Jetson Nano Carrier Board design without UPHY (U27) - for USB3.0

[alex.imp]

Hello,
I am working with the Jetson Nano schematics for my project. I have designed a custom carrier board with Ethernet Port, Debug USB, USB2.0, USB3.0…

The Ethernet is working as expected.
For the Debug USB and USB2.0 I used this example schematic and it worked fine…

But for USB3.0 I am facing an issue to get it operational… I have used the reference schematic from Product design guide… (UPHY from the Carrier board sch is not used as I require only 1 USB3.0)…

I have studied the form for similar topics and found that I might require customization with Pinmux configuration (DT File) but have no concrete direction. Please suggest steps to solve this issue / point me to a appropriate solution.

[DaneLLL]

Hi,
For programming device tree, please refer to adaptation guide:
https://docs.nvidia.com/jetson/archives/l4t-archived/l4t-3261/index.html#page/Tegra%20Linux%20Driver%20Package%20Development%20Guide/adaptation_and_bringup_nano.html#wwpID0E0DM0HA

[alex.imp]

Hi @DaneLLL, Thank you for the quick reference link.

I am trying to understand these concepts… Can you please guide me through?

I have located the .txt files in the source. But not sure where to make the changes to use the USB1_D_N, USB1_D_P, USBSS_RX_N, USBSS_RX_P, USBSS_TX_N, USBSS_TX_P from the SoM as USB3.0 without the requirement of U27.

[DaneLLL]

Hi,
Looks like the USB3 type-A port is same pair USB3-0/USB2-1 as Jetson Nano developer kit. Probably the issue is in VBUS pin. Do you have same design to use pin #239 to control VBUS?

[alex.imp]

VBUS is powered from the main power source (5V). The #239 is open in my schematics.

[DaneLLL]

Hi,
The VBUS pin is defined in device tree. Please remove it and try again. Generally it is better to have a VBUS detection pin to trigger enumeration. Not sure if it works properly with a always-on VBUS pin.