System synthesis based on a formal computational model and skeletons

Formal approaches to HW and system design have not been generally adopted because designers often view the modelling concepts used in these approaches as unsuitable for their problems. Moreover, they are frequently on a too high abstraction level to allow for efficient synthesis with today's techniques. We address this problem with a synthesis method which bridges the gap between a highly abstract functional model and an efficient hardware implementation. The functional model is strictly formal and based on formal semantics, a pure functional language, and the synchrony hypothesis. However, the use of skeletons in conjunction with a proper computational model allows a hardware interpretation, where the structure is given by skeletons and the combinatorial logic by elementary functions. Thus, without compromising the formal properties we offer an effective modelling technique on a high abstraction level which is still natural for hardware designers, and is the basis for synthesis into an efficient implementation. Furthermore, we describe a design methodology which uses the modelling concepts and the synthesis method. It contains a design exploration phase and defines how and when design decisions are formally introduced into the synthesis process. Finally, we illustrate design space exploration and synthesis with a FIFO component taken from an ATM switch.