[嵌入式]stm32定时器4重映射

```c
void TIM4_Cap_Init(u16 arr,u16 psc)
{
    //定义结构体
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_ICInitTypeDef TIM_ICInitStructure;
    NVIC_InitTypeDef NVIC_InitStructure;
    GPIO_InitTypeDef GPIO_InitStructure;

    //使能时钟
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD|RCC_APB2Periph_AFIO, ENABLE);
 
   //GPIO_AFIODeInit();  //刚开始没有这个语句，所以一直没有重映射成功
   GPIO_PinRemapConfig(GPIO_Remap_TIM4 , ENABLE); //这个就是重映射功能函数
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4,ENABLE);



    //配置TIM4 
    TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1;
    TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up;
    TIM_TimeBaseStructure.TIM_Period=arr;
    TIM_TimeBaseStructure.TIM_Prescaler=psc;
    TIM_TimeBaseInit(TIM4,&TIM_TimeBaseStructure);


    //配置TIM4 Channel输入捕获
    TIM_ICInitStructure.TIM_Channel=TIM_Channel_1;
    TIM_ICInitStructure.TIM_ICFilter=0x00;
    TIM_ICInitStructure.TIM_ICPolarity=TIM_ICPolarity_Rising;//上升沿捕获
    TIM_ICInitStructure.TIM_ICPrescaler=TIM_ICPSC_DIV1;
    TIM_ICInitStructure.TIM_ICSelection=TIM_ICSelection_DirectTI;
    TIM_ICInit(TIM4,&TIM_ICInitStructure);
		
		//配置TIM4 Channe2输入捕获
    TIM_ICInitStructure.TIM_Channel=TIM_Channel_2;
    TIM_ICInitStructure.TIM_ICFilter=0x00;
    TIM_ICInitStructure.TIM_ICPolarity=TIM_ICPolarity_Rising;//上升沿捕获
    TIM_ICInitStructure.TIM_ICPrescaler=TIM_ICPSC_DIV1;
    TIM_ICInitStructure.TIM_ICSelection=TIM_ICSelection_DirectTI;
    TIM_ICInit(TIM4,&TIM_ICInitStructure);
		
   //配置TIM4 Channe3输入捕获
    TIM_ICInitStructure.TIM_Channel=TIM_Channel_3;
    TIM_ICInitStructure.TIM_ICFilter=0x00;
    TIM_ICInitStructure.TIM_ICPolarity=TIM_ICPolarity_Rising;//上升沿捕获
    TIM_ICInitStructure.TIM_ICPrescaler=TIM_ICPSC_DIV1;
    TIM_ICInitStructure.TIM_ICSelection=TIM_ICSelection_DirectTI;
    TIM_ICInit(TIM4,&TIM_ICInitStructure);
		
		//配置TIM4 Channe4输入捕获
    TIM_ICInitStructure.TIM_Channel=TIM_Channel_4;
    TIM_ICInitStructure.TIM_ICFilter=0x00;
    TIM_ICInitStructure.TIM_ICPolarity=TIM_ICPolarity_Rising;//上升沿捕获
    TIM_ICInitStructure.TIM_ICPrescaler=TIM_ICPSC_DIV1;
    TIM_ICInitStructure.TIM_ICSelection=TIM_ICSelection_DirectTI;
    TIM_ICInit(TIM4,&TIM_ICInitStructure);
		


    //配置GPIO口 PB6789
    GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IPD;//下拉输入模式
    GPIO_InitStructure.GPIO_Pin=GPIO_Pin_12;
    GPIO_Init(GPIOD,&GPIO_InitStructure);
    GPIO_ResetBits(GPIOD,GPIO_Pin_12);

    GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IPD;//下拉输入模式
    GPIO_InitStructure.GPIO_Pin=GPIO_Pin_13;
    GPIO_Init(GPIOD,&GPIO_InitStructure);
    GPIO_ResetBits(GPIOD,GPIO_Pin_13);
		
		GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IPD;//下拉输入模式
    GPIO_InitStructure.GPIO_Pin=GPIO_Pin_14;
    GPIO_Init(GPIOD,&GPIO_InitStructure);
    GPIO_ResetBits(GPIOD,GPIO_Pin_14);

    GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IPD;//下拉输入模式
    GPIO_InitStructure.GPIO_Pin=GPIO_Pin_15;
    GPIO_Init(GPIOD,&GPIO_InitStructure);
    GPIO_ResetBits(GPIOD,GPIO_Pin_15);

    //配置中断分组
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
    NVIC_InitStructure.NVIC_IRQChannel=TIM4_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3; //抢占优先级3
    NVIC_InitStructure.NVIC_IRQChannelSubPriority=0; //子优先级2
    NVIC_Init(&NVIC_InitStructure);


    TIM_Cmd(TIM4,ENABLE);//使能TIM4
    TIM_ITConfig(TIM4,TIM_IT_Update,ENABLE);//允许溢出中断
    TIM_ITConfig(TIM4,TIM_IT_CC1,ENABLE);//允许捕获中断
		TIM_ITConfig(TIM4,TIM_IT_CC2,ENABLE);
		TIM_ITConfig(TIM4,TIM_IT_CC3,ENABLE);
		TIM_ITConfig(TIM4,TIM_IT_CC4,ENABLE);
}