stm32f030c8t6休眠模式为啥唤醒后串口错乱，中断打开没按也能触发？

用的是STM32f030c8t6

程序
GPIOB ->MODER  = 0xffffffff;
  GPIOC ->MODER  = 0xffffffff;
  GPIOF ->MODER  = 0xffffffff;
  GPIOA ->MODER  = 0xffffffff;
  GPIOB ->MODER  = ~(0x03<<6);  
  EXti->IMR |=(0x01<<3);
  PWR_EnterSTOPMode(PWR_Regulator_LowPower, PWR_STOPEntry_WFI);