ASYL: A Rule-Based System for Controller Synthesis

A rule-based approach has been investigated for two items of the synthesis area: the state assignment of controllers and the logic minimization. Local optimization rules defined on a control flowgraph have been defined for the first point. These are expressed as constraints on the codes of the internal variables. An encoding algorithm tries to respect most of these contraints. The results appeared to be very convincing. For the second point, the rules intend to cope with different technological targets and the meta rules intend to express different optimization strategies. The results are less spectacular, especially, of course, for a target where algorithmic solutions exist, but some interesting experiences on the rule-based approach are reported.