QCA based Priority Encoder using Toffoli gate

This paper presents a design of a reversible priority encoder that is an important element for encoding and decoding addresses. Promising nanotechnology, Quantum-dot Cellular Automata (QCA), is a possible platform for implementing reversible circuits. In this paper, a reversible 4 to 2 priority encoder architecture is proposed with low complexity on the QCA platform. In order to implement a reversible encoder circuit, the low-cost design of the Toffoli gate is proposed. Structural analysis using the QCADesigner simulation tool is carried out to evaluate the proposed designs.