MULTILANGUAGE SPECIFICATION FOR SYSTEM DESIGN AND CODESIGN

This chapter discusses specification languages and intermediate models used for system-level design. Languages are used during one of the most important steps of system design: the specification of the system to be designed. A plethora of specification languages exists. Each claims superiority but excels only within a restricted application domain. Selecting a language is generally a trade off between several criteria such as the expressive power of the language, the automation capabilities provided by the model underlying the language and the availability of tools and methods supporting the language. Additionally, for some applications, several languages need to be used for the specification of different modules of the same design. Multilanguage solutions are required for the design of heterogeneous systems where different parts belong to different application classes e.g. control/data or continuous/discrete. All system design tools use languages as input. They generally use an intermediate form to perform refinements and transformation of the initial specification. There are only few computation models. These may be dataor control-oriented. In both cases, these may be synchronous or asynchronous. The next section details three system-level modeling approaches to introduce homogeneous and heterogeneous modeling for codesign. Each of the modeling strategies implies a different organization of the codesign environment. Section 3 deals with intermediate forms for codesign. Section 4 introduces several languages and outlines a comparative study of these languages. Finally, section 5 deals with multilanguage modeling and cosimulation.