[BUG] CubeMX, weird behavior of the Clock config view

[Pavel A.]

On STM32H753, I want to change the clock source of I2C1.

Previously it was HSI with divisor 4 that gives 16 MHz.

I noticed that PLL3R outputs almost 16 MHz and try to change I2C1 to this source.

Then Cube craps out and declares conflict. Auto-resolving it changes settings of PLL1 and clock rates of other peripherals.

 

What's wrong with it?

Finally I managed to tweak PLL3 ... maybe by pure luck.

CubeMX ver 6.2.1

[TDK]

The outputs from DIVMx, which are the input to the PLL, need to be within 1-16MHz. Seems like it should be giving you an error in the top picture as well. Could be more clearly written in the RM, but it's there.

 

[Pavel A.]

Thank you TDK!

Well, then bug report:

• When PLLn (1-3) is unused, clock config should not show invalid or meaningless values.
• When PLLn parameters are auto-resolved, changes should not affect other PLLs, if possible.