Basics

Adders

An adder performs addition of two bits.

The half adder has two inputs - A and B - and two outputs, the sum S and carry C.

The output of a half adder is the sum of two one-bit numbers, with C being the most significant of these two outputs.

A full adder has three inputs - A, B, and a carry in Cin - and two outputs - the sum S and carry Cout - such that multiple adders can be used to add larger numbers.

These two components are made of standard gates: