Abstract
To construct a reversible sequential circuit, reversible sequential elements are required. This work presents novel designs of reversible sequential elements such as the D latch, JK latch, and T latch. Based on these reversible latches, we construct the designs of the corresponding flip-flops. Then we further discuss the physical implementations of our designs based on electron waveguide Y-branch switch technology. Test costs, including test generation and test application, of reversible sequential circuits with these reversible flip-flops are also discussed. Compared with previous work, the implementation cost of our new designs, including the number of gates and the number of garbage outputs, is significantly reduced. The number of gates in our designs is 47.4% of the designs in previous work on average. The number of garbage outputs in our designs is 25% of the designs in previous work on average. © 2008 ACM.