Reversible Logic Gates- An introduction

Reversible circuits or Gates can generates unique output vector form each input vector, and vice versa, i.e., there is a one to one correspondence between the input and output vectors. Thus, the number of outputs in a reversible gate or circuit has the same as the number of inputs, and commonly used traditional NOT gate is the only reversible gate. More formally, a reversible logic gate is a K-input, K-output (denoted K*K) device that maps each possible input pattern into a unique output pattern. While constructing reversible circuits with the help of reversible gates, some restrictions should be strictly maintained.

·        Fan-out is not permitted

·        Loops are not permitted