Integrated Device Technology, Inc.

COMMERCIAL TEMPERATURE RANGE

OCTOBER 1996

©1996 Integrated Device Technology, Inc.

DSC-2721/4

IDT71342SA/LA

HIGH-SPEED

4K x 8 DUAL-PORT

STATIC RAM WITH SEMAPHORE

FEATURES:

• High-speed access

— Commercial: 20/25/35/45/55/70ns (max.)

• Low-power operation

— IDT71342SA

Active: 500mW (typ.)

Standby: 5mW (typ.)

— IDT71342LA

Active: 500mW (typ.)

Standby: 1mW (typ.)

• Fully asynchronous operation from either port

• Full on-chip hardware support of semaphore signalling

between ports

• Battery backup operation—2V data retention

• TTL-compatible; single 5V (

±10%) power supply

• Available in plastic packages

• Industrial temperature range (–40

°C to +85°C) is avail-

able, tested to military electrical specifications

DESCRIPTION:

The IDT71342 is an extremely high-speed 4K x 8 Dual-Port

Static RAM with full on-chip hardware support of semaphore

signalling between the two ports.

The IDT71342 provides two independent ports with separate

control, address, and I/O pins that permit independent,

asynchronous access for reads or writes to any location in

memory. To assist in arbitrating between ports, a fully

independent semaphore logic block is provided. This block

contains unassigned flags which can be accessed by either

side; however, only one side can control the flag at any time.

An automatic power down feature, controlled by

CE and SEM,

permits the on-chip circuitry of each port to enter a very low

standby power mode (both

CE and SEM High).

Fabricated using IDT’s CMOS high-performance

technology, this device typically operates on only 500mW of

power. Low-power (LA) versions offer battery backup data

retention capability, with each port typically consuming 200

µW

from a 2V battery. The device is packaged in either a 64-pin

TQFP, thin quad plastic flatpack, or a 52-pin PLCC.

1

FUNCTIONAL BLOCK DIAGRAM

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

6.05

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

2721 drw 01

COLUMN

I/O

COLUMN

I/O

MEMORY

ARRAY

LEFT SIDE

ADDRESS

DECODE

LOGIC

RIGHT SIDE

ADDRESS

DECODE

LOGIC

SEMAPHORE

LOGIC

R/

R/