FCT (Functional Circuit Testing) and EOL validation for our i.MX8QXP-based platform.

[Ram2]

Hi NXP Team,

We are currently working on FCT and EOL validation for our i.MX8QXP-based board.

As of now, we are using a USB-to-UART converter connected to the SoC to invoke AT commands for validating LTE, eSIM, GNSS, CPU, and PMIC via a serial interface from the host PC.

However, our final hardware setup includes a direct USB device mode interface, and we would like to understand:

Whether it is possible to use the USB interface USB-to-USB to directly send AT commands from PC to target,
What USB gadget,class driver  would be best suited for this use case,
Any recommended way to expose a virtual serial port over USB to allow the host to send AT commands (similar to what’s done via USB-UART today)
Any caveats or limitations for using this method in mass production (EOL testing).

Please let us know your recommendations or if you foresee any challenges with this approach.