拿起书本 发表于 2013-8-7 22:47
测试后,发现进去一次之后就没再进中断了。
but为啥会进去一次了?不是一次都不应该进中断的吗 ...
同学,注意这个函数的最后一句的功能。
/**
Initializes the TIMx Time Base Unit peripheral according to
* the specified parameters in the TIM_TimeBaseInitStruct.
* @param TIMx: where x can be 1 to 17 to select the TIM peripheral.
* @param TIM_TimeBaseInitStruct: pointer to a TIM_TimeBaseInitTypeDef
* structure that contains the configuration information for the
* specified TIM peripheral.
* @retval None
*/
void TIM_TimeBaseInit(TIM_TypeDef* TIMx, TIM_TimeBaseInitTypeDef* TIM_TimeBaseInitStruct)
{
uint16_t tmpcr1 = 0;
/* Check the parameters */
assert_param(IS_TIM_ALL_PERIPH(TIMx));
assert_param(IS_TIM_COUNTER_MODE(TIM_TimeBaseInitStruct->TIM_CounterMode));
assert_param(IS_TIM_CKD_DIV(TIM_TimeBaseInitStruct->TIM_ClockDivision));
tmpcr1 = TIMx->CR1;
if((TIMx == TIM1) || (TIMx == TIM8)|| (TIMx == TIM2) || (TIMx == TIM3)||
(TIMx == TIM4) || (TIMx == TIM5))
{
/* Select the Counter Mode */
tmpcr1 &= (uint16_t)(~((uint16_t)(TIM_CR1_DIR | TIM_CR1_CMS)));
tmpcr1 |= (uint32_t)TIM_TimeBaseInitStruct->TIM_CounterMode;
}
if((TIMx != TIM6) && (TIMx != TIM7))
{
/* Set the clock division */
tmpcr1 &= (uint16_t)(~((uint16_t)TIM_CR1_CKD));
tmpcr1 |= (uint32_t)TIM_TimeBaseInitStruct->TIM_ClockDivision;
}
TIMx->CR1 = tmpcr1;
/* Set the Autoreload value */
TIMx->ARR = TIM_TimeBaseInitStruct->TIM_Period ;
/* Set the Prescaler value */
TIMx->PSC = TIM_TimeBaseInitStruct->TIM_Prescaler;
if ((TIMx == TIM1) || (TIMx == TIM8)|| (TIMx == TIM15)|| (TIMx == TIM16) || (TIMx == TIM17))
{
/* Set the Repetition Counter value */
TIMx->RCR = TIM_TimeBaseInitStruct->TIM_RepetitionCounter;
}
/* Generate an update event to reload the Prescaler and the Repetition counter
values immediately */
TIMx->EGR = TIM_PSCReloadMode_Immediate;
}
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