TPS65987D: "DP Mode" is not being recognized

Hi,

Thank you for your query, we have received your request. Please give our team some time to look at this and we will provide a response in the next few days.

Thank you for your patience as we work through a high intake of E2E posts.

Best,

USB-C/PD Team

Hi Kevin,

Thanks for reaching out on E2E!

Can you please share a PD log and your project file with me?

Thank you,

Kevin

Sorry, what is a PD Log. Is the just saving the output from the "Debug Log" in the GUI?

For_TI_20240403.pjt

DebugLog.csv

Hi Kevin,

A PD log is a capture that decodes the CC lines communication between two devices.

It will tell us if the PD successfully entered DP ALT mode when a connection was established.

Thank you,

Kevin

I see. Is there a way to capture and save that log through the TPS6598X GUI? Or are you referring to a more sophisticated trace using a PD Analyzer, like described in SLVA844B. I don't have such a device. 

My assumption was that the device was never entering DP Alt mode because the GPIO0 register never changes from 0x0. 

I am also getting this popup in Windows when I try to connect a USB-C display device. This is the same pop-up I see if I plugged the same USB-C display into a non-Alt-Mode port. It just doesn't seem that the TPS65987D is correctly identifying the DP device.

Hi Kevin,

You may be able to get a simple log using the debug log function in GUI debug mode. However, we would most likely need a full PD analyzer log to debug the Display Port issue since that would allow us to see the full DP negotiations. I'll let Kevin from our team take back over from here. He may be able to at least confirm your project configuration for DP.

Best,

Alex

Kevin, thanks for feedback.

The project file you sent unfortunately did not work to enable DP Mode. I also noticed that USB3 mode no longer works either. If I revert back to the project file I posted, USB3 mode works again. Was there another setting you changed that may have disabled USB3?

I do have a couple other follow-ups:

1. Because I never see the "DP Mode" register change, can you confirm that this does appear to be a negotiation issue between the device and the TPS65987D? I would like to be able to rule out the TUSB1146 and anything else upstream (such as the DP signaling).
2. Is the negotiation purely a communication issue or could there be something in the HW design that is wrong. For example, CC lines or HPD not connected correctly, boot config wrong, etc.?
3. Shouldn't I be able to force the TPS65987D into DP mode by setting its default value to 0x1? I did try this, and the value does default to 0x1, but even when plugging a DP device into the USB-C port, I do not get video.
4. What is the difference between these firmware: f707.10.10 (TPS65987_88_F707_10_10.bin) and f907.14.14 (TPS65987_88_F907_14_14.bin)

Thanks

Hi Kevin,

Thanks for reporting back to me!

KevinMD said:

Because I never see the "DP Mode" register change, can you confirm that this does appear to be a negotiation issue between the device and the TPS65987D? I would like to be able to rule out the TUSB1146 and anything else upstream (such as the DP signaling).

Yes I  would believe that to be true.

KevinMD said:

Is the negotiation purely a communication issue or could there be something in the HW design that is wrong. For example, CC lines or HPD not connected correctly, boot config wrong, etc.?

Unfortunately without a PD log, I would be unable to tell.

KevinMD said:

Shouldn't I be able to force the TPS65987D into DP mode by setting its default value to 0x1? I did try this, and the value does default to 0x1, but even when plugging a DP device into the USB-C port, I do not get video.

You could force the IO high, but the far end device would also need to negotiate a DP connection as well in order for video to work.

KevinMD said:

What is the difference between these firmware: f707.10.10 (TPS65987_88_F707_10_10.bin) and f907.14.14 (TPS65987_88_F907_14_14.bin)

F707.10.10 is for the TPS65987D, whereas the f907.14.14 is for the TPS65987DK.

Which device are you using here? Are you using the TPS65987D or TPS65987DK?

Thank you,

Kevin

Thanks again.

I'm use a TPS65987D. 

Hi Kevin,

Thanks for the clarification!

Can you try taking a snapshot of what the data status register 0x5F reports when you connect with your PD?

Thank you,

Kevin Kosta

Kevin,

Sorry for the delay in getting back to you. 

However, I can't seem to find a way to read 0x5F in the GUI. I don't see it shown anywhere in the Debug Mode or in the Raw View either. Could you help me?

Thanks

Hi Kevin,

No worries!

Let me double check and see if this device supports that register in 0x5F.

I see it in the TRM so I would assume its under the debug registers.

Thank you,

Kevin

Hi Kevin,

It does not look as though 5F is supported with this device.

Can you check the DIP SID Status register? 

I think we will still need a PD log to debug this if possible.

Thank you,

Kevin