USB 3.0 Dual role mode possible?

[thomas20]

Hi all,

I saw multiple posts about USB3.0/… But no real concrete answer to following question:
Is it possible to implement USB3.0 dual role mode? (not usb 2.0 otg or something).

Thanks in advance!

[DaneLLL]

Hi,
If dual mode means Jetson Nano is in host and device modes at the same time, this is not supported.

[thomas20]

Hi DaneLLL,

Thanks for your reply. Let me sketch the situation with a bit more detail - there seems to be quite some confusion with USB2, OTG, USB3, DRP, etc etc.

General notes:

• this is not about the DK systems, but rather based on a custom carrier for the Nano/XavierNX

• the end goal here is getting transfer speeds from the Jetson TO a PC/laptop of 5Gbps

• the ‘flash port’ (USB_0), which on the DK is also a USB2.0 OTG capable is not important. If it needs to be disabled to enable SuperSpeed - no problem.

Ideal scenario:

We put together the USB_SS and the USB2 ports + a “Dual-role port (DRP) controller” (HD3SS3220) on a USB-C connector. The Jetson system has two modes - when e.g. a ‘flash drive’ is connected it works as a host, when a laptop is connected it works as a device. The “DRP controller” helps managing the CC lines etc. This is currently implemented in our hardware.

OK scenario:

The Jetson serves purely, fixed-mode, as a USB3 device. Connecting a ‘flash drive’ doesn’t work. Connecting a laptop works at USB3 SuperSpeed. The linux ‘gadget’ system works as expected.

The question is, therefore: Does the XUSB controller support the USB3/USB-C DRP mode?

If yes, do you perhaps have an example of how to configure it?

If no, is there an example of using the USB3 in a SuperSpeed “device” mode? According to the TRM it should be supported, there is also a mention of ‘either USB2 or USB3 interface can be active’ - how can you switch to the USB3 one?

Thanks in advance!

[DaneLLL]

Hi,
The modes are advancing and mat not work properly on Jetson Nano. We would suggest run as the developer kit to have USB3 host mode and USB2 device mode.