Cost effective universal shift register in quantum dot cellular automata using clock zone-based crossover

Abstract

Quantum-Dot Cellular Automata (QCA) is a modern nanotechnology, which uses quantum cells to express the binary information without current flow. It has emerged as suitable alternative to current CMOS architecture. The design of combinational and sequential circuit seems to be a challenging task in QCA technology. In this paper, a novel cost effective universal shift register is proposed. Initially a novel 2 to 1 multiplexer and D flip-flop with fewer numbers of majority gate and inverters are designed. Then these proposed designs are utilized to build the cost effective universal shift register. Here the clock zone-based crossover (CZBC) is used for interconnection to reduce the circuit complexity and cost function of the proposed design. Using the QCA designer environment and QCAPro designer tool, the proposed design is experimentally verified and tested for overall energy dissipation. As compared to the existing literature, the simulation result shows that the proposed configuration reduces cell count by 38%, majority gate by 30% and latency by 68%. The proposed clock zone-based crossover universal shift register (CZBCUSR) achieves 23% better QCA cost function and 32% higher device density due to utilization of CZBC, lesser number of majority gate and inverter.