STM32输入捕获低频时寄存器溢出问题，频繁进入更新中断。

只看该作者 · 2018-6-13 08:20

一个老项目，以前是测试固定频率，没考虑溢出问题，运行良好，

现在偶尔会有低频，所以得兼顾，但是加入更新中断后，频繁进入中断，是哪里出问题了？

输入捕获从模式复位，更新中断进行计数累加，记录溢出。

static void TIM2_Mode_Config(void)

{

    TIM_TimeBaseInitTypeDef   TIM_TimeBaseStructure;

    TIM_ICInitTypeDef  TIM_ICInitStructure;

    TIM_DeInit(TIM2);

    

    /* Time base configuration */

    

    TIM_TimeBaseStructure.TIM_Period = 0xffff;          

    TIM_TimeBaseStructure.TIM_Prescaler = 71;

    TIM_TimeBaseStructure.TIM_ClockDivision = 0;    

    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; 

    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

    

    TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;

    TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;

    TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;

    

    TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV4;

    //选择输入比较滤波器 0x0 - 0xF

    TIM_ICInitStructure.TIM_ICFilter = 0x8;  //0x8

    

    TIM_PWMIConfig(TIM2, &TIM_ICInitStructure);

    

    /* Select the TIM3 Input Trigger: TI2FP2 */

    TIM_SelectInputTrigger(TIM2, TIM_TS_TI2FP2);

    

    /* Select the slave Mode: Reset Mode */

    TIM_SelectSlaveMode(TIM2, TIM_SlaveMode_Reset);

    

    /* Enable the Master/Slave Mode */

    TIM_SelectMasterSlaveMode(TIM2, TIM_MasterSlaveMode_Enable);    

    

    /* Enable the CC2 Interrupt Request */

    TIM_ITConfig(TIM2, TIM_IT_Update|TIM_IT_CC2, ENABLE);

    

    /* TIM enable counter */

    TIM_Cmd(TIM2, ENABLE);    

}





void TIM2_ISR(void)

{

    Uint32 IC2Value;



        if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET)

        {

                TIM_ClearITPendingBit(TIM2, TIM_IT_Update);  //清除溢出中断标志位 

                cnt_TIM2_IT_Update ++;

        }



        if (TIM_GetITStatus(TIM2, TIM_IT_CC2) != RESET)

        {

                IC2Value = TIM_GetCapture2(TIM2);

                TIM_ClearITPendingBit(TIM2, TIM_IT_CC2); //清除捕获中断标志位 



                IC2Value += (cnt_TIM2_IT_Update * 0xFFFF);

                cnt_TIM2_IT_Update = 0;  //清零

        }

}