FULL ADDER

In full adder, there are 3 inputs, two of them are A and B and other is C-IN. C is called Carry-in. This is like we are adding two bits with carry. SUM = (A XOR B) XOR C-IN When any one of the input or all of the input has "1", then its value is '1' else '0' CARRY-OUT = when any two or three of the input has "1" then its value is '1', else 0. Full adder needs 3 inputs, while two adder needs 2. Truth table A B C-IN C-OUT SUM 0 0 0 0 0 0 0 1 0 1 0 1 0 0 1 1 0 0 0 1 0 1 1 1 0 1 0 1 1 0 1 1 0 1 0 1 1 1 1 1