How do I get system clock frequency?

[dhruvin91]

Hi,
I am looking to add 10 ms delay in the code. I am not sure if there is any delay function in chibios. But I can add a delay function if I knew the clock frequency. I tried to find out what clock frequency my code has but didn't get anywhere.

Does anyone know how to find clock frequency in mycode or add delay?
Thank you.

[Giovanni]

It is in any demo...

chThdSleepMilliseconds()

...or in the documentation...

http://chibios.sourceforge.net/html/gro ... e4cad9f56f

...or you may also look at this article...

http://www.chibios.org/dokuwiki/doku.ph ... :kb:timing

Giovanni

[dhruvin91]

does this work when I am not using threads?
Thank you.

[Faisal Mehmood]

I guess you would have figured it out already. In case you didn't:
When the kernel has been initialized, the main() function becomes a thread as well. It is documented in the demo:

Code: Select all

/*
 * Application entry point.
 */
int main(void) {

  /*
   * System initializations.
   * - HAL initialization, this also initializes the configured device drivers
   *   and performs the board-specific initializations.
   * - Kernel initialization, the main() function becomes a thread and the
   *   RTOS is active.
   */
  halInit();
  chSysInit();
  (remaining demo follows...)
  

ChThdSleepMilliseconds() will 'sleep' the main 'thread' for the specified milliseconds.

[Guillaume227]

Going back to the title question (the op was actually interested in adding delay to his code so the discussion stopped there) :
I do not see anywhere in the API a method that returns the clock frequency which the MCU is set to.
What's the recommended way to access that value?

[Giovanni]

Hi,

For STM32 it is STM32_HCLK, it is HAL exporting it.

Giovanni

[electronic_eel]

Wouldn't it make sense to provide the frequency in a hardware-independent way?

Or is there some limitation that makes it hardware dependant?