STM32f411CE RCC / Timings

[Alan_37]

Hello

I am using STM32f411CE there is something wrong with the RCC Settings in Flowcode

I use STM32 Cube MX to calculate the setting no matter what settings I put HSI or HSE
if I simply make a Loop with a C13=1, 300ms delay, C13=0, 300ms Delay, I always get 45ms Delay
when measuring with oscilloscope no matter what setting I put .

I also tried 16mhz HSI direct everything /1 same result .

Any help Please .

[LeighM]

Have you set the clock speed in project settings, to the frequency of the external crystal?
Just checking
Otherwise, could you post an example project?

[Alan_37]

Hi , LeighM

Yes I have set the clock speed LOL ,

I just found it , it was the Auto clear watchdog selected in the options
removing it all works fine now, still don't know why that would happen .

I also wanted to ask why the 411 is limited to 26Mhz in Flowcode
when in the data sheet say it can go up to 100Mhz with PLL

[LeighM]

Ah, well done.

As there are a number of internal clocks, everything relates to the input clock frequency (internal, or external crystal)
So it's the input clock frequency that is limited to 26Mhz (and is set in the project options clock speed)

[Alan_37]

So if I set the clock frequency say to 70Mhz via PLL and in flowcode options
I write 25Mhz cos that is the external oscillator frequency , Will flowcode be able to
calculate the right timings ?

[LeighM]

Yes, that's correct

[Alan_37]

Ok I see ,

Coming from Mcu's like AVR that dose not have PLL , I did not know that flowcade can calculate the internal PLL clocks
well that's cool

Maybe a for next update may I suggests flowcode displaying the calculated PLL clocks that would be nice .

Thanks