TDA2PXEVM: Backchannel Problem with UB960-UB953

Nicolas Rausch

Part Number: TDA2PXEVM

Hey,

I am setting up the ar0220 sensor with UB953 to TDA2px. When I set the backchannel frequency to 50mbps as recommended for UB953 the serdes link does not work because the serializer can´t be reached via i2c. I already searched the forum and apparently more people have the same problem, but since their threads weren´t solved, I decided to ask again.

With backchannel frequency set to 25mbps the connection is working fine.

Also I tried the setup with the exact same initialisation for serdes on the TDA3rvp and there it works right away without any problems.

How come that 50mbps works fine with tda3rvp (also UB960) but on tda2px it results in an unreachable serializer?

In another thread someone said he just had to retry writing to the serializer several times and then it would work at one point, I tried that but it didn´t work for me.

I am using PSDK3.3.

best regards,

Nicolas Rausch

over 5 years ago

0 Brijesh Jadav over 5 years ago

TI__Guru**** 398480 points

Hi Nicolas,

Any specific reason why you require 50mbps back channel requirement?

Why this is not working is still under debug.

Rgds,

Brijesh

0 Nicolas Rausch over 5 years ago in reply to Brijesh Jadav

Expert 1155 points

Hey Brijesh,

yes I need 50 mbps to properly set up the camera in order to achieve the right fps with the used resolution.

So if you say this is issue is still under debug it means that this is a known problem and you weren´t able to fix it yet?

best regards,

nico

0 Stefan Koncar over 5 years ago in reply to Brijesh Jadav

Genius 3050 points

Hi Brijesh,

The original question is post by me. On some boards we have, serializer can't be reached via I2C, on some a lot of retries is required. Now I'm facing same issue again. Can you confirm this is known problem for TI and you are trying to fix it? A lot of people have same problem.

Best regards,
Stefan.

0 Nicolas Rausch over 5 years ago in reply to Stefan Koncar

Expert 1155 points

any updates on this?

0 Stefan Koncar over 5 years ago in reply to Nicolas Rausch

Genius 3050 points

Hi,

I don't have any new information - also waiting for the reply.

Regards,

Stefan.

0 Brijesh Jadav over 5 years ago in reply to Stefan Koncar

TI__Guru**** 398480 points

Hi Stefan,

We are still trying to figure out why this is not working.
But i still could not understand why 25mbps back channel frequency will not work. could you please help me understand?

Rgds,
Brijesh

0 Stefan Koncar over 5 years ago in reply to Brijesh Jadav

Genius 3050 points

Hi Brijesh,

25 Mbps BC is working but with 25 Mbps BC rate we can't achieve enough FPD link throughput for FULL_HD@60fps, only for FULL_HD@30fps.
Please, look at this post - I explained this problem: e2e.ti.com/.../718750

Best Regards,
Stefan.

0 Brijesh Jadav over 5 years ago in reply to Stefan Koncar

TI__Guru**** 398480 points

Hi Stefan,

I am sorry i could not understand, on this e2e thread, you mentioned that After you changed BC rate to 50 Mbps and after modification of M, HS_CLK_DIV and N parameters to get exactly 25 MHz CLKOUT, you got 60 fps without any noise. Does this mean you are able to get 50Mbps BC and full hd 60fps output?

Rgds,
Brijesh

0 Stefan Koncar over 5 years ago in reply to Brijesh Jadav

Genius 3050 points

Hi Brijesh,

One few boards I'm able to get FullHD@60fps output, but still I2C issue is somehow present, as I said on the forum. But, on some other boards I can't access to UB953, regardless of the number of attempts (same HW). I think that I read on some post that someone even tried with TDA2p EVM + FUSION and couldn't access to UB953 when BC rate is 50 Mbps.

Best Regards,
Stefan.

0 Brijesh Jadav over 5 years ago in reply to Stefan Koncar

TI__Guru**** 398480 points

Hi Stefan,

We are still looking into this issue, there are some changes required on Fusion board to fix it.
I will update you when we have complete changes.

Rgds,
Brijesh

0 Stefan Koncar over 5 years ago in reply to Brijesh Jadav

Genius 3050 points

Hi Brijesh,

Thank you very much. This is very important for us, keep me up to date.
Do you have information where is the problem - is it maybe related to PoC network?

Best Regards,
Stefan.

0 Brijesh Jadav over 5 years ago in reply to Stefan Koncar

TI__Guru**** 398480 points

Stefan,

It might require redesign of the board. It is under discussion. Will share more details as and when i get it.
Meanwhile can we please close this thread for the time being? we can reopen it or start a new thread later on.

Regards,
Brijesh

0 Stefan Koncar over 5 years ago in reply to Brijesh Jadav

Genius 3050 points

Brijesh,

Thank you.
For me it's OK to close this thread. We will also soon redesign our board, so will need to apply these changes.
You can send me any new information on mail: stefan.koncar@rt-rk.com or you can write new post here.

I didn't start this thread so I can't mark answer as resolved.

Best Regards,
Stefan.

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TDA2PXEVM: Backchannel Problem with UB960-UB953