Compiling Modechart Speciications

The Modechart speciication language is a formalism for the speciication of real-time systems. A toolset for speciication, analysis and simulation for Modechart speciications exists for supporting the design and construction of real-time systems CHLR93]. This paper introduces a new tool in the the toolset: a compiler for a class of Modechart speciications, namely, that of deterministic system speciications, extended by a subclass of the non-deterministic system speciications. The object code that the compiler generates is in Esterel, a member of the synchronous family of programming languages for real-time systems. We discuss a broad approach to the implementation of timing speciications, providing a range of implementation options, from the basic time step unrolling of states in Esterel, to the use of system timers. The compiler presented herein allows the speciier to obtain a correct implementation of a modechart program, including timing constraints.