TLF6437

August 1991

DM74LS952 (DM86LS52)

Dual Rank 8-Bit TRI-STATE

Shift Register

General Description

These circuits are TRI-STATE edge-triggered 8-bit IO reg-

isters in parallel with 8-bit serial shift registers which are

capable of operating in any of the following modes parallel

load from IO pins to register ‘‘A’’ parallel transfer down

from register ‘‘A’’ to serial shift register ‘‘B’’ parallel transfer

up from shift register ‘‘B’’ to register ‘‘A’’ serial shift of regis-

ter ‘‘B’’ synchronously clear Since the registers are edge-

triggered by the positive transition of the clock the control

lines which determine the mode or operation are completely

independent of the logic level applied to the clock De-

signed for bus-oriented systems these circuits have their

TRI-STATE inputs and outputs on the same pins

Features

Y

Registers are edge-triggered by the positive transition

of the clock

Y

All inputs are PNP transistors

Y

Input disable dominates over output disable

Y

Output high impedance state does not impede any oth-

er mode of operation

Y

8-bit IO pins are TRI-STATE buffers

Y

Typical shift frequency is 36 MHz

Y

Typical power dissipation is 305 mW

Y

All control inputs are active when in an ‘‘L’’ logic state

Y

Devices can be cascaded into N-bit word

Connection Diagram

Dual-In-Line Package

TLF6437 – 1

Top View

Order Number DM74LS952N or DM86LS52N

See NS Package Number N18A

Pin Description

CLKClock

GNDGround

IO 1

IO 88-bit IO pins

TRI-STATE

is a registered trademark of National Semiconductor Corporation

C1995 National Semiconductor Corporation

RRD-B30M105Printed in U S A