TLF5320

January 1988

MM54HC181MM74HC181

Arithmetic Logic UnitsFunction Generators

General Description

These arithmetic logic units (ALU)function generators uti-

lize advanced silicon-gate CMOS technology They possess

the high noise immunity and low power consumption of

standard CMOS integrated circuits as well as the ability to

drive 10 LS-TTL loads

The MM54HC181MM74HC181 are arithmetic logic unit

(ALU)function generators that have a complexity of 75

equivalent gates on a monolithic chip These circuits per-

form 16 binary arithmetic operations on two 4-bit words as

shown in Tables 1 and 2 These operations are selected by

the four function-select lines (S0 S1 S2 S3) and include

addition

subtraction

decrement

and straight transfer

When performing arithmetic manipulations the internal car-

ries must be enabled by applying a low-level voltage to the

mode control input (M) A full carry look-ahead scheme is

made available in these devices for fast simultaneous carry

generation by means of two cascade-outputs (pins 15 and

17) for the four bits in the package When used in conjunc-

tion with the MM54HC182 or MM74HC182 full carry look-

ahead circuits high-speed arithmetic operations can be per-

formed The method of cascading HC182 circuits with these

ALU’s to provide multi-level full carry look-ahead is illustrat-

ed under typical applications data for the MM54HC182

MM74HC182

the ripple-carry delay has also been minimized so that arith-

metic manipulations for small word lengths can be per-

formed without external circuitry

Features

Y

Full look-ahead for high-speed operations on

long words

Y

Arithmetic operating modes

Addition

Subtraction

Shift operand a one position magnitude comparison

Plus twelve other arithmetic operations

Y

Logic function modes

Exclusive-OR

Comparator

AND NAND OR NOR

Plus ten other logic operations

Y

Wide operating voltage range 2V – 6V

Y

Low input current 1 mA maximum

Y

Low quiescent current 80 mA maximum

Connection Diagram

Dual-In-Line Package

TLF5320 – 1

Top View

Order Number MM54HC181 or MM74HC181

Pin Designations

Designation

Pin Nos

Function

A3 A2 A1 A0

19 21 23 2

Word A Inputs

B3 B2 B1 B0

18 20 22 1

Word B Inputs

S3 S2 S1 S0

3 4 5 6

Function-Select

Inputs

7

Inv Carry Input

M8

Mode Control

Input

F3 F2 F1 F0

13 11 10 9

Function Outputs

14

Comparator Outputs

P15

Carry Propagate

Output

16

Inv Carry Output

G17

Carry Generate

Output

24

Supply Voltage

GND

12

Ground

C1995 National Semiconductor Corporation

RRD-B30M105Printed in U S A