sn75dp130 pin swap

Adam Torma

I would like to do some pin swapping on the . TI’s EVM apparently uses the connector on output side, but I want to put it on input side so the P’s and n’s are reversed on both sides of part. Lane 0-3 will be reversed as well. This product is only passing the data through, and is not interpreting anything.

Also, the link training is done from source side. It will be controlled on my side so I will know if it’s lane 0 or 3.

Should be able to be controlled via i2c.

So the question is:

Is there anything specific I need to do for the p vs. n since the part is differential in.

Also…can this be done with LVDS repeaters…Same question?

over 12 years ago

0 Diego Cortes over 12 years ago

TI__Mastermind 36085 points

Hello Adam,

We are reviewing your post and we will reply soon.

Regards,

Diego.

0 Michael Campbell over 12 years ago

TI__Intellectual 1800 points

Are you supporting DP++ or just DP? For DP++, the DP130 has a different EQ setting for lane 3. Lane 3 for DP++ is TMDS_CLK and the DP130 has a fixed 3dB of EQ for that lane.

Regarding the question on P/N, the redriver doesn't care about polarity. The important thing is the polarity is matched on the input and output.

0 Adam Torma over 12 years ago in reply to Michael Campbell

TI__Mastermind 45680 points

Michael,

I'm just supporting just DP, not DP++, so no TMDS signalling. I assume that means that lanes 0 to 3 are equivalent, each with its own equalization setting? Please confirm.

Re. p/n interchangaability, that's great news! What I was hoping to hear. Thank you!

Thank you,

Adam

0 Michael Campbell over 12 years ago in reply to Adam Torma

TI__Intellectual 1800 points

Yes, if you are only supporting DP then all lanes are the same.

Regard,

Mike

0 Adam Torma over 12 years ago in reply to Michael Campbell

TI__Mastermind 45680 points

Mike,

Thank you so much for the quick sanity check.

Adam

0 Mizanur Chowdhury over 10 years ago in reply to Michael Campbell

TI__Genius 17270 points

Hello Michael,

In light of your comments I assume one can also swap the main link lanes around 0,1,2,3 for DP application as for DP all lanes are same ? Customer wants to swap the lanes to line up with the connector.

Thanks and regards,
Mizanur

0 Moises Garcia over 10 years ago in reply to Mizanur Chowdhury

TI__Mastermind 23815 points

Hi Adam,

Yes, you can swap lanes as long as the lane is matched on the input and output.
Remember this only work if application is DP not DP++.

Regards

0 Morten Leikvoll over 9 years ago in reply to Moises Garcia

Prodigy 60 points

I'd like to reopen this case. I would like to swap lane order on both input and output (put the DP130 on the bottom of the PCB), but I'm using the aux snooping link training feature. My understanding says this will fail, as the aux snooper would be addressing lane0 equalizer settings for lane3, and 1 for 2. The datasheet says nothing about this. Please elaborate.

0 Moises Garcia over 9 years ago in reply to Morten Leikvoll

TI__Mastermind 23815 points

Hi Morten,

Yes you will have problems if you use link training, you need to configure DP130 via I2C

Regards

0 Morten Leikvoll over 9 years ago in reply to Moises Garcia

Prodigy 60 points

Thanks for the reply. I hope a future revision or similar chip will get a register bit to allow swapping.

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sn75dp130 pin swap