State the application of a Half Adder. Draw the truth table and circuit diagram for a Half Adder.
Computer Science20173 marksDrawing
Draw: Circuit diagram for a Half Adder
Answer
Answer
AI
Application: a Half Adder adds two single-bit binary numbers and gives a Sum bit and a Carry bit; it is the basic building block of adders (a Full Adder is made from two Half Adders) and of the arithmetic circuits in the ALU. It cannot take a carry-in from a previous stage.
Truth table:
A
B
Sum
Carry
0
0
0
0
0
1
1
0
1
0
1
0
1
1
0
1
$Sum = A \oplus B = A'B + AB'$ and $Carry = A \cdot B$.
Circuit diagram: inputs A and B go to an XOR gate (output Sum) and to an AND gate (output Carry).
