Binary Adder | Digital Circuits - Electronics and Communication Engineering (ECE) PDF Download

What is Binary Adder?

• The registers play an important role in performing the micro-operations. The registers hold the digital component and the data which performs the arithmetic operation. The Binary Adder is a logical circuit which is used to perform the addition operation of two binary number of any length.
• The Binary Adder is formed with the help of the Full-Adder circuit. The Full-Adders are connected in series, and the output carry of the first Adder will be treated as the input carry of the next Full-Adder.

N-Bit Parallel Adder

4-bit Binary Adder

• The 'A' and 'B' are the augend, and addend bits are defined by the subscript numbers. The subscripts start from right to left, and the lower-order bit is defined by subscript '0'.
• The C₀, C₁, C₂, and C3 are the carry inputs which are connected together as a chain using Full Adder. The C4 is the carry output produced by the last Full-Adder.
• The Cout of the first Adder is connected as the C_in of the next Full-Adder.
• The S₀, S₁, S₂, and S₃ are the sum outputs that produce the sum of augend and addend bits.
• The inputs for the input variable 'A' and 'B' are fetched from different source registers. For example, the bit for the input variable 'A' comes from register 'R₁', and a bit for the input variable 'B' comes from register 'R₂'.
• The outcome produced by adding both input variables is stored into either third register or to one of the source registers.