Tim3测输入频率，CH1、CH2不能同时使用问题

alonso · 发表于 2013-3-22 14:37:25

我用Tim3的CH1、CH2同时测量速度传感器的输入频率，结果发现两个通道不能同时使用，烦劳原子哥帮我看看，Tim3配置代码如下：
void TIM3_Config(void)
{
TIM_ICInitTypeDef TIM_ICInitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

    //TIM3 Periph clocks enable
    //RCC_APB2PeriphClockCmd(FREQIN_RCC_APB2, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);

    GPIO_PinRemapConfig(GPIO_FullRemap_TIM3, ENABLE);

    TIM_TimeBaseStructure.TIM_Period = 0xffff;
    TIM_TimeBaseStructure.TIM_Prescaler = 719;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Down;

    TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

    TIM_ICInitStructure.TIM_Channel = TIM_Channel_1;
    TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
    TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
    TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
   TIM_ICInitStructure.TIM_ICFilter = 0x0;

    //TIM_ICInit(TIM3, &TIM_ICInitStructure);
    TIM_PWMIConfig(TIM3, &TIM_ICInitStructure);
    TIM_SelectInputTrigger(TIM3, TIM_TS_TI1FP1);
    TIM_SelectSlaveMode(TIM3, TIM_SlaveMode_Reset);
    TIM_SelectMasterSlaveMode(TIM3, TIM_MasterSlaveMode_Enable);

    TIM_Cmd(TIM3, ENABLE);
    TIM_ITConfig(TIM3, TIM_IT_CC1, ENABLE);

    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_DIV1;
    TIM_ICInitStructure.TIM_ICFilter = 0x0;

    TIM_PWMIConfig(TIM3, &TIM_ICInitStructure);
    TIM_SelectInputTrigger(TIM3, TIM_TS_TI2FP2);
    TIM_SelectSlaveMode(TIM3, TIM_SlaveMode_Reset);
    TIM_SelectMasterSlaveMode(TIM3, TIM_MasterSlaveMode_Enable);

TIM_ITConfig(TIM3, TIM_IT_CC2, ENABLE);
TIM_Cmd(TIM3, ENABLE);
}
红色和蓝色部分代码，哪个写在下面哪个通道好使，我不明白问题出在哪里，烦劳指点下。