SN74AS298A

QUADRUPLE 2-INPUT MULTIPLEXER

WITH STORAGE

SDAS219B – DECEMBER 1983 – REVISED DECEMBER 1994

Copyright

1

POST OFFICE BOX 655303

Synchronously Stores Data With System

Clock

– 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

Small-Outline (D) Packages and Standard

Plastic (N) 300-mil DIPs

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

D OR N PACKAGE

(TOP VIEW)

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

B2

A2

A1

B1

C2

D2

D1

GND

CLK

WS

C1

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.