DESIGN AND SIMULATION OF MODULAR QUANTUM-DOT CELLULAR AUTOMATA MULTIPLEXERS FOR MEMORY ACCESSING

摘要

Multiplexers are extremely important parts of signal control systems. Some critical circuits of computing systems, like memories, use large multiplexers in order to present the value of a specific memory cell to their output. Several quantum-dot cellular automata (QCA) circuits have been designed and the need for a QCA memory access system becomes prominent. A modular 2~n to 1 QCA multiplexer covering small area could reduce the size of such circuits and conclusively could increase circuit integration. In this paper we present a novel design of a small size, modular quantum-dot cellular automata (QCA) 2~n to 1 multiplexer that can be used for memory addressing. The design objective is to develop a modular design methodology which can be used to implement 2~n to 1 multiplexers using building blocks. For the QCA implementation a careful consideration is taken into account concerning the design in order to increase the circuit stability.