
Define 'Correct'. Conways 'life' and the central clock - jacquesm
http://jacquesmattheij.com/Define+Correct+-+Conways+life+and+the+central+clock
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jonsen
"Karl's book takes clockless concurrent process to be fundamental(as it is in
nature)." - from a review of _Computer Science Reconsidered_ :

[http://www.amazon.com/Computer-Science-Reconsidered-
Invocati...](http://www.amazon.com/Computer-Science-Reconsidered-Invocation-
Expression/dp/0471798142/)

From the same author:

[http://www.amazon.com/Logically-Determined-Design-
Clockless-...](http://www.amazon.com/Logically-Determined-Design-Clockless-
Convention/dp/0471684783/)

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wgj
Each cell could implement a Phase Locked Loop that locks to one of its
neighbors. This would decentralize the clock while the system remains self-
referentially synchronous. You would still need a reference signal to start
the system's initial frequency and phase, but then I think you can remove the
reference and the system would continue in sync.

<http://en.wikipedia.org/wiki/Phase-locked_loop>

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jacquesm
I've once seen this amazing little demo of electronic 'fireflies' that self
synchronized after an initial period of instability.

<http://www.instructables.com/id/Synchronizing-Fireflies/>

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jws
The author is doomed.
<http://en.wikipedia.org/wiki/Metastability_in_electronics>

In short if your digital circuit is going to accept arbitrary patterns of
inputs then there will be cases that cause it to produce non-stable output for
arbitrary periods of time. Curse you, laws of physics.

~~~
jacquesm
From that same wikipedia article:

> Metastable states are believed to be inherent features of asynchronous
> digital systems and systems with more than one clock domain, but careful
> design can often make the probability of a system failing very small indeed.

Which is more or less what I'm getting at, I wonder about the 'careful design'
domain. Not perfect, but good enough to get the job done.

