定时器中断实验

 int main(void)
 {    
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2,);
    LED_Init();
    delay_init();
     TIM3_Int_Init(4999,7199);//500ms
     while(1)
    {
        LED1=!LED1;
        TIM_ClearITPendingBit(TIM3,TIM_IT_Update);
     }
 }

timer.c

#include "timer.h"
#include "led.h"
void TIM3_Int_Init(u16 arr,u16 psc)  //定时器初始化
{
    TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStrue;
    
    NVIC_InitTypeDef NVIC_InitStructure;
    
    
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);
    TIM_TimeBaseInitStrue.TIM_Period=arr;
    TIM_TimeBaseInitStrue.TIM_Prescaler=psc;
    TIM_TimeBaseInitStrue.TIM_CounterMode=TIM_CounterMode_Up;
    TIM_TimeBaseInitStrue.TIM_ClockDivision=TIM_CKD_DIV1;
    TIM_TimeBaseInit(TIM3,&TIM_TimeBaseInitStrue);
    
    TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE);//使能定时器更新中断
    NVIC_InitStructure.NVIC_IRQChannel=TIM3_IRQn;//TIM3中断
    NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;//IRQ通道被使能
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0;//先抢占优先级设置为0
    NVIC_InitStructure.NVIC_IRQChannelSubPriority=3;//从优先级3级
    NVIC_Init(&NVIC_InitStructure);//初始化NVIC寄存器
    
    TIM_Cmd(TIM3,ENABLE);//定时器3使能
}    
void     TIM3_IRQHandler(void)
{
    if(TIM_GetITStatus(TIM3,TIM_IT_Update)!=RESET)
    {
        LED1=!LED1;
        TIM_ClearITPendingBit(TIM3,TIM_IT_Update);
    }    
}