STm32f407: Which Registers control HSI or HSE oscillator selection and PLL clock source?

[Ash1]

Hi 

I want to understand "which register decides whether HSI or HSE oscillator is selected for PLL clock source in STM32F407"(selection of the HSI or HSE oscillator as PLL clock source"

B.R

Ash

[Andrew Neil]

See the Reference Manual - it will be linked from the 'Documentation' tab on the Product Page for the chip.

You'd need to give the full part number (not just STM32F407) to get to the correct page.

You can also configure it graphically using CubeMX (either standalone or within CubeIDE), then examine the generated code.

BTW: I edited your title - just "STM32F407" doesn't give much indication of what the thread is actually asking.

[STTwo-32 · Accepted solution]

Hello @Ash1 

According to the RM0090, the PLL source is selected throw the PLLSRC bit of the RCC_PLLCFGR register:

For your coming requests, please have a look at our documents, almost all details are well provided there as said @Andrew Neil .

Best Regards.

STTwo-32