spacewar at gmail.com
Fri Feb 3 15:12:51 CST 2017
On Fri, Feb 3, 2017 at 2:00 PM, dwight <dkelvey at hotmail.com> wrote:
> I once worked with a device that came close to telling you
> that U15 was failing.
> It was called a signature analyzer.
> It was good as a first pass production tester.
It required that the device under test be put in a state where the signals
had predictable waveforms, since it basically was just computing a 16-bit
hash of samples of the waveforms, referenced to clock and start signals.
Typically the device under test would be put in a special signature test
mode to do that.
> It needed a pin bed to match the board under test.
For automated full-board testing, yes. But signature testing was also used
with a probe on individual signals for field diagnostic purposes.
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