DS92LV0421 and DS92LV0422: BIST MODE

Heinrich Oosthuizen

Other Parts Discussed in Thread: DS92LV0421, DS92LV0422

I want to use the DS92LV0421 in BIST mode as test equipment (TE) to generate PRBS7 data to a Unit Under test (UUT). The data source and sink will be test equipment with the Unit Under Test (UUT) in between.

My configuration will be as follows: DS92LV0421(TE) (BISTEN=1) ---> DS92LV0422 (UUT) (BISTEN=0)--->DS92LV0421(TE) (BISTEN=0) --->DS92LV0422 (TE) (BISTEN=1).

With this configuration there is a PRBS generator (TE) at the start of the link and a PRBS checker (TE) at the end of the link.

Will the PRBS7 data be passed through by the 2 converters in the middle (UUT) with BISTEN set to 0 . The error detector in the converter at the end of the link will be used for BERT.

over 8 years ago

0 Michael Lu (Santa Clara) over 8 years ago

TI__Mastermind 29655 points

Hi Heinrich,

We have not validated the behavior of the DS92LV0421/22 in this particular scenario, but I don't see any issues with this setup. When the DS92LV0421/22 is based in BIST mode, it is expecting that there is some kind of interconnect media between the serializer and deserializer. Based on your setup, the PRBS-7 data should simply be serialized and deserialized normally with the middle DS92LV0421/22 pair.

Is there a reason you are using this configuration instead of just one SerDes pair? If the DS92LV0421 is a known golden unit, would you be able to determine based on the DS92LV0422 PASS output whether the DS92LV0422 is functioning correctly or not?

Thanks,

Michael

0 Heinrich Oosthuizen over 8 years ago in reply to Michael Lu (Santa Clara)

Prodigy 60 points

Hi Michael,

Thank you for the answer. The idea is to use the upstream serializer and downstream de-serializer as test equipment for the PCB Assembly under test. It should be a more cost effective solution than using a FPGA as data generator and checker.

The setup will consist of two PCB Assemblies. The one being Test Equipment (TE) and the other the Unit Under Test (UUT).

Thanks.

Heinrich.

0 Michael Lu (Santa Clara) over 8 years ago in reply to Heinrich Oosthuizen

TI__Mastermind 29655 points

Hi Heinrich,

Was there a picture in the last post? I was unable to view it, but I think I got the idea.

Your idea seems reasonable to me. I would recommend that you test with several known good and known faulty units to determine the accuracy of the setup.

Regards,

Michael

0 Heinrich Oosthuizen over 8 years ago in reply to Michael Lu (Santa Clara)

Prodigy 60 points

Hi Michael,

Yes, there was a picture in the last post. Here it is again inserted with the Paste from Word button?

Thank you.

Regards.

Heinrich

0 Michael Lu (Santa Clara) over 8 years ago in reply to Heinrich Oosthuizen

TI__Mastermind 29655 points

Hi Heinrich,

It doesn't seem to be displaying. Usually what I do in the forum is click the "Use rich formatting" button and then upload the image (which I save as a screenshot .jpg) to my post.

Michael

0 Heinrich Oosthuizen over 8 years ago in reply to Michael Lu (Santa Clara)

Prodigy 60 points

Hi Michael,

Here it is again. Inserted as a fie.

Regards.

Heinrich

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DS92LV0421 and DS92LV0422: BIST MODE