Hardware-software cosynthesis of multitask MPSoCs with real-time constraints

The cosynthesis problem addressed in this paper involves three subproblems: selection of appropriate processing elements, mapping and scheduling of function blocks to the selected processing elements, and schedulability analysis. We have presented a cosynthesis framework in our earlier work (Oh and Ha, 1999) that defines an iteration loop of three steps that attack the subproblems separately. Despite many good features, our previous technique has a severe restriction that a task monopolizes the entire system once activated. But in general we may obtain higher performance if multiple tasks can be running concurrently on different processor cores. It is the main contribution of this paper that we extend the previous framework to be applicable for general multiprocessor systems with diverse operating policies. We demonstrate the performance improvement from the proposed work with a multi-media real-time application, DVR system, and randomly generated multi-task graphs