STM32H7 ADC_CR Boost bits

[jowakar122]

I am using NUCLEO_H723ZG in which I am using 12-bit resolution ADC. Below is the clock used for ADC:

Moreover, I have used DIV2 clock prescaler. So my BOOST bits in ADC_CR register should be 11 as it is mentioned in the reference manual.

I checked those BOOST bits while debugging and they are set 10 instead of 11.

So I assumed the clock frequency to be 50 MHz and checked all the condition. With that all condition the BOOST bits changes accordingly.

Although 64 MHz is shown there but the clock frequency used is 50 MHz?

[TDK]

The relevant clock rate for the BOOST value is the clock at the ADC--after all the prescalers. You have an input of 64 MHz, a prescaler of 2, and a fixed prescaler of 2, so the clock rate at the ADC is 16 MHz, which lines up with BOOST=10.