我是在定时器中断里通过串口发送数据，PVD中断设置的2.9V，掉电时在PVD中断里保存数据，然后上电时读取，可是偶尔会出现上电读取的数据是前一次保存的(也就是上一次的数据没有保存上)，如果把定时器中断关了，串口发送在while里进行，保存读取都没有问题，请问这是怎么回事啊？定时器中断与PVD中断的优先级如下：
  if(TIM == TIM1)
      NVIC_InitStructure.NVIC_IRQChannel = TIM1_UP_IRQn;
  else if(TIM == TIM2)
          NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
 
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
 
  NVIC_Init(&NVIC_InitStructure);
 
 
 
  NVIC_InitStructure.NVIC_IRQChannel = PVD_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);

PVD中断如下：

void PVD_IRQHandler(void)
{       
  EXTI_ClearITPendingBit(EXTI_Line16); 
if(PWR_GetFlagStatus(PWR_FLAG_PVDO)) 
 {
        EE_WriteVariable(0x5555, r);
        EE_WriteVariable(0x6666, zero);         
        PWR_ClearFlag(PWR_FLAG_PVDO);
 
 }