2019-02-11 07:27 AM
Hello.
We have custom board with STM32H743XI mcu and USB3320. Power supply for microcontroller is 1.8V. When initialized USB1_HS in Full Speed mode, PC recognized board like VCP and data transaction is ok. But when initialized in High Speed mode, PC dont recognized board. We used generator for REFCLK.
Our design of USB3320:
2019-02-26 02:44 AM
Hello. Problem resolved. Was bad PCB routing of ULPI lines between STM and USB3320. Line DIR was smaller that other lines. But it started working when pins speed changed from HIGH_SPEED to VERY HIGH SPEED.