Asynchronous circuits and systems: a promising design alternative

Despite the recommendations of several Roadmaps published a few years ago, asynchronous circuits are only very recently becoming an industrial / comme rcial reality. The semiconductor industry is starting to give a serious con sideration to the introduction of asynchronous technology into products and design flows. The paper introduces the design and applications of asynchronous circuits. Differences between synchronous and asynchronous circuits are first highlig hted, and the main classes of asynchronous circuits introduced and compared . The main design methodologies available today are then briefly reviewed. Finally, it is shown that asynchronous logic may appear to be a key technol ogy for the design of future telecommunication applications. The major pote ntials and properties of asynchronous circuits are described and illustrate d with recently fabricated circuits and systems borrowed from both academic and industrial projects.