3.3 VOLT CMOS SyncFIFOTM
512 x 36
1,024 x 36
IDT72V3631
IDT72V3641
IDT72V3651
2,048 x 36
• Available in 132-pin plastic quad flat package (PQFP) or space-
saving 120-pin thin quad flat package (TQFP)
• Pin and functionally compatible versions of the 5V operating
IDT723631/723641/723651
FEATURES
• Storage capacity:
IDT72V3631 - 512 x 36
IDT72V3641 - 1,024 x 36
IDT72V3651 - 2,048 x 36
• Easily expandable in width and depth
•
Industrial temperature range (–40°C to +85°C) is available
• Supports clock frequencies up to 67 MHz
• Fast access times of 10ns
• Free-running CLKA and CLKB can be asynchronous or coinci-
dent (permits simultaneous reading and writing of data on a
single clock edge)
• Clocked FIFO buffering data from Port A to Port B
• Synchronous read retransmit capability
• Mailbox register in each direction
• Programmable Almost-Full and Almost-Empty flags
• Microprocessor interface control logic
• Input Ready (IR) and Almost-Full (AF) flags synchronized by
CLKA
DESCRIPTION
TheIDT72V3631/72V3641/72V3651arepinandfunctionallycompatible
versonsoftheIDT723631/723641/723651,designedtorunoffa3.3Vsupply
forexceptionallylow-powerconsumption. Thesedevicesaremonolithichigh-
speed,low-power,CMOSclockedFIFOmemory. Itsupportsclockfrequencies
upto67MHzandhasreadaccesstimesasfastas10ns. The512/1,024/2,048
x36dual-portSRAMFIFObuffersdatafromportAtoPortB. TheFIFOmemory
has retransmitcapability, whichallows previouslyreaddata tobe accessed
again. The FIFOoperates inFirstWordFallThroughmode andhas flags to
indicateemptyandfullconditionsandconditionsandtwoprogrammableflags
(Almost-FullandAlmost-Empty)toindicatewhenaselectednumberofwords
isstoredinmemory. Communicationbetweeneachportmaytakeplacewith
• Output Ready (OR) and Almost-Empty (AE) flags synchronized
by CLKB
FUNCTIONAL BLOCK DIAGRAM
MBF1
Mail 1
Register
CLKA
CSA
W/RA
ENA
MBA
Port-A
Control
Logic
RAM ARRAY
512 x 36
1,024 x 36
2,048 x 36
Reset
Logic
RST
RTM
36
Read
Pointer
Write
Pointer
RFM
A
0
- A35
B0 - B35
Status Flag
OR
AE
IR
AF
Logic
Flag Offset
Registers
FS
0
/SD
FS /SEN
1
10
CLKB
CSB
W/RB
ENB
MBB
Port-B
Control
Logic
Mail 2
Register
4658 drw 01
MBF2
IDTandtheIDTlogoaretrademarkofIntegratedDeviceTechnology, Inc. SyncFIFOisatrademarkofIntegratedDeviceTechnology, Inc.
COMMERCIAL TEMPERATURE RANGE
NOVEMBER 2003
1
1
2003 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice.
DSC-4658/2