M74HC181
TRUTH TABLE 1
SELECTION
S3 S2 S1 S0
M = H LOGIC
FUNCTIONS
ACTIVE LOW DATA
M = L ARITHMETIC OPERATIONS
Cn = L (no carry)
Cn = H (with carry)
L L L L F=A
F = A minus 1
L L L H F = AB
F = AB minus 1
L L H L F=A+B
F = AB minus 1
L L H H F=1
F = minus 1 (2’s Compl)
L H L L F=A+B
F = A plus (A + B)
L H L H F=B
F =AB plus (A + B)
L H H L F=A⊕B
F = A minus B minus 1
L H H H F=A+B
F=A+B
H L L L F = AB
F = A plus (A + B)
H L L H F=A⊕B
F = A plus B
H L H L F=B
F =AB plus (A + B)
H L H H F=A+B
F=A+B
H H L L F=0
F = A plus A*
H H L H F = AB
F = AB plus A
H H H L F = AB
F = AB plus A
H H H H F=A
F=A
* : Each bit is shifted to the next more significant position.
F=A
F = AB
F = (AB)
F = Zero
F = A plus (A + B) plus 1
F = AB plus (A + B) plus 1
F = A minus B
F = (A + B) plus 1
F = A plus (A + B) plus 1
F = A plus B plus 1
F = AB plus (A + B) plus 1
F = (A + B) plus 1
F = A plus A plus 1
F = AB plus A plus 1
F = AB plus A plus 1
F = A plus 1
FIGURE 1
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