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BLOCK DIAGRAM
(ACTIVE LOW)
3
FUNCTION
4
SELECT
5
INPUTS
6
S0 S1 S2 S3
2
A0
23
A1
WORD A
21
A2
19
A3
1
B0
22
B1
WORD B
20
B2
18
B3
CARRY IN
7
C n
MODE CONTROL
8
MC
Function Select
S3
S2
L
L
L
L
L
L
L
L
L
H
L
H
L
H
L
H
H
L
H
L
H
L
H
L
H
H
H
H
H
H
H
H
* Expressed as two's complements. For arithmetic function with C n in the opposite state, the resulting
function is as shown plus 1.
MOTOROLA CMOS LOGIC DATA
V DD = PIN 24
V SS = PIN 12
F0
9
OUTPUT
F1
10
FUNCTION
F2
11
F3
13
A = B
14
COMPARISON OUTPUT
C n+4
16
RIPPLE CARRY OUTPUT
G
17
LOOK AHEAD
CARRY OUTPUTS
P
15
TRUTH TABLE
Inputs/Outputs Active Low
Logic
Arithmetic*
Function
Function
S1
S0
(MC = H)
(MC = L, C n = L)
L
L
A
A minus 1
L
H
AB
AB minus 1
H
L
A + B
AB minus 1
H
H
Logic "1"
minus 1
L
L
A + B
A plus (A + B)
L
H
B
AB plus (A + B)
H
L
A
B
A minus B minus 1
H
H
A + B
A + B
L
L
AB
A plus (A + B)
L
H
A
B
A plus B
H
L
B
AB plus (A + B)
H
H
A + B
A + B
L
L
Logic "0"
A plus A
L
H
AB
AB plus A
H
L
AB
AB plus A
H
H
A
A
BLOCK DIAGRAM
(ACTIVE HIGH)
3
4
5
6
S0 S1 S2 S3
2
A0
23
A1
21
A2
19
A3
1
B0
22
B1
20
B2
18
B3
7
C n
8
MC
Inputs/Outputs Active High
Logic
Arithmetic*
Function
Function
(MC = H)
(MC = L, C n = H)
A
A
A + B
A + B
AB
A + B
Logic "0"
minus 1
AB
A plus AB
B
(A + B) plus AB
A
B
A minus B minus 1
AB
AB minus 1
A + B
A plus AB
A
B
A plus B
B
(A + B) plus AB
AB
AB minus 1
Logic "1"
A plus A
A + B
(A + B) plus A
A + B
(A + B) plus A
A
A minus 1
F0
9
F1
10
F2
11
F3
13
A = B
14
C n+4
16
G
17
P
15
MC14581B
6–493
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