当进入TIM4中断后，用单步执行还是没法清0 UIF标致，把程序贴片

void TIM4_Configuration(void)
{ 
  /*
   TIM4_TimeBaseInit(TIM4_PRESCALER_128 ,200);   //煦?128   RES=200
   TIM4_ARRPreloadConfig(ENABLE);         //赻雄蚾婥妏夔
   TIM4_PrescalerConfig(TIM4_PRESCALER_128,TIM4_PSCRELOADMODE_IMMEDIATE);
   TIM4_SetAutoreload(200);
   TIM4_Cmd(ENABLE);   //數杅?妏夔                
   TIM4_ITConfig(TIM4_IT_UPDATE,ENABLE);    //笢剿羲宎
  */

  TIM4->IER=0x00;//輦砦笢剿
  TIM4->EGR=0X01;//埰勍奀夔載陔岈璃
  TIM4->SCR=0x07;// 數杅?奀笘=翋奀笘/128=16MHZ/128=125KHZ=8us
  TIM4->ARR=51;//赻雄蚾婥硉˙隅奀笚?=8us*51=408us
  TIM4->CNTR=51;//數杅?場硉
  TIM4->CR1=0x01;//奀夔數杅?

}



INTERRUPT_HANDLER(TIM4_UPD_OVF_IRQHandler, 23)    //隅奀21.2US
{
  /* In order to detect unexpected events during development,
     it is recommended to set a breakpoint on the following instruction.
  */


       //TimingDelay_Decrement();
       TIM4_ClearITPendingBit(TIM4_IT_UPDATE);
       TIM4->SR1 &=0xfe;

}


int main(void)
{
        
        /* 扢离俋窒16M儒淥峈炵苀翋奀笘 */ 
        SystemClock_Init(HSE_Clock);
        Key_Init();
        LED_Init();

        Tim1_Init();     //PC1~4岆PWM 怀堤

        TIM4_Configuration();


        enableInterrupts();        /* 羲?軞笢剿 */



        while (1)
        {


           Operation();



        }
}