TL/F/9821
DM54LS181/DM74LS181
4-Bit
Arithmetic
Logic
Unit
June 1992
DM54LS181/DM74LS181
4-Bit Arithmetic Logic Unit
General Description
The ’LS181 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
Y
Provides 16 arithmetic operations: add, subtract, com-
pare, double, plus twelve other arithmetic operations
Y
Provides all 16 logic operations of two variables: exclu-
sive-OR, compare, AND, NAND, OR, NOR, plus ten
other logic operations
Y
Full lookahead for high speed arithmetic operation on
long words
Connection Diagram
Dual-In-Line Package
TL/F/9821–1
Order Number DM54LS181J, DM54LS181W or DM74LS181N
See NS Package Number J24A, N24A or W24C
Pin Names Description
A0–A3 Operand Inputs (Active LOW)
B0–B3 Operand Inputs (Active LOW)
S0–S3 Function Select Inputs
M Mode Control Input
C
n
Carry Input
F0–F3 Function Outputs (Active LOW)
A e B Comparator Output
G Carry Generate Output (Active LOW)
P Carry Propagate Output (Active LOW)
C
na4
Carry Output
C
1995 National Semiconductor Corporation RRD-B30M115/Printed in U. S. A.