlogoareregisteredtrademarksofIntegratedDeviceTechnology,Inc. TheSyncFIFOisatrademarkofIntegratedDeviceTechnology,Inc.  
COMMERICAL TEMPERATURE RANGE  
NOVEMBER 2003  
1
DSC-4676/4  
2003 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice.  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
(Port A) and two unidirectional 18-bit buses (Port B transmits data, Port C  
receivesdata.) FIFOdatacanbereadoutofPortBandwrittenintoPortCusing  
either18-bitor9-bitformatswithachoiceofBig-orLittle-Endianconfigurations.  
These devices are a synchronous (clocked) FIFO, meaning each port  
employsasynchronousinterface. Alldatatransfersthroughaportaregated  
totheLOW-to-HIGHtransitionofaportclockbyenablesignals.Theclocksfor  
each port are independent of one another and can be asynchronous or  
DESCRIPTION  
TheIDT72V3686/72V3696/72V36106aredesignedtorunoffa3.3Vsupply  
for exceptionally low-power consumption. These devices are a monolithic,  
high-speed, low-power, CMOS Triple Bus synchronous (clocked) FIFO  
memorywhichsupportsclockfrequenciesupto100MHzandhasreadaccess  
timesasfastas6.5ns. Twoindependent16,384/32,768/65,536x36dual-port  
SRAMFIFOsonboardeachchipbufferdatabetweenabidirectional36-bitbus  
PIN CONFIGURATION  
INDEX  
W/RA  
ENA  
CLKA  
GND  
A35  
A34  
A33  
A32  
Vcc  
A31  
A30  
GND  
A29  
A28  
A27  
A26  
A25  
A24  
1
2
3
4
5
6
7
8
CLKB  
PRS2/RT2  
LOOP  
C17  
C16  
C15  
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  
C14  
RTM  
MBC  
C13  
C12  
C11  
C10  
C9  
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  
C8  
VCC  
C7  
C6  
SIZEB  
GND  
C5  
C4  
C3  
C2  
C1  
A23  
BE/FWFT  
GND  
A22  
Vcc  
A21  
A20  
A19  
A18  
GND  
A17  
A16  
A15  
A14  
A13  
Vcc  
A12  
GND  
A11  
A10  
C0  
GND  
B17  
B16  
SIZEC  
VCC  
B15  
B14  
B13  
B12  
GND  
B11  
B10  
4676 drw02  
TQFP (PK128-1, order code: PF)  
TOP VIEW  
2
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
coincident. The enables for each port are arranged to provide a simple aselectednumberofwordsremainintheFIFOmemory. AFAandAFCindicate  
bidirectionalinterfacebetweenmicroprocessorsand/orbuseswithsynchro- whenthe FIFOcontains more thana selectednumberofwords.  
nouscontrol.  
FFA/IRA,FFC/IRC,AFAand AFCaretwo-stagesynchronizedtothePort  
CommunicationbetweeneachportmaybypasstheFIFOsviatwomailbox Clockthatwritesdataintoitsarray. EFA/ORA,EFB/ORB,AEA,andAEBare  
registers.Themailboxregisters'widthmatchestheselectedbuswidthofports two-stage synchronized to the Port Clock that reads data from its array.  
BandC. Eachmailboxregisterhas aflag(MBF1and MBF2)tosignalwhen Programmableoffsets forAEA, AEB,AFA,AFCareloaded inparallelusing  
newmailhas beenstored.  
PortAorinserialviatheSDinput.Fivedefaultoffsetsettingsarealsoprovided.  
TwokindsofresetareavailableontheseFIFOs:MasterResetandPartial TheAEAandAEBthresholdcanbesetat8,16, 64,256,and1,024locations  
Reset. MasterResetinitializesthereadandwritepointerstothefirstlocation fromtheemptyboundaryandtheAFAandAFCthresholdcanbesetat8,16,  
ofthememoryarrayandselectsserialflagprogramming,parallelflagprogram- 64,256or1,024locationsfromthefullboundary. Allthesechoicesaremade  
ming,or oneoffivepossibledefaultflagoffsetsettings,8,16,64,256or1,024. using the FS0, FS1 and FS2 inputs during Master Reset.  
Each FIFO has its own, independent Master Reset pin, MRS1 and MRS2.  
InterspersedParitycanalsobeselectedduringaMasterResetoftheFIFO.  
PartialResetalsosetsthereadandwritepointerstothefirstlocationofthe IfInterspersedParityisselectedthenduringparallelprogrammingoftheflag  
memory. UnlikeMasterReset,anysettingsexistingpriortoPartialReset(i.e., offsetvalues,thedevicewillignoredatalineA8.IfNon-InterspersedParityis  
programmingmethodandpartialflagdefaultoffsets)areretained. PartialReset selectedthendatalineA8willbecomeavalidbit.  
is useful since it permits flushing of the FIFO memory without changing any  
ALoopbackfunctionisprovidedonPortA.WhentheLoopfeatureisselected  
configurationsettings. EachFIFOhasitsown,independentPartialResetpin, viatheLOOPpin,thedataoutputfromFIFO2willbedirectedtothedatainput  
PRS1andPRS2.NotethattheRetransmitMode,RTMpinmustbeLOWatthe ofFIFO1.IfLoopisselectedandPortAisset-upforwriteoperationviaW/RA  
pointapartialresetisperformed.  
pin,thendataoutputfromFIFO2willbewrittentoFIFO1,butwillnotbeplaced  
BothFIFO'shaveRetramsmitcapability,whenaRetransmitisperformedon ontheoutputPortA(A0-A35).IfPortAisset-upforreadoperationviaW/RA  
arespectiveFIFOonlythereadpointerisresettothefirstmemorylocation.A thendataoutputfromFIFO2willbewrittenintoFIFO1andplacedontoPortA  
RetransmitisperformedbyusingtheRetransmitMode,RTMpininconjunction (A0-A35).TheLoopwillcontinuetohappenprovidedthatFIFO1isnotfulland  
withtheRetransmitpinsRT1orRT2,foreachrespectiveFIFO.Notethatthe FIFO2is notempty.IfduringaLoopsequenceFIFO1becomes fullthenany  
twoRetransmitpins RT1andRT2 are muxedwiththe PartialResetpins.  
datathatcontinues tobereadoutfromFIFO2willonlybeplacedonthePort  
Thesedeviceshavetwomodesofoperation:IntheIDTStandardmode,the A(A0-A35)lines,providedthatPortAisset-upforreadoperation.Ifduringa  
firstwordwrittentoanemptyFIFOisdepositedintothememoryarray. Aread LoopsequencetheFIFO2becomesempty,thenthelastwordfromFIFO2will  
operationisrequiredtoaccessthatword(alongwithallotherwordsresiding continue tobe clockedintoFIFO1untilFIFO1becomes fulloruntilthe Loop  
inmemory). IntheFirstWordFallThroughmode(FWFT),thefirstwordwritten functionisstopped.TheLoopfeaturecanbeusefulwhenperformingsystem  
to an empty FIFO appears automatically on the outputs, no read operation debuggingandremoteloopbacks.  
required (Nevertheless, accessing subsequent words does necessitate a  
formal read request). The state of the BE/FWFT pin during Master Reset awidthexpansionrequiresnoadditional,externalcomponents. Furthermore,  
determinesthemodeinuse. twoIDT72V3686/72V3696/72V36106FIFOscanbecombinedwithunidirec-  
TwoormoreFIFOsmaybeusedinparalleltocreatewiderdatapaths. Such  
EachFIFOhasacombinedEmpty/OutputReadyFlag(EFA/ORAandEFB/ tionalFIFOscapableofFirstWordFallThroughtiming(i.e.theSuperSyncFIFO  
ORB)anda combinedFull/InputReadyFlag(FFA/IRAand FFC/IRC). The family)toformadepthexpansion.  
EF and FF functions are selected in the IDT Standard mode. EF indicates  
If, at any time, the FIFO is not actively performing a function, the chip will  
whetherornottheFIFOmemoryisempty. FFshowswhetherthememoryis automatically power down. During the power down state, supply current  
fullornot. TheIRandORfunctionsareselectedintheFirstWordFallThrough consumption(ICC)isataminimum. Initiatinganyoperation(byactivatingcontrol  
mode. IRindicateswhetherornottheFIFOhasavailablememorylocations. inputs)willimmediatelytakethedeviceoutofthepowerdownstate.  
ORshowswhethertheFIFOhasdataavailableforreadingornot. Itmarksthe  
presenceofvaliddataontheoutputs.  
TheIDT72V3686/72V3696/72V36106arecharacterizedforoperationfrom  
0°Cto70°C. Industrial temperature range (-40°C to +85°C)is available by  
EachFIFOhasaprogrammableAlmost-Emptyflag(AEAandAEB)anda specialorder.TheyarefabricatedusingIDT’shighspeed,submicronCMOS  
programmableAlmost-Fullflag(AFAandAFC). AEAandAEB indicatewhen technology.  
3
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
PIN DESCRIPTIONS  
Symbol  
A0-A35  
AEA  
Name  
PortAData  
I/O  
Description  
I/O 36-bitbidirectionaldataportforsideA.  
PortAAlmost-  
EmptyFlag  
O
O
O
O
ProgrammableAlmost-EmptyflagsynchronizedtoCLKA. ItisLOWwhenthenumberofwordsinFIFO2  
islessthanorequaltothevalueintheAlmost-EmptyAOffsetregister,X2.  
AEB  
AFA  
AFC  
PortBAlmost-  
EmptyFlag  
ProgrammableAlmost-EmptyflagsynchronizedtoCLKB. ItisLOWwhenthenumberofwordsinFIFO1  
islessthanorequaltothevalueintheAlmost-EmptyBOffsetregister,X1.  
PortAAlmost-  
Full Flag  
ProgrammableAlmost-FullflagsynchronizedtoCLKA.ItisLOWwhenthenumberofemptylocations  
inFIFO1is less thanorequaltothevalueintheAlmost-FullAOffsetregister,Y1.  
PortCAlmost-  
Full Flag  
ProgrammableAlmost-FullflagsynchronizedtoCLKC.ItisLOWwhenthenumberofemptylocations  
inFIFO2is less thanorequaltothe value inthe Almost-FullCOffsetregister, Y2.  
B0-B17  
PortBData  
O
I
18-bitoutputdataportforsideB.  
BE/FWFT  
Big-Endian/  
FirstWordFall  
ThroughSelect  
This is a dual purpose pin. During Master Reset, a HIGH on BE will select Big-Endian operation.  
In this case, depending on the bus size, themost significant byte or word on Port A is read from  
PortBfirst(A-to-Bdata flow)oris writtentoPortCfirst(C-to-Adata flow). ALOWonBEwillselect  
Little-Endianoperation.Inthis case,theleastsignificantbyteorwordonPortAis readfromPortBfirst  
(A-to-Bdata flow)oris writtentoPortCfirst(C-to-Adata flow).  
AfterMasterReset, this pinselects the timingmode. AHIGHonFWFT selects IDTStandardmode, a  
LOWselectsFirstWordFallThroughmode.Oncethetimingmodehasbeenselected,thelevelon  
FWFT must be static throughout device operation.  
C0-C17  
CLKA  
PortC Data  
PortAClock  
I
I
18-bitinputdataportforsideC.  
CLKAis acontinuous clockthatsynchronizes alldatatransfers throughPortAandcanbe  
asynchronous or coincident to CLKB. FFA/IRA, EFA/ORA, AFA, and AEA are all synchronized to  
theLOW-to-HIGHtransitionofCLKA.  
CLKB  
CLKC  
CSA  
PortBClock  
PortCClock  
I
I
CLKBis acontinuous clockthatsynchronizes alldatatransfers throughPortBandcanbeasynchronous  
or coincident to CLKA. EFB/ORB and AEB are synchronized to the LOW-to-HIGH transition of CLKB.  
CLKCis acontinuous clockthatsynchronizes alldatatransfers throughPortCandcanbeasynchronous  
or coincident to CLKA. FFC/IRC and AFC are synchronized to the LOW-to-HIGH transition of CLKC.  
Port A Chip  
Select  
I
CSA mustbe LOWtoenable toLOW-to-HIGHtransitionofCLKAtoreadorwrite onPortA. The A0-A35  
outputs are in the high-impedance state when CSA is HIGH.  
CSB  
Port B Chip  
Select  
I
CSB mustbe LOWtoenable a LOW-to-HIGHtransitionofCLKBtoreaddata onPortB. The B0-B17  
outputs are in the high-impedance state when CSB is HIGH.  
EFA/ORA  
PortAEmpty/  
OutputReady  
Flag  
O
This is a dualfunctionpin. Inthe IDTStandardmode, the EFA functionis selected. EFA indicates  
whetherornotthe FIFO2memoryis empty. Inthe FWFTmode, the ORAfunctionis selected. ORA  
indicates the presence of valid data on the A0-A35 outputs, available for reading. EFA/ORA is  
synchronizedtotheLOW-to-HIGHtransitionofCLKA.  
EFB/ORB  
PortBEmpty/  
OutputReadyFlag  
O
This is a dualfunctionpin. Inthe IDTStandardmode, the EFB functionis selected. EFB indicates  
whetherornotthe FIFO1memoryis empty. Inthe FWFTmode, the ORBfunctionis selected. ORB  
indicatesthepresenceofvaliddataontheB0-B17outputs,availableforreading. EFB/ORBissynchronized  
totheLOW-to-HIGHtransitionofCLKB.  
ENA  
PortAEnable  
I
ENAmustbe HIGHtoenable a LOW-to-HIGHtransitionofCLKAtoreadorwrite data onPortA.  
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 whether or not there is space available for writing to the FIFO1 memory. FFA/IRA is  
synchronizedtotheLOW-to-HIGHtransitionofCLKA.  
FFC/IRC  
Port C Full/  
Input Ready Flag  
O
This is a dualfunctionpin. Inthe IDTStandardmode, the FFCfunctionis selected. FFC indicates  
whether or not the FIFO2 memory is full. In the FWFT mode, the IRC function is selected. IRC  
indicates whether or not there is space available for writing to the FIFO2 memory. FFC/IRC is  
synchronizedtotheLOW-to-HIGHtransitionofCLKC.  
4
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
PINDESCRIPTIONS(CONTINUED)  
Symbol  
Name  
I/O  
Description  
FS0/SD  
FlagOffsetSelect0/  
SerialData  
I
FS1/SENandFS0/SDaredual-purposeinputsusedforflagOffsetregisterprogramming.DuringMasterReset,  
FS1/SENandFS0/SD,togetherwithFS2,selecttheflagoffsetprogrammingmethod. ThreeOffsetregister  
programming methods are available: automatically load one of five preset values (8, 16, 64, 256 or 1,024),  
parallelloadfromPortA, andserialload.  
FS1/SEN FlagOffsetSelect1/  
I
I
SerialEnable  
WhenserialloadisselectedforflagOffsetregisterprogramming,FS1/SEN isusedasanenablesynchronousto  
the LOW-to-HIGHtransitionofCLKA. WhenFS1/SEN is LOW, a risingedge onCLKAloadthe bitpresenton  
FS0/SDintothe XandYregisters. The numberofbitwrites requiredtoprogramthe Offsetregisters is 56forthe  
72V3686, 60 for the 72V3696, and 64 for the 72V36106. The first bit write stores the Y-register (Y1) MSB and  
thelastbitwritestorestheX-register(X2)LSB.  
FS2(1)  
FlagOffsetSelect2  
LOOP  
LoopbackSelect  
I
I
This pinselects theloopbackfeatureforPortA.DuringLoopbackdatafromFIFO2willbedirectedtotheinputof  
FIFO1. toinitiate a Loopthe LOOP pinmustbe heldLOWandthe ENApinmustbe HIGH.  
A HIGH level on MBA chooses a mailbox register for a Port A read or write operation. When the A0-A35  
outputsareactive,aHIGHlevelonMBAselectsdatafromthemail2registerforoutputandaLOWlevelselects  
FIFO2output-registerdataforoutput.  
MBA  
Port A Mailbox  
Select  
MBB  
Port B Mailbox  
Select  
I
I
A HIGH level on MBB chooses a mailbox register for a Port B read operation. When the B0-B17 outputs are  
active,aHIGHlevelonMBBselectsdatafromthemail1registerforoutputandaLOWlevelselectsFIFO1output  
registerdataforoutput.  
MBC  
Port C Mailbox  
Select  
A HIGH level on MBC chooses the mail2 register for a Port C write operation. This pin must be HIGH during  
MasterReset.  
MBF1  
Mail1Register  
Flag  
O MBF1issetLOWbyaLOW-to-HIGHtransitionofCLKAthatwritesdatatothemail1register.Writestothemail1  
register are inhibited while MBF1 is LOW. MBF1 is set HIGH by a LOW-to-HIGH transition of CLKB when a  
Port B read is selected and MBB is HIGH. MBF1 is set HIGH following either a Master or Partial Reset of FIFO1.  
MBF2  
MRS1  
Mail2Register  
Flag  
O MBF2issetLOWbyaLOW-to-HIGHtransitionofCLKCthatwritesdatatothemail2register.Writestothemail2  
registerare inhibitedwhile MBF2 is LOW. MBF2 is setHIGHbya LOW-to-HIGHtransitionofCLKAwhena  
Port A read is selected and MBA is HIGH. MBF2 is set HIGH following either a Master or Partial Reset of FIFO2.  
MasterReset  
I
ALOWonthis pin initializes theFIFO1readandwritepointers tothefirstlocationofmemoryandsets thePortB  
outputregistertoallzeroes. ALOW-to-HIGHtransitiononMRS1selectstheprogrammingmethod(serialor  
parallel)andone offive programmable flagdefaultoffsets forFIFO1andFIFO2. Italsoconfigures ports Band  
Cforbus size andendianarrangement. FourLOW-to-HIGHtransitions ofCLKAandfourLOW-to-HIGH  
transitionsofCLKBmustoccurwhileMRS1isLOW.  
MRS2  
MasterReset  
I
ALOWonthispininitializestheFIFO2readandwritepointerstothefirstlocationofmemoryandsetsthePortA  
outputregistertoallzeroes. ALOW-to-HIGHtransitiononMRS2,toggledsimultaneouslywithMRS1,selects  
theprogrammingmethod(serialorparallel)andoneof thefiveflagdefaultoffsetsforFIFO2.FourLOW-to-HIGH  
transitionsofCLKAandfourLOW-to-HIGHtransitionsofCLKCmustoccurwhileMRS2isLOW.  
PRS1/  
RT1  
PartialReset/  
RetransmitFIFO1  
I
ThispinismuxedforbothPartialReset andRetransmitoperations,itisusedinconjunctionwiththeRTMpin. IfRTM  
isinaLOWcondition,aLOWonthispinperformsaPartialResetonFIFO1andinitializestheFIFO1readandwrite  
pointerstothefirstlocationofmemoryandsetsthePortBoutputregistertoallzeroes.DuringPartialReset,thecurrently  
selectedbussize,endianarrangement,programmingmethod(serialorparallel),andprogrammableflagsettingsare  
allretained. IfRTMis HIGH, a LOWonthis pinperforms a Retransmitandinitializes the FIFO1readpointeronlyto  
thefirstmemorylocation.  
PRS2/  
PartialReset/  
I ThispinismuxedforbothPartialReset andRetransmitoperations,itisusedinconjunctionwiththeRTMpin. IfRTM  
RT2  
RetransmitFIFO2  
isinaLOWcondition,aLOWonthispinperformsaPartialResetonFIFO2andinitializestheFIFO2readandwrite  
selectedbussize,endianarrangement,programmingmethod(serialorparallel),andprogrammableflagsettingsare  
allretained. IfRTMis HIGH, a LOWonthis pinperforms a Retransmitandinitializes the FIFO2readpointeronlyto  
thefirstmemorylocation.  
RENB  
RTM  
Port B Read Enable  
RetransmitMode  
I
RENBmustbe HIGHtoenable a LOW-to-HIGHtransitionofCLKBtoreaddata onPortB.  
I
Thispinisusedinconjunctionwiththe RT1andRT2pins.WhenRTMisHIGHaRetransmitisperformedonFIFO1  
or FIFO2 respectively.  
5
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
PINDESCRIPTIONS(CONTINUED)  
Symbol  
Name  
PortB  
I/O  
Description  
(1)  
SIZEB  
I
SIZEBdetermines the bus widthofPortB. AHIGHonthis pinselects byte (9-bit)bus size. ALOWonthis pin  
selects word(18-bit)bus size. SIZEBworks withSIZECandBEtoselectthe bus size andendianarrangement  
forports BandC. The levelofSIZEBmustbe staticthroughoutdevice operation.  
BusSizeSelect  
(1)  
SIZEC  
Port C  
BusSizeSelect  
I
SIZEC determines the bus width of Port C. A HIGH on this pin selects byte (9-bit) bus size. A LOW on this pin  
selects word(18-bit)bus size. SIZECworks withSIZEBandBEtoselectthe bus size andendianarrangement  
forports BandC. The levelofSIZECmustbe staticthroughoutdevice operation.  
WENC  
PortCWriteEnable  
I
I
WENCmustbeHIGHtoenableaLOW-to-HIGHtransitionofCLKCtowritedataonPortC.  
W/RA  
PortAWrite/  
ReadSelect  
AHIGHselects a write operationanda LOWselects a readoperationonPortAfora LOW-to-HIGHtransitionof  
CLKA. The A0-A35 outputs are in the HIGH impedance state when W/RA is HIGH.  
NOTE:  
1. FS2, SIZEB and SIZEC inputs are not TTL compatible. These inputs should be tied to GND or VCC.  
6
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
ABSOLUTE MAXIMUM RATINGS OVER OPERATING FREE-AIR  
TEMPERATURE RANGE (Unless otherwise noted)(1)  
Symbol  
Rating  
Commercial  
–0.5to+4.6  
–0.5 to VCC+0.5  
–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  
mA  
mA  
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.  
3.15  
2
Typ.  
3.3  
Max.  
3.45  
VCC+0.5  
0.8  
Unit  
V
High-LevelInputVoltage  
Low-LevelInputVoltage  
High-LevelOutputCurrent  
Low-LevelOutputCurrent  
OperatingTemperature  
V
VIL  
0
V
IOH  
–4  
mA  
mA  
°C  
IOL  
8
TA  
70  
NOTE:  
1. Vcc = 3.3V ± 0.15V, JEDEC JESD8-A compliant  
ELECTRICAL CHARACTERISTICS OVER RECOMMENDED OPERATING  
FREE-AIR TEMPERATURE RANGE (Unless otherwise noted)  
IDT72V3686  
IDT72V3696  
IDT72V36106  
Commercial  
tCLK = 10, 15 ns(2)  
Symbol  
Parameter  
OutputLogic"1"Voltage  
Test Conditions  
Min.  
Typ.  
Max.  
Unit  
VOH  
VCC = 3.0V,  
IOH = –4 mA  
2.4  
V
VOL  
ILI  
OutputLogic"0"Voltage  
VCC = 3.0V,  
VCC = 3.6V,  
VCC = 3.6V,  
IOL = 8 mA  
4
0.5  
±5  
±5  
5
V
InputLeakageCurrent(AnyInput)  
OutputLeakageCurrent  
VI = VCC or 0  
VO = VCC or 0  
VI = VCC - 0.2V or 0  
VI = VCC - 0.2V or 0  
f = 1 MHz  
µA  
µA  
mA  
mA  
pF  
ILO  
(3)  
ICC2  
Standby Current (with CLKA, CLKB and CLKC running) VCC = 3.6V,  
(3)  
ICC3  
StandbyCurrent(noclocksrunning)  
InputCapacitance  
VCC = 3.6V,  
VI = 0,  
5
(4)  
CIN  
(4)  
COUT  
OutputCapacitance  
VO = 0,  
f = 1 MHZ  
8
pF  
NOTES:  
1. All typical values are at VCC = 3.3V, TA = 25°C.  
2. Vcc = 3.3V ± 0.15V, TA = 0° to +70°; JEDEC JESD8-A compliant.  
3. For additional ICC information, see Figure 1, Typical Characteristics: Supply Current (ICC) vs. Clock Frequency (fS).  
4. Characterized values, not currently tested.  
7
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
DETERMINING ACTIVE CURRENT CONSUMPTION AND POWER DISSIPATION  
TheICC(f)currentforthegraphinFigure1wastakenwhilesimultaneouslyreadingandwritingaFIFOontheIDT72V3686/72V3696/72V36106withCLKA,  
CLKBandCLKCsettofS. Alldata inputs anddata outputs change state duringeachclockcycle toconsume the highestsupplycurrent. Data outputs were  
disconnectedtonormalizethegraphtoazerocapacitanceload. Oncethecapacitanceloadperdata-outputchannelandthenumberofthesedevice'sinputs  
driven by TTL HIGH levels are known, the power dissipation can be calculated with the equation below.  
CALCULATING POWER DISSIPATION  
With ICC(f) taken from Figure 1, the maximum power dissipation (PT) of these FIFOs may be calculated by:  
2
PT = VCC x ICC(f) + Σ(CL x VCC x fo)  
N
where:  
N
CL  
fo  
=
=
=
number of used outputs (36-bit (long word), 18-bit (word) or 9-bit (byte) bus size)  
outputcapacitanceload  
switchingfrequencyofanoutput  
100  
90  
VCC = 3.6V  
80  
70  
60  
VCC = 3.0V  
VCC = 3.3V  
fdata = 1/2 fS  
TA  
= 25°C  
CL  
= 0 pF  
50  
40  
30  
20  
10  
0
100  
0
10  
20  
30  
40  
50  
Clock Frequency MHz  
60  
70  
90  
80  
4676 drw03  
fS  
Figure 1. Typical Characteristics: Supply Current (ICC) vs. Clock Frequency (fS)  
8
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
TIMING REQUIREMENTS OVER RECOMMENDED RANGES OF SUPPLY  
VOLTAGE AND OPERATING FREE-AIR TEMPERATURE  
(Vcc = 3.3V ± 0.15V; TA = 0ο C to +70ο C;JEDEC JESD8-A compliant)  
IDT72V3686L10  
IDT72V3696L10  
IDT72V36106L10  
IDT72V3686L15  
IDT72V3696L15  
IDT72V36106L15  
Symbol  
fS  
Parameter  
Min.  
10  
4.5  
4.5  
3
Max.  
Min.  
15  
6
Max.  
Unit  
MHz  
ns  
Clock Frequency, CLKA, CLKB, or CLKC  
100  
66.7  
tCLK  
tCLKH  
tCLKL  
tDS  
Clock Cycle Time, CLKA, CLKB, or CLKC  
Pulse Duration, CLKA, CLKB, or CLKC HIGH  
Pulse Duration, CLKA, CLKB, ORCLKCLOW  
Setup Time, A0-A35 before CLKAandC0-C17before CLKC↑  
ns  
6
ns  
4
ns  
tENS1  
SetupTime, CSA andW/RA before CLKA; CSB  
beforeCLKB↑  
4
4.5  
ns  
tENS2  
tRSTS  
SetupTime, ENA, andMBAbefore CLKA;RENB  
3
5
4.5  
5
ns  
ns  
and MBB before CLKB; WENC and MBC before CLKC↑  
Setup Time, MRS1, MRS2, PRS1, PRS2, RT1 or RT2  
(1)  
LOWbeforeCLKAorCLKB↑  
tFSS  
tBES  
Setup Time, FS0, FS1, FS2 before MRS1 and MRS2 HIGH  
SetupTime, BE/FWFT beforeMRS1 andMRS2 HIGH  
SetupTime,FS0/SDbeforeCLKA↑  
7.5  
7.5  
3
8.5  
7.5  
4
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
tSDS  
tSENS  
tFWS  
tRTMS  
tDH  
SetupTime,FS1/SENbeforeCLKA↑  
3
4
SetupTime,BE/FWFTbeforeCLKA↑  
0
0
Setup Time, RTM before RT1; RTM before RT2  
HoldTime, A0-A35afterCLKAandC0-C17afterCLKC↑  
5
5
0.5  
0.5  
1
tENH  
HoldTime, CSA, W/RA, ENA, andMBAafterCLKA;CSB,  
RENB, andMBBafterCLKB;WENCandMBCafterCLKC↑  
1
tRSTH  
Hold Time, MRS1, MRS2, PRS1, PRS2, RT1 or RT2  
4
4
ns  
(1)  
LOWafterCLKAorCLKB↑  
tFSH  
Hold Time, FS0, FS1, FS2 after MRS1 and MRS2 HIGH  
Hold Time, BE/FWFT after MRS1 and MRS2 HIGH  
HoldTime, FS0/SDafterCLKA↑  
2
2
2
2
ns  
ns  
ns  
ns  
ns  
ns  
ns  
tBEH  
tSDH  
0.5  
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  
5
5
(2)  
tSKEW1  
SkewTime, betweenCLKAandCLKBfor EFB/ORBand  
FFA/IRA; between CLKAand CLKCfor EFA/ORA and  
FFC/IRC  
5
7.5  
(2,3)  
tSKEW2  
SkewTime,betweenCLKAandCLKBfor AEBandAFA;  
between CLKAand CLKCfor AEA and AFC  
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 among CLKA cycle, CLKB cycle, and CLKC cycle.  
3. Design simulated, not tested.  
9
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
SWITCHING CHARACTERISTICS OVER RECOMMENDED RANGES OF SUPPLY  
VOLTAGE AND OPERATING FREE-AIR TEMPERATURE, CL = 30PF  
(Vcc = 3.3V ± 0.15V; TA = 0ο C to +70ο C;JEDEC JESD8-A compliant)  
IDT72V3686L10  
IDT72V3696L10  
IDT72V36106L10  
IDT72V3686L15  
IDT72V3696L15  
IDT72V36106L15  
Symbol  
tA  
Parameter  
Min.  
2
Max.  
Min.  
2
Max.  
10  
Unit  
ns  
Access Time,CLKAtoA0-A35andCLKBtoB0-B17  
6.5  
6.5  
tWFF  
PropagationDelayTime, CLKAtoFFA/IRAandCLKCto  
FFC/IRC  
2
2
8
ns  
tREF  
PropagationDelayTime,CLKAtoEFA/ORAandCLKBto  
EFB/ORB  
1
6.5  
1
8
ns  
tPAE  
tPAF  
tPMF  
PropagationDelayTime,CLKAtoAEAandCLKBtoAEB  
Propagation Delay Time, CLKAto AFA and CLKCto AFC  
1
1
0
6.5  
6.5  
6.5  
1
1
0
8
8
8
ns  
ns  
ns  
Propagation Delay Time, CLKAto MBF1 LOW orMBF2  
HIGH, CLKBto MBF1 HIGH, and CLKCto MBF2 LOW  
tPMR  
tMDV  
tRSF  
PropagationDelayTime, CLKAtoB0-B17(1) andCLKC↑  
2
2
1
6.5  
8
2
2
1
10  
10  
15  
ns  
ns  
ns  
toA0-A35(2)  
Propagation Delay Time, MBA to A0-A35 valid and MBB to  
B0-B17 valid  
Propagation Delay Time, MRS1 or PRS1 LOW to AEB  
LOW, AFA HIGH, and MBF1 HIGH and MRS2 or PRS2  
LOW to AEA LOW, AFC HIGH, andMBF2 HIGH  
10  
tEN  
Enable Time, CSA orW/RALOWtoA0-A35Active and  
CSBLOWtoB0-B17Active  
2
1
6
6
2
1
10  
8
ns  
ns  
tDIS  
Disable Time, CSA or W/RA HIGH to A0-A35 at high  
impedance and CSB HIGHtoB0-B17atHIGHimpedance  
NOTES:  
1. Writing data to the mail1 register when the B0-B17 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. Vcc = 3.3V ± 0.15V; TA = 0° to +70°.  
10  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
RETRANSMIT (RT1, RT2)  
SIGNALDESCRIPTION  
TheFIFO1memoryofthesedevicesundergoesaRetransmitbytakingits  
associatedRetransmit (RT1)inputLOWforatleastfourPortAClock(CLKA)  
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  
pointerofFIFO1tothefirstmemorylocation.  
The RTM pin must be HIGH during the time of Retransmit. Note that the  
RT1inputismuxedwiththePRS1input,thestateoftheRTMpindetermining  
whetherthispinperformsaRetransmitorPartialReset.Also,theRT2inputis  
muxedwiththePRS2input,thestateoftheRTMpindeterminingwhetherthis  
pinperformsaRetransmitorPartialReset.SeeFigures30,31,32and33for  
Retransmittimingdiagrams.  
MASTER RESET (MRS1, MRS2)  
Afterpowerup,aMasterResetoperationmustbeperformedbyproviding  
a LOW pulse to MRS1 and MRS2 simultaneously. Afterwards, the FIFO1  
memoryoftheIDT72V3686/72V3696/72V36106undergoesacompletereset  
bytakingitsassociatedMasterReset(MRS1)inputLOWforatleastfourPort  
AClock(CLKA)andfourPortBClock(CLKB)LOW-to-HIGHtransitions. The  
FIFO2memoryundergoes acompleteresetbytakingits associatedMaster  
Reset(MRS2)inputLOWforatleastfourPortAClock(CLKA)andfourPort  
CClock(CLKC)LOW-to-HIGHtransitions. TheMasterResetinputscanswitch  
asynchronouslytotheclocks. AMasterResetinitializestheassociatedreadand  
writepointerstothefirstlocationofthememoryandforcestheFull/InputReady  
flag(FFA/IRA,FFC/IRC)LOW,theEmpty/OutputReadyflag(EFA/ORA,EFB/  
ORB)LOW,theAlmost-Emptyflag(AEA,AEB)LOWandtheAlmost-Fullflag  
(AFA,AFC)HIGH. AMasterResetalsoforces the associatedMailboxFlag  
(MBF1,MBF2)oftheparallelmailboxregisterHIGH. AfteraMasterReset,the  
FIFO'sFull/InputReadyflagissetHIGHaftertwoWriteClockcycles. Thenthe  
FIFO is ready to be written to.  
ALOW-to-HIGHtransitionontheFIFO1MasterReset(MRS1)inputlatches  
thevalueoftheBig-Endian(BE)inputfordeterminingtheorderbywhichbytes  
aretransferredthroughPortsBandC. ItalsolatchesthevaluesoftheFlagSelect  
(FS0, FS1 and FS2) inputs for choosing the Almost-Full and Almost-Empty  
offsetsandprogrammingmethod.  
ALOW-to-HIGHtransitionontheFIFO2MasterReset(MRS2)clearstheflag  
offset registers of FIFO2 (X2, Y2). A LOW-to-HIGH transition on the FIFO2  
Master Reset (MRS2) together with the FIFO1 Master Reset input (MRS1)  
latchesthevalueoftheBig-Endian(BE)inputforPortsBandCandalsolatches  
thevaluesoftheFlagSelect(FS0,FS1andFS2)inputsforchoosingtheAlmost-  
FullandAlmost-Emptyoffsetsandprogrammingmethod(fordetailsseeTable  
1,FlagProgramming,andAlmost-EmptyandAlmost-Fullflagoffsetprogram-  
ming section). The relevant Master Reset timing diagrams can be found in  
Figure 4 and 5.  
BIG-ENDIAN/FIRST WORD FALL THROUGH (BE/FWFT)  
— ENDIAN SELECTION  
Thisisadualpurposepin.AtthetimeofMasterReset,theBEselectfunction  
isactive,permittingachoiceofBig-orLittle-Endianbytearrangementfordata  
writtentoPortCorreadfromPortB.Thisselectiondeterminestheorderbywhich  
bytes(orwords)ofdataaretransferredthroughthoseports.Forthefollowing  
illustrations,notethatbothports B andCareconfiguredtohaveabyte(ora  
word) bus size.  
AHIGHontheBE/FWFTinputwhentheMasterReset(MRS1,MRS2)inputs  
go from LOW to HIGH will select a Big-Endian arrangement. When data is  
movinginthedirectionfromPortAtoPortB,themostsignificantbyte(word)of  
thelongwordwrittentoPortAwillbereadfromPortBfirst;theleastsignificant  
byte(word)ofthelongwordwrittentoPortAwillbereadfromPortBlast.When  
dataismovinginthedirectionfromPortCtoPortA,thebyte(word)writtento  
PortCfirstwillbereadfromPortAasthemostsignificantbyte(word)ofthelong  
word;thebyte(word)writtentoPortClastwillbereadfromPortAastheleast  
significantbyte(word)ofthelongword.  
NotethatMBCmustbeHIGHduringMasterReset(untilFFA/IRAandFFC/  
IRC go HIGH). MBA and MBB are "don't care" inputs1 during Master Reset.  
ALOWontheBE/FWFTinputwhentheMasterReset(MRS1,MRS2)inputs  
gofromLOWtoHIGHwillselecta Little-Endianarrangement. Whendata is  
movinginthedirectionfromPortAtoPortB,theleastsignificantbyte(word)of  
thelongwordwrittentoPortAwillbereadfromPortBfirst;themostsignificant  
byte(word)ofthelongwordwrittentoPortAwillbereadfromPortBlast.When  
dataismovinginthedirectionfromPortCtoPortA,thebyte(word)writtento  
PortCfirstwillbereadfromPortAastheleastsignificantbyte(word)ofthelong  
word;thebyte(word)writtentoPortClastwillbereadfromPortAasthemost  
significantbyte(word)ofthelongword.RefertoFigure2and3forillustrations  
oftheBEfunction.SeeFigure4(FIFO1MasterReset)and5(FIFO2Master  
Reset)forEndianSelecttimingdiagrams.  
PARTIAL RESET (PRS1, PRS2)  
TheFIFO1memoryofthesedevicesundergoesalimitedresetbytakingits  
associatedPartialReset(PRS1)inputLOWforatleastfourPortAClock(CLKA)  
andfourPortBClock(CLKB)LOW-to-HIGHtransitions.TheFIFO2memory  
undergoesalimitedresetbytakingitsassociatedPartialReset(PRS2)input  
LOWforatleastfourPortAClock(CLKA)andfourPortCClock(CLKC)LOW-  
to-HIGHtransitions.TheRTMpinmustbeLOWduringthetimeofpartialreset.  
ThePartialResetinputscanswitchasynchronouslytotheclocks.APartialReset  
initializestheinternalreadandwritepointersandforcestheFull/InputReady  
flag(FFA/IRA,FFC/IRC)LOW,theEmpty/OutputReadyflag(EFA/ORA,EFB/  
ORB)LOW,theAlmost-Emptyflag(AEA,AEB)LOW,andtheAlmost-Fullflag  
(AFA,AFC)HIGH.APartialResetalsoforcestheMailboxFlag(MBF1,MBF2)  
oftheparallelmailboxregisterHIGH.AfteraPartialReset,theFIFO’sFull/Input  
ReadyflagissetHIGHaftertwoWriteClockcycles.  
Whateverflagoffsets,programmingmethod(parallelorserial),andtiming  
mode(FWFTorIDTStandardmode)arecurrentlyselectedatthetimeaPartial  
Resetisinitiated,thosesettingswill remainunchangeduponcompletionofthe  
resetoperation.APartialResetmaybeusefulinthecasewherereprogramming  
aFIFOfollowingaMasterResetwouldbeinconvenient. SeeFigure6and7  
forPartialResettimingdiagrams.  
TIMING MODE SELECTION  
AfterMasterReset,theFWFTselectfunctionisavailable,permittingachoice  
between two possible timing modes: IDT Standard mode or First Word Fall  
Through(FWFT)mode.OncetheMasterReset(MRS1, MRS2)inputisHIGH,  
aHIGHontheBE/FWFTinputduringthenextLOW-to-HIGHtransitionofCLKA  
(forFIFO1)andCLKC(forFIFO2)willselectIDTStandardmode.Thismode  
usestheEmptyFlagfunction(EFA,EFB)toindicatewhetherornotthereare  
any words present in the FIFO memory. It uses the Full Flag function (FFA,  
FFC)toindicatewhetherornottheFIFOmemoryhasanyfreespaceforwriting.  
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  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
InIDTStandardmode,everywordreadfromtheFIFO,includingthefirst,must returnsHIGH.FlagOffsetregistersassociatedwithFIFO2areloadedwithone  
be requestedusinga formalreadoperation. ofthepresetvaluesinthesamewaywithFIFO2MasterReset(MRS2)toggled  
Once the Master Reset (MRS1, MRS2) input is HIGH, a LOW on the BE/ simultaneously with FIFO1 Master Reset (MRS1). For relevant Preset value  
FWFTinputduringthenextLOW-to-HIGHtransitionofCLKA(forFIFO1)and loading timing diagrams, see Figure 4 and 5.  
CLKC(forFIFO2)willselectFWFTmode.ThismodeusestheOutputReady  
function(ORA,ORB)toindicatewhetherornotthereisvaliddataatthedata — PARALLEL LOAD FROM PORT A  
outputs(A0-A35orB0-B17).ItalsousestheInputReadyfunction(IRA,IRC)  
ToprogramtheX1,X2,Y1,andY2registersfromPortA,performaMaster  
toindicatewhetherornottheFIFOmemoryhasanyfreespaceforwriting.In ResetonbothFlFOs simultaneouslywithFS2HIGHorLOW, FS0andFS1  
theFWFTmode,thefirstwordwrittentoanemptyFIFOgoesdirectlytothedata LOWduringtheLOW-to-HIGHtransitionofMRS1andMRS2.ThestateofFS2  
outputs,noreadrequestnecessary.Subsequentwordsmustbeaccessedby atthispointofresetwilldeterminewhethertheparallelprogrammingmethodhas  
performingaformalreadoperation.  
Interspersed Parity or Non-Interspersed Parity. Refer to Table 1 for Flag  
FollowingMasterReset,thelevelappliedtotheBE/FWFTinputtochoose Programming Flag Offset setup . It is important to note that once parallel  
thedesiredtimingmodemustremainstaticthroughoutFIFOoperation. Refer programminghasbeenselectedduringaMasterResetbyholdingbothFS0  
toFigure4(FIFO1MasterReset)andFigure5(FIFO2MasterReset)forFirst & FS1 LOW, these inputs must remain LOW during all subsequent FIFO  
WordFallThroughselecttimingdiagrams.  
operation. They can only be toggled HIGH when future Master Resets are  
performedandotherprogrammingmethodsaredesired.  
PROGRAMMINGTHEALMOST-EMPTYANDALMOST-FULLFLAGS  
Afterthisresetiscomplete,thefirstfourwritestoFIFO1donotstoredatain  
FourregistersintheseFIFOsareusedtoholdtheoffsetvaluesfortheAlmost- RAM but load the Offset registers in the order Y1, X1, Y2, X2. For Non-  
EmptyandAlmost-Fullflags.ThePortBAlmost-Emptyflag(AEB)Offsetregister InterspersedParitymodethePortAdatainputsusedbytheOffsetregistersare  
islabeledX1andthePortAAlmost-Emptyflag(AEA)Offsetregisterislabeled (A13-A0), (A14-A0), or (A15-A0) for the IDT72V3686, IDT72V3696, or  
X2.ThePortAAlmost-Fullflag(AFA)OffsetregisterislabeledY1andthePort IDT72V36106, respectively. For Interspersed Parity mode the Port A data  
CAlmost-Fullflag(AFC)OffsetregisterislabeledY2.Theindexofeachregister inputsusedbytheOffsetregistersare(A14-A9,A7-A0),(A15-A9,A7-A0),or  
namecorrespondstoitsFIFOnumber.TheOffsetregisterscanbeloadedwith (A16-A9, A7-A0) for the IDT72V3686, IDT72V3696, or IDT72V36106,  
preset values during the reset of a FIFO, programmed in parallel using the respectively.Thehighestnumberedinputisusedasthemostsignificantbitof  
FIFO’sPortAdatainputs,orprogrammedinserialusingtheSerialData(SD) the binarynumberineachcase. Validprogrammingvalues forthe registers  
input (see Table 1).  
rangefrom1to16,380fortheIDT72V3686;1to32,764fortheIDT72V3696;  
FS0/SD,FS1/SENandFS2functionthesamewayinbothIDTStandardand and 1 to 65,532 for the IDT72V36106. After all the Offset registers are  
FWFTmodes.  
programmed from Port A, the Port C Full/Input Ready flag (FFC/IRC) is set  
HIGH,andbothFIFOsbeginnormaloperation.RefertoFigure8foratiming  
diagramillustrationforparallelprogrammingoftheflagoffsetvalues.  
— PRESET VALUES  
ToloadaFIFO’sAlmost-EmptyflagandAlmost-FullflagOffsetregisterswith  
oneofthefivepresetvalueslistedinTable1,theflagselectinputsmustbeHIGH INTERSPERSED PARITY  
orLOWduringamasterreset.Forexample,toloadthepresetvalueof64into  
InterspersedParityisselectedduringaMasterResetoftheFIFO.Referto  
X1 and Y1, FS0, FS1 and FS2 must be HIGH when FlFO1 reset (MRS1) Table1fortheset-upconfigurationofInterspersedParity.TheInterspersed  
TABLE 1 FLAG PROGRAMMING  
FS2  
FS1/SEN  
FS0/SD  
MRS1  
MRS2  
X1 AND Y1 REGlSTERS(1)  
X2 AND Y2 REGlSTERS(2)  
H
H
H
H
H
H
L
L
L
L
L
H
L
H
H
H
H
L
L
H
H
L
L
H
L
L
H
H
L
X
X
X
X
X
X
X
X
X
X
64  
X
X
64  
16  
X
L
X
16  
H
H
H
H
H
H
L
8
X
X
8
256  
X
X
256  
1,024  
X
1,024  
X
SerialprogrammingviaSD  
SerialprogrammingviaSD  
(3,5)  
(3,5)  
L
ParallelprogrammingviaPortA  
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 AFC.  
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  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
TABLE 2 PORT A ENABLE FUNCTION TABLE  
CSA  
W/RA  
ENA  
MBA  
CLKA  
LOOP  
Data A(A0-A35) I/O  
PORT FUNCTION  
H
L
L
L
L
L
L
L
L
X
H
H
H
L
X
L
X
X
L
X
X
X
X
H
H
H
H
H
H
H
H
L
High-Impedance  
Input  
None  
None  
H
H
L
Input  
FIFO1 write  
Mail1write  
H
L
Input  
Output  
Output  
Output  
Output  
Output  
None  
L
H
L
L
FIFO2read  
None  
L
H
H
L
L
H
H
Mail2 read (set MBF2 HIGH)  
H
LoopthedataoutputofFIFO2toinput  
of FIFO1 only  
L
L
H
L
L
Output  
LoopthedataoutputofFIFO2toinput  
of FIFO1 and put data on Port A  
TABLE 3 PORT B ENABLE FUNCTION TABLE  
CSB  
RENB  
MBB  
CLKB  
Data B (B0-B17) Outputs  
PORT FUNCTION  
H
L
L
L
L
X
L
X
L
X
X
X
High-Impedance  
Output  
None  
None  
H
L
L
Output  
FIFO1read  
H
H
Output  
None  
H
Output  
Mail1 read (set MBF1 HIGH)  
TABLE 4 PORT C ENABLE FUNCTION TABLE  
WENC  
MBC  
CLKC  
Data C (C0-C17) Inputs  
PORT FUNCTION  
H
H
L
L
L
H
L
X
X
Input  
Input  
Input  
Input  
FIFO2 write  
Mail2write  
None  
H
None  
Parityfunctionallowstheusertoselectthelocationoftheparitybitsintheword  
loadedintotheparallelport(A0-An)duringprogrammingoftheflagoffsetvalues.  
IfInterspersedParityisselectedthenduringparallelprogrammingoftheflag  
offsetvalues,thedevicewillignoredatalineA8.IfNon-InterspersedParityis  
selectedthendatalineA8willbecomeavalidbit.IfInterspersedParityisselected  
serialprogrammingoftheoffsetvaluesisnotpermitted,onlyparallelprogram-  
ming can be done.  
IRC)flagalsoremainsLOWthroughouttheserialprogrammingprocess,until  
allregisterbitsarewritten.FFC/IRCissetHIGHbytheLOW-to-HIGHtransition  
ofCLKCafterthelastbitis loadedtoallownormalFIFO2operation.  
SeeFigure9timingdiagram, SerialProgrammingoftheAlmost-FullFlag  
andAlmost-EmptyFlagOffsetValuesafterReset(IDTStandardandFWFT  
Modes).  
FIFO WRITE/READ OPERATION  
— SERIAL LOAD  
The state ofthe PortAdata (A0-A35)outputs is controlledbyPortAChip  
Select(CSA)andPortAWrite/ReadSelect(W/RA).TheA0-A35outputsare  
inthehigh-impedancestatewheneitherCSAorW/RAisHIGH.TheA0-A35  
outputs are active whenbothCSA andW/RAare LOW.  
Data is loaded into FIFO1 from the A0-A35 inputs on a LOW-to-HIGH  
transitionofCLKAwhenCSA is LOW,W/RAis HIGH,ENAis HIGH,MBAis  
LOW,andFFA/IRAisHIGH.DataisreadfromFIFO2totheA0-A35outputs  
byaLOW-to-HIGHtransitionofCLKAwhenCSAisLOW,W/RAisLOW,ENA  
isHIGH,MBAisLOW,andEFA/ORAisHIGH(seeTable2).FIFOreadsand  
writes on Port A are independent of any concurrent Port B or Port C  
operation.  
The state of the Port B data (B0-B17) outputs is controlled by the Port B  
Chip Select (CSB). The B0-B17 outputs are in the high-impedance state  
when CSB is HIGH. The B0-B17 outputs are active when CSB is LOW.  
Data is read from FIFO1 to the B0-B17 outputs by a LOW-to-HIGH  
transitionofCLKBwhenCSBisLOW,RENBisHIGH,MBBisLOWandEFB/  
ToprogramtheX1,X2,Y1,andY2registersserially,initiateaMasterReset  
withFS2LOW,FS0/SDLOWandFS1/SENHIGHduringtheLOW-to-HIGH  
transitionofMRS1andMRS2.Afterthisresetiscomplete,theXandYregister  
valuesareloadedbit-wisethroughtheFS0/SDinputoneachLOW-to-HIGH  
transitionofCLKAthattheFS1/SENinputisLOW.Thereare56-,60-,or64-  
bit writes needed to complete the programming for the IDT72V3686,  
IDT72V3696,orIDT72V36106,respectively.Thefourregistersarewrittenin  
theorderY1,X1,Y2andfinally,X2.Thefirst-bitwritestoresthemostsignificant  
bitoftheY1registerandthelast-bitwritestorestheleastsignificantbitoftheX2  
register. Each register value can be programmed from 1 to 16,380  
(IDT72V3686), 1 to 32,764 (IDT72V3696), or 1 to 65,532 (IDT72V36106).  
WhentheoptiontoprogramtheOffsetregistersseriallyischosen,thePort  
AFull/InputReady(FFA/IRA)flagremainsLOWuntilallregisterbitsarewritten.  
FFA/IRAissetHIGHbytheLOW-to-HIGHtransitionofCLKAafterthelastbit  
isloadedtoallownormalFIFO1operation.ThePortBFull/InputReady(FFC/  
13  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
ORB is HIGH (see Table 3). FIFO reads on Port B are independent of any diagramsforPortBandPortC,togetherwithBus-MatchingandEndianselect  
concurrentPortAandPortCoperations.  
operation, can be found in Figure 11 to 14.  
Data is loaded into FIFO2 from the C0-C17 inputs on a LOW-to-HIGH  
transitionofCLKCwhenWENBisHIGH,MBCisLOW,andFFC/IRCisHIGH LOOPBACK (LOOP)  
(seeTable4).FIFOwritesonPortCareindependentofanyconcurrentPort  
A and Port B operation.  
ALoopbackfunctionisprovidedonPortAandisselectedbysettingtheLOOP  
pinLOW.WhentheLoopfeatureisselected,thedataoutputfromFIFO2willbe  
ThesetupandholdtimeconstraintsforCSAandW/RAwithregardtoCLKA directedtothedatainputofFIFO1.IfLoopisselectedandPortAisset-upfor  
as well as CSB with regard to CLKB are only for enabling write and read writeoperationviatheW/RApinbeingHIGH,thendataoutputfromFIFO2will  
operationsandarenotrelatedtohigh-impedancecontrolofthedataoutputs. bewrittentoFIFO1,oneveryLOW-to-HIGHtransitionofCLKA,providedCSA  
IfENAis LOWduringa clockcycle, either CSA orW/RAmaychange states isLOWandENAisHIGH.However,FIFO2dataoutputwillnotbeplacedon  
duringthe setupandholdtime windowofthe cycle. This is alsotrue forCSB theoutputPortA(A0-A35).IfPortAisset-upforreadoperationviatheW/RA  
whenRENBis LOW.  
pinbeingLOW,thendataoutputfromFIFO2willbewrittenintoFIFO1onevery  
WhenoperatingtheFIFOinFWFTmodeandtheOutputReadyflagisLOW, LOW-to-HIGHtransitionofCLKA,providedCSAisLOWandENAisHIGH.Also  
thenextwordwrittenisautomaticallysenttotheFIFO’soutputregisterbythe FIFO2datawillbeoutputtoPortA(A0-A35).WhentheLOOPpinisHIGHthen  
LOW-to-HIGHtransitionoftheportclockthatsetstheOutputReadyflagHIGH. PortAoperatesinthenormalmanner.RefertoTable2fortheinputset-upof  
WhentheOutputReadyflagisHIGH,subsequentdataisclockedtotheoutput theLoopfeature.  
registersonlywhenareadisselectedusingCSA,W/RA,ENAandMBAatPort  
A or using CSB, RENB and MBB at Port B.  
TheLoopoperationwillcontinuetohappenprovidedthatFIFO1isnotfull  
andFIFO2isnotempty.IfduringaLoopsequenceFIFO1becomesfullthen  
WhenoperatingtheFIFOinIDTStandardmode,thefirstwordwillcausethe anydata thatcontinues tobe readoutfromFIFO2willonlybe placedonthe  
EmptyFlagtochangestateonthesecondLOW-to-HIGHtransitionoftheRead Port A (A0-A35) lines, (provided that Port A is set-up for read operation). If  
Clock.Thedatawordwillnotbeautomaticallysenttotheoutputregister. Instead, duringaLoopsequencetheFIFO2becomesempty,thenthelastwordfrom  
dataresidingintheFIFO’smemoryarrayisclockedtotheoutputregisteronly FIFO2willcontinuetobeclockedintoFIFO1untilFIFO1becomesfulloruntil  
whena readis selectedusing CSA, W/RA, ENAandMBAatPortAorusing theLoopfunctionisstopped.TheLoopfeaturecanbeusefulwhenperforming  
CSB,RENBandMBBatPortB.Relevantwriteandreadtimingdiagramsfor systemdebuggingandremoteloopbacks.SeeFigures34and35forLoopback  
Port A can be found in Figure 10 and 15. Relevant read and write timing timingdiagrams.  
TABLE 5 FIFO1 FLAG OPERATION (IDT Standard and FWFT modes)  
Synchronized  
to CLKB  
Synchronized  
to CLKA  
Number of Words in FIFO Memory(1,2)  
(3)  
(3)  
(3)  
IDT72V3686  
IDT72V3696  
IDT72V36106  
EFB/ORB  
AEB  
L
AFA  
H
FFA/IRA  
0
0
0
L
H
H
H
H
H
H
H
H
L
1toX1  
1toX1  
1toX1  
L
H
(X1+1)to[16,384-(Y1+1)]  
(16,384-Y1)to16,383  
16,384  
(X1+1)to[32,768-(Y1+1)]  
(32,768-Y1)to32,767  
32,768  
(X1+1)to[65,536-(Y1+1)]  
(65,536-Y1)to65,535  
65,536  
H
H
H
L
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. Dataintheoutputregisterdoes notcountas a"wordinFIFOmemory".SinceinFWFTmode,thefirstwordwrittentoanemptyFIFOgoes unrequestedtotheoutputregister(noreadoperation  
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 6 FIFO2 FLAG OPERATION (IDT Standard and FWFT modes)  
Synchronized  
to CLKA  
Synchronized  
to CLKC  
Number of Words in FIFO Memory(1,2)  
(3)  
(3)  
(3)  
IDT72V3686  
IDT72V3696  
IDT72V36106  
EFA/ORA  
AEA  
AFC  
FFC/IRC  
0
0
1toX2  
0
1toX2  
L
H
H
H
H
L
L
H
H
H
L
H
H
H
H
L
1toX2  
(X2+1)to[16,384-(Y2+1)]  
(16,384-Y2)to16,383  
16,384  
(X2+1)to[32,768-(Y2+1)]  
(32,768-Y2)to32,767  
32,768  
(X2+1)to[65,536-(Y2+1)]  
(65,536-Y2)to65,535  
65,536  
H
H
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. Dataintheoutputregisterdoes notcountas a"wordinFIFOmemory".SinceinFWFTmode,thefirstwordwrittentoanemptyFIFOgoes unrequestedtotheoutputregister(noreadoperation  
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 AFC. Both X2 and Y2 are selected during a FIFO2 reset or port A programming.  
4. The ORA and IRC functions are active during FWFT mode; the EFA and FFC functions are active in IDT Standard mode.  
14  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
controls a Full/Input Ready flag monitors a write pointer and read pointer  
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/InputReadyflagisLOWiflessthantwo  
cyclesoftheFull/InputReadyflagsynchronizingclockhaveelapsedsincethe  
nextmemorywritelocationhasbeenread.ThesecondLOW-to-HIGHtransition  
ontheFull/InputReadyflagsynchronizingclockafterthereadsetstheFull/Input  
Ready flag HIGH.  
SYNCHRONIZED FIFO FLAGS  
EachFIFOissynchronizedtoitsportclockthroughatleasttwoflip-flopstages.  
This is done to improve flag signal reliability by reducing the probability of  
metastableeventswhenCLKAoperatesasynchronouslywithrespecttoeither  
CLKB or CLKC. EFA/ORA, AEA, FFA/IRA, and AFA are synchronized to  
CLKA.EFB/ORBandAEBaresynchronizedtoCLKB.FFC/IRCandAFCare  
synchronizedtoCLKC.Tables5and6showtherelationshipofeachportflag  
to FIFO1 and FIFO2.  
ALOW-to-HIGHtransitiononaFull/InputReadyflagsynchronizingclock  
beginsthefirstsynchronizationcycleofareadiftheclocktransitionoccursat  
timetSKEW1 orgreateraftertheread.Otherwise,thesubsequentclockcycle  
can be the first synchronization cycle (see Figure 20, 21, 22, and 23).  
EMPTY/OUTPUTREADYFLAGS(EFA/ORA,EFB/ORB)  
Thesearedualpurposeflags.IntheFWFTmode,theOutputReady(ORA,  
ORB)functionisselected.WhentheOutputReadyflagisHIGH,newdatais  
presentintheFIFOoutputregister.WhentheOutputReadyflagisLOW,the  
previousdatawordispresentintheFIFOoutputregisterandattemptedFIFO  
reads are ignored.  
ALMOST-EMPTYFLAGS(AEA,AEB)  
TheAlmost-EmptyflagofaFIFOissynchronizedtotheportclockthatreads  
datafromitsarray.ThestatemachinethatcontrolsanAlmost-Emptyflagmonitors  
a write pointer and read pointer comparator that indicates when the FIFO  
memory status is almost-empty, almost-empty+1, or almost-empty+2. The  
almost-emptystateisdefinedbythecontentsofregisterX1forAEBandregister  
X2forAEA.TheseregistersareloadedwithpresetvaluesduringaFIFOreset,  
programmedfromPortA,orprogrammedserially(seetheAlmost-Emptyflag  
andAlmost-Fullflagoffsetprogrammingsection).AnAlmost-EmptyflagisLOW  
whenits FIFOcontains Xorless words andis HIGHwhenits FIFOcontains  
(X+1)ormorewords.AdatawordpresentintheFIFOoutputregisterhasbeen  
readfrommemory.  
IntheIDTStandardmode,theEmptyFlag(EFA,EFB)functionisselected.  
WhentheEmptyFlagisHIGH,dataisavailableintheFIFO’sRAMmemoryfor  
readingtotheoutputregister.WhentheEmptyFlagisLOW,thepreviousdata  
word is present in the FIFO output register and attempted FIFO reads are  
ignored.  
TheEmpty/OutputReadyflagofaFIFOissynchronizedtotheportclockthat  
readsdatafromitsarray.ForboththeFWFTandIDTStandardmodes,theFIFO  
readpointerisincrementedeachtimeanewwordisclockedtoitsoutputregister.  
The state machine that controls an Output Ready flag monitors a write pointer  
and read pointer comparator that indicates when the FIFO memory status is  
empty, empty+1, or empty+2.  
TwoLOW-to-HIGHtransitionsoftheAlmost-Emptyflagsynchronizingclock  
arerequiredafteraFIFOwriteforitsAlmost-Emptyflagtoreflectthenewlevel  
offill.Therefore,theAlmost-FullflagofaFIFOcontaining(X+1)ormorewords  
remainsLOWiftwocyclesofitssynchronizingclockhavenotelapsedsincethe  
writethatfilledthememorytothe(X+1)level.AnAlmost-EmptyflagissetHIGH  
bythesecondLOW-to-HIGHtransitionofitssynchronizingclockaftertheFIFO  
writethatfillsmemorytothe(X+1)level.ALOW-to-HIGHtransitionofanAlmost-  
Emptyflagsynchronizingclockbeginsthefirstsynchronizationcycleifitoccurs  
at time tSKEW2 or greater after the write that fills the FIFO to (X+1) words.  
Otherwise,thesubsequentsynchronizingclockcyclemaybethefirstsynchro-  
nization cycle. (See Figure 24 and 25).  
InFWFTmode,fromthetimeawordiswrittentoaFIFO,itcanbeshiftedto  
theFIFOoutputregisterinaminimumofthreecyclesoftheOutputReadyflag  
synchronizing clock. Therefore, an Output Ready flag is LOW if a word in  
memoryisthenextdatatobesenttotheFlFOoutputregisterandthreecycles  
oftheportclockthatreadsdatafromtheFIFOhavenotelapsedsincethetime  
thewordwaswritten.TheOutputReadyflagoftheFIFOremainsLOWuntilthe  
thirdLOW-to-HIGHtransitionofthesynchronizingclockoccurs,simultaneously  
forcingtheOutputReadyflagHIGHandshiftingthewordtotheFIFOoutput  
register.  
InIDTStandardmode,fromthetimeawordiswrittentoaFIFO,theEmpty  
Flagwillindicatethepresenceofdataavailableforreadinginaminimumoftwo  
cyclesoftheEmptyFlagsynchronizingclock.Therefore,anEmptyFlagisLOW  
ifawordinmemoryisthenextdatatobesenttotheFlFOoutputregisterand  
twocyclesoftheportClockthatreadsdatafromtheFIFOhavenotelapsedsince  
thetimethewordwaswritten.TheEmptyFlagoftheFIFOremainsLOWuntil  
thesecondLOW-to-HIGHtransitionofthesynchronizingclockoccurs,forcing  
the Empty Flag HIGH; only then can data be read.  
ALMOST-FULL FLAGS (AFA, AFC)  
TheAlmost-FullflagofaFIFOissynchronizedtotheportclockthatwrites  
datatoitsarray.ThestatemachinethatcontrolsanAlmost-Fullflagmonitorsa  
writepointerandreadpointercomparatorthatindicateswhentheFIFOmemory  
statusisalmost-full,almost-full-1,oralmost-full-2.Thealmost-fullstateisdefined  
bythecontentsofregisterY1forAFAandregisterY2forAFC.Theseregisters  
areloadedwithpresetvaluesduringaFlFOreset,programmedfromPortA,  
or programmed serially (see Almost-Empty flag and Almost-Full flag offset  
programmingsection).AnAlmost-FullflagisLOWwhenthenumberofwords  
in its FIFO is greater than or equal to (16,384-Y), (32,768-Y), or (65,536-Y)  
fortheIDT72V3686,IDT72V3696,orIDT72V36106respectively.AnAlmost-  
FullflagisHIGHwhenthenumberofwordsinitsFIFOislessthanorequalto  
[16,384-(Y+1)], [32,768-(Y+1)], or [65,536-(Y+1)] for the IDT72V3686,  
IDT72V3696,orIDT72V36106respectively.Notethatadatawordpresentin  
theFIFOoutputregisterhas beenreadfrommemory.  
ALOW-to-HIGHtransitiononanEmpty/OutputReadyflagsynchronizing  
clockbeginsthefirstsynchronizationcycleofawriteiftheclocktransitionoccurs  
attimetSKEW1orgreaterafterthewrite.Otherwise,thesubsequentclockcycle  
can be the first synchronization cycle (see Figure 16, 17, 18 and 19).  
FULL/INPUT READY FLAGS (FFA/IRA, FFC/IRC)  
These are dual purpose flags. In FWFT mode, the Input Ready (IRA and  
IRC)functionisselected.InIDTStandardmode,theFullFlag(FFAandFFC)  
functionisselected.Forbothtimingmodes,whentheFull/InputReadyflagis  
HIGH,amemorylocationisfreeintheFIFOtoreceivenewdata.Nomemory  
locationsarefreewhentheFull/InputReadyflagisLOWandattemptedwrites  
to the FIFO are ignored.  
TheFull/InputReadyflagofaFlFOissynchronizedtotheportclockthatwrites  
datatoits array.ForbothFWFTandIDTStandardmodes,eachtimeaword  
is written to a FIFO, its write pointer is incremented. The state machine that  
TwoLOW-to-HIGHtransitionsoftheAlmost-Fullflagsynchronizingclockare  
requiredafteraFIFOreadforitsAlmost-Fullflagtoreflectthenewleveloffill.  
Therefore,theAlmost-FullflagofaFIFOcontaining[16,384/32,768/65,536-  
(Y+1)]orlesswordsremainsLOWiftwocyclesofitssynchronizingclockhave  
not elapsed since the read that reduced the number of words in memory to  
15  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
[16,384/32,768/65,536-(Y+1)].AnAlmost-FullflagissetHIGHbythesecond BUS SIZING  
LOW-to-HIGH transition of its synchronizing clock after the FIFO read that  
reducesthenumberofwordsinmemoryto[16,384/32,768/65,536-(Y+1)].A  
LOW-to-HIGHtransitionofanAlmost-Fullflagsynchronizingclockbeginsthe  
firstsynchronizationcycleifitoccursattimetSKEW2orgreaterafterthereadthat  
reduces the number of words in memory to [16,384/32,768/65,536-(Y+1)].  
Otherwise,thesubsequentsynchronizingclockcyclemaybethefirstsynchro-  
nization cycle (see Figure 26 and 27).  
PortBmaybeconfiguredineitheran18-bitwordora9-bitbyteformatfor  
data read from FIFO1. Port C may be configured in either an 18-bit word or  
a 9-bit byte format for data written to FIFO2. The bus size can be selected  
independentlyforPorts BandC. The levelappliedtothe PortBSize Select  
(SIZEB)inputdeterminesthePortBbussizeandthelevelappliedtothePort  
CSizeSelect(SIZEC)inputdeterminesthePortCbussize.Theselevelsshould  
bestaticthroughoutFIFOoperation.Bothbussizeselectionsareimplemented  
atthecompletionofMasterReset,bythetimetheFull/InputReadyflagisset  
HIGH, as shown in Figure 2 and 3.  
MAILBOX REGISTERS  
EachFIFOhasan18-bitbypassregisterallowingthepassageofcommand  
andcontrolinformationfromPortAtoPortBorfromPortCtoPortAwithoutputting  
itinqueue.TheMailboxSelect(MBA,MBB andMBC)inputschoosebetween  
amailregisterandaFIFOforaportdatatransferoperation.Theusablewidth  
ofboththeMail1andMail2registersmatchestheselectedbussizeforportsB  
and C.  
WhensendingdatafromPortAtoPortBviatheMail1Register,thefollowing  
isthecase: ALOW-to-HIGHtransitiononCLKAwritesdatatotheMail1Register  
whena PortAwrite is selectedby CSA, W/RA, andENAwithMBAHIGH. If  
theselectedPortBbussizeis18bits,thentheusablewidthoftheMail1Register  
employs data lines A0-A17. (Inthis case, A18-A35are dontcare inputs.) If  
theselectedPortBbussizeis9bits,thentheusablewidthoftheMail1Register  
employs data lines A0-A8. (Inthis case, A9-A35are dontcare inputs.)  
WhensendingdatafromPortCtoPortAviatheMail2Register,thefollowing  
isthecase: ALOW-to-HIGHtransitiononCLKCwritesdatatotheMail2Register  
whenaPortCwriteisselectedbyWENCwithMBCHIGH.IftheselectedPort  
Cbussizeis18bits,thentheusablewidthoftheMail2Registeremploysdata  
linesC0-C17.IftheselectedPortCbussizeis9bits,thentheusablewidthof  
theMail2RegisteremploysdatalinesC0-C8.(Inthiscase,C9-C17aredont  
careinputs.)  
TwodifferentmethodsforsequencingdatatransferareavailableforPorts  
BandCregardlessofwhetherthebussizeselectionisbyte-orword-size.They  
arereferredtoasBig-Endian(mostsignificantbytefirst)andLittle-Endian(least  
significantbytefirst).ThelevelappliedtotheBig-EndianSelect(BE)inputduring  
theLOW-to-HIGHtransitionofMRS1andMRS2selectstheendianmethodthat  
willbeactiveduringFIFOoperation.ThisselectionappliestobothportsBand  
C.TheendianmethodisimplementedatthecompletionofMasterReset,by  
thetimetheFull/InputReadyflagissetHIGH,asshowninFigure2and3(see  
EndianSelectionsection).  
Only36-bitlongworddataiswrittentoorreadfromthetwoFIFOmemories  
onthesedevices.Bus-Matchingoperationsaredoneafterdataisreadfrom  
the FIFO1 RAM (Port B) and before data is written to the FIFO2 RAM (Port  
C).TheEndianselectoperationsarenotavailablewhentransferringdatavia  
mailboxregisters.Furthermore,boththeword-andbyte-sizebusselections  
limitthewidthofthedatabusthatcanbeusedformailregisteroperations.In  
thiscase,onlythosebytelanesbelongingtotheselectedword-orbyte-size  
buscancarrymailboxdata.Theremainingdataoutputswillbeindeterminate.  
Theremainingdatainputswillbedontcareinputs.Forexample,whenaword-  
sizebusisselectedonPortB,thenmailboxdatacanbetransmittedonlyfrom  
A0-A17toB0-B17.Whenabyte-sizebusisselectedonPortB,thenmailbox  
datacanbetransmittedonlyfromA0-A8toB0-B8.Similarly,whenaword-size  
busisselectedonPortC,thenmailboxdatacanbetransmittedonlyfromC0-  
C17toA18-A35.Whenabyte-sizebusisselectedonPortC,thenmailboxdata  
canbetransmittedonlyfromC0-C8toA18-A26.  
Writingdatatoamailregistersetsitscorrespondingflag(MBF1orMBF2)  
LOW.AttemptedwritestoamailregisterareignoredwhilethemailflagisLOW.  
Whendataoutputsofaportareactive,thedataonthebuscomesfromthe  
FIFOoutputregisterwhentheportMailboxselectinputisLOWandfromthe  
mailregisterwhentheportmailboxselectinputisHIGH.  
TheMail1RegisterFlag(MBF1)issetHIGHbyaLOW-to-HIGHtransition  
onCLKBwhenaPortBreadisselectedbyCSB,andRENBwithMBBHIGH.  
Foran18-bitbussize,18bitsofmailboxdataareplacedonB0-B17.Forthe  
9-bitbussize,9bitsofmailboxdataareplacedonB0-B8.(Inthiscase,B9-B17  
areindeterminate.)  
TheMail2RegisterFlag(MBF2)issetHIGHbyaLOW-to-HIGHtransition  
onCLKAwhenaPortAreadis selectedbyCSA,W/RA,andENAwithMBA  
HIGH.Thedatainamailregisterremainsintactafteritisreadandchangesonly  
whennewdataiswrittentotheregister.Foran18-bitbussize,18bitsofmailbox  
dataappearon A18-A35. (Inthiscase,A0-A17areindeterminate.) Fora9-  
bitbussize,9bitsofmailboxdataappearonA18-A26.(Inthiscase,A0-A17  
andA27-A35areindeterminate.)  
Thedatainamailregisterremains intactafteritis readandchanges only  
whennewdataiswrittentotheregister.TheEndianSelectfeaturehasnoeffect  
onmailboxdata.  
NotethatMBCmustbeHIGHduringMasterReset(until FFA/IRAand FFC/  
IRCgoHIGH. MBAandMBBaredon'tcareinputsduringMasterReset.For  
mailregisterandmailregisterflagtimingdiagrams,seeFigure28and29.  
BUS-MATCHING FIFO1 READS  
DataisreadfromtheFIFO1RAMin36-bitlongwordincrements.SincePort  
Bcanhave a byte orwordsize, onlythe firstone ortwobytes appearonthe  
selectedportionoftheFIFO1outputregister,withtherestofthelongwordstored  
inauxiliaryregisters.Inthiscase,subsequentFIFO1readsoutputtherestof  
the long word to the FIFO1 output register in the order shown by Figure 2.  
WhenreadingdatafromFIFO1inbyteformat,theunusedB9-B17outputs  
areindeterminate.  
BUS-MATCHING FIFO2 WRITES  
DataiswrittentotheFIFO2RAMin36-bitlongwordincrements.Datawritten  
toFIFO2withabyteorwordbussizestorestheinitialbytesorwordsinauxiliary  
registers.TheCLKCrisingedgethatwritesthefourthbyteorthesecondword  
oflongwordtoFIFO2alsostorestheentirelongwordintheFIFO2memory.  
The bytes are arranged in the manner shown in Figure 3.  
WhenwritingdatatoFIFO2inbyteformat,theunusedC9-C17inputsare  
don'tcareinputs.  
16  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
A26  
A18  
A8  
A0  
A35  
A27  
A17  
A9  
BYTE ORDER ON PORT A:  
D
A
B
C
Write to FIFO1  
B17  
B9  
B8  
B0  
BYTE ORDER ON PORT B:  
1st: Read from FIFO1  
2nd: Read from FIFO1  
BE  
H
SIZEB  
L
A
B
B17  
B9  
B8  
B0  
C
D
(b) WORD SIZE BIG ENDIAN  
B17  
B9  
B8  
B8  
B0  
B0  
1st: Read from FIFO1  
2nd: Read from FIFO1  
BE  
L
SIZEB  
L
C
D
B17  
B9  
A
B
(c) WORD SIZE LITTLE ENDIAN  
B17  
B17  
B17  
B17  
B9  
B9  
B9  
B9  
B8  
B0  
B0  
B0  
1st: Read from FIFO1  
2nd: Read from FIFO1  
BE  
H
SIZEB  
H
A
B8  
B
B8  
3rd: Read from FIFO1  
4th: Read from FIFO1  
C
B8  
B0  
D
(d) BYTE SIZE BIG ENDIAN  
B17  
B9  
B8  
B0  
B0  
B0  
BE SIZEB  
1st: Read from FIFO1  
2nd: Read from FIFO1  
D
L
H
B17  
B9  
B8  
C
B17  
B9  
B9  
B8  
B
3rd: Read from FIFO1  
B17  
B8  
B0  
A
4th: Read from FIFO1  
4676 drw04  
(e) BYTE SIZE LITTLE ENDIAN  
Figure 2. Port B Bus Sizing  
17  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
A26  
A18  
A8  
A0  
A35  
A27  
A17  
A9  
BYTE ORDER ON PORT A:  
D
A
B
C
Read from FIFO2  
C17  
C9  
C9  
C8  
C0  
C0  
BYTE ORDER ON PORT C:  
1st: Write to FIFO2  
2nd: Write to FIFO2  
BE  
H
SIZEC  
L
A
B
C17  
C8  
C
D
(b) WORD SIZE BIG ENDIAN  
C17  
C9  
C8  
C0  
C0  
1st: Write to FIFO2  
2nd: Write to FIFO2  
BE  
L
SIZEC  
L
C
D
C17  
C9  
C8  
A
B
(c) WORD SIZE LITTLE ENDIAN  
C17  
C9  
C9  
C9  
C9  
C8  
C8  
C8  
C8  
C0  
1st: Write to FIFO2  
2nd: Write to FIFO2  
BE  
H
SIZEC  
H
A
C17  
C17  
C17  
C0  
B
C0  
C0  
3rd: Write to FIFO2  
4th: Write to FIFO2  
C
D
(d) BYTE SIZE BIG ENDIAN  
C17  
C17  
C17  
C17  
C9  
C9  
C9  
C9  
C8  
C0  
BE SIZEC  
1st: Write to FIFO2  
2nd: Write to FIFO2  
D
L
H
C8  
C8  
C0  
C0  
C
B
3rd: Write to FIFO2  
C8  
C0  
A
4th: Write to FIFO2  
4676 drw05  
(e) BYTE SIZE LITTLE ENDIAN  
Figure 3. Port C Bus Sizing  
18  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
CLKA  
CLKB  
1
2
tRSTH  
t
RSTS  
MRS1  
tBEH  
t
BES  
tFWS  
BE/FWFT  
BE  
0,1  
FWFT  
t
FSS  
tFSH  
FS2,FS1,  
FS0  
t
WFF  
t
WFF  
FFA/IRA  
(2)  
REF  
t
EFB/ORB  
t
RSF  
AEB  
t
RSF  
AFA  
t
RSF  
MBF1  
RTM LOW  
4676 drw06  
LOOP  
HIGH  
NOTES:  
1. PRS1 and MBC must be HIGH during Master Reset until the rising edge of FFA/IRA goes HIGH.  
2. 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 Master Reset and Loading X1 and Y1 with a Preset Value of Eight (IDT Standard and FWFT Modes)  
1
2
CLKC  
CLKA  
tRSTH  
t
RSTS  
MRS2(3)  
t
BES  
tBEH  
tFWS  
BE  
0,1  
BE/FWFT  
FWFT  
t
FSS  
tFSH  
FS2,FS1,  
FS0  
t
WFF  
tWFF  
FFC/IRC  
EFA/ORA  
AEA  
(2)  
REF  
t
t
t
RSF  
RSF  
AFC  
t
RSF  
MBF2  
RTM LOW  
LOOP  
NOTES:  
HIGH  
4676 drw07  
1. PRS2 and MBC must be HIGH during Master Reset until the rising edge of FFC/IRC goes HIGH.  
2. If BE/FWFT is HIGH, then EFA/ORA will go LOW one CLKA cycle earlier than in this case where BE/FWFT is LOW.  
3. MRS2 must toggle simultaneously with MRS1.  
Figure 5. FIFO2 Master Reset and Loading X2 and Y2 with a Preset Value of Eight (IDT Standard and FWFT Modes)  
19  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
1
2
CLKA  
CLKB  
tRSTH  
t
RSTS  
PRS1  
t
WFF  
t
WFF  
FFA/IRA  
(2)  
REF  
t
EFB/ORB  
t
RSF  
AEB  
t
RSF  
AFA  
t
RSF  
MBF1  
RTM LOW  
4676 drw08  
NOTES:  
1. MRS1 must be HIGH during Partial Reset.  
2. 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 6. FIFO1 Partial Reset (IDT Standard and FWFT Modes)  
CLKC  
CLKA  
t
RSTS  
tRSTH  
PRS2  
t
WFF  
t
WFF  
FFC/IRC  
(2)  
REF  
t
EFA/ORA  
t
RSF  
AEA  
t
RSF  
AFC  
t
RSF  
MBF1  
4676 drw09  
NOTES:  
1. MRS2 must be HIGH during Partial Reset.  
2. If BE/FWFT is HIGH, then EFA/ORA will go LOW one CLKA cycle earlier than in this case where BE/FWFT is LOW.  
Figure 7. FIFO2 Partial Reset (IDT Standard and FWFT Modes)  
20  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
CLKA  
4
MRS1,  
MRS2  
t
FSS  
t
FSH  
FS2  
t
FSS  
t
FSH  
0,0  
FS1,FS0  
t
WFF  
FFA/IRA  
(1)  
tSKEW1  
tENS2  
tENH  
ENA  
tDH  
tDS  
A0-A35  
First Word to FIFO1  
AEA Offset  
AFA Offset  
AEB Offset  
AFC Offset  
(Y2)  
(X2)  
(Y1)  
(X1)  
CLKC  
1
2
t
WFF  
FFC/IRC  
4676 drw10  
NOTES:  
1. tSKEW1 is the minimum time between the rising CLKA edge and a rising CLKC edge for FFC/IRC to transition HIGH in the next cycle. If the time between the rising edge of CLKA and rising  
edge of CLKC is less than tSKEW1, then FFC/IRC may transition HIGH one CLKC 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 8. 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
FSH  
t
FSS  
FS2  
t
WFF  
(1)  
SKEW  
t
FFA/IRA  
FS1/SEN  
FS0/SD(3)  
t
SENS  
t
SENH  
t
FSS  
t
SENS  
tSENH  
tSPH  
tSDS  
t
SDH  
tSDS  
tSDH  
AFA Offset  
(Y1) MSB  
AEA Offset  
(X2) LSB  
CLKC  
4
t
WFF  
4676 drw11  
FFC/IRC  
NOTES:  
1. tSKEW1 is the minimum time between the rising CLKA edge and a rising CLKC edge for FFC/IRC to transition HIGH in the next cycle. If the time between the rising edge of CLKA and rising  
edge of CLKC is less than tSKEW1, then FFC/IRC may transition HIGH one CLKC 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, FFC/IRC is set HIGH.  
3. Programmable offsets are written serially to the SD input in the order AFA offset (Y1), AEB offset (X1), AFC offset (Y2), and AEA offset (X2).  
Figure 9. Serial Programming of the Almost-Full Flag and Almost-Empty Flag Offset Values after Reset (IDT Standard and FWFT Modes)  
21  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
tCLK  
tCLKH  
tCLKL  
CLKA  
FFA/IRA HIGH  
t
ENH  
ENH  
t
ENS1  
CSA  
t
t
ENS1  
W/RA  
tENH  
tENS2  
MBA  
ENA  
tENH  
tENH  
tENH  
tENS2  
tENS2  
tENS2  
tDH  
t
DS  
W1(1)  
W2(1)  
A0-A35  
No Operation  
4676 drw12  
NOTE:  
1. Written to FIFO1.  
Figure 10. Port A Write Cycle Timing for FIFO1 (IDT Standard and FWFT Modes)  
CLKC  
FFC/IRC HIGH  
tENS2  
tENS2  
tENH  
tENH  
MBC  
tENS2  
tENS2  
tENH  
tENH  
WENC  
tDH  
tDS  
C0-C17  
4676 drw13  
DATA SIZE TABLE FOR WORD WRITES TO FIFO2  
(1)  
SIZE MODE  
WRITE  
NO.  
DATA WRITTEN  
TO FIFO2  
DATA READ FROM FIFO2  
SIZEC  
BE  
C17-C9  
C8-C0  
A35-A27  
A26-A18  
A17-A9  
A8-A0  
L
L
H
1
2
A
C
B
D
A
B
C
D
L
1
2
C
A
D
B
A
B
C
D
NOTE:  
1. BE is selected at Master Reset; SIZEB and SIZEC must be static throughout device operation.  
Figure 11. Port C Word Write Cycle Timing for FIFO2 (IDT Standard and FWFT Modes)  
22  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
CLKC  
FFC/IRC HIGH  
t
ENS2  
ENS2  
t
ENH  
ENH  
t
ENH  
MBC  
tENS2  
t
t
t
ENH  
WENC  
tDS  
tDH  
C0-C8  
4676 drw14  
DATA SIZE TABLE FOR BYTE WRITES TO FIFO2  
SIZE MODE(1)  
WRITE  
NO.  
DATA WRITTEN  
TO FIFO2  
C8-C0  
DATA READ FROM FIFO2  
SIZEC  
BE  
A35-A27  
A26-A18  
A17-A9  
A8-A0  
1
2
3
4
1
2
3
4
A
B
C
D
D
C
B
A
H
H
H
A
B
C
D
L
A
B
C
D
NOTE:  
1. BE is selected at Master Reset; SIZEB and SIZEC must be static throughout device operation.  
Figure 12. Port C Byte Write Cycle Timing for FIFO2 (IDT Standard and FWFT Modes)  
CLKB  
EFB/ORB HIGH  
CSB  
MBB  
tENS2  
tENH  
RENB  
No Operation  
Read 2  
t
DIS  
DIS  
t
A
t
MDV  
t
A
t
EN  
B0-B17  
Read 1  
Read 2  
Previous Data  
(Standard Mode)  
OR  
t
t
MDV  
t
A
t
A
tEN  
B0-B17  
(FWFT Mode)  
Read 1  
Read 3  
4676 drw15  
DATA SIZE TABLE FOR WORD READS FROM FIFO1  
SIZE MODE(1)  
DATA WRITTEN TO FIFO1  
READ  
NO.  
DATA READ FROM FIFO1  
SIZEB  
BE  
A35-A27  
A26-A18  
A17-A9  
A8-A0  
B17-B9  
B8-B0  
B
H
H
H
A
B
C
D
1
2
1
2
A
C
C
A
D
L
A
B
C
D
D
B
NOTE:  
1. BE is selected at Master Reset; SIZEB and SIZEC must be static throughout device operation.  
Figure 13. Port B Word Read Cycle Timing for FIFO1 (IDT Standard and FWFT Modes)  
23  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
CLKB  
EFB/ORB  
HIGH  
CSB  
MBB  
tENS2  
tENH  
RENB  
No Operation  
t
DIS  
DIS  
t
MDV  
t
A
t
A
t
A
tA  
t
EN  
B0-B8  
Previous Data  
Read 2  
Read 3  
Read 4  
Read 5  
Read 1  
(Standard Mode)  
t
t
MDV  
OR  
tA  
tA  
t
A
t
A
t
EN  
B0-B8  
Read 1  
Read 2  
Read 3  
Read 4  
(FWFT Mode)  
4676 drw16  
NOTE:  
1. Unused bytes B9-B17 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  
SIZEB  
BE  
A35-A27  
A26-A18  
A17-A9  
A8-A0  
1
2
3
4
A
B
C
D
H
H
H
A
B
C
D
1
2
3
4
D
C
B
A
L
A
B
C
D
NOTE:  
1. BE is selected at Master Reset; SIZEB must be static throughout device operation.  
Figure 14. Port B Byte Read Cycle Timing for FIFO1 (IDT Standard and FWFT Modes)  
tCLK  
tCLKH  
tCLKL  
CLKA  
EFA/ORA  
HIGH  
CSA  
W/RA  
MBA  
tENS2  
tENS2  
tENH  
tENH  
tENH  
tENS2  
ENA  
No Operation  
W2(1)  
t
MDV  
tDIS  
t
A
tA  
t
EN  
A0-A35  
W1(1)  
W2(1)  
Previous Data  
(
Standard Mode)  
tDIS  
t
MDV  
OR  
tA  
t
A
t
EN  
A0-A35  
(FWFT Mode)  
W3(1)  
W1(1)  
4676 drw17  
NOTE:  
1. Read From FIFO2.  
Figure 15. Port A Read Cycle Timing for FIFO2 (IDT Standard and FWFT Modes)  
24  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
t
CLK  
t
CLKL  
t
CLKH  
CLKA  
LOW  
CSA  
WRA HIGH  
tENS2  
tENH  
MBA  
tENS2  
tENH  
ENA  
IRA  
HIGH  
tDS  
tDH  
W1  
A0-A35  
CLKHt  
CLKtCLKL  
(1)  
SKEW1  
t
t
CLKB  
3
1
2
t
REF  
t
REF  
FIFO1 Empty  
LOW  
ORB  
CSB  
MBB LOW  
tENS2  
tENH  
RENB  
tA  
tA  
Read 1  
Read 2  
B0-B17  
4676 drw18  
NOTES:  
1. tSKEW1 is 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 tSKEW1, 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 (the word-size case is shown).  
Figure 16. ORB Flag Timing and First Data Word Fall Through when FIFO1 is Empty (FWFT Mode)  
25  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
tCLK  
tCLKH tCLKL  
CLKA  
LOW  
HIGH  
CSA  
WRA  
tENH  
tENH  
tENS2  
tENS2  
MBA  
ENA  
FFA  
HIGH  
tDS  
tDH  
A0-A35  
W1  
tCLKHtCLK  
(1)  
tSKEW1  
tCLKL  
CLKB  
1
2
tREF  
tREF  
EFB  
CSB  
FIFO1 Empty  
LOW  
MBB LOW  
tENS2  
tENH  
RENB  
B0-B17  
NOTES:  
tA  
tA  
Read 1  
Read 2  
4676 drw 19  
1. tSKEW1 is 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 tSKEW1, 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 (the word-size case is shown).  
Figure 17. EFB Flag Timing and First Data Read Fall Through when FIFO1 is Empty (IDT Standard Mode)  
26  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
t
CLK  
CLKH  
tCLKL  
t
CLKC  
tENS2  
tENH  
MBC  
tENS2  
tENH  
WENC  
IRC  
HIGH  
tDH  
tDS  
tDH  
tDS  
Write 1  
Write 2  
C0-C17  
t
CLK  
(1)  
SKEW1  
t
CLKH  
tCLKL  
t
CLKA  
1
2
3
t
REF  
t
REF  
ORA FIFO2 Empty  
CSA LOW  
LOW  
LOW  
W/RA  
MBA  
tENS2  
tENH  
ENA  
tA  
Old Data in FIFO2 Output Register  
A0-A35  
W1  
4676 drw 20  
NOTES:  
1. tSKEW1 is the minimum time between a rising CLKC 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 CLKC edge and the rising CLKA edge is less than tSKEW1, 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 C size is word or byte, tSKEW1 is referenced to the rising CLKC edge that writes the last word or byte write of the long word, respectively.  
Figure 18. ORA Flag Timing and First Data Word Fall through when FIFO2 is Empty (FWFT Mode)  
27  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
t
CLK  
CLKH  
tCLKL  
t
CLKC  
tENS2  
tENH  
MBC  
tENS2  
tENH  
WENC  
FFC  
HIGH  
tDS  
tDH  
t
DS  
tDH  
Write 1  
Write 2  
C0-C17  
t
CLK  
(1)  
SKEW1  
t
CLKH  
t
tCLKL  
1
2
CLKA  
t
REF  
t
REF  
EFA  
CSA  
FIFO2 Empty  
LOW  
LOW  
LOW  
W/RA  
MBA  
tENS2  
tENH  
ENA  
A0-A35  
NOTES:  
tA  
W1  
4676 drw 21  
1. tSKEW1 is the minimum time between a rising CLKC edge and a rising CLKA edge for EFA to transition HIGH in the next CLKA cycle. If the time between the rising CLKC edge and rising  
CLKA edge is less than tSKEW1, then the transition of EFA HIGH may occur one CLKA cycle later than shown.  
2. If Port C size is word or byte, tSKEW1 is referenced to the rising CLKC edge that writes the last word or byte of the long word, respectively.  
Figure 19. EFA Flag Timing and First Data Read when FIFO2 is Empty (IDT Standard Mode)  
28  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
tCLK  
tCLKH  
tCLKL  
CLKB  
CSB LOW  
LOW  
MBB  
tENS2  
tENH  
RENB  
ORB  
HIGH  
tA  
tA  
Read 1  
Read 2  
B0-B17  
Previous Word in  
FIFO1 Output Register  
(1)  
tSKEW1  
t
CLK tCLKL  
tCLKH  
CLKA  
IRA  
1
2
t
WFF  
t
WFF  
FIFO1 Full  
CSA LOW  
W/RA HIGH  
tENH  
tENS2  
MBA  
tENS2  
tENH  
ENA  
tDS  
tDH  
Write  
A0-A35  
To FIFO1  
4676 drw 22  
NOTES:  
1. tSKEW1 is 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 (the word-size case is shown).  
Figure 20. IRA Flag Timing and First Available Write when FIFO1 is Full (FWFT Mode)  
29  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
tCLK  
tCLKH  
tCLKL  
CLKB  
CSB  
LOW  
LOW  
MBB  
tENS2  
tENH  
RENB  
EFB  
HIGH  
tA  
tA  
Read 1  
Read 2  
B0-B17  
Previous Word in  
FIFO1 Output Register  
(1)  
tSKEW1  
t
t
CLKH CLK tCLKL  
CLKA  
1
2
t
WFF  
t
WFF  
FFA  
FIFO1 Full  
CSA LOW  
W/RA  
HIGH  
tENS2  
tENH  
MBA  
tENS2  
tENH  
ENA  
tDS  
tDH  
Write  
A0-A35  
4676 drw 23  
To FIFO1  
NOTES:  
1. tSKEW1 is 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, tSKEW1 is referenced from the rising CLKB edge that reads the last word or byte of the long word, respectively (the word-size case is shown).  
Figure 21. FFA Flag Timing and First Available Write when FIFO1 is Full (IDT Standard Mode)  
30  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
tCLK  
tCLKH  
tCLKL  
CLKA  
CSA  
LOW  
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  
CLKC  
1
2
t
WFF  
t
WFF  
IRC FIFO2 Full  
tENS2  
tENH  
MBC  
WENC  
C0-C17  
t
ENS2  
t
ENH  
tDS  
tDS  
tDH  
tDH  
Write  
4676 drw 24  
To FIFO2  
NOTES:  
1. tSKEW1 is the minimum time between a rising CLKC edge and a rising CLKC edge for IRC to transition HIGH in the next CLKC cycle. If the time between the rising CLKA edge and rising  
CLKC edge is less than tSKEW1, then IRC may transition HIGH one CLKC cycle later than shown.  
2. If Port C size is word or byte, IRC is set LOW by the last word or byte write of the long word, respectively (the word-size case is shown).  
Figure 22. IRC Flag Timing and First Available Write when FIFO2 is Full (FWFT Mode)  
31  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
tCLK  
tCLKH  
tCLKL  
CLKA  
CSA  
LOW  
LOW  
W/RA  
LOW  
MBA  
ENA  
tENS2  
tENH  
EFA  
HIGH  
tA  
Previous Word in FIFO2 Output Register  
Next Word From FIFO2  
A0-A35  
(1)  
tCLK  
tSKEW1  
tCLKH  
tCLKL  
CLKC  
1
2
t
WFF  
tWFF  
FIFO2 Full  
FFC  
tENS2  
tENH  
MBC  
ENC  
tENS2  
tENH  
tDH  
tDS  
tDS  
tDH  
Write  
C0-C17  
To FIFO2  
4676 drw 25  
NOTES:  
1. tSKEW1 is the minimum time between a rising CLKA edge and a rising CLKC edge for FFC to transition HIGH in the next CLKC cycle. If the time between the rising CLKA edge and rising  
CLKC edge is less than tSKEW1, then FFC may transition HIGH one CLKC cycle later than shown.  
2. If Port C size is word or byte, FFC is set LOW by the last word or byte write of the long word, respectively (the word-size case is shown).  
Figure 23. FFC Flag Timing and First Available Write when FIFO2 is Full (IDT Standard Mode)  
CLKA  
tENH  
tENS2  
ENA  
(1)  
tSKEW2  
CLKB  
1
2
t
PAE  
t
PAE  
AEB  
X1 Word in FIFO1  
(X1+1) Words in FIFO1  
ENS2  
t
tENH  
RENB  
4676 drw 26  
NOTES:  
1. tSKEW2 is 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 tSKEW2, 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, 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 24. Timing for AEB when FIFO1 is Almost-Empty (IDT Standard and FWFT Modes)  
32  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
CLKC  
tENH  
tENS2  
WENC  
CLKA  
(1)  
tSKEW2  
1
2
t
PAE  
t
PAE  
AEA  
X2 Words in FIFO2  
(X2+1) Words in FIFO2  
ENS2  
t
tENH  
ENA  
4676 drw 27  
NOTES:  
1. tSKEW2 is the minimum time between a rising CLKC edge and a rising CLKA edge for AEA to transition HIGH in the next CLKA cycle. If the time between the rising CLKC edge and rising  
CLKA edge is less than tSKEW2, then AEA may transition HIGH one CLKA cycle later than shown.  
2. FIFO2 Write (MBC = 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 C size is word or byte, tSKEW2 is referenced to the rising CLKC edge that writes the last word or byte of the long word, respectively.  
Figure 25. Timing for AEA when FIFO2 is Almost-Empty (IDT Standard and FWFT Modes)  
(1)  
tSKEW2  
1
2
CLKA  
ENA  
tENS2  
tENH  
t
PAF  
tPAF  
(D-Y1) Words in FIFO1  
ENH  
[D-(Y1+1)] Words in FIFO1  
AFA  
CLKB  
t
tENS2  
RENB  
4676 drw 28  
NOTES:  
1. tSKEW2 is 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 tSKEW2, 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, MBB = LOW). Data in the FIFO1 output register has been read from the FIFO.  
3. D = Maximum FIFO Depth = 16,384 for the IDT72V3686, 32,768 for the IDT72V3696, 65,536 for the IDT72V36106.  
4. If Port B size is word or byte, tSKEW2 is referenced from the rising CLKB edge that reads the last word or byte of the long word, respectively.  
Figure 26. Timing for AFA when FIFO1 is Almost-Full (IDT Standard and FWFT Modes)  
(1)  
tSKEW2  
1
2
CLKC  
tENH  
tENS2  
WENC  
AFC  
t
PAF  
t
PAF  
(D-Y2) Words in FIFO2  
[D-(Y2+1)] Words in FIFO2  
CLKA  
tENS2  
tENH  
ENA  
4676 drw 29  
NOTES:  
1. tSKEW2 is the minimum time between a rising CLKC edge and a rising CLKA edge for AFC to transition HIGH in the next CLKC cycle. If the time between the rising CLKC edge and rising  
CLKA edge is less than tSKEW2, then AFC may transition HIGH one CLKC cycle later than shown.  
2. FIFO2 write (MBC = 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 = 16,384 for the IDT72V3686, 32,768 for the IDT72V3696, 65,536 for the IDT72V36106.  
4. Port C size is word or byte, AFC is set LOW by the last word or byte write of the long word, respectively.  
Figure 27. Timing for AFC when FIFO2 is Almost-Full (IDT Standard and FWFT Modes)  
33  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
CLKA  
tENS1  
tENH  
CSA  
W/RA  
MBA  
ENA  
t
ENS1  
t
ENH  
t
ENS2  
ENS2  
t
ENH  
ENH  
t
t
tDH  
tDS  
W1  
A0-A35  
CLKB  
MBF1  
t
PMF  
t
PMF  
CSB  
MBB  
tENH  
tENS2  
RENB  
t
PMR  
tDIS  
tEN  
t
MDV  
W1 (Remains valid in Mail1 Register after read)  
FIFO1 Output Register  
B0-B17  
4676 drw 30  
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. 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-B17 will  
be indeterminate).  
Figure 28. Timing for Mail1 Register and MBF1 Flag (IDT Standard and FWFT Modes)  
CLKC  
tENH  
tENS2  
MBC  
ENC  
tENS2  
tENH  
tDH  
tDS  
C0-C17  
CLKA  
W1  
t
PMF  
t
PMF  
MBF2  
CSA  
W/RA  
MBA  
ENA  
tENS2  
tENH  
t
PMR  
tEN  
t
DIS  
t
MDV  
A0-A35  
W1 (Remains valid in Mail2 Register after read)  
FIFO2 Output Register  
4676 drw 31  
NOTE:  
1. IfPortCis configuredforwordsize, data canbe writtentothe Mail2registerusingC0-C17. Inthis firstcase, A18-A35willhave validdata (A0-A17willbe indeterminate). IfPortCis configured  
for byte size, data can be written to the Mail2 register using C0-C8 (C9-C17 are don't care inputs). In this second case, A18-A26 will have valid data (A0-A17 and A27-A35 will be  
indeterminate).  
Figure 29. Timing for Mail2 Register and MBF2 Flag (IDT Standard and FWFT Modes)  
34  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
CLKA  
CLKB  
4
1
2
3
2
3
4
1
tENS2  
tENH  
RENB  
RT1  
t
RSTH  
t
RSTS  
t
RTMS  
t
RTMH  
RTM  
EFB  
(2)  
REF  
(2)  
REF  
t
t
tA  
B0-Bn  
Wx  
W1  
4676 drw 32  
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 Retransmit  
setup procedure. D = 16,384, 32,768 and 65,536 for the IDT72V3686, IDT72V3696 and IDT72V36106 respectively.  
Figure 30. Retransmit Timing for FIFO1 (IDT Standard Mode)  
CLKC  
CLKA  
4
1
2
3
2
3
4
1
tENS2  
tENH  
ENA  
RT2  
t
RSTH  
t
RSTS  
t
RTMS  
t
RTMH  
RTM  
EFA  
(2)  
REF  
(2)  
REF  
t
t
tA  
A0-An  
Wx  
W1  
4676 drw 33  
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, FFC will be LOW throughout the Retransmit  
setup procedure. D = 16,384, 32,768 and 65,536 for the IDT72V3686, IDT72V3696 and IDT72V36106 respectively.  
Figure 31. Retransmit Timing for FIFO2 (IDT Standard Mode)  
35  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
CLKA  
CLKB  
4
1
2
3
2
3
4
1
RENB LOW  
tRSTH  
t
RSTS  
RT1  
RTM  
ORB  
t
RTMS  
t
RTMH  
(2)  
REF  
(2)  
REF  
t
t
tA  
B0-Bn  
Wx  
W1  
4676 drw 34  
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 = 16,385, 32,769 and 65,537 for the IDT72V3686, IDT72V3696 and IDT72V36106 respectively.  
Figure 32. Retransmit Timing for FIFO1 (FWFT Mode)  
CLKC  
CLKA  
4
1
2
3
2
3
4
1
ENA LOW  
tRSTH  
t
RSTS  
RT2  
RTM  
ORA  
t
RTMS  
t
RTMH  
(2)  
REF  
(2)  
REF  
t
t
tA  
A0-An  
Wx  
W1  
4676 drw 35  
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, IRC will be LOW throughout the Retransmit  
setup procedure. D = 16,385, 32,769 and 65,537 for the IDT72V3686, IDT72V3696 and IDT72V36106 respectively.  
Figure 33. Retransmit Timing for FIFO2 (FWFT Mode)  
36  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
tCLK  
tCLKH  
tCLKL  
CLKA  
LOOP  
CSA  
W/RA  
MBA  
ENA  
tENS2  
tENS2  
tENH  
tENH  
tENH  
tENS2  
No Operation  
Wn+1  
tDIS  
tMDV  
tA  
tA  
tEN  
Wn(1)  
Write to FIFO 1  
Wn-1(1)  
Write to FIFO 1  
A0-A35  
4676 drw 36  
NOTES:  
1. Data is read from FIFO2 and written into FIFO1 & placed on Port A simultaneously. The first data word written into FIFO1 is the Previous Data Word (Wn-1)  
2. All FIFO status flags operate as normal, based on the contents of respective FIFO's.  
3. Loopback is available in both Standard IDT and FWFT modes. The diagram above is for both.  
Figure 34. Loopback Operation (FIFO2 data transfer to FIFO1 and Port A)  
tCLK  
tCLKH  
tCLKL  
CLKA  
LOOP  
CSA  
W/RA  
MBA  
ENA  
t
ENS2  
t
ENS2  
t
ENH  
tENH  
t
ENH  
t
ENS2  
No Operation  
Wn+1  
tDIS  
t
MDV  
t
A
t
A
tEN  
(4) WRITE  
to FIFO 1  
Wn(1)  
Write to FIFO 1  
Wn-1(1)  
Write to FIFO 1  
A0-A35  
HIGH-Z  
4676 drw 37  
NOTES:  
1. Data is read from FIFO2 and written into FIFO1 only. The data from FIFO2 is NOT placed on Port A. Port A is held in the high impedance state.  
2. All FIFO status flags operate as normal, based on the contents of respective FIFO's.  
3. Loopback is available in both Standard IDT and FWFT modes. The diagram above is for both.  
4. Write operations to FIFO1 cannot be accessed via Port A.  
Figure 35. Loopback Operation (FIFO2 data transfer to FIFO1)  
37  
IDT72V3686/72V3696/72V36106 3.3V CMOS TRIPLE BUS SyncFIFOTM  
WITH BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65, 536 x 36  
COMMERCIALTEMPERATURERANGE  
PARAMETER MEASUREMENT INFORMATION  
3.3V  
330Ω  
From Output  
Under Test  
30 pF (1)  
510Ω  
PROPAGATION DELAY  
LOAD CIRCUIT  
3V  
3V  
Timing  
Input  
1.5V  
High-Level  
1.5V  
Input  
GND  
1.5V  
GND  
3V  
t
S
th  
tW  
3V  
Data,  
Enable  
Input  
1.5V  
1.5V  
Low-Level  
1.5V  
1.5V  
GND  
Input  
GND  
VOLTAGE WAVEFORMS  
SETUP AND HOLD TIMES  
VOLTAGE WAVEFORMS  
PULSE DURATIONS  
3V  
Output  
Enable  
1.5V  
1.5V  
tPZL  
GND  
tPLZ  
3V  
3V  
Input  
1.5V  
1.5V  
1.5V  
Low-Level  
Output  
GND  
V
OL  
tPD  
t
PZH  
tPD  
V
OH  
V
OH  
In-Phase  
Output  
1.5V  
1.5V  
High-Level  
Output  
1.5V  
V
t
PHZ  
OL  
OV  
VOLTAGE WAVEFORMS  
ENABLE AND DISABLE TIMES  
VOLTAGE WAVEFORMS  
PROPAGATION DELAY TIMES  
4676 drw 38  
NOTE:  
1. Includes probe and jig capacitance.  
Figure 36. Load Circuit and Voltage Waveforms  
38  
ORDERING INFORMATION  
IDT  
XXXXXX  
X
XX  
XX  
X
Device Type Power  
Speed  
Package  
Process/  
Temperature  
Range  
BLANK  
PF  
Commercial (0°C to +70°C)  
Thin Quad Flat Pack (TQFP, PK128-1)  
10  
15  
Clock Cycle Time (tCLK  
)
Commercial Only  
Low Power  
Speed in Nanoseconds  
L
72V3686  
72V3696  
72V36106  
16,384 x 36 x 2 3.3V Triple Bus SyncFIFO with Bus-Matching  
32,768 x 36 x 2 3.3V Triple Bus SyncFIFO with Bus-Matching  
65,536 x 36 x 2 3.3V Triple Bus SyncFIFO with Bus-Matching  
4676 drw 39  
NOTE:  
1. Industrial temperature range is available by special order.  
DATASHEETDOCUMENTHISTORY  
11/08/2000  
12/14/2000  
03/27/2001  
11/04/2003  
pgs. 1, 7, 9, 10, 13, 22 and 39  
pgs. 5 and 6.  
pgs. 7 and 8.  
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  
39  

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