Digital Logic | Sample question

Question

The number of full and half-adders required to add $32$-bit numbers is______________________

Answer 1

$31$ Full adders  and $1$ half adder required .

Comments

we can generalize for it, if $n$ bit numbers are there, $(n-1)$ Full adder and $1$ half adder required.

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yes sir if question will only ask the FA then Ans will $32$  so only FA  they asking  then $n$ are required and if both are used then your statment is true.

Answer 2

To add two 32-bit numbers, you would typically use 32 full-adders. Each full-adder adds three inputs: two bits from the numbers being added (A and B) and a carry input from the previous less significant bit addition.

For the least significant bit (LSB), you only need a half-adder because there is no carry input from a less significant bit. A half-adder adds two inputs (A and B) and produces a sum and a carry.

So, for a 32-bit addition, you would need 31 full-adders (for bits 1 to 31) and 1 half-adder (for the LSB), totaling 32 adders.