Some recent asynchronous system design methodologies

We present an in-depth study of some techniques for asynchronous system design, analysis, and verification. After defining basic terminology, we take one simple example - a four-phase t o two-phase converter - and present its design using (a) classical flow-tables; (b) Signal Transition Graphs of [8]; and (c) Trace Theory of [15]. We then present necessary and sufficient conditions for Delay Insensitivity, proposed by [38], and illustrate it on our example. Finally, we present the work of [13] on the verification of asynchronous circuits, and illustrate it on the circuits derived in the paper. The following points are emphasized: (i) presentation of techniques at more depth than in a general survey; (ii) illustration of all t h e aspects discussed on a common example; (hi) comparative study of the works presented. Many interesting works had to be left out, solely because of our lack of space and time.