CMOS PARALLEL-TO-SERIAL FIFO
2048
X
9
4096
X
9
Integrated Device Technology, Inc.
IDT72131
IDT72141
FEATURES:
鈥?35ns parallel port access time, 45ns cycle time
鈥?50MHz serial port shift rate
鈥?Expandable in depth and width with no external
components
鈥?Programmable word lengths including 7-9, 16-18, 32-36
bit using Flexishift鈩?serial output without using any
additional components
鈥?Multiple status flags: Full, Almost-Full (1/8 from full),
Half-Full, Almost Empty (1/8 from empty), and Empty
鈥?Asynchronous and simultaneous read and write
operations
鈥?Dual-Port zero fall-through architecture
鈥?Retransmit capability in single device mode
鈥?Produced with high-performance, low power CMOS
technology
鈥?Available in 28-pin plastic DIP
鈥?Industrial temperature range (-40
o
C to +85
o
C) is avail-
able, tested to military electrical specifications
DESCRIPTION:
The IDT72131/72141 are high-speed, low power parallel-
to-serial FIFOs. These FIFOs are ideally suited to serial
communications applications, tape/disk controllers, and local
area networks (LANs). The IDT72131/72141 can be config-
ured with the IDTs serial-to-parallel FIFOs (IDT72132/72142)
for bidirectional serial data buffering.
The FIFO has a 9-bit parallel input port and a serial output
port. Wider and deeper parallel-to-serial data buffers can be
built using multiple IDT72131/72141 chips. IDTs unique
Flexishift serial expansion logic (SOX,
NR
) makes width
expansion possible with no additional components. These
FIFOs will expand to a variety of word widths including 8, 9, 16,
and 32 bits. The IDT72131/141 can also be directly connected
for depth expansion.
Five flags are provided to monitor the FIFO. The full and
empty flags prevent any FIFO data overflow or underflow
conditions. The almost-full (7/8), half-full, and almost empty
(1/8) flags signal memory utilization within the FIFO.
The IDT72131/72141 is fabricated using IDTs high-speed
submicron CMOS technology.
FUNCTIONAL BLOCK DIAGRAM
D
0
-D
8
PIN CONFIGURATION
W
D
4
D
3
D
2
D
1
NEXT READ
POINTER
NR
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
Vcc
D
5
D
6
D
7
D
8
EF
FLAG
LOGIC
AEF
/HF
FF
WRITE
POINTER
RAM ARRAY
2048 x 9
4096 x 9
W
D
0
XI
SOX
SOCP
SO
P28-1
&
C28-3
23
22
21
20
19
18
17
16
15
FL/RT
RS
EF
XO/HF
GND
Q
8
Q
7
Q
6
RS
FL/RT
RESET LOGIC
SOCP
EXPANSION
LOGIC
SERIAL OUTPUT
CIRCUITRY
SOX
SO
AEF
FF
Q
4
GND
XI
XO/
NR
Q
4
Q
6
Q
7
Q
8
2751 drw 01
DIP
TOP VIEW
2751 drw 02a
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
COMMERCIAL TEMPERATURE RANGES
漏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-2751/6
5.34
1
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