SN75DP130: FPGA used SN75DP130 as DP to PC converter, but some appear AUX timeout

Kailyn Chen

Part Number: SN75DP130

Hello,

One customer confirm DP IP function with FPGA. He used SN75DP130 as DP to PC converter, but some display appeared AUX timeout. The detailed test results are as following:

1. HP223, DP port1： AUX communication normally, and display is normally lighted.

2.HP224,LG, DP port0: AUX timeout.

3.Samsung: only displayed once during tests, and other tested results are all AUX timeout.

1. LG：N/P amplitude too small, is not compatible with AUX protocal.

2. HP223 port1：work normally

3.HP224 port0（AUX timeout）： compared with port 1 above, the differences are marked red circle.

Please give me some advice

Best regards

Kailyn

over 2 years ago

0 David (ASIC) Liu over 2 years ago

TI__Guru**** 176281 points

Kailyn

Are they probing on the AUX_SRC or AUX_SNK?

In the failing case, is HPD_SNK being asserted already when the DP130 is powered and never toggles?

Can you also share their DP130 schematic?

Thanks

David

0 Kailyn Chen over 2 years ago in reply to David (ASIC) Liu

TI__Genius 9560 points

Hi David，

Thank you very much for your reply.

As to the HPD_SNK, the display has always connected DP130 and has no plug or insert.

Below is the schematic:

Best regards

kailyn

0 David (ASIC) Liu over 2 years ago in reply to Kailyn Chen

TI__Guru**** 176281 points

Kailyn

Where do they probe the AUX signal?

And in the non-working case, does HPD_SNK already go high when DP130 powers up and never toggles?

Thanks

David

0 Kailyn Chen over 2 years ago in reply to David (ASIC) Liu

TI__Genius 9560 points

David (ASIC) Liu said:
Where do they probe the AUX signal?

They probe the AUX sink signal。

David (ASIC) Liu said:
And in the non-working case, does HPD_SNK already go high when DP130 powers up and never toggles?

The customer feedback that DP130 is always powered，and HPD_SNK always connected to display and no hot plug operation.

0 David (ASIC) Liu over 2 years ago in reply to Kailyn Chen

TI__Guru**** 176281 points

Kailyn

Is AUX voltage correct if they toggle the HPD_SNK?

Thanks

David

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SN75DP130: FPGA used SN75DP130 as DP to PC converter, but some appear AUX timeout