STM32CubeMX Clock configuration error

[benjaminbrammer9]

Posted on November 14, 2016 at 16:59

Hi guys,

I want to use the internal 8MHz HSI reference for generating my clocks, but allthough there is now clock speed error to resolve I still get an error that the HSI is not recommended for the PLL as input. Why is that? And if this is the case, why does STM offer the possibility to do so?

here's an image of my clock configuration.

best regards

Benjamin

[Jeanne Joly]

Posted on November 15, 2016 at 16:59

Hi brammer.benjamin,

In some application note on the clock configuration tool, you can find in the chapter clock scheme : 

''For accuracyreasons, the USB peripheral must only be driven by the PLL configured with theHSE clock source.''

On the picture you shared, I can see that you activated USB and in this case, as written previously, only HSE clock source can be activated.

I hope it is clearer.

BR

Eric Dampierre.

[benjaminbrammer9]

Posted on November 18, 2016 at 10:01

Thanks for your reply!

Yes, now it is clear, so I will implement an external crystal.

best regards

Benjamin