2 Jun
1999
2 Jun
'99
11:15 a.m.
"Richard Erlacher" <edick(a)idcomm.com> wrote:
--snip--
The logic analyzer won't hide significant
information about the logic and
timing. If you sample at twice the frequency of the fastest harmonic you
want to observe, you won't miss a thing.
It is not just frequency issues. Levels can be a problem as
well. I've seen circuits with mixed HC, LS, 4000 and other.
You set the input for one and the other is wrong. Also,
your 2X has to be twice the frequency of the response
of the IC circuit and not just twice the clock speed.
Also, the 2X sampling rule is only true for repetitive
signals. This is a basic sampling law thing.
100 Mhz isn't really fast enough to truly see what is
going on in even an old 8080 processor board. Glitch
catching helps but can still hide correct operation.
Where I currently work, we are completely out of the
ball park were current day LA's are of much use but
that is another problem. We still have them and can,
under limited conditions, use them.