STM32   USART1中断进不了串口 别的中断(外部)都可以进去,就是USART1_IRQn进不去
void NVIC_Configuration(void)
{
  NVIC_InitTypeDef NVIC_InitStructure;   NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
  NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
}

 不加这句不卡NVIC_Init(&NVIC_InitStructure);
加上这句就卡住不动了.
????请高手解决!!!