Efficient design of reversible alu in quantum-dot cellular automata

Quantum dot-cellular automata (QCA) based reversible logic is the foundations of emerging nanotechnological computing systems. It promises extremely low power consumption with high density and operating frequency. This work focuses on design of an efficient reversible ALU (Arithmetic Logic Unit) and its realization in QCA. We have considered existing 3 × 3 RUG (Reversible Universal Gate) as the basic building block, and also present a HDLQ model of RUG having 52.2% fault tolerance capability. Further, the reversible ALU has synthesized with reversible logic unit (RLU) and reversible arithmetic unit (RAU). We also present QCA implementation of RLU and RAU with minimum complexity and cell count. The proposed ALU requires only 68 MVs (Majority Voter), which is 35% more area efficient than the existing work. It is simulated using QCADesigner to verify the proposed designs which can be also embedded with ultra low power complex digital system.