Synthesis of Small Reversible and Pseudo-Reversible Circuits Using Y-Gates and Inverse Y-Gates

This paper presents synthesis of reversible circuits using the Y-gate. The standard reversible circuit has the same number of input and output signals. Such circuits are in general built from reversible gates that similarly have the same number of inputs and outputs. In new technologies, the Y-gate has unequal number of inputs and outputs and so the circuit composed of such gates can have either equal (standard model) or unequal numbers of input and output signals. We introduce the concepts of pseudo-reversible functions. First, a brief overview of reversible logic, Y-gates and Prolog, which form the foundation for this work, is presented. This is followed by the description of an exhaustive search algorithm that generates all circuits from Y gates under certain constraints. We give examples of synthesized circuits.