Binary Half Adder
A binary half adder is a digital circuit which adds two 1-bit binary numbers, and also provides a carry. It is the basic building block within the arithmetic logic unit (ALU) of a microprocessor.This half adder uses NOT, AND, and OR gates only. In this article, we look at how to design a binary half adder using boolean algebra to find the expressions for the sum (S), and carry (C) functions.
As you look at the diagram, you will notice that the sum function (S) is the equivalent of the EX-OR gate, and therefore it could be simplified.
This type of circuit accepts two binary inputs to produce a corrosponding sum and carry outputs. It is a half adder because there are no provisions for adding the carry from the previous element.
Truth Table
| A | B | S | C |
| 0 | 0 | 0 | 0 |
| 0 | 1 | 1 | 0 |
| 1 | 0 | 1 | 0 |
| 1 | 1 | 0 | 1 |
Boolean Expression
