54ACT399

Quad 2-Port Register

General Description

The ’AC/ACT399 is the logical equivalent of a quad 2-input

multiplexer feeding into four edge-triggered flip-flops. A com-

mon Select input determines which of the two 4-bit words is

accepted. The selected data enters the flip-flop on the rising

edge of the clock.

Features

n Select inputs from two data sources

n Fully positive edge-triggered operation

n Outputs source/sink 24 mA

n ACT399 has TTL-compatible inputs

Logic Symbols

Connection Diagrams

Pin Names

Description

S

Common Select Input

CP

Clock Pulse Input

I

Data Inputs from Source 0

I

Data Inputs from Source 1

Q

Register True Outputs

DS100356-1

IEEE/IEC

DS100356-5

Pin Assignment

for DIP and Flatpak

DS100356-3

Pin Assignment

for LCC

DS100356-2

August 1998

© 1998 National Semiconductor Corporation

DS100356

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