Refinement Method Hao Shen Fr?ed?eric P?etrot System Level Synthesis Group, TIMA Laboratory, INP Grenoble 43, Avenue F?elix Viallet, 38031, Grenoble, France {hao.shen@imag.fr frederic.petrot@imag.fr} Abstract The complexity of today's Multi-Processors System-on- Chip (MPSoC) requires new design methodologies to solve time-to-market and design cost problems. In SoC for which several subsystems are connected together, we notice that lots of design time is wasted on solving the inter-subsystem (global) communication problem. In this paper, we pro- pose a novel communication exploration method based on a multi-abstraction levels exploration. With this work, the inter-subsystem communication structure can be optimized at the beginning of the design process by using simulation models at three different abstraction levels. The simula- tion at the higher abstraction level allows designers to ex- plore parameters of the interconnection model at the more detailed abstraction level. Some design loop cases can be avoided by using this exploration method. With the Motion- JPEG case study, we illustrate the whole communication exploration process step by step. From experimental results, we show that compared with the cycle accurate simulation, the inter-subsystem communication can be well optimized and evaluated at higher abstraction levels.