CONTREX: Design of embedded mixed-criticality CONTRol systems under consideration of EXtra-functional properties

The increasing processing power of today’s HW/SW platforms leads to the integration of more and more functions in a single device. Additional design challenges arise when these functions share computing resources and belong to different criticality levels. CONTREX complements current activities in the area of predictable computing platforms and segregation mechanisms with techniques to consider the extra-functional properties, i.e., timing constraints, power, and temperature. CONTREX enables energy efficient and cost aware design through analysis and optimization of these properties with regard to application demands at different criticality levels. This article presents an overview of the CONTREX European project, its main innovative technology (extension of a model based design approach, functional and extra-functional analysis with executable models and run-time management) and the final results of three industrial use-cases from different domain (avionics, automotive and telecommunication).The work leading to these results has received funding from the European Community’s Seventh Framework Programme FP7/2007-2011 under grant agreement no. 611146

Structural Contracts – Motivating Contracts to Ensure Extra-Functional Semantics

Part 2: System-Level DesignInternational audienceIn our work we aim at a composable and consistent specification and verification of contracts for extra-functional properties, such as power consumption or temperature. To this end, a necessary precondition for the semantical correctness of such properties is to ensure the structurally correct modeling of their interdependences.While this can be solved by a tailoring of the Component Based Design (CmpBD) frameworks, the resulting design constraints are specific to tools and viewpoints, not being sufficiently configurable for the designers. To solve this problem within the contract framework, Contract Based Design (CBD) with explicit port variables provides also no configurable but sound methodology for structurally relating the properties between different components and views. For that, we propose the idea of structural contracts. Using implicit structural ports, structural guarantees can be given according to the Component Based Design structure. Expressing structural design constraints by the means of structural assumptions, the CmpBD constraints can become part of the Contract Based Design framework and, thus, can be checked for compatibility and refinement.As a result, structural contracts enable the contract based specification and verification of structural rules for the correct modeling of functional and extra-functional interdependences. Providing both, property specifications and Component Based Design constraints by contracts, the approach is flexible and sound