如题，STM32U595，USB要使用HIGH SPEED，也就是480M总线速度，手册上说的HS必须要用HSE做时钟源，但是现在试了下，用HSI做时钟源，也是可以的，这是个例还是确实可以用HSI做时钟源？如果批量出产品，用HSI做USB HS时钟源，会不会经常故障，良品率不高？

USB on-the-go high-speed (OTG_HS) The devices embed an USB OTG high-speed device/host/OTG peripheral with integrated transceivers. The OTG_HS peripheral is compliant with the USB 2.0 specification and with the OTG 2.0 specification. It has software-configurable endpoint setting and supports suspend/resume. This interface requires a precise 60 MHz clock that is generated from the internal USB PHY PLL (the clock source must use a HSE crystal oscillator).

这个地方手册都明确强调MUST了，当然要基于HSE时钟源来进行USB、CAN之类的通信了。至于你现在手头开发板使用HSI可以，不代表所有板子及场合都行。总之，按手册的来。