On the combination of assertions and virtual prototyping for the design of safety-critical systems

Embedded systems for safety-critical applications need design methods, which comply with the requirements of such sensitive systems. This paper proposes a new approach to the design of such systems and presents first results. We introduce the method of Virtual Prototyping in combination with assertions for an UML-based system design. This means that we build an abstract model of a heterogeneous embedded system including functional and especially timing constraints from the very beginning. The Unified Modeling Language (UML) has been extended to model complex heterogeneous systems rather than just software. The Virtual Prototype is made executable on an open simulator platform. From the simulation we derive information about the system's functional and timing behavior, which is fed back to the UML system level. This paper discusses the assertion-based design process and its implementation by corresponding design tools, and it shows how assertions can vastly improve the quality of embedded system design.