Theoretically, if you know the number of clock pulses in the gate window
and the EXACT data stream and timing, you could calculate the signature.
In fact, I have done exactly this in the trivial case where the data
probe is connected to Vcc. The resulting table of number of clocks
and the resulting signature will tell you how many clocks are in the
gate window, which is useful for troubleshooting.
I think the way it was actually done was to take a known good instrument,
probe all of the pins and write down the signatures on a table.
I don't think anyone, least of all me, is arguing for SA on new build equipment.
Paul
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On Fri, Jul 14, 2023 at 06:32:06PM +0100, Adrian Godwin wrote:
I wouldn't argue for SA on new builds, I think it was a production tool
whose time has passed.
But if you like it and are writing software for a new device it's probably
possible to calculate the results of specific test patterns, or simulate
them.
I do think it's simpler to work with a scope or logic analyser and debug
intelligently, but still, it wouldn't be impossible.
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Unix/Linux - We don't do windows
