QCA circuit design of optimal universal logic gate ULG.2 based on modular methodology

Abstract

In order to reduce the number of wire-crossings in quantum-dot cellular automata(QCA) circuits and the types of QCA logic gates in logic synthesis,based on the introduction of basic principles of QCA,QCA logic devices and modular design methodology,a novel QCA optimal universal logic gate ULG.2 was designed.Three circuits of full adder/subtraction,full comparator and 4-to-1 multiplexer were implemented with the optimal QCA universal logic gate ULG.2.Simulation by using the QCADesigner tool for the proposed QCA circuits confirms that the proposed circuits have correct logic function and their performance was improved dramatically in comparison to the other previous designs.Especially,the proposed 4-to-1 multiplexer was reduced 31.8%QCA cells and 62.5% number of wire-crossings compared with the traditional design based on majority gates and inverters.