Synthesis of pipelined systems for the contemporaneous execution of periodic and aperiodic tasks with hard real-time constraints

Summary form only given. We address the design of pipelined systems able to sustain the throughput of a given periodic task and, at the same time, to serve aperiodic requests associated with hard real-time constraints. The proposed method is based on the allocation of the global graph (periodic and aperiodic tasks), over-dimensioning the design of the system devoted to process the periodic task, deserving the unused parts of the resources to the management of aperiodic requests. A formal definition of such a mapping problem, together with the formalization of the searching space, is given. The searching space is structured in a way such as the minimization process moves toward a solution, which satisfies, if possible, all the real-time constraints and has minimal HW requirements. Once formulated as a minimization problem, the pipelined architecture and the corresponding scheduling are determined by means of a simulated annealing algorithm. A theorem is given to ensure that all the feasible mappings are reachable in the optimization process.