An Operational Semantics and Compiler for Real-time Speciications

The Modechart speciication language is a formalism for the speciication and implementation of real-time systems. The semantics of the language was formally deened axiomatically in Real-Time Logic. This paper presents the semantics for Modechart in an operational style and a compiler for automatically synthesizing speciications. Modechart is a synchronous language, which assumes the synchronous model of concurrency and broadcast of events. The synchronous model assumes the system to be theoretically much faster than the environment. Modechart allows both deterministic and non-deterministic real-time speciications. The semantics for the class of deterministic speciications is introduced rst, followed by the deenition of the non-deterministic semantics. The deterministic semantics naturally derives a Modechart compiler, which provides automatic synthesis of formal speciications. An extension to the compiler presented provides support for a subset of the class of non-deterministic speciications, very useful in practice. We characterize this class and show how it can be used in automatic code generation for engineering real-time applications.