>I wanted to do the phase comparator in software, which is somewhat
>complicated by the fact that it won't act in continuous time.  I take 2
>samples of the sync input one instruction apart:


Why?  Is a 74HC4046 too slow?  (That would give you a choice of phase
detectors and VCO all in one package. )

What's the advantage of a software PLL in this application?

(Maybe I'm missing the obvious.  It happens to me all the time... ;-)


newell