Modelling and distributed simulation of asynchronous hardware

Synchronous VLSI design is approaching a critical point, with clock distribution becoming an increasingly costly and complicated issue and power consumption rapidly emerging as a major concern. Hence, recently, there has been a resurgence of interest in asynchronous digital design techniques as they promise to liberate VLSI systems from clock skew problems, offer the potential for low power and high performance and encourage a modular design philosophy which makes incremental technological migration a much easier task. This activity has revealed a need for modelling and simulation techniques suitable for the asynchronous design style. Contributing to the quest for modelling and simulation techniques suitable for asynchronous design, and motivated by the increasing debate regarding the potential of CSP for this purpose, this paper investigates the suitability of occam, a CSP-based programming language, for the modelling and simulation of complex asynchronous systems. A generic modelling framework is introduced and issues arising from the parallel semantics of CSP/occam when the latter is employed to perform simulation are addressed.