Full-Adder: The half-adder does not take the carry bit from its previous stage into

account. This carry bit from its previous stage is called carry-in bit. A combinational

logic circuit that adds two data bits, A and B, and a carry-in bit, Cin , is called a full-

adder. The Boolean functions describing the full-adder are:

S = (x ⊕ y) ⊕ Cin C = xy + Cin (x ⊕ y)