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Half – Adder

A Half-adder circuit needs two binary inputs and two binary outputs. The input variable shows the augend and addend bits whereas the output variable produces the sum and carry. We can understand the function of a half-adder by formulating a truth table. The truth table for a half-adder is:

• ‘x’ and ‘y’ are the two inputs, and S (Sum) and C (Carry) are the two outputs.
• The Carry output is ‘0’ unless both the inputs are 1.
• ‘S’ represents the least significant bit of the sum.

The simplified sum of products (SOP) expressions is:

S = x’y+xy’, C = xy

The logic diagram for a half-adder circuit can be represented as: