54ACT399 Datasheet, PDF (1/6 Pages) National Semiconductor (TI) – Quad 2-Port Register

August 1998
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 I_CC reduced by 50%
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 Assignment
for DIP and Flatpak
DS100356-1
IEEE/IEC
DS100356-3
Pin Assignment
for LCC
DS100356-5
Pin Names
S
CP
I_0a–I _0d
I_1a– I_1d
Q_a– Q_d
Description
Common Select Input
Clock Pulse Input
Data Inputs from Source 0
Data Inputs from Source 1
Register True Outputs
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FACT^® is a registered trademark of Fairchild Semiconductor Corporation.
© 1998 National Semiconductor Corporation DS100356
DS100356-2
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