Automatic synthesis of extended burst-mode circuits using generalized C-elements

Presents a new automatic synthesis technique for extended burst-mode circuits, a class of asynchronous circuits that allows multiple input changes between state transitions and a choice of next states based on input signal levels. The target implementation is a pseudo-static asymmetric CMOS complex gate for each output, known as a generalized C-element. The synthesis algorithm generates hazard-free covers for the set and reset functions of each output using Nowick and Dill´s (1995) exact hazard-free logic minimization algorithm. Each output circuit is formed by mapping its set and reset logic to N and P stacks of an asymmetric CMOS gate connected to a sustainer; long-series stacks are decomposed into static gates followed by short stacks. A simple heuristic is used to ensure that no short-circuit paths exist from V_dd to ground. The resulting circuits for small- to medium-size extended burst-mode specifications are 40% smaller and 30% faster than the two-level circuits generated by a 3D synthesis tool, and significantly smaller and faster than the complex-gate circuits generated by the method of Kudva et al. (1996)