On Semiconductor Logic Adder & Subtractor
Logic adders and subtractors are digital circuits used to perform arithmetic operations on two binary numbers. They can be used to add two numbers, subtract one number from another, or to find the difference between two numbers. The most common type of adder is called a half-adder, which consists of two inputs and one output. Half-adders can be used to add two single-bit binary numbers, with the output being the sum of the two inputs, and a carry out bit. A full-adder is an adder circuit with three inputs, two outputs and two carry inputs. Full-adders can be used to add three binary numbers and have the output being the sum of the three inputs, and a carry out bit. Subtractors are similar to adders, but instead of adding two binary numbers, it subtracts one binary number from another. This can be done either in the binary-coded decimal (BCD) or the excess three (EX-3) form.