ADC12DJ3200EVM: Not able to see repeated ILA patterns and D21.5 patterns at JESD Rx side.

Thakur Rohit Singh

Part Number: ADC12DJ3200EVM
Other Parts Discussed in Thread: ADC12DJ3200

Hi team

This is in continuation to my previous post https://e2e.ti.com/support/data-converters-group/data-converters/f/data-converters-forum/1056907/adc12dj3200evm-sync-signal-is-always-low/3921297#3921297

Since my SYNC status is high and LINK is up, I am trying different internal patterns of ADC12DJ3200. Ramp pattern, transport layer pattern, K28.5 works fine. But when i am trying repeated ILA pattern and D21.5 pattern i am not getting expected results. When i am selecting D21.5 pattern, my SYNC status is always low and link is never up. JESD register x208 reads value 04.

In case of repeated ILA pattern, as per data sheet "In this test mode, the JESD204B link layer operates normally, except that the ILA sequence (ILAS) repeats
indefinitely instead of starting the data phase" but i am getting below waveforms at my end. Highlighted is the portion of data where initial ILA sequence ends, i cant see repetition of ILA sequence in the waveform.

any clues?

Regards

Rohit

over 3 years ago

0 Thakur Rohit Singh over 3 years ago

Prodigy 110 points

Can anybody help me with this?

Regards

Rohit

0 Ameet Bagwe over 3 years ago

TI__Intellectual 1720 points

Hi Rohit,

Are these waveforms representing the output of the PHY or the output of the JESD IP?

Regards,

Ameet

0 Thakur Rohit Singh over 3 years ago in reply to Ameet Bagwe

Prodigy 110 points

Hi Ameet

This is output of the JESD IP.

Regards

Rohit

0 Ameet Bagwe over 3 years ago in reply to Thakur Rohit Singh

TI__Intellectual 1720 points

Hi Rohit,

I believe you may have generated the JESD IP with descrambler turned on. Kindly try ILA the test with it turned off and let me know if you still see the issue. The ILA sequence isn’t scrambled by the transmitter.

Regarding your query about the D21.5 sequence, the JESD Rx IP is looking for a string of K28.5 characters (on all lanes) before it changes SYNCn from 0 to 1. In the 21.5 test mode, the IP doesn’t find them and hence will keep the SYNCn low.

Regards,

Ameet

0 Thakur Rohit Singh over 3 years ago in reply to Ameet Bagwe

Prodigy 110 points

Hi Ameet

Thanks, I disabled the descrambler at the JESD Rx IP and it worked.

Regarding, D21.5 you mentioned that JESD Rx IP doesn't find K28.5 characters and hence stay low. May know then how this particular D21.5 pattern can be tested at the Rx side? How do we know whether D21.5 pattern is sent and detected?

Regards

Rohit

+1 Ameet Bagwe over 3 years ago in reply to Thakur Rohit Singh

TI__Intellectual 1720 points

Hi Rohit,

You will need to test/monitor this at the output of the PHY, and not the JESD IP.

Regards,

Ameet

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ADC12DJ3200EVM: Not able to see repeated ILA patterns and D21.5 patterns at JESD Rx side.