From: John Conover <john@email.johncon.com>
Subject: Re: BNF/YACC'able state machine verification
Date: Wed, 5 Jun 1996 22:23:11 -0700
Hi Rick. If you recall, sometime last year, I suggested that what we really, really, needed was some kind of a BNF/YACC verification gizmo for digital circuits. It was in reference to the complexity of state machine design in a contemporary microprocessor. The idea being that a high level state machine definition language, similar to BNF but instead of a stack implementation language, it would be a state machine language, and a suitable grammar checker, something like YACC, could be used to verify the "correctness" of design of multiply coupled state machines, or something to that effect. In the new IEEE spectrum is an article from someone at Compass that uses TAG files to come pretty close to that, with an RTL language, and state machine register checking algorithm that detects dead, (or non-attainable), and terminal states. It is a two page article, and is thus pretty sparse with information, but might have some practical uses. I had looked at TAG several years ago, but my feeling, at least at the time, was that the concept was not very extensible. FYI. John -- John Conover, john@email.johncon.com, http://www.johncon.com/