Author Topic: Triggering on Data Strobe encoding for eye pattern  (Read 815 times)

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Offline bitbangerTopic starter

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Triggering on Data Strobe encoding for eye pattern
« on: December 21, 2018, 12:53:48 am »
Hi Folks -

I'd like to generate an eye pattern on a 100Mbps serial link, that features a data strobe clock.

Unfortunately my scope doesn't feature any clock recovery functionality, technically no in-built eye functionality either, I'm just hoping to rely on persistence. I assume I can't simply trigger on this strobe? Or can I and just accept the reduced number of triggers?

I keep reading mention of implicit triggering based on a fixed time base - how does this work? It sounds like this relies on auto sweep with the timebase set according to expected bit rate/unit interval? Even then, I don't see how the triggering is prevented from drifting.

Would appreciate any insight you can offer.
« Last Edit: December 21, 2018, 12:56:44 am by bitbanger »
 

Offline tggzzz

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Re: Triggering on Data Strobe encoding for eye pattern
« Reply #1 on: December 21, 2018, 08:29:42 am »
There's no point in your scope having any clock recovery facility, since your circuits performance depends on its own clock recovery circuit.

Use your circuits clock recover circuit, or simply trigger on a rising edge halfway between the high anf low voltages.
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