CMOS ASYNCHRONOUS FIFO WITH
RETRANSMIT
1K x 9, 2K x 9, 4K x 9
Integrated Device Technology, Inc.
IDT72021
IDT72031
IDT72041
FEATURES:
• First-In/First-Out Dual-Port memory
• Bit organization
– IDT72021—1K x 9
– IDT72031—2K x 9
– IDT72041—4K x 9
• Ultra high speed
– IDT72021—25ns access time
– IDT72031—35ns access time
– IDT72041—35ns access time
• Easily expandable in word depth and/or width
• Asynchronous and simultaneous read and write
• Functionally equivalent to IDT7202/03/04 with Output
Enable (
OE
) and Almost Empty/Almost Full Flag (
AEF
)
• Four status flags: Full, Empty, Half-Full (single device
mode), and Almost Empty/Almost Full (7/8 empty or 7/8
full in single device mode)
• Output Enable controls the data output port
• Auto-retransmit capability
• Available in 32-pin DIP and PLCC
• Military product compliant to MIL-STD-883, Class B
• Industrial temperature range (-40
o
C to +85
o
C) is avail
able, tested to military electrical specifications
DESCRIPTION:
IDT72021/031/041s are high-speed, low-power, dual-port
memory devices commonly known as FIFOs (First-In/First-
Out). Data can be written into and read from the memory at
independent rates. The order of information stored and ex-
tracted does not change, but the rate of data entering the FIFO
might be different than the rate leaving the FIFO. Unlike a
Static RAM, no address information is required because the
read and write pointers advance sequentially. The IDT72021/
031/041s can perform asynchronous and simultaneous read
and write operations. There are four status flags, (
HF
,
FF
,
EF
,
AEF
) to monitor data overflow and underflow. Output Enable
(
OE
) is provided to control the flow of data through the output
port. Additional key features are Write (
W
), Read (
R
), Retrans-
mit (
RT
), First Load (
FL
), Expansion In (
XI
) and Expansion Out
(
XO
). The IDT72021/031/041s are designed for those appli-
cations requiring data control flags and Output Enable (
OE
) in
multiprocessing and rate buffer applications.
The IDT72021/031/041s are fabricated using IDT’s CMOS
technology. Military grade product is manufactured in compli-
ance with the latest version of MIL-STD-883, Class B, for high
reliability systems.
FUNCTIONAL BLOCK DIAGRAM
DATA INPUT
(D
0
–D
8
)
W
WRITE
CONTROL
1
2
WRITE
POINTER
1024/
2048/
4096
THREE-
STATE
BUFFERS
RAM
ARRAY
1024 x 9
2048 x 9
4096 x 9
READ
POINTER
OE
RESET
LOGIC
RS
FL/RT
R
READ
CONTROL
FLAG
LOGIC
EXPANSION
LOGIC
DATA OUTPUTS
(Q
0
–Q
8
)
EF
FF
AEF
XI
XO/HF
2677 drw 01
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
FAST is a trademark of National Semiconductor Co.
MILITARY AND COMMERCIAL TEMPERATURE RANGES
©1996
Integrated Device Technology, Inc.
For latest information contact IDT's web site at www.idt.com or fax-on-demand at 408-492-8391.
DECEMBER 1996
DSC-2677/7
5.09
1
IDT [ INTEGRATED DEVICE TECHNOLOGY ]
