The Gateway to Computer Science Excellence
First time here? Checkout the FAQ!
+1 vote
Minimum number of half adders and OR gates required to build a n-bit binary adder is?

(Give circuit diagram)
asked in Digital Logic by Active (1.1k points)
retagged by | 89 views

2 Answers

0 votes
2n half adder and n OR gates
answered by Junior (795 points)
0 votes
It requires (2n-1) half adders and (n-1) 2 input  OR gates

for example: for 16 bit binary (parallel) adders we require 16 Full Adders to implement

                     that implies we need  n Full adders,

                     else 1 Half Adder , 15 Full Adders  -> 1 HA,(n-1) FA

                     else  31 HA, 0 FA -> (2n-1) HA

                  for first HA we don't require  any OR gate and for the rest of the half adders we need (n-1) OR gates.

finally we need (2n-1) half adders and (n-1) OR gates
answered by (499 points)
Gotcha! For LSB we don't need 1FA right

Quick search syntax
tags tag:apple
author user:martin
title title:apple
content content:apple
exclude -tag:apple
force match +apple
views views:100
score score:10
answers answers:2
is accepted isaccepted:true
is closed isclosed:true

28,832 questions
36,676 answers
34,638 users