这两个函数有什么区别？

只看该作者 · 2014-5-3 10:22

TIM_ITRxExternalClockConfig 设置 TIMx 内部触发为外部时钟模式
TIM_TIxExternalClockConfig 设置 TIMx 触发为外部时钟

都是把定时器的内部触发改为外部触发。不知有什么区别。

只看该作者 · 2014-5-3 10:37

触发源的时钟选择和触发源选择

3万 · 2014-5-3 11:51

本帖最后由 mmuuss586 于 2014-5-3 11:56 编辑

楼上正解。

楼主，看下函数的原型就明白了

/**
  * @brief  Configures the TIMx Trigger as External Clock
  * @param  TIMx: where x can be 2, 3, 4, 5 or 9 to select the TIM peripheral.
  * @param  TIM_TIxExternalCLKSource: Trigger source.
  * This parameter can be one of the following values:
  *    @arg TIM_TIxExternalCLK1Source_TI1ED: TI1 Edge Detector.
  *    @arg TIM_TIxExternalCLK1Source_TI1: Filtered Timer Input 1.
  *    @arg TIM_TIxExternalCLK1Source_TI2: Filtered Timer Input 2.
  * @param  TIM_ICPolarity: specifies the TIx Polarity.
  * This parameter can be one of the following values:
  *    @arg TIM_ICPolarity_Rising:
  *    @arg TIM_ICPolarity_Falling:
  * @param  ICFilter : specifies the filter value.
  * This parameter must be a value between 0x0 and 0xF.
  * @retval None
  */
void TIM_TIxExternalClockConfig(TIM_TypeDef* TIMx, uint16_t TIM_TIxExternalCLKSource,
                              uint16_t TIM_ICPolarity, uint16_t ICFilter)
{
  /* Check the parameters */
  assert_param(IS_TIM_LIST2_PERIPH(TIMx));
  assert_param(IS_TIM_IC_POLARITY(TIM_ICPolarity));
  assert_param(IS_TIM_IC_FILTER(ICFilter));

  /* Configure the Timer Input Clock Source */
  if (TIM_TIxExternalCLKSource == TIM_TIxExternalCLK1Source_TI2)
  {
TI2_Config(TIMx, TIM_ICPolarity, TIM_ICSelection_DirectTI, ICFilter);
  }
  else
  {
TI1_Config(TIMx, TIM_ICPolarity, TIM_ICSelection_DirectTI, ICFilter);
  }
  /* Select the Trigger source */
  TIM_SelectInputTrigger(TIMx, TIM_TIxExternalCLKSource);
  /* Select the External clock mode1 */
  TIMx->SMCR |= TIM_SlaveMode_External1;
}

3万 · 2014-5-3 11:53

/**
  * @brief  Configures the TIMx Internal Trigger as External Clock
  * @param  TIMx: where x can be 2, 3, 4, 5 or 9 to select the TIM peripheral.
  * @param  TIM_ITRSource: Trigger source.
  * This parameter can be one of the following values:
  * @param  TIM_TS_ITR0: Internal Trigger 0.
  * @param  TIM_TS_ITR1: Internal Trigger 1.
  * @param  TIM_TS_ITR2: Internal Trigger 2.
  * @param  TIM_TS_ITR3: Internal Trigger 3.
  * @retval None
  */
void TIM_ITRxExternalClockConfig(TIM_TypeDef* TIMx, uint16_t TIM_InputTriggerSource)
{
  /* Check the parameters */
  assert_param(IS_TIM_LIST2_PERIPH(TIMx));
  assert_param(IS_TIM_INTERNAL_TRIGGER_SELECTION(TIM_InputTriggerSource));
  /* Select the Internal Trigger */
  TIM_SelectInputTrigger(TIMx, TIM_InputTriggerSource);
  /* Select the External clock mode1 */
  TIMx->SMCR |= TIM_SlaveMode_External1;
}

1万 · 2014-5-4 09:59

本帖最后由香水城于 2014-5-4 10:05 编辑

看图说话：

TIM_ITRxExternalClockConfig，从图中标号为2的四个信号源中选择一个作为counter的时钟

TIM_TIxExternalClockConfig，从图中标号为3的三个信号源中选择一个作为counter的时钟