USB C connector using onboard USB and PCI-E mux


I am working on a USB Type C interface for a carrier board. I am planning on using a TI TUSB321 controller to handle the orientation detection and initialisation part of the protocol, and in their application note they recommend using a separate multiplexer to switch the USB SS RX and TX pairs, depending on the detected orientation. However I have noticed that the Jetson seems to have a suitable multiplexer built in, multiplexing the USB_SS0 and PEX1 lines to connect to the PEX lane 0. The relevant note in the OEM design guide states “PCIe interface #2 can be brought to the PEX1 pins, or USB 3.0 port #1 to the USB_SS0 pins on Jetson TX2 depending on
the setting of a multiplexor on the module. The selection is controlled by QSPI_IO2 configured as a GPIO.”

So my question is, can I simply connect one set of TX and RX lines to the PEX1 TX and RX connections, and the other to the standard USB_SS0 lines, and then use the QSPI_IO2 GPIO to switch between them based on detected orientation?

Many thanks.

Hi gareth,

Sure, it should work, please check the related part in OEM DG to change PEX lines to USB lines.