Talk:Virtual finite state machine

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[edit] Canonical state machine

Am confused here. The canonical hardware models are usually considered the Meely and the Moore models. And folks seem to prefer the Moore as "more canonical" because the state is the only determiner of the output.

The hardware state register is simply either (i) 2 banks of D flip-flops clocked with phases 1 and 2 (or the equivalent) or (ii) a single phase D flip-flop with delay. The output feeds back to the lookup table (made in any of a number of manners -- usually a state decoder followed by encoding logic -- very simple). This is as primitive as it gets -- this is the fully atomized state machine.

So my point is: there doesn't seem to be any thing as an "entry action" and "exit action", rather just a "state action". That is, if we do insist that these two actions are to exist then we can atomize the so-called state further into two successive state actions -- into two (or more) successive states.

I do agree that when designing software a person might create a so-called 'state' -- a sequence of instructions that is entered via a "state table". This pseudostate indeed does have many actions but as an instruction sequence. I've done this myself in my work. In this case, what is an "entry action" versus an "exit action" -- how do you define them? For example, the following table is from Turing (1936) page 120 in the Undecidable. Here we see something more like "pseudostates" with many actions inside each "state" aka m-configuration":

Config	Config	Behavior	Behavior
m-config.	symbol	operations	final m-config
b	-	Pe, R, Pe, R, P0, R, R, Po, L, L	o
o	1	R, Px, L, L, L	o
o	0	-	q
q	Any	R, R	q
q	None	P1, L	p
p	x	E, R	q
p	e	R	f
p	None	L, L	p
f	Any	R, R	f
f	None	P0, L, L	o

Take any of these rows: what is the "entry action" and what is the "exit action"?wvbaileyWvbailey 17:33, 16 August 2006 (UTC)