TIM2 clock source disabld but timer still running correctly?

[Ricko]

Hi,

as you can see from the screenshot below I have TIM2 clock source set to disable but the PWM is still running as configured and generates PWM. And it has been like that for the entire project for a while so I just noticed.

Does the time start function automatically select the source to some default like the Internal clock? Or is that Clock source referring to something else? Just asking because I want to make sure the code is running correctly for the right configuration not because of some other settings that somehow override these.

Thank you

[SofLit · Accepted solution]

Hello,

When Clock source is disabled, HAL_TIM_ConfigClockSource() is not generated and when "Internal Clock" is selected, the following code is generated:

  sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
  if (HAL_TIM_ConfigClockSource(&htim2, &sClockSourceConfig) != HAL_OK)
  {
    Error_Handler();
  }

And according to HAL_TIM_ConfigClockSource() implementation TIM_CLOCKSOURCE_INTERNAL does almost nothing, just some bit reset before: 

  /* Reset the SMS, TS, ECE, ETPS and ETRF bits */
  tmpsmcr = htim->Instance->SMCR;
  tmpsmcr &= ~(TIM_SMCR_SMS | TIM_SMCR_TS);
  tmpsmcr &= ~(TIM_SMCR_ETF | TIM_SMCR_ETPS | TIM_SMCR_ECE | TIM_SMCR_ETP);
  htim->Instance->SMCR = tmpsmcr;

  switch (sClockSourceConfig->ClockSource)
  {
    case TIM_CLOCKSOURCE_INTERNAL:
    {
      assert_param(IS_TIM_INSTANCE(htim->Instance));
      break;
    }

So "Internal Clock" and "Disable" seems to have the same behavior.