抽象的

DESIGN OF ADDER / SUBTRACTOR CIRCUITS BASED ON REVERSIBLE GATES

V.Kamalakannan, Shilpakala.V, Ravi.H.N

Reversible logic has extensive applications in quantum computing, it is a unconventional form of computing where the computational process is reversible, i.e., time-invertible. The main motivation behind the study of this technology is aimed at implementing reversible computing where they offer what is predicted to be the only potential way to improve the energy efficiency of computers beyond von Neumann-Landauer limit. It is relatively new and emerging area in the field of computing that taught us to think physically about computation Quantum Computing will be a total change in how the computer will operate and function. The reversible arithmetic circuits are efficient in terms of number of reversible gates, garbage output and quantum cost. In this paper design Reversible Binary Adder- Subtractor- Mux, Adder-Subtractor- TR Gate., Adder-Subtractor- Hybrid are proposed. In all the three design approaches, the Adder and Subtractor are realized in a single unit as compared to only full adder/subtractor in the existing design. The performance analysis is verified using number reversible gates, Garbage input/outputs and Quantum Cost.The reversible 4-bit full adder/ subtractor design unit is compared with conventional ripple carry adder, carry look ahead adder, carry skip adder, Manchester carry adder based on their performance with respect to area, timing and power. Hence the proposed work is useful in low power applications where both adder and subtractor units are required