Modal processes: towards enhanced retargetability through control composition of distributed embedded systems

To explore different points in the design space of an embedded system, it is important to be able to compose a design from reusable design components, and then map the resulting system description onto several possible target architectures with different partitionings of functionality. Today´s specification models support composition styles that work well for data communication but not for control communication between concurrent processes to be mapped onto a distributed architecture. We propose a new retargetable system specification model that combines the best properties of process-based and hierarchical-FSM-based methods for modular composition of data and control. The model lends itself to automated synthesis of the run-time system for coordinating tasks on different processors in the system. The model and synthesis method are illustrated with several examples of embedded systems.