TUSB9261: TUSB9261 USB SS RESETs after SS training , on USB0 port of Keystone 2 K2E.

Frederic SANSON

Part Number: TUSB9261
Other Parts Discussed in Thread: AM5K2E04

Hi,

As described in our former thread concerning this topic: "TUSB9261: USB repetitive RESET Burst during boot after Super Speed negotiation - Interface forum - Interface - TI E2E support forums"

we observed that the bridge doesn't behave the same way in our design integrating on the same PCB the Soc and the bridge, compared to an exploratory set up constituted of the K2E EVM board with the TUSB9261 demo board connected to the USB0 slot of the K2E EVM.

In our design random repetivive resets of the USB after SS training is observed, and none with the K2E EVM connected to TUSB9261 DEMO Board.

In some additional case we observed the USB bus to revert in SUSPEND mode until a new RESET occure, and this several consecutive times, inducing a long time for the SoC to discover devices on the BUS

Eye diagram aperture of USB3 SS diff signal seems correct in our design ( Keysight 33GHz scope used for this characterisation).

may the Bridge or the SoC Phi very sensitive to PS noise ?

We projects to replace one buck providing 1.1V to Bridge by a less noisy LDO.

Any ideas and suggestions from you are welcome.

Best regards

Fred

over 1 year ago

0 Ryan Kitto over 1 year ago

TI__Mastermind 40935 points

Hi Frederic,

I am discussing this internally with the team, and I will work on getting an answer back to you by EOD Monday. Thanks in advance.

Thanks,

Ryan

0 Nicholaus_Malone over 1 year ago in reply to Ryan Kitto

TI__Mastermind 27925 points

Hi Frederic,

The power filtering recommended by the TUSB9261 implementation guide in Section 2. The EVM schematic is also available there. Can you share your schematic so I can check and see if they match?

TUSB9261 Implementation Guide (Rev. E)

Regards,

Nicholaus

0 Nicholaus_Malone over 1 year ago in reply to Nicholaus_Malone

TI__Mastermind 27925 points

Hi Fred,

Are you able to provide the schematic?

Regards,

Nicholaus

0 Nicholaus_Malone over 1 year ago in reply to Nicholaus_Malone

TI__Mastermind 27925 points

Hi Fred,

Do you still need a schematic review? If not, then I will close the issue due to inactivity.

Thanks,

Nicholaus

0 Frederic SANSON over 1 year ago in reply to Nicholaus_Malone

Prodigy 30 points

Bridge side ,with filter on his main PS

and his 1V1 power supply:

and the Keystone side connexions

K2E side

Hi Nicholaus,

here are our schematics (already partially provided in the former topic related to bridge/usb reset itself.

Thank for your review and suggestions.

best regards

Frederic

0 Nicholaus_Malone over 1 year ago in reply to Frederic SANSON

TI__Mastermind 27925 points

Thanks Fred,

It looks like there is significant power filtering for the TUSB9261, and so I wouldn't expect noise to be an issue for that part, but I will continue to review the schematic to make sure. I can't speak to the requirements for the AM5K2E04, but I will let you know if I find anything. Were you ever able to get support for the embedded processor team for that? There is one item in the AM5K2E04 errata that seems interesting: "USB Hangs When Doing a Master Access to Reserved Space". Does your software attempt to access reserved space in one setup and not the other?

Something else I noticed on the schematic the resistor divider is not correct. R730 be updated to 90.9kohm.
"Design requirements - 90.9kohm (1%) and 10kohm (1%) voltage divider" - Previous E2E issue

Below are the two setups. Let me know if my understanding is correct.

Setup #1: EVMK2EX Development kit with 66AK2E05 + TUSB9261DEMO Evaluation board (passing)
Setup #2: Custom PCB with integrated AM5K2E04 and TUSB9261 (failing)

I will follow-up if there are any more findings.

Regards,

Nicholaus

0 Nicholaus_Malone over 1 year ago in reply to Nicholaus_Malone

TI__Mastermind 27925 points

Hi Fred,

Were you able to get support from the EP team?

Regards,

Nicholaus

0 Nicholaus_Malone over 1 year ago in reply to Nicholaus_Malone

TI__Mastermind 27925 points

Closing due to inactivity.

Regards,

Nicholaus