A Systematic Design Space Exploration of MPSoC Based on Synchronous Data Flow Specification

The design space exploration (DSE) problem addressed in this paper is to find out Multi-Processor System-on-Chip architectures for a given multi-task signal processing application aiming to minimize the system cost while satisfying the real-time constraints. It involves the following three sub-problems: selecting processing elements, mapping an application to the processing elements, and determining the communication architecture. The proposed approach consists of two inner design loops: one is a cosynthesis loop that determines the selection of PEs and the mapping of a given application to the PEs, and the other is a communication architecture synthesis loop to find the hierarchical shared bus architecture. We specify an application with a synchronous data flow (SDF) model of computation that has well-matched semantics with the algorithmic function flow in DSP applications. To solve the problem, we need to compare the estimated performance of design points and choose the best ones. The common method of simulation-based performance estimation is too time-consuming to explore the wide design space. Thanks to the analytical properties of the SDF model, the performance estimation can be done without HW/SW cosimulation in both loops. A global feedback from the communication architecture synthesis step to the cosynthesis step forms the proposed DSE framework. We use a real-life application, 4-channel Digital Video Recorder (DVR) that is a multi-task example, as well as randomly generated graphs to show the viability of the proposed approach.