Can Nano Dev Kit (and Nano SoM) support or multiple USB 3.0 device interfaces at the same time ?

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1

I working on a design using the Jetson Nano SoM that needs multiple USB 3.0 device interfaces (and possibly one USB 3.0 host interface).

In the documentation for the XUSB peripheral, it looks like it supports 4 USB 3.0 interfaces (SS1-SS4) (Figure 53 in the Technical Reference manual, Tegra_X1_TRM_DP07225001_v1.3p.pdf) but it looks like only 1 port (the OTG port) can be set as a device while all others are host.

In the Jetson Nano dev kit schematic (Jetson_Nano_Carrier_Board_Concept_Schematics.pdf, pg6), it looks like the PCIe shared pins are setup only for 4 lane PCIe and a single USB 3.0 port.

Is it possible to reconfigure the outputs of the SoM per the Nano technical reference manual(pg 1326) for Use Case 1A that supports PCIe 2lanes and USB SS2, SS3, SS1, and SS0 (where one port can be device/OTG and the others be hosts) or is it possible to somehow configure the XUSB for more than 1 device port?

Any help would be appreciated!
Bill

2

Hi,
The product design guide is the guiance for designing custom board:
https://developer.nvidia.com/embedded/dlc/jetson-nano-product-design-guide

We would suggest you follow the guidance to design the board. The default board is the hardware we have fully verified. Would be better to copy most of the design.

3

Thanks for the quick reply. I’ve reviewed the TM (technical reference manual, Tegra_X1_TRM_DP07225001_v1.3p.pdf) again and the Product Design guide and I am still not sure whether or how the Nano SoM can be configured to support both 1 device and 3 host USB 3.0 ports by muxing the PCIe/USB3 pins. In the Nano dev kit, it looks like only 1 USB3 host port is exposed which is connected to a USB3 hub which presents multiple USB A connection.
In our design, we would like to use the Use Case 1A configuration from section 22.7 in the TM where:
PCIE Lane 1 set to PCIE x2 (controller 0) - TegraX1 pins PEX_RX/TX1_N/P, module pins PCIE0_RX/TX3_N/P
PCIE Lane 2 set to PCIE x2 (controller 0) - TegraX1 pins PEX_RX/TX2_N/P, module pins PCIE0_RX/TX2_N/P
PCIE Lane 3 set to USB SS (Port 2) Host - TegraX1 pins PEX_RX/TX2_N/P, module pins PCIE0_RX/TX0_N/P
PCIE Lane 4 set to USB SS (Port 3) Host - TegraX1 pins PEX_RX/TX2_N/P, module pins PCIE0_RX/TX1_N/P
PCIE Lane 5 set to USB SS (Port 1) Host - TegraX1 pins PEX_RX/TX5_N/P, no module pins seem to expose this lane
PCIE Lane 6 set to USB SS (Port 0) Device - TegraX1 pins PEX_RX/TX6_N/P, module pins USBSS_RX/TX_N/P

Is there a way to configure the Nano SoM as above?

A colleague of mine did note that in the Jetson TX2 dev kit, multiple USB ports are configured (USB_SS1_RX/TX is assigned to PEX_RX/TX2 and USB_SS0_RX/TX assigned to PEX_RX/TX0).

Please let me know.

4

Hi,
For using Jetson Nano, we would suggest you follow the USB lane mapping of default carrier board. This is the design we have verified. For customizing USB lane mapping, you may consider TX1 or TX2.

5

This answer doesn’t help me understand whether I will be able to use the Nano SOM in my design, even if not supported by the Nano Dev Kit. Can you provide me with a contact that can help answer the question I’ve presented above please?

6

Hi wvpowell,
The design is invalid on Nano. Please also check adaptation guide(Table 2):

You can see only PEX_TX6/PEX_RX6 can be used as USB3.0 function.

If you use TX1 module, you can use two USB3 ports. Please check Table 15:
https://developer.nvidia.com/embedded/dlc/Tegra_Linux_Driver_Package_TX1_Adaptation_Guide
http://developer.nvidia.com/embedded/dlc/jetson-tx1-oem-product-design-guide
For using two USB3 ports, you can use config #3 and #4.

Due to the design of Nano/TX1 module, it is not possible to customize four USB3 ports.

7

When you say the “the design is invalid on the Nano”, do you mean:

  • That the USB3 port (even the one on Lane 6) cannot be configured as a USB device?
  • That PCIe Lanes 4 and 5 cannot be configured as USB hosts?
  • That the XUSB driver software would need to be modified to recognize that other PCIe lanes might be assigned to something else?

I don’t see Table 15 in the document you referenced:
If you use TX1 module, you can use two USB3 ports. Please check Table 15:

Can you provide the page #?

I agree 4 USB 3.0 ports on Nano not possible because PCIE Lane 5 is not brought out, but seems like 3 would be possible… (Lane 3, Lane 4, and Lane 6)

8

Hi,
Table 15 is in product design guide, not adaptation guide. My apology for giving wrong link. It is corrected.

This is possible. There is guidance of modifying device tree. Please check ‘For an OTG (On-The-Go) Port’ in adaptation guide.

This is not possible. Lane 4 cannot be configured as USB host. Pins of lane 5 are not used.