Design of Testable Universal Logic Gate Targeting Minimum Wire-Crossings in QCA Logic Circuit

This work proposes a testable QCA (Quantum-Dot Cellular Automata) logic gate (UQCALG) realizing the universal functions. The design of UQCALG is based on the Coupled Majority Minority (CMVMIN) QCA structure with the target to reduce wire crossings as well as the number of clock cycles required to operate a QCA circuit. The characterization of defects in such design leads to synthesis of a test block, realized with the majority and minority voters, that ensures the desired testability of a circuit. The experimental designs establish that the UQCALG can result in cost effective design of testable QCA logic circuits that may not be possible with conventional ULG (Universal Logic Gate).