How many full adders are required to construct an m-bit parallel adder ?
A.
m/2
B.
m-1
C.
m
D.
m+1
Answer: Option B
Explanation:
We need an adder for every bit. So we should need m full adders. A full adder adds a carry bit to two inputs and produces an output and a carry. But the most significant bits can use a half adder, which differs from the full adder as in that it has no carry input, so we need m-1 full adders in m bit parllel adder.