USING FPGAS TO IMPLEMENT SELF-TIMED SYSTEMS

Asynchronous or self-timed systems that do not rely on a global clock to keep system components synchronized can offer significant advantages over traditional clocked circuits in a variety of applications. In order to ease the complexity of this style of design, however, suitable self-timed circuit primitives must be available to the system designer. This article describes a technique for building self-timed circuits and systems using a library of circuit primitives implemented using Actel field programmable gate arrays (FPGAs). The library modules use a two-phase transition signaling protocol for control signals and a bundled protocol for data signals. A first-in first-out (FIFO) buffer and a simple routing chip are presented as examples of building self-timed circuits using FPGAs.