Implementing Synchronous Behaviors On CFSM Networks

Abstract

The Polis codesign system is based on a mixed concurrency model. Synchronous Communicating Finite State Machines (CFSMs) in the networks nodes can use synchronous concurrency as found in synchronous circuits or programs written in Esterel-like languages. The network itself is asychronous and the CFSMs communicate by one-place buffers. We show that networks can also be used to accurately implement synchronous behaviors in a distributed way, thus closely relating the two models. Precisely, we show that the behavior of a constructive (possibly cyclic) synchronous circuit can be nicely simulated on a CFSM network,with one CFSM for each gate. The constructive semantics of circuits is compositional, which makes it possible to use mixed synchronous / asynchronous strategies to efficiently implement globally synchronous behaviors.