void Usart2_Init(u32 bound)
        {
  //GPIO¶Ë¿úéèÖÃ
  GPIO_InitTypeDef GPIO_InitStructure;
        USART_InitTypeDef USART_InitStructure;
        NVIC_InitTypeDef NVIC_InitStructure;
         
        RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);       
        RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);

        //USART2_TX   
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;       
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  //USART2_RX         
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
               
        //¿aÆôó3éä
        GPIO_PinRemapConfig(GPIO_Remap_USART2,ENABLE);

   //USART 3õê¼»ˉéèÖÃ

        USART_InitStructure.USART_BaudRate = bound;
        USART_InitStructure.USART_WordLength = USART_WordLength_8b;
        USART_InitStructure.USART_StopBits = USART_StopBits_1;
        USART_InitStructure.USART_Parity = USART_Parity_No;
        USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
        USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;       
  USART_Init(USART2, &USART_InitStructure);

  NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
  USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);

  USART_Cmd(USART2, ENABLE);

}
void USART2_IRQHandler(void)  
{
  if(USART_GetITStatus(USART2,USART_IT_RXNE)!=RESET)       
        {
  USART_SendData(USART2, USART_ReceiveData(USART2));
        USART_ClearITPendingBit(USART2,USART_IT_RXNE);
        }         
}

这个代码哪里的问题啊，接收到的数据可以直接发出去，串口助手收到的是对的，但是接收到的数据在LCD显示是10，而且不会改变，这是怎么回事啊？