Design of Reversible Logic Alu Using Quantum Dot Cellular Automata

Abstract

Conservative logic is a logic which reflects the property that there is equal number of one’s in the inputs as well as in the output. It can be reversible or irreversible in nature. Reversibility is nothing but the circuit exhibits one-to-one mapping between input and output vector, and also represents for each input vector there is an unique output vector and vice versa. Reversibility is mainly preferred because it can provide the methodology for designing low power circuits. Unlike computation mechanisms that involve the transfer of electrons, as in CMOS gates, QCA computation does not involve electron transfer between adjacent QCA cells. Hence power dissipation is very less in circuits designed with QCA cells. Since only few electrons are involved in QCA computations, it is susceptible to thermal issues. Therefore it is important to consider power as an important parameter during the QCA design process. The major advantages of this technology are lesser power dissipation, improved speed and dense structures. In this project design of reversible combinational circuits like ALUs which is designed with new gates, Mux, Adders, based on QCA technology is proposed to provide advantages like reduction in no of quantum cost, garbage outputs, complexity of gates, area.