I'm using an STM32H750 MCU to run an application that communicates with a computer via USB in CDC ACM mode. The application uses USBX from Eclipse ThreadX and an external USB PHY (USB3300) to perform high-speed communication. My application works fine when running in PCD_SPEED_FULL mode (12 Mb/s), but when running in PCD_SPEED_HIGH mode (480 Mb/s), some computers don't recognize the device. Initially, I thought the computer's USB port didn't support high-speed devices, but I've already connected another device that was identified as 480Mb/s on the same USB port. Does anyone have any idea why the STM32+USB3300 isn't identified when it's in high-speed mode, even on a USB port that can identify devices with that speed?
