TPS65988DK: Connection issue by using TBT3 cable

Gary Teng

Part Number: TPS65988DK
Other Parts Discussed in Thread: TPS65994AE

Hi all,

My customer use TPS65988DK in docking application with goshin ridge platform. They find a strange condition: When using TBT3 cable to connect with Dell XPS13 9310 (might be used 99x as PD controller), they'll see VCONN SWAP message transmitted between host and slave side so all connection are failed. But if they use TBT4/USB4 cable, the commination is ok. And there's no problem on other laptop. Would you plase helping to check what's wrong in their setting? (Customer said older version FW might not have the issue) Thanks for your kindly help.

GUI version: 6.3.3 FW version: F907.14.07

Best regards,

Gary Teng

8561.Desktop.rar

over 3 years ago

0 Christodulos Tsongas over 3 years ago

TI__Genius 13255 points

Under Port Control (0x29) in the project, try setting Process VCONN Swap to 0.

0 Gary Teng over 3 years ago in reply to Christodulos Tsongas

Genius 5900 points

Hi Sir,

We think stop VCONN SWAP might solve the issue too. But we want to know why that happened. In fact, customer has another project using 988AE but that don't have the same issue. Do you have any comment about that?

Regards,

Gary

65988_F907_14_07_GUI633_90W_20211201.pjt

0 Christodulos Tsongas over 3 years ago in reply to Gary Teng

TI__Genius 13255 points

By 998AE do you mean the TPS65994AE? If so then the TPS65994AE is not the same FW which would mean different configurations and behavior.

0 Gary Teng over 3 years ago in reply to Christodulos Tsongas

Genius 5900 points

Sorry about my TYPO. I mean 988DK. Our customer has 2 988DK projects with the same base FW. One has that problem and another is OK (but it has another smart power issue...). You can check the two PJTs attached above.

Regards,

Gary

0 Christodulos Tsongas over 3 years ago in reply to Gary Teng

TI__Genius 13255 points

It Tx Identity look to differ between the two. Also the USB4 device disrupts the VCONN swap by entering an Alternate mode. Disabling the Process VCONN Swap will stop the device from continually doing the swap message

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TPS65988DK: Connection issue by using TBT3 cable