# Design of a basic half-adder

I know that a half-adder is a combination of the gates: XOR, AND. But how are they combined? And can you give a example and explain which one is the XOR and which one is the AND.

• google.co.uk/… Google is everyone's friend! – Andy aka Jan 6 '15 at 12:46
• Google 'half-adder'... Wikipedia has an article 'Adder_(electronics)' explaining this aswell. – 1k5 Jan 6 '15 at 12:48

(source: circuitstoday.com)

S = sum of A and B, C = carry (A and B both 1).

For a half adder with inputs A and B

SUM = A XOR B
CARRY = A AND B