Property-Preservation Synthesis for Unified Control- and Data-Oriented Models †

1. Property-Preservation Synthesis for Unified Control- and Data-Oriented Models† Oana Florescu, Jeroen Voeten, Henk Corporaal o.florescu@tue.nl Introduction • Actions - need small computation time (control action) -immediate (urgent) execution • Time-intensive computations - need considerable amount of execution time (multimedia algorithms) - finish before a deadline Model-driven design of real-time embedded systems [1] • suitable models for real-time analysis • correctness-preserving synthesis Current Approach From Model to Realisation [3] Real-Time Systems POOSL [2] Models UML model POOSL model Controller()() in?input(x); computation(x)(y); delay T; out!output(y). ε-closeness ε = max(ε1, ε2) Transition system • Preservation of all properties up to ε • Internal computations are not observed from outside • But they induce a largeε However • Only observable properties (of actions) are interesting • Computations need to be scheduled up to a deadline Model execution Proposed Approach Intuition • Computation split into small parts → small ε Mathematical support – observation equivalence • Models have the same observable properties • Implementations of both observation equivalent models preserve their observable properties, but with different strengths: splitting computations preemptive scheduling By scheduling computations, P is preserved stronger Conclusions • Abstract from unobservable computations which are scheduled to meet their deadlines • Time-deviations are given only by observable actions • Stronger preservation of observable properties References [1] J. Huang, J. Voeten, O. Florescu, P. vd Putten and H. Corporaal. Advances in Design and Specification Languages for SoCs, chapter Predictability in real-time system development. Kluwer Academic Publishers, 2005. [2] P. vd Putten and J. Voeten. Specification of Reactive Hardware/Software Systems. PhD thesis, Eindhoven University of Technology, Eindhoven NL, 1997. [3] J. Huang, J. Voeten and M. Geilen. Real-time property preservation in approximations of timed systems. 1st ACM & IEEE International Conference on Formal Methods and Models for Codesign (MEMOCODE'2003), June 2003. ε = max(ε1, ε2) ε’ = max(ε1, ε2, ε3, ε4) < ε †Research carried out as part of the BodeRC project. Department of Electrical Engineering Electronic Systems