1 //通用定时器3中断初始化

 2 //这里时钟选择为APB1的2倍，而APB1为36M

 3 //    Tout =( (arr+1)*(psc+1) )/Ft  us

 4 //arr：自动重装值。

 5 //psc：时钟预分频数

 6 //这里使用的是定时器3!

 7 void TIM3_Int_Init(u16 arr,u16 psc)

 8 {

 9     TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure  ;

10     NVIC_InitTypeDef NVIC_InitStructure;

11

12     RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //时钟使能

13

14     //定时器TIM3初始化

15     TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值

16     TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值

17     TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //设置时钟分割:TDTS = Tck_tim

18     TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //TIM向上计数模式

19     TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根据指定的参数初始化TIMx的时间基数单位

20

21     TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE ); //使能指定的TIM3中断,允许更新中断

22

23     //中断优先级NVIC设置

24     NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;  //TIM3中断

25     NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;  //先占优先级0级

26     NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;  //从优先级3级

27     NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能

28     NVIC_Init(&NVIC_InitStructure);  //初始化NVIC寄存器

29

30

31     TIM_Cmd(TIM3, ENABLE);  //使能TIMx

32 }

 1 //中断服务程序

 2 void TIM3_IRQHandler(void)   //TIM3中断

 3 {

 4     if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET)  //检查TIM3更新中断发生与否

 5         {

 6         TIM_ClearITPendingBit(TIM3, TIM_IT_Update  );  //清除TIMx更新中断标志

 7         //LED1=!LED1;

 8         //LED0=!LED0;

 9         //CLK=!CLK;

10         //GPIO_SetBits(GPIOB,GPIO_Pin_5);

11

12 //                 if(MyPwmChangeFlag==0)//  if  is  0    do  low process

13 //                 {

14 //                     GPIO_ResetBits(GPIOB,GPIO_Pin_5);

15 //                     TIM3_Int_Init(MyPwmPeriod-MyPwmHigh-1,72-1);

16 //                     TIM_Cmd(TIM3, ENABLE);  //使能TIMx

17 //                     MyPwmChangeFlag=1;

18 //                 }

19 //                 else if(MyPwmChangeFlag==1)

20 //                 {

21 //                     GPIO_SetBits(GPIOB,GPIO_Pin_5);

22 //                     TIM3_Int_Init(MyPwmHigh-1,72-1);

23 //                     TIM_Cmd(TIM3, ENABLE);  //使能TIMx

24 //                     MyPwmChangeFlag=0;

25 //                 }

26                 CLK=~CLK;

27                 if(MyPwmChangeFlag)

28                 {

29                     TIM3->ARR=99;

30                     TIM3->CNT=0;

31                     MyPwmChangeFlag=0;

32                 }

33                 else

34                 {

35                     TIM3->ARR=49;

36                     TIM3->CNT=0;

37                     MyPwmChangeFlag=1;

38                 }

39

40

41         }

42 }