Showing clock incompatibility while selecting USB_OTG_FS in STM32F205VE

[Abin]

Hai ,

I enabled USB_OTG_HS in STM32F205VE and default frequency as 15 MHz. At this situation , It is showing the Error in the clock configuration and when we select the option "Resolve clock issue Automatically" then the Clock becomes 120 MHz. Don't this protocol work in lower frequency?

In addition to that , I need to use SPI and FSMC in the same controller. Whether any issue will arise in future? Can anybody help me?

[TDK]

USB requires a reliable 48 MHz clock. You can typically use a PLL to generate this from common crystal frequencies.

Using SPI, FSMC and USB together poses no issues. SPI and FSMC clocks do not need to be exact unlike the USB.

[Abin]

Thank You So Much for your reply! I will check this.

[Piranha]

Actually the RC based oscillators are more reliable than crystal oscillators. Especially in environments with vibration. But, of course, here we actually care for a specific accuracy and stability.

[Abin]

But RC oscillator will be affected by Temperature. Am I correct?

[Piranha]

All of them are, but the RC based ones are affected much more than the crystal based ones.