定时器多路输入捕获

小伟

if(tsr&0x02)//捕获1发生捕获事件

                   {       

                            if(TIM4CH1_CAPTURE_STA&0X40)                   //捕获到一个上升沿             

                            {                                

                                     TIM4CH1_CAPTURE_STA|=0X80;            //标记成功捕获到一次低电平脉宽

                                TIM4CH1_CAPTURE_VAL=TIM4->CCR1;         //获取当前的捕获值.

                                    TIM4->CCER|=1<<1;                          //CC1P=1 设置为下降沿捕获

                            }else                                                                        //还未开始,第一次捕获下降沿

                            {

                                     TIM4CH1_CAPTURE_STA=0;                     //清空

                                     TIM4CH1_CAPTURE_VAL=0;

                                     TIM4CH1_CAPTURE_STA|=0X40;            //标记捕获到了下降沿

                          //      TIM4->CNT=0;                                               //计数器清空

                                flag1=TIM4->CCR1;                                      //捕获下降沿计数器的值

                                    TIM4->CCER&=~(1<<1);                                     //CC1P=0设置为上升沿捕获

  Stm32_Clock_Init(9); //系统时钟设置

   delay_init(72); //延时初始化 

   uart_init(72,9600);

   LED_Init();           //PA.7输出PWM

   TIM3_PWM_Init(7199,999); //分频。PWM频率=72000/1000=72Khz/7200=10HZ=0.1S 

   TIM4_Cap_Init(0XFFFF,72-1); //以72MHZ/72=1Mhz的频率计数,

if(TIM4CH1_CAPTURE_STA&0X80)//成功捕获到了一次高电平

{

// temp1=TIM4CH1_CAPTURE_STA&0X3F1;

// temp1=temp1*65536+0XFFFF; //溢出时间总和

temp1=TIM4CH1_CAPTURE_VAL-flag1; //得到总的高电平时间

printf("LOW1:%d us\r\n",temp1); //打印总的高点平时间

TIM4CH1_CAPTURE_STA=0; //开启下一次捕获

 

我用定时器4进行4路输入捕获，这是一路的中断，标红色的是记录捕获时CRR1的值，那么低电平脉宽是不是等于TIM4CH1_CAPTURE_VA-  flag1，如果有溢出又怎么算

正点原子

溢出你就要做溢出处理了。