26 May
2011
26 May
'11
11:02 a.m.
On Wed, May 25, 2011 at 12:50, Mark Kahrs <mark.kahrs at gmail.com> wrote:
You know, it all depends on the person. ?Personally, I
call the logic
analyzer the "tool of last resort" or "the dreaded logic analyzer".
?When
you need it, you need it and nothing else will do. ?But often you can get a
long way with a 'scope and a logic probe (in the ancient days when strobes
were easily accessible).
As with everything, the logic analyzer is just a tool, and is the
right tool for those jobs that require a logic analyzer. If you're
debugging a sequencing circuit, or other heaps of logic that can't
easily be compartmentalized, it can be the tool that will solve the
problem in minutes rather than days.
Since these days most "random bunch of logic" is in FPGAs and their
ilk, pretty much every HDL development tool comes with a simulator
that is effectively a logic analyzer on virtual signals. And it's
very useful.
When I was working for Castleton debugging DSPs (I was hired as a
software guy) I shocked everyone by fixing a random intermittent
glitch by grabbing the board and hooking up the logic analyzer: I
found that one control signal was changing at the same time as the
clock signal, thus it wasn't always latched correctly. Got the
hardware guys to reprogram the FPGA to move the signal 1/4 clock ahead
in time, and the thing turned out to be rock solid. My boss had no
idea how I did it, and I gained major respect from the hardware group.
Joe.
--
Joachim Thiemann :: http://www.tsp.ece.mcgill.ca/~jthiem