SN74AS298A
QUADRUPLE 2-INPUT MULTIPLEXER
WITH STORAGE

SDAS219B - DECEMBER 1983 - REVISED DECEMBER 1994

features

• 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

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.

a1, a2, etc. = the level of steady-state input at A1, A2, etc.
Q_A0, Q_B0, etc. = the level of Q_A, Q_B, etc. entered on the most recent transition of CLK