TIM2定时器通道4进行输入捕获疑问

jklw0713 · 发表于 2014-11-5 16:46:28

我理解是通道1 和2 可以设置为 TIM_SelectInputTrigger(TIM2, TIM_TS_TI1FP1); TIM_SelectInputTrigger(TIM2, TIM_TS_TI2FP2);

那么通道3 和4 设置成什么貌似没有TIM_TS_TI4FP4 作输入源进行捕获啊，我采用的时钟选择为：外部输入模式1.

TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;//定时器初始化结构
TIM_ICInitTypeDef TIM_ICInitStructure;         //通道输入初始化结构
NVIC_InitTypeDef NVIC_InitStructure;

TIM_DeInit(TIM2);

//TIM2输出初始化
TIM_TimeBaseStructure.TIM_Period = 0x7FFF;     //周期0～FFFF
TIM_TimeBaseStructure.TIM_Prescaler = 5;       //时钟分频
TIM_TimeBaseStructure.TIM_ClockDivision = 0;   //时钟分割
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;//模式
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);//基本初始化

//TIM2通道的捕捉初始化
TIM_ICInitStructure.TIM_Channel = TIM_Channel_4;//通道选择
TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;//管脚与寄存器对应关系
TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;//分频器
TIM_ICInitStructure.TIM_ICFilter = 0x0;        //滤波设置，经历几个周期跳变认定波形稳定0x0～0xF
TIM_ICInit(TIM2, &TIM_ICInitStructure);        //初始化

TIM_SelectInputTrigger(TIM2, TIM_TS_TI2FP2);   //选择时钟触发源
TIM_SelectSlaveMode(TIM2, TIM_SlaveMode_Reset);//触发方式
TIM_SelectMasterSlaveMode(TIM2, TIM_MasterSlaveMode_Enable); //启动定时器的被动触发

NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

TIM_ITConfig(TIM2, TIM_IT_CC4, ENABLE);        //打开中断
TIM_Cmd(TIM2, ENABLE);                         //启动TIM2

//==========================================================================

求高人指点下