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
IDT72801
IDT72811
IDT72821
IDT72831
IDT72841
IDT72851
.EATURES:
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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
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)
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
°
°
DESCRIPTION:
The IDT72801/72811/72821/72831/72841/72851 are dual synchronous
(clocked) FIFOs. The device is functionally equivalent to two IDT72201/72211/
72221/72231/72241/72251 FIFOs in a single package with all associated
control, data, and flag lines assigned to separate pins.
Each of the two FIFOs (designated FIFO A and FIFO B) contained in the
IDT72801/72811/72821/72831/72841/72851 has a 9-bit input data port (DA0
- DA8, DB0 - DB8) and a 9-bit output data port (QA0 - QA8, QB0 - QB8). Each
input port is controlled by a free-running clock (WCLKA, WCLKB), and two Write
Enable pins (WENA1, WENA2,
WENB1,
WENB2). Data is written into each of
the two arrays on every rising clock edge of the Write Clock (WCLKA, WCLKB)
when the appropriate write enable pins are asserted.
The output port of each FIFO bank is controlled by its associated clock pin
(RCLKA, RCLKB) and two Read Enable pins (RENA1,
RENA2, RENB1,
RENB2).
The Read Clock can be tied to the Write Clock for single clock operation
or the two clocks can run asynchronous of one another for dual clock operation.
An Output Enable pin (OEA,
OEB)
is provided on the read port of each FIFO
for three-state output control.
Each of the two FIFOs has two fixed flags, Empty (EFA,
EFB)
and Full (FFA,
FFB).
Two programmable flags, Almost-Empty (PAEA,
PAEB)
and Almost-Full
(PAFA,
PAFB),
are provided for each FIFO bank to improve memory utilization.
If not programmed, the programmable flags default to empty+7 for
PAEA
and
PAEB,
and full-7 for
PAFA
and
PAFB.
The IDT72801/72811/72821/72831/72841/72851 architecture lends itself
to many flexible configurations such as:
• 2-level priority data buffering
• Bidirectional operation
• Width expansion
• Depth expansion
These FIFOs is fabricated using IDT's high-performance submicron
CMOS technology.
.UNCTIONAL BLOCK DIAGRAM
WCLKA
WENA1
WENA2
DA0 - DA8
EFA
PAEA
PAFA
LDA
FFA
WCLKB
WENB1
WENB2
DB0 - DB8
LDB
INPUT REGISTER
OFFSET REGISTER
FLAG
LOGIC
INPUT REGISTER
OFFSET REGISTER
EFB
PAEB
PAFB
FFB
WRITE CONTROL
LOGIC
RAM ARRAY
256 x 9, 512 x 9,
1024 x 9, 2048 x 9,
4096 x 9, 8192 x 9
WRITE CONTROL
LOGIC
RAM ARRAY
256 x 9, 512 x 9,
1024 x 9, 2048 x 9,
4096 x 9, 8192 x 9
FLAG
LOGIC
WRITE POINTER
READ POINTER
WRITE POINTER
READ POINTER
READ CONTROL
LOGIC
READ CONTROL
LOGIC
OUTPUT REGISTER
RESET LOGIC
RESET LOGIC
OUTPUT REGISTER
RSA
OEA
QA0 - QA8
RCLKA
RENA1
RENA2
RSB
OEB
QB0 - QB8
RCLKB
RENB1
RENB2
3034 drw 01
SyncFIFO is a trademark and the IDT logo is a registered trademark of Integrated Device Technology, Inc.
COMMERCIAL AND INDUSTRIAL TEMPERATURE RANGE
2001
Integrated Device Technology, Inc.
APRIL 2001
DSC-3034/1
IDT [ INTEGRATED DEVICE TECHNOLOGY ]
