定时器中断实验

常用库函数：定时器参数初始化

void TIM_TimeBaseInit(TIM_TypeDef*TIMx,

                                            TIM_TimeBaseInitTypeDef*TIM_TimeBaseInitStruct);

typedefstruct

{

  uint16_t TIM_Prescaler;       //预分频系数

  uint16_t TIM_CounterMode;    //计数模式是向上还是向下

  uint16_t TIM_Period;       //自动装载值

  uint16_t TIM_ClockDivision; //捕获里用到

  uint8_t TIM_RepetitionCounter;//高级定时器用到

} TIM_TimeBaseInitTypeDef

--定时器使能函数：

void TIM_Cmd(TIM_TypeDef*TIMx,FunctionalStateNewState)

--定时器中断使能函数：

void TIM_ITConfig(TIM_TypeDef*TIMx, uint16_t TIM_IT, FunctionalStateNewState);

--状态标志位获取和清除

FlagStatusTIM_GetFlagStatus(TIM_TypeDef*TIMx, uint16_t TIM_FLAG);

void TIM_ClearFlag(TIM_TypeDef*TIMx, uint16_t TIM_FLAG);

ITStatusTIM_GetITStatus(TIM_TypeDef*TIMx, uint16_t TIM_IT);

void TIM_ClearITPendingBit(TIM_TypeDef*TIMx, uint16_t TIM_IT);

--定时器中断实现步骤：

① 能定时器时钟。

       RCC_APB1PeriphClockCmd();

②  初始化定时器，配置ARR,PSC。

      TIM_TimeBaseInit();

③开启定时器中断，配置NVIC。

      void TIM_ITConfig();

      NVIC_Init();

④  使能定时器。

      TIM_Cmd();

⑥  编写中断服务函数。

      TIMx_IRQHandler();

Tout（溢出时间）=（ARR+1)(PSC+1)/Tclk

通过定时器中断配置，每500ms中断一次，然后中断服务函数中控制LED实现LED1状态取反（闪烁）。

void TIM3_Int_Init(u16 arr ,u16 psc){TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;NVIC_InitTypeDef NVIC_InitStructure; RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3 , ENABLE);    TIM_TimeBaseStructure.TIM_Prescaler = arr;TIM_TimeBaseStructure.TIM_Period = psc;     TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up;     TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE);//使能更新中断       NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;      NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;    NVIC_Init(&NVIC_InitStructure);TIM_Cmd(TIM3, ENABLE);    TIM_ClearFlag(TIM2, TIM_FLAG_Update);        TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE);   }void TIM3_IRQHandler(void){if(TIM_GetITStatus(TIM3 , TIM_IT_Update) != RESET ){LED1=!LED1;TIM_ClearITPendingBit(TIM3 , TIM_FLAG_Update);}}int main(void){ NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); delay_init(); LED_Init(); TIM3_Int_Init(4999 ,7199); while(1);}