Transformational partitioning for co-design of multiprocessor systems

This paper presents the underlying methodology of Cosmos, an interactive approach for hardware/software co-design capable of handling multiprocessor systems and distributed architectures. The approach covers the co-design process through a set of user guided transformations allowing semi-automatic partitioning. The transformations are based on a powerful set of primitives for functional partitioning, structural reorganization and communication transformation. It leads to a fast transformation of a system-level specification into an architecture with a short design time and fast exploration of design space. The application of this approach is illustrated using a design example starting from a system-level specification given in SDL to a distributed hardware/software architecture described in C/VHDL. We show that the use of transformational approach allows: 1) application of the expertise of the designer during partitioning; 2) the user to understand the results of the co-design process; 3) the process to take into account partial existing solutions; 4) large design space exploration; and 5) the designer to start from a very high-level specification language of the system to be designed.