Optimized design of full-subtractor using new SRG reversible logic gates and VHDL simulation

Reversible logic has comprehensive applications in communications, quantum computing, low power VLSI design, computer graphics, cryptography, nanotechnology and optical computing. It has received significant attention in low power dissipating circuit design in the past few years. While several researchers have inspected the design of reversible logic units, there is not much reported works on reversible subtractors. In this paper we proposed the quantum equivalent circuit for SRG (SRG refers to Samiur Rahman Gate) gate and we have computed the quantum cost of SRG gate. We also showed that how SRG gate can work singly as a Full-subtractor circuit. It is being tried to design the circuit optimal in terms of number of reversible gates, number of garbage outputs, number of constant inputs and quantum cost with compared to the existing circuits. All the designs have nanometric scales.