Asynchronous Logic

Asynchr onous logic is enjoying a r esurgence of inter est among academic and industrial resear chers after two decades of near total neglect. Why is this? This tutorial presents the r easons for the r enewed inter est and discusses the curr ent state of development of asynchr onous design. Ther are many ways to design chips without clocks, so some backgr ound is offer ed to the various differnt asynchr onous design methodologies used by various gr oups ar ound the world today . One such style, called ‘micr opipelines’ was developed by Ivan Sutherland and formed the basis of his 1988 T uring Award Lecture. This appr oach has been adopted by a group at Manchester University in England and used to develop fully asynchr onous implementations of the ARM 32-bit RISC micr oprocessor . The or ganization and key implementation details of these AMULET pr ocessors will be described. Finally, speculation will be offerd on the futur e of asynchr onous design techniques in a world curr ently dominated by clocked cir uits.