void TIM3_Int_Init(u16 arr,u16 psc)
{
       
        TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
        GPIO_InitTypeDef  GPIO_InitStructure;
//        TIM_ICInitTypeDef  TIM_ICInitStructure;
        NVIC_InitTypeDef NVIC_InitStructure;
       
        RCC_APB2PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);  ///使能TIM3时钟
        RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);//使能GPIOA时钟
        //PA0配置
        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//复用功能
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;//100MHz
        GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推完输出
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN;//上拉
  GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化
       
        GPIO_PinAFConfig(GPIOA,GPIO_PinSource6,GPIO_AF_TIM3); //PA0复用位定时器5
       
  TIM_TimeBaseInitStructure.TIM_Period = arr;         //自动重装载值
        TIM_TimeBaseInitStructure.TIM_Prescaler=psc;  //定时器分频
        TIM_TimeBaseInitStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式
        TIM_TimeBaseInitStructure.TIM_ClockDivision=TIM_CKD_DIV1;
        TIM_TimeBaseInit(TIM3,&TIM_TimeBaseInitStructure);//初始化TIM3
               
        TIM_TIxExternalClockConfig(TIM3, TIM_TIxExternalCLK1Source_TI1, TIM_ICPolarity_Rising, 0);
  
        TIM_CounterModeConfig(TIM3,TIM_CounterMode_Up);//计数模式
//        TIM_TIxExternalClockConfig(TIM5,TIM_TIxExternalCLK1Source_TI2,TIM_ICPolarity_Rising,0);
//   TIM_ETRClockMode1Config(TIM2,TIM_ExtTRGPSC_OFF,TIM_ExtTRGPolarity_NonInverted,0);
        TIM_ITConfig(TIM3,TIM_IT_CC2|TIM_IT_Update,ENABLE);        //允许更新中断
//        TIM_SetAutoreload(TIM2,9);
        TIM_SetCounter(TIM3,0);//设置计数初值
        TIM_Cmd(TIM3,ENABLE); //使能定时器3
       
        NVIC_InitStructure.NVIC_IRQChannel=TIM3_IRQn; //            
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0x01; //
        NVIC_InitStructure.NVIC_IRQChannelSubPriority=0x02; //
        NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
        NVIC_Init(&NVIC_InitStructure);
       
}


不知道怎样设置对不对，麻烦大神帮我看一下，原子哥哥也来帮我看一下吧