I am barely new to the embedded world and for a new project I require a 1μs timer. I am using the discovery board STM32F407VG.

These are the settings on how I have configured the timer:

• Basic timer 6 at a clock frequency of 84 MHz

• Following this formula I set the Prescaler to 0 and the Counter period to 83 to obtain a period of 1μs:

  • Counter Period = ( Time base required (in seconds) × ( Timer clock source / (Prescaler + 1) ) ) - 1

  • Counter Period = ( 0.000001 × ( 84000000 / (0 + 1) ) ) - 1 = 83

Then, I use this function with the flag TIM_FLAG_UPDATE:

static void microDelay (uint32_t delay){

    while (delay){
      if(__HAL_TIM_GET_FLAG(&htim6, TIM_FLAG_UPDATE)){
    	  __HAL_TIM_CLEAR_FLAG(&htim6, TIM_FLAG_UPDATE);
    	  delay--;
      }
    }
}

I haven't had any issues so far. I tested it with a logic analyzer by toggling a pin, and I didn't encounter any problems. My concern is that in a few tutorials, I saw that they simply matched the prescaler value to the timer clock frequency to obtain a Timer clock source of 1MHz and then set the Counter period to its maximum value. Then, they used the following function:

void delay_us (uint16_t us)
{
	__HAL_TIM_SET_COUNTER(&htim1,0);  
	while (__HAL_TIM_GET_COUNTER(&htim1) < us);  
}

Maybe I am being too fussy, but with this solution, if you enter a value bigger than the counter period the while loop will loop forever... and I don't see that problem in my solution.

However, do you think my solution could lead a further problems? Maybe, I am missing something that could make the timer fail in the future.

Thanks