On Fri, Jul 1, 2011 at 4:04 PM, Dave Tweed wrote: > Well, that idea (the actual quote is, "No choice between near-simultaneou= s > events can be made unambiguously within a preset deadline.") comes from t= he > same paper and the reference goes to an enormous website in which it woul= d > take some time to track down the context in which it was made. I was actually only presenting that article for the fact that it mentions m-stability persisting after additional clock pulses. I got my statement of this fundamental property from: http://research.microsoft.com/en-us/um/people/lamport/pubs/buridan.pdf Although, I too will admit that I am not completely convinced by his argume= nts. > > My understanding is that the "choice" we're talking about here is which > came first, the data edge or the (first) clock edge? The fact that the > metastability is gone after the second clock edge does not answer that > particular question; in fact, it erases all of the available information > about that question. You now have the answer to a different question: > Did the data edge occur before the second clock edge? (Yes!) I interpret the question a little differently: what was the logic state of the signal at the first clock edge? > > If there is no second clock edge, then the principle holds: The metastabl= e > state -- and the inability to decide -- can persist indefinitely. > > -- Dave > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .