关于TIM3定时器通道1，2的输入捕获问题

Fong0716 · 发表于 2018-8-3 11:30:09

之前我是用TIM1的CH1，后面发现设置无法进入捕获中断，论坛很多人也有这种情况。
然后我就换为TIM3的CH1，CH2作为输入捕获，单通道测试都是良好。
但是设置同时工作，发现CH1的中断标志位一直会触发，这是什么情况?

代码如下：
void input_capture_timer_init(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;
TIM_ICInitTypeDef TIM3_ICInitStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //使能 TIMx 时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); //使能 GPIOx 时钟

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7; //PAx 清除之前设置
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; // 上拉输入
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_SetBits(GPIOA,GPIO_Pin_6); //PAx
GPIO_SetBits(GPIOA,GPIO_Pin_7); //PAx

//初始化定时器 TIMx
TIM_TimeBaseStructure.TIM_Period = arr; //设定计数器自动重装值
TIM_TimeBaseStructure.TIM_Prescaler = psc; //预分频器
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //设置时钟分割
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //向上计数
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //初始化 TIMx 的时间基数单位

//初始化 TIMx 输入捕获参数
TIM3_ICInitStructure.TIM_Channel = TIM_Channel_1|TIM_Channel_2;  //选择输入端 ICx 映射到 TIx 上
TIM3_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Falling; //下降沿捕获
TIM3_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //映射到 TIx 上
TIM3_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; //配置输入分频,不分频
TIM3_ICInitStructure.TIM_ICFilter = 0x00;//IC1F=0000 配置输入滤波器不滤波
TIM_ICInit(TIM3, &TIM3_ICInitStructure);

//中断分组初始化
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn ; //TIMx 中断
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2; //先占优先级 2 级
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //从优先级 0 级
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ 通道被使能
NVIC_Init(&NVIC_InitStructure); //初始化外设 NVIC 寄存器

TIM_ITConfig(TIM3, TIM_IT_CC1 | TIM_IT_CC2,ENABLE);
//允许更新中断 CC1IE 捕获中断
TIM_Cmd(TIM3,ENABLE ); //使能定时器x
}

void TIM3_IRQHandler(void)
{
static int a = 0,b = 0;
// if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET) {
// TIM_ClearITPendingBit(TIM3, TIM_IT_Update );
// }
if (TIM_GetITStatus(TIM3, TIM_IT_CC1) != RESET) {
a++;
TIM_ClearITPendingBit(TIM3, TIM_IT_CC1);
}
if (TIM_GetITStatus(TIM3, TIM_IT_CC2) != RESET) {
b++;
TIM_ClearITPendingBit(TIM3, TIM_IT_CC2);
}
}

Fong0716 · 发表于 2018-8-3 11:30:10

longqizhiwu 发表于 2018-8-3 14:39
TIM3_ICInitStructure.TIM_Channel = TIM_Channel_1|TIM_Channel_2;
以上这行代码是错误的，导致你的中断 ...

是的。我按照你说的改动了一下，
//初始化 TIMx 输入捕获参数
TIM3_ICInitStructure.TIM_Channel = TIM_Channel_1; //选择输入端 ICx 映射到 TIx 上
TIM3_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Falling; //下降沿捕获
TIM3_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //映射到 TIx 上
TIM3_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; //配置输入分频,不分频
TIM3_ICInitStructure.TIM_ICFilter = 0x00;//IC1F=0000 配置输入滤波器不滤波
TIM_ICInit(TIM3, &TIM3_ICInitStructure);

TIM3_ICInitStructure.TIM_Channel = TIM_Channel_2; //选择输入端 ICx 映射到 TIx 上
TIM3_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Falling; //下降沿捕获
TIM3_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //映射到 TIx 上
TIM3_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; //配置输入分频,不分频
TIM3_ICInitStructure.TIM_ICFilter = 0x00;//IC1F=0000 配置输入滤波器不滤波
TIM_ICInit(TIM3, &TIM3_ICInitStructure);

这样就正常了。
两种写法实际有什么区别呢？