Design of Multiplexers using Reversible Logic Technique

Abstract

Reversible logic is promising as it can be applied to different applications in low power like nanocomputing especially in quantum computing. Reversible logic is a technioue for power reduction. Reversible circuits are similar to digital circuits but they work using reversible logic gates. This study focuses on reducing the garbage output and ancilla inputs in reversible multiplexers, thereby reducing the power consumption. In this study two designs of Multiplexers are given. Design1 is using TwinSJ gate and AJ gate. 2:1, 4:1 and 8:1 multiplexers are built. In Design 2, a new gate (SJ gate) is built which functions as 2:1 multiplexer. It has 4*4 configuration. The inputs are suitably configured so that it performs various logic functions. Using this SJ gate and other basic reversible logic gates, 2:1, 4:1 and 8:1 multiplexers are built. In 2:1 multiplexer, Ancilla inputs are improved to '0' from 5 and garbage output has been reduced to 2 against 7 in existing design. 4:1 multiplexers are built with ‘0’ ancilla inputs against 2 and 11 in existing designs. Garbage output of the proposed 4:1 multiplexer is 5 against 6 and 16 in existing designs. 8:1 multiplexer is built with 1 ancilla input and 11 garbage output against 2 and 12 respectively in existing design. This is designed using VHDL code - xilinx 14.7 for verification purpose and simulated on ISIM.