i.MX 8QuadXPlus MEK USB_OTG1 in Host Mode causes UUU failure

[ET_Dev]

Hello,

Our hardware design is based on the MEK design. We want to use the USB_OTG1 port as a host port for a cellular modem, and to use this port as a host we are populating R1194. This connects the VCC_PER_5V0 power rail to the USB_OTG1_VBUS pin on the processor. This enables the host mode and we are able to communicate with the cellular modem.

However, in this configuration (R1194 populated) UUU fails. With the error

HID(W):LIBUSB_ERROR_IO

If we remove R1194 the board reverts back to usual behaviour (cellular modem disconnects and UUU becomes operational) 

How do we fix this?

We want to use USB_OTG1 as a host and we want UUU to be functional on the other USB C connector.  

[ET_Dev]

Hello Rita Wang

Are your design the same with our reference board? - Yes.

If you make the USB_OTG1 in host mode, it can not work on the device mode and use the uuu tool. - We are making USB_OTG1 in Host mode. But in the reference design (and our design) the USB C port is connected to the USB_OTG2 and USB_SS3 on the Processor. 

So the question is  - why is USB_OTG1 port mode (host) causing failure of uuu on a completely different USB port (USB_OTG2 or USB_SS3)? 

I hope I am making this clear. 

[Rita_Wang]

For the i.MX8QXP support two usb:

• 1x USB 3.0 OTG with dual role functionality (with PHY) - can be used as USB
2.0
• 1x USB 2.0 OTG (with PHY)

The i.MX 8QuadXPlus MEK board has one USB Type-C connector on the top side. The i.MX 8QuadXPlus applications processor has one USB3/USB2 OTG module, which is specified to perform USB 3.0 dual role and USB 2.0 On-The-Go (OTG), compatible with the USB 3.0 specifications and USB 2.0 specifications with OTG supplementary specifications. The USB3/USB2 OTG module supports two independent USB cores (1× USB3.0 dual-role, 1× USB2.0 OTG). The processor has an additional USB 2.0 OTG module, which can be used separately and independently.
The USB_SS3 and USB_OTG2 are connected to the USB Type-C connector in the MEK board. The USB_OTG1 is connected to the USB OTG connector in the base board.

[ET_Dev]

Hello Rita Wang

Noted on the details you have shared, and yes this is inline with our board as well. Issue however is when we make USB_OTG_1 to host mode, this is causing failure of UUU on the USB C port. Please help check this issue. 

[Rita_Wang]

You mean when you make USB_OTG_1 to host mode, this is causing failure of UUU on the USB C port.

when you make USB_OTG_1 to OTG mode, it is well to use the UUU on the USB C port?

[ET_Dev]

You mean when you make USB_OTG_1 to host mode, this is causing failure of UUU on the USB C port.

- Yes. 

when you make USB_OTG_1 to OTG mode, it is well to use the UUU on the USB C port?

- We have not tested this and I am not sure how to do this either. If you can tell me how to do this I can check this as well. 

[Rita_Wang]

 You can try to DNP R1194 to see if it can work.

[Rita_Wang]

Are your design the same with our reference board?

If you make the USB_OTG1 in host mode, it can not work on the device mode and use the uuu tool.