Synthesizing hardware from Occam

For the hardware designer the currently available `standard´ languages are ELLA in the United Kingdom and VHDL in the United States. Initially both of these languages were intended to be used in design at a relatively low level, that is, they were designed as hardware description languages but they have now been generalised so that they can be used at the higher levels of system design. These two languages suffer from a major drawback; they have no formal basis, that is, they have no formal semantics, and so proving properties of any design is difficult or impossible. Thus errors in the implementation of a design in these languages can only be detected by simulation rather than mathematical equivalence. Hardware description languages are useful in the design implementation in that, providing that suitable libraries are available, it is possible to generate chips directly from the language description. Designing at a higher level of abstraction implies describing the behaviour of the required system and then transforming this into a structural and behavioural description at a lower level, possibly in a hardware description language, before implementation can proceed