HEF4557BP 查看數據表（PDF） - Philips Electronics

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HEF4557BP

1-to-64 bit variable length shift register

Philips Electronics 

Philips Semiconductors

1-to-64 bit variable length shift register

Product specification

HEF4557B

LSI

DESCRIPTION

The HEF4557B is a static clocked serial shift register

whose length may be programmed to be any number of

bits between 1 and 64. The number of bits selected is

equal to the sum of the subscripts of the enabled length

control inputs (L1, L2, L4, L8, L16 and L32) plus one. Serial

data may be selected from the DA or DB data inputs with

the A/B select input. This feature is useful for recirculation

purposes. Information on DA or DB is shifted into the first

register position and all the data in the register is shifted

one position to the right on the LOW to HIGH transition of

CP0 while CP1 is LOW or on the HIGH to LOW transition

of CP1 while CP0 is HIGH. A HIGH on master reset (MR)

resets the register and forces O to LOW and O to HIGH,

independent of the other inputs.

PINNING

DA, DB

A/B

CP0

CP1

MR

L1 to L32

O, O

Fig.1 Functional diagram.

data inputs

select data input

clock input

clock enable input

asynchronous master reset

bit-length control inputs

buffered outputs

HEF4557BP(N): 16-lead DIL; plastic

(SOT38-1)

HEF4557BD(F): 16-lead DIL; ceramic (cerdip)

(SOT74)

HEF4557BT(D): 16-lead SO; plastic

(SOT109-1)

( ): Package Designator North America

FAMILY DATA, IDD LIMITS category LSI

See Family Specifications

Fig.2 Pinning diagram.

January 1995

2

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