Polychronous Methodology For System Design: A True Concurrency Approach

As embedded systems have become pervasive and ubiquitous in contemporary technologies, their development requires highly reliable design approaches. One of these approaches is the so-called synchronous programming paradigm, where its mathematical basis provides the required formal concepts to satisfy correctness expectations. Among these synchronous programming concepts, the multi-clocked model of computation of polychrony stands out for its capability to give high-level and homogeneous descriptions of concurrent systems, where its concurrent parts may evolve asynchronously to each other and synchronize intermittently. In this paper, we propose a ´true concurrency´ semantic model of polychrony using pomsets. This formulation of polychrony closes the gap between synchrony and asynchrony by giving a uniform characterization of both synchronous and asynchronous observations by considering the causality and functional dependency structure of a pomset. The results in this paper also show that the existing tagged-signal model for polychrony uses an unnecessary artifact namely, tags, which complicate the semantic theory unduly