A Tools Flow for Automatic Synthesis of Extended Burst-Mode Asynchronous State Machines

Abstract

Asynchronous design is an interesting alternative to solve the difficulties of the synchronous counterpart related to clock, like clock skew and clock distribution problems. However, the lack of tools for automatic synthesis is a major drawback. Asynchronous Finite State Machines are widely used in the control of asynchronous digital systems and are usually implemented as Huffman machines with fed-back outputs (HMFO). However, it can be implemented as Huffman Machines (HM) which has the advantage of better interaction with fast environments, reducing the cost of timing analysis and has potential for better latency time, compared to HMFO. Interestingly, state of the art tools like 3D and SAGAAS does not synthesize asynchronous circuits in HM architecture, only HMFO. Nevertheless both uses Extended Burst-Mode (XBM) specification as its input. This paper proposes an algorithm based on genetic algorithms for state assignment of XBM_HMs, which is important step in the synthesis. This paper also proposes a tools flow for automatic synthesis of XBM specifications in the HM architecture.