A Dual Spring System Case-Study Model in Rosetta

Abstract Introduction Rosetta [1,2,3] is a system-level design language, being developed by two of the authors, Alexander and Barton, as part of the SLDL Initiative [4] currently sponsored by Accellera (formerly VHDL International) and ECSI. The SLDL Initiative was originally sponsored by the EDA Industry Council, and moved under the auspices of VI and ECSI in 1999. Rosetta addresses a need for a language in which designers can specify the requirements and constraints on a system that spans multiple design domains. Requirements describe functional behaviour that a system must exhibit, and constraints describe operational bounds within which the system must remain. The different design domains include digital and analogue electronic subsystems, and the mechanical, optical, fluidic and thermal subsystems with which they interact. Various computational models are most appropriate to describe aspects of systems in different domains. Example computational models include finite and infinite state-based, discrete event, discrete time, and continuous time. The Rosetta language is extensible to allow designs to be expressed using each of these computational models, and to allow expression of the interactions between descriptions in each computational model. The language achieves this extensibility be being based on a formal semantic underpinning and by including facilities for reflection. In combination, these features allow definition of syntax and semantics of new Rosetta domains for expressing requirements and constraints using different computational models. This paper describes a model of a dualspring mechanical system, developed as a design case study in Rosetta. The design was originally specified informally using a combination of English language and mathematical equations. The information in this specification formed the basis of a Rosetta specification, in which the requirements and constraints are expressed formally in a manner that is amenable to analysis and computation. The model is expressed in the logic domain in terms of continuous mathematical equations that describe the mechanical system