LS1021A - USB 3.0 Port will not enumerate at USB 2.0 High Speed

[sm7777]

Hello,

I'm currently looking at an issue with the LS1021a whereby the USB 3.0 port enumerates fine at both at SS & FS, but is not enumerating at HS.

Looking at the USB DP/DM pair with a scope, the LS1021A is not putting out a K-chirp during reset after the bus enumerates at FS.

Has anyone else encountered this problem?

Thanks and best regards,

Steve

[yipingwang]

Hello Steve Merritt,

USB 3.0 provides backward compatibility, any USB 3.0 port has a USB 2.0 PHY signals and additional super-speed signals section. 
 USB 2.0 host controllers and hubs provide capabilities so that full-speed and low-speed data can be transmitted at high speed between and the host controller and the hub, but transmitted between the hub and the device at full-speed or low-speed.

We have tested TWR-LS1021a USB 3.0 port to work at USB 2.0 mode without any problem. You could refer to TWR-LS1021a  hardware design. You could download document "QorIQ LS1021A Design Checklist" from https://www.nxp.com/products/processors-and-microcontrollers/arm-based-processors-and-mcus/qoriq-lay...  to check USB PHY pin checklist.

In addition is it possible for you to program LSDK u-boot on your custom target board to do more verification? Because we have some errata fixed in u-boot source code. Eg. A-009798: USB high speed squelch threshold adjustment

If your problem remains, you could create a case in our internal system to review your hardware design.

Thanks,

Yiping