SN74AS298A Datasheet, PDF (1/7 Pages) Texas Instruments – QUADRUPLE 2-INPUT MULTIPLEXER WITH STORAGE

• Selects One of Two 4-Bit Data Sources and
Synchronously Stores Data With System
Clock
• Applications:
– Dual Source for Operands and Constants
in Arithmetic Processor; Can Release
Processor Register Files for Acquiring
New Data
– Implements Separate Registers Capable
of Parallel Exchange of Contents, Yet
Retains External Load Capability
– Has Universal-Type Register for
Implementing Various Shift Patterns,
Including Compound Left-Right
Capability
• Package Options Include Plastic
Small-Outline (D) Packages and Standard
Plastic (N) 300-mil DIPs
SN74AS298A
QUADRUPLE 2-INPUT MULTIPLEXER
WITH STORAGE
SDAS219B – DECEMBER 1983 – REVISED DECEMBER 1994
D OR N PACKAGE
(TOP VIEW)
B2 1
A2 2
A1 3
B1 4
C2 5
D2 6
D1 7
GND 8
16 V_CC
15 Q_A
14 Q_B
13 Q_C
12 Q_D
11 CLK
10 WS
9 C1
description
The SN74AS298A is a quadruple 2-input multiplexer with storage that provides essentially the equivalent
functional capabilities of two separate MSI functions (SN74AS157 and ′AS175A) in a 16-pin package.
When the word-select (WS) input is low, word 1 (A1, B1, C1, D1) is applied to the flip-flops. A high input to WS
causes the selection of word 2 (A2, B2, C2, D2). The selected word is clocked to the output terminals on the
negative-going edge of the clock pulse.
The SN74AS298A is characterized for operation from 0°C to 70°C.
FUNCTION TABLE
INPUTS
OUTPUTS†
WS CLK QA QB QC QD
L
↓
a1
b1
c1
d1
H
↓
a2
b2
c2
d2
X
H QA0 QB0 QC0 QD0
† _{a1, a2, etc. = the level of steady-state input at A1,}
A2, etc.
QA0, QB0, etc. = the level of QA, QB, etc. entered
on the most recent ↓ transition of CLK
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
Copyright © 1994, Texas Instruments Incorporated
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