//¶¨ê±Æ÷5í¨μà1êäèë2¶»ñÅäÖÃ
//arr￡o×Ô¶ˉÖØ×°Öμ(TIM2,TIM5êÇ32λμÄ!!)
//psc￡oê±ÖóÔ¤·ÖÆμêy
void TIM5_CH1_Cap_Init(u32 arr,u16 psc)
{
        GPIO_InitTypeDef GPIO_InitStructure;
        TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
        NVIC_InitTypeDef NVIC_InitStructure;

       
        RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM5,ENABLE);          //TIM5ê±Öóê1Äü   
        RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);         //ê1ÄüPORTAê±Öó       
       
        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; //GPIOA0
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//¸′óÃ1|Äü
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;        //Ëù¶è100MHz
        GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //íÆíì¸′óÃêä3ö
        GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN; //ÏÂà-
        GPIO_Init(GPIOA,&GPIO_InitStructure); //3õê¼»ˉPA0

        GPIO_PinAFConfig(GPIOA,GPIO_PinSource0,GPIO_AF_TIM5); //PA0¸′óÃ붨ê±Æ÷5

          
        TIM_TimeBaseStructure.TIM_Prescaler=psc;  //¶¨ê±Æ÷·ÖÆμ
        TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //ÏòéϼÆêyÄ￡ê½
        TIM_TimeBaseStructure.TIM_Period=arr;   //×Ô¶ˉÖØ×°ÔØÖμ
        TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1;
       
        TIM_TimeBaseInit(TIM5,&TIM_TimeBaseStructure);
       

        //3õê¼»ˉTIM5êäèë2¶»ñ2Îêy
        TIM5_ICInitStructure.TIM_Channel = TIM_Channel_1; //CC1S=01         Ñ¡Ôñêäèë¶Ë IC1ó3éäμ½TI1éÏ
  TIM5_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;        //éÏéyÑØ2¶»ñ
  TIM5_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //ó3éäμ½TI1éÏ
  TIM5_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;         //ÅäÖÃêäèë·ÖÆμ,2»·ÖÆμ
  TIM5_ICInitStructure.TIM_ICFilter = 0x00;//IC1F=0000 ÅäÖÃêäèëÂË2¨Æ÷ 2»ÂË2¨
  TIM_ICInit(TIM5, &TIM5_ICInitStructure);
               
        TIM_ITConfig(TIM5,TIM_IT_Update|TIM_IT_CC1,ENABLE);//ÔêDí¸üDÂÖD¶Ï ,ÔêDíCC1IE2¶»ñÖD¶Ï       
       
  TIM_Cmd(TIM5,ENABLE );         //ê1Äü¶¨ê±Æ÷5


  NVIC_InitStructure.NVIC_IRQChannel = TIM5_IRQn;
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=2;//ÇàÕ¼óÅÏ輶3
        NVIC_InitStructure.NVIC_IRQChannelSubPriority =0;                //×óóÅÏ輶3
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                        //IRQí¨μàê1Äü
        NVIC_Init(&NVIC_InitStructure);        //¸ù¾YÖ¸¶¨μÄ2Îêy3õê¼»ˉVIC¼Ä′æÆ÷¡￠
       
       
}
这是原子哥的定时器捕获的库函数代码中定时器的初始化，我理解A0被映射为定时器的输入捕获通道，但是A0的初始化中
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //íÆíì¸′óÃêä3ö
这行代码设置为推挽输出了，不懂是为什么，请教各位大神