void TIM5_IRQHandler(void)
{         if((TIM5CH1_CAPTURE_STA&0X80)==0)//???????????? 
 {
  if(TIM_GetITStatus(TIM5, TIM_IT_Update) != RESET)//????
  {     
   if(TIM5CH1_CAPTURE_STA&0X40)//???­??????????????
   {
    if((TIM5CH1_CAPTURE_STA&0X3F)==0X3F)//?????????¤??
    {
     TIM5CH1_CAPTURE_STA|=0X80;  //±ê????????????????
     TIM5CH1_CAPTURE_VAL=0XFFFFFFFF;
    }else TIM5CH1_CAPTURE_STA++;
   } 
  }
  if(TIM_GetITStatus(TIM5, TIM_IT_CC1) != RESET)//????1·??ú????????
  { 
   if(TIM5CH1_CAPTURE_STA&0X40)  //????????????????   
   {      
    TIM5CH1_CAPTURE_STA|=0X80;  //±ê?????????????????????????í
     TIM5CH1_CAPTURE_VAL=TIM_GetCapture1(TIM5);//?????±?°????????.
     TIM_OC1PolarityConfig(TIM5,TIM_ICPolarity_Rising); //CC1P=0 ?è??????????????
   }else          //????????,????????????????
   {
    TIM5CH1_CAPTURE_STA=0;   //????
    TIM5CH1_CAPTURE_VAL=0;
    TIM5CH1_CAPTURE_STA|=0X40;  //±ê????????????????
    TIM_Cmd(TIM5,DISABLE);  //??±??¨?±?÷5
     TIM_SetCounter(TIM5,0);//TIM5???????????±??????????
     TIM_OC1PolarityConfig(TIM5,TIM_ICPolarity_Falling);  //CC1P=1 ?è??????????????
    TIM_Cmd(TIM5,ENABLE );  //?????¨?±?÷5
   }     
  }                    
  }
 TIM_ClearITPendingBit(TIM5, TIM_IT_CC1|TIM_IT_Update); //????????±ê????
}

红 {MOD}标注的一行代码，这里关闭定时器TIM5，不知道在这里有什么用，我试着把他注释掉，做了几组实验，测试如下：

TIM_Cmd(TIM5,DISABLE)：此时高电平时间为：2281163 us

TIM_Cmd(TIM5,ENABLE)：此时高电平时间为：2395628 us
两次按键时间差不多，没看出DISABLE 和ENABLE 的区别，请问原子哥，这里代码加了一个TIM5不使能是为了什么考虑？