74HC/HCT181 Philips Semiconductors (Acquired by NXP), 74HC/HCT181 Datasheet - Page 5

• Manufacturer Part Number: 74HC/HCT181
• Description: 4-bit Arithmetic Logic Unit
• Manufacturer: Philips Semiconductors (Acquired by NXP)

Philips Semiconductors
FUNCTION TABLES
Notes to the function tables
1. Each bit is shifted to the next more significant position.
2. Arithmetic operations expressed in 2s complement
1998 Jun 10
S
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
4-bit arithmetic logic unit
3
MODE SELECT
notation.
H = HIGH voltage level
L = LOW voltage level
INPUTS
S
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
2
S
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
1
S
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
0
A
A + B
AB
logical 0
AB
B
A
AB
A + B
A
B
AB
logical 1
A + B
A + B
A
LOGIC
ACTIVE HIGH INPUTS AND
(M=H)
B
B
OUTPUTS
A
A + B
A + B
minus 1
A plus AB
(A + B) plus AB
A minus B minus 1
AB minus 1
A plus AB
A plus B
(A + B) plus AB
AB minus 1
A plus A
(A + B) plus A
(A + B) plus A
A minus 1
ARITHMETIC
(M=L; C
(1)
n
=H)
(2)
5
Notes to the function tables
1. Each bit is shifted to the next more significant position.
2. Arithmetic operations expressed in 2s complement
S
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
3
MODE SELECT
notation.
H = HIGH voltage level
L = LOW voltage level
INPUTS
S
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
2
S
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
1
S
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
0
A
AB
A + B
logical 1
A + B
B
A
A + B
AB
A
B
A + B
logical 0
AB
AB
A
LOGIC
ACTIVE LOW INPUTS AND
(M=H)
B
B
74HC/HCT181
OUTPUTS
A minus 1
AB minus 1
AB minus 1
minus 1
A plus (A + B)
AB plus (A + B)
A minus B minus 1
A + B
A plus (A + B)
A plus B
AB plus (A + B)
A + B
A plus A
AB plus A
AB plus A
A
Product specification
ARITHMETIC
(M=L; C
(1)
n
=L)
(2)