Integrated Device Technology, Inc.

COMMERCIAL TEMPERATURE RANGES

DECEMBER 1996

©1996 Integrated Device Technology, Inc.

DSC-2751/6

5.34

1

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.

FEATURES:

•

35ns parallel port access time, 45ns cycle time

•

50MHz serial port shift rate

•

Expandable in depth and width with no external

components

•

Programmable word lengths including 7-9, 16-18, 32-36

bit using Flexishift

™ serial output without using any

additional components

•

Multiple status flags: Full, Almost-Full (1/8 from full),

Half-Full, Almost Empty (1/8 from empty), and Empty

•

Asynchronous and simultaneous read and write

operations

•

Dual-Port zero fall-through architecture

•

Retransmit capability in single device mode

•

Produced with high-performance, low power CMOS

technology

•

Available in 28-pin plastic DIP

•

able, tested to military electrical specifications

FUNCTIONAL BLOCK DIAGRAM

CMOS PARALLEL-TO-SERIAL FIFO

IDT72131

IDT72141

5

6

7

8

9

10

11

12

FF

W

1

2

3

4

26

25

24

23

22

21

20

19

Vcc

18

17

16

15

P28-1

&

C28-3

D

XI

SOX

FL/RT

RS

EF

XO/HF

SOCP

SO

AEF

GND

13

14

28

27

GND

NR

2751 drw 02a

0

PIN CONFIGURATION

DIP

TOP VIEW

2751 drw 01

RAM ARRAY

2048 x 9

4096 x 9

WRITE

POINTER

NEXT READ

POINTER

FLAG

LOGIC

EF

AEF

/HF

FF

NR

8

W

RESET LOGIC

RS

EXPANSION

LOGIC

XI

FL/RT

XO/

SERIAL OUTPUT

CIRCUITRY

SOCP

SOX

SO

The IDT logo is a registered trademark of Integrated Device Technology, Inc.

For latest information contact IDT's web site at www.idt.com or fax-on-demand at 408-492-8391.