On limitations and extensions of STG model for designing asynchronous control circuits

A number of limitations of the current status of signal transition graphs (STGs), a model which has recently become popular for designing asynchronous interface circuits, are discussed. The major syntactic and semantic restrictions that can be lifted are safety, free-choice net structure and binary signal labeling. A number of instructive examples of interface control circuit specifications, which are semantically correct yet free from such restrictions, are presented. Adequate techniques for analysis and implementation of the extended STG model are discussed.<
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