© 2000 Fairchild Semiconductor Corporation

DS009821

www.fairchildsemi.com

October 1988

Revised April 2000

DM74LS181

4-Bit Arithmetic Logic Unit

General Description

The DM74LS181 is a 4-bit Arithmetic Logic Unit (ALU)

which can perform all the possible 16 logic operations on

two variables and a variety of arithmetic operations.

Features

s Provides 16 arithmetic operations: add, subtract, com-

pare, double, plus twelve other arithmetic operations

s Provides all 16 logic operations of two variables:

exclusive-OR, compare, AND, NAND, OR, NOR, plus

ten other logic operations

s Full lookahead for high speed arithmetic operation on

long words

Ordering Code:

Logic Symbols

Active High Operands

Active Low Operands

GND

= Pin 12

Connection Diagram

Pin Descriptions

Order Number

Package Number

Package Description

DM74LS181N

N24A

24-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-010, 0.600 Wide

Pin Names

Description

A0–A3

Operand Inputs (Active LOW)

B0–B3

Operand Inputs (Active LOW)

S0–S3

Function Select Inputs

M

Mode Control Input

Carry Input

F0–F3

Function Outputs (Active LOW)

A

= B

Comparator Output

G

Carry Generate Output (Active LOW)

P

Carry Propagate Output (Active LOW)

Carry Output