Architecture Exploration of Real-time Systems Based on Multi-Objective Optimization

11 pp; International audience; This article deals with real-time embedded system design and verification. Real-time embedded systems are frequentlydesigned according to multi-tasking architectures that have timing constraints to meet. The design of real-time embeddedsystems expressed as a set of tasks raises a major challenge since designers have to decide how functions of the system mustbe assigned to tasks. Assigning each function to a different task will result in a high number of tasks, and then in higherpreemption overhead. In contrast, mapping many functions on a limited number of tasks leads to a less flexible design whichis more expensive to change when the functions of the system evolve. This article presents a method based on an optimizationtechnique to investigate the assignment of functions to tasks. We propose a multi-objective evolution strategy formulation whichboth minimizes the number of preemptions and maximizes task laxities. Our method allows designers to explore the search spaceof all possible function to task assignments and to find good tradeoffs between the two optimization objectives among schedulablesolutions. After explaining our mapping approach, we present a set of experiments which demonstrates its effectiveness fordifferent system sizes.