TIM定时器设置好以后只能触发一次中断函数是为什么标志位清零了

龙行 · 发表于 2015-8-13 10:06:51

[mw_shl_code=c,true]TIM_ICInitTypeDef TIM5_ICInitStructure; void TIM5_CH3_Init(u32 arr,u16 psc) { GPIO_InitTypeDef GPIO_InitStructure; TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; NVIC_InitTypeDef NVIC_InitStructure; RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM5,ENABLE); //TIM5时钟使能 RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE); //使能PORTA时钟 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2; //GPIOA0 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(GPIOA,&GPIO_InitStructure); //初始化PA0 GPIO_PinAFConfig(GPIOA,GPIO_PinSource2,GPIO_AF_TIM5); //PA0复用位定时器5 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(TIM5,&TIM_TimeBaseStructure); //初始化TIM5输入捕获参数 TIM5_ICInitStructure.TIM_Channel = TIM_Channel_3; //CC1S=01 选择输入端 IC1映射到TI1上 TIM5_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; //上升沿捕获 TIM5_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //映射到TI1上 TIM5_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; //配置输入分频,不分频 TIM5_ICInitStructure.TIM_ICFilter = 0x00;//IC1F=0000 配置输入滤波器不滤波 TIM_ICInit(TIM5, &TIM5_ICInitStructure); TIM_ITConfig(TIM5,TIM_IT_Update|TIM_IT_CC3,ENABLE);//允许更新中断 ,允许CC1IE捕获中断 TIM_Cmd(TIM5,ENABLE ); //使能定时器5 NVIC_InitStructure.NVIC_IRQChannel = TIM5_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=2;//抢占优先级3 NVIC_InitStructure.NVIC_IRQChannelSubPriority =0; //子优先级3 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、 } u8 TIM5CH3_CAPTURE_STA=0; //输入捕获状态 u32 TIM5CH3_CAPTURE_VAL; //输入捕获值(TIM2/TIM5是32位) //定时器5中断服务程序 void TIM5_IRQHandler(void) { if((TIM5CH3_CAPTURE_STA&0X80)==0)//还未成功捕获 { if(TIM_GetITStatus(TIM5, TIM_IT_Update) != RESET)//溢出发生更新中断 { if(TIM5CH3_CAPTURE_STA&0X40)//已经捕获到高电平了 { if((TIM5CH3_CAPTURE_STA&0X3F)==0X3F)//高电平太长了 { TIM5CH3_CAPTURE_STA|=0X80; //标记成功捕获了一次 TIM5CH3_CAPTURE_VAL=0XFFFFFFFF; }else TIM5CH3_CAPTURE_STA++; } } if(TIM_GetITStatus(TIM5, TIM_IT_CC3) != RESET)//捕获1发生捕获事件发生捕获中断 { if(TIM5CH3_CAPTURE_STA&0X40) //捕获到一个下降沿 { TIM5CH3_CAPTURE_STA|=0X80; //标记成功捕获到一次高电平脉宽 TIM5CH3_CAPTURE_VAL=TIM_GetCapture3(TIM5);//获取当前的捕获值. TIM_OC3PolarityConfig(TIM5,TIM_ICPolarity_Rising); //CC1P=0 设置为上升沿捕获 }else //还未开始,第一次捕获上升沿 { TIM5CH3_CAPTURE_STA=0; //清空 TIM5CH3_CAPTURE_VAL=0; TIM5CH3_CAPTURE_STA|=0X40; //标记捕获到了上升沿 TIM_Cmd(TIM5,ENABLE ); //使能定时器5 TIM_SetCounter(TIM5,0); TIM_OC3PolarityConfig(TIM5,TIM_ICPolarity_Falling); //CC1P=1 设置为下降沿捕获 TIM_Cmd(TIM5,ENABLE ); //使能定时器5 } } } TIM_ClearITPendingBit(TIM5,TIM_IT_CC3|TIM_IT_Update); //清除中断标志位 } [/mw_shl_code]