现在做电机编码器A,B相测电平脉冲，使用定时器8的通道1和通道2，现在是如果这两个通道捕获中断打开，串口助手无数据显示，如果只打开一个通道的捕获中断，则串口助手有数据显示。有没有遇到过此情况的朋友。谢谢
配置代码如下：
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;


RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM8,ENABLE);   //TIM8时钟使能    
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE); //使能PORTC时钟

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6; //GPIOC6
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//复用功能
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz; //速度100MHz
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽复用输出
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN; //下拉
GPIO_Init(GPIOC, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7; //GPIOC7
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//复用功能
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz; //速度100MHz
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽复用输出
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN; //下拉

GPIO_Init(GPIOC,&GPIO_InitStructure); //初始化PC6

GPIO_PinAFConfig(GPIOC,GPIO_PinSource6,GPIO_AF_TIM8); //PC6复用位定时器8
GPIO_PinAFConfig(GPIOC,GPIO_PinSource7,GPIO_AF_TIM8); //PC6复用位定时器8
 
TIM_TimeBaseStructure.TIM_Prescaler=psc;  //定时器分频
TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式
TIM_TimeBaseStructure.TIM_Period=arr;   //自动重装载值
TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1; 

TIM_TimeBaseInit(TIM8,&TIM_TimeBaseStructure);


//初始化TIM8输入捕获参数
TIM8_ICInitStructure.TIM_Channel = TIM_Channel_1; //CC1S=01 选择输入端 IC1映射到TI1上
TIM8_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; //上升沿捕获
TIM8_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //映射到TI1上
TIM8_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; //配置输入分频,不分频 
TIM8_ICInitStructure.TIM_ICFilter = 0x00;//IC1F=0000 配置输入滤波器 不滤波
TIM_ICInit(TIM8, &TIM8_ICInitStructure);
  
//初始化TIM8输入捕获参数
TIM8_ICInitStructure.TIM_Channel = TIM_Channel_2; //CC1S=01 选择输入端 IC1映射到TI2上
TIM8_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; //上升沿捕获
TIM8_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //映射到TI2上
TIM8_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; //配置输入分频,不分频 
TIM8_ICInitStructure.TIM_ICFilter = 0x00;//IC1F=0000 配置输入滤波器 不滤波
TIM_ICInit(TIM8, &TIM8_ICInitStructure);



TIM_ITConfig(TIM8,TIM_IT_CC1,ENABLE);//允许更新中断 ,允许CC1IE捕获中断
TIM_ITConfig(TIM8,TIM_IT_CC2,ENABLE);//允许更新中断 ,允许CC1IE捕获中断
TIM_ITConfig(TIM8,TIM_IT_Update,ENABLE);
TIM_Cmd(TIM8,ENABLE ); //使能定时器8
 
NVIC_InitStructure.NVIC_IRQChannel = TIM8_CC_IRQn|TIM8_UP_TIM13_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=2;
NVIC_InitStructure.NVIC_IRQChannelSubPriority =0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道使能
NVIC_Init(&NVIC_InitStructure); //根据指定的参数初始化VIC寄存器、