Testable Reversible Latches for Molecular QCA

Nanotechnologies, including molecular QCA, are susceptible to high error rates. In this paper, we present the design of testable reversible latches (D latch, T Latch, JK Latch, RS Latch), based on reversible conservative logic for molecular QCA. Conservative reversible circuits are a specific type of reversible circuits in which there would be an equal number of Is in the output as there would be on the input, in addition to one- to-one mapping. The proposed latches require only two test vectors, all Os and all Is, for detecting any unidirectional stuck-at faults. The design of QCA layouts and the verification of the latch designs performed using the QCA designer tool are presented.