Breaking step: the return of asynchronous logic

Virtually all digital design is based on a synchronous approach. However, there are signs that it is beginning to hit some fundamental limitations. These limitations are described by the author. Asynchronous design as a means to overcome these limitations is then discussed. The way in which asynchronous circuits operate is discussed. The Amulet project at Manchester University, which adopted the micropipeline approach in investigating the application of asynchronous techniques to the reduction of high-performance microprocessors, is described. Future prospects for asynchronous design are briefly reviewed