New Approach to Design and Implementation XOR Gate in QCA Technology


Department of Computer Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran.


Quantum-dot cellular automata (QCA) is a novel technology that encodes binary information with state of electrons instead of voltage levels. QCA computations offer ultra-low power consumption, high speed and density construction. Majority voter and inverter are the most important gates in this technology and other gates and circuits can be implemented with them. In this paper, we design a novel fault tolerant two-input XOR gate. That is implemented in single layer without any wire crossing. One of the fundamental logical gates in digital circuits is exclusive-OR (XOR). Many circuits can be implemented with XOR such as full adder, comparator and so on. We design this gate according to Boolean expressions with one three-input majority gate and one five-input majority gate. The proposed design has significant improvement in terms of area, complexity, latency, and cell count in comparison to the previous designs. This component is suitable for designing fault tolerant QCA circuits.  We simulate our design in QCA Designer and QCA Pro and achieved results are presented in this paper.


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