IDT72801
IDT72811
IDT72821
IDT72831
IDT72841
IDT72851
DUAL CMOS SyncFIFO™
DUAL 256 x 9, DUAL 512 x 9,
DUAL 1,024 x 9, DUAL 2,048 x 9,
DUAL 4,096 x 9, DUAL 8,192 x 9
Eachofthe twoFIFOs (designatedFIFOAandFIFOB)containedinthe
IDT72801/72811/72821/72831/72841/72851hasa9-bitinputdataport(DA0
-DA8,DB0-DB8)anda9-bitoutputdataport(QA0-QA8,QB0-QB8).Each
inputportiscontrolledbyafree-runningclock(WCLKA,WCLKB),andtwoWrite
Enablepins(WENA1,WENA2,WENB1,WENB2). Dataiswrittenintoeachof
thetwoarraysoneveryrisingclockedgeoftheWriteClock(WCLKA,WCLKB)
whenthe appropriate write enable pins are asserted.
FEATURES:
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The IDT72801 is equivalent to two IDT72201 256 x 9 FIFOs
The IDT72811 is equivalent to two IDT72211 512 x 9 FIFOs
The IDT72821 is equivalent to two IDT72221 1,024 x 9 FIFOs
The IDT72831 is equivalent to two IDT72231 2,048 x 9 FIFOs
The IDT72841 is equivalent to two IDT72241 4,096 x 9 FIFOs
The IDT72851 is equivalent to two IDT72251 8,192 x 9 FIFOs
TheoutputportofeachFIFObankiscontrolledbyitsassociated clockpin
(RCLKA, RCLKB) and two Read Enable pins (RENA1, RENA2, RENB1,
RENB2).TheReadClockcanbetiedtotheWriteClockforsingleclockoperation
orthetwoclockscanrunasynchronousofoneanotherfordualclockoperation.
An Output Enable pin (OEA, OEB) is provided on the read port of each FIFO
forthree-stateoutputcontrol.
• Offers optimal combination of large capacity, high speed,
design flexibility and small footprint
• Ideal for prioritization, bidirectional, and width expansion
applications
• 10 ns read/write cycle time for the IDT72801/72811/72821/72831/
72841 (excluding the IDT72851)
EachofthetwoFIFOshastwofixedflags,Empty(EFA,EFB)andFull(FFA,
FFB). Twoprogrammableflags,Almost-Empty(PAEA,PAEB)andAlmost-Full
(PAFA,PAFB),areprovidedforeachFIFObanktoimprovememoryutilization.
Ifnotprogrammed,theprogrammableflagsdefaulttoempty+7forPAEAand
PAEB, and full-7 for PAFA and PAFB.
TheIDT72801/72811/72821/72831/72841/72851architecturelendsitself
tomanyflexibleconfigurationssuchas:
• 2-levelprioritydatabuffering
• 15 ns read/write cycle time for the IDT72851
• Separate control lines and data lines for each FIFO
• Separate Empty, Full, Programmable Almost-Empty and Almost-
Full flags for each FIFO
• Enable puts output data lines in high-impedance state
• Space-saving 64-pin Thin Quad Flat Pack (TQFP) and Slim Thin
Quad Flatpack (STQFP)
•
Industrial temperature range (–40°C to +85°C) is available
• Bidirectional operation
• Width expansion
DESCRIPTION:
• Depthexpansion
These FIFOs is fabricated using IDT's high-performance submicron
CMOS technology.
TheIDT72801/72811/72821/72831/72841/72851aredualsynchronous
(clocked)FIFOs. ThedeviceisfunctionallyequivalenttotwoIDT72201/72211/
72221/72231/72241/72251 FIFOs in a single package with all associated
control,data,andflaglinesassignedtoseparatepins.
FUNCTIONAL BLOCK DIAGRAM
EFA
WCLKB
PAEA
PAFA
FFA
WCLKA
WENA1
WENA2
WENB1
DA0 - DA8
DB0 - DB8
LDA
LDB
WENB2
INPUT REGISTER
OFFSET REGISTER
OFFSET REGISTER
INPUT REGISTER
EFB
FLAG
LOGIC
WRITE CONTROL
LOGIC
FLAG
LOGIC
WRITE CONTROL
LOGIC
PAEB
PAFB
FFB
RAM ARRAY
256 x 9, 512 x 9,
1024 x 9, 2048 x 9,
4096 x 9, 8192 x 9
RAM ARRAY
256 x 9, 512 x 9,
1024 x 9, 2048 x 9,
4096 x 9, 8192 x 9
WRITE POINTER
READ POINTER
READ POINTER
WRITE POINTER
READ CONTROL
LOGIC
READ CONTROL
LOGIC
OUTPUT REGISTER
OUTPUT REGISTER
RESET LOGIC
RESET LOGIC
RCLKB
RSA
RSB
OEA
OEB
RCLKA
RENA1
RENA2
RENB1
QB0 - QB8
QA0 - QA8
RENB2
3034 drw 01
IDT, IDT logo and the SyncFIFOlogo are trademarks of Integrated Device Technology, Inc.
COMMERCIAL AND INDUSTRIAL TEMPERATURE RANGE
APRIL 2001
1
2001 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice.
DSC-3034/2