The Ternary Quantum-dot Cellular Automata Memorizing Cell

Abstract

Quantum-dot Cellular Automata (QCA) were demonstrated to be a possible candidate for the implementation of a future multi-valued processing platform. Recent papers show that the introduction of adiabatic switching and the elegant application of the adiabatic pipelining concept in the QCA logic design can be used to efficiently solve the issues of the elementary ternary QCA logic primitives. The architectures of the resulting ternary QCAs become similar to their binary counterparts and thus the design rules for large circuit design remain similar to those developed for the binary QCA domain. In spite of this the design of the binary QCA SR memorizing cell cannot be directly transferred to the ternary domain, mostly because the control logic cannot properly handle the third value. We here propose a ternary QCA memorizing cell that efficiently exploits the pipelining mechanism at a wire level. It is centered on the circulating memory model (i.e. the memory in motion concept), which proved to be an efficient concept in memorizing cell design in the binary QCA domain. The proposed memorizing cell is capable of serving as one trit (ternary digit) of memory and represents a step forward to the ternary register, one of the basic building blocks of a ternary processor.