（基于3.0固件库，芯片stm32f103rbt6）
1、配置串口的管脚和时钟

由于串口1、2是在GPIOA上：

所以要是能串口GPIOA、AFIO和1或者2的串口时钟，代码如下：

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA |

RCC_APB2Periph_AFIO|

           RCC_APB2Periph_USART1 ,

           ENABLE);

2、对串口的具体物理管脚进行相应的配置：

/* A9 USART1_Tx */

   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;

   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;//推挽输出-TX

   GPIO_Init(GPIOA, &GPIO_InitStructure);

   /* A10 USART1_Rx  */

   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;

   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//浮空输入-RX

GPIO_Init(GPIOA, &GPIO_InitStructure);

3、在设置波特率、数据位、停止位。。。。。。。

完整测试程序如下：

串口的配置：

void USART_Configuration(void)
{
   GPIO_InitTypeDef GPIO_InitStructure;
   USART_InitTypeDef USART_InitStructure;
USART_ClockInitTypeDef USART_ClockInitStructure;

//
   RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA |
           RCC_APB2Periph_AFIO |
           RCC_APB2Periph_USART1 ,
           ENABLE);

   /* A9 USART1_Tx */
   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  //
   GPIO_Init(GPIOA, &GPIO_InitStructure);

   /* A10 USART1_Rx  */
   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//
   GPIO_Init(GPIOA, &GPIO_InitStructure);


USART_InitStructure.USART_BaudRate = 9600;
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_ClockInitStructure.USART_Clock = USART_Clock_Disable;
USART_ClockInitStructure.USART_CPOL = USART_CPOL_Low;
USART_ClockInitStructure.USART_CPHA = USART_CPHA_2Edge;
USART_ClockInitStructure.USART_LastBit = USART_LastBit_Disable;

USART_ClockInit(USART1, &USART_ClockInitStructure);
   USART_Init(USART1, &USART_InitStructure);
   /* Enable the USARTx */
   USART_Cmd(USART1, ENABLE);


//
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);

// A2 ×?T2X
   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);

   // A3 ×?R2X
   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
   GPIO_Init(GPIOA, &GPIO_InitStructure);

USART_InitStructure.USART_BaudRate = 9600;
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_ClockInitStructure.USART_Clock = USART_Clock_Disable;
USART_ClockInitStructure.USART_CPOL = USART_CPOL_Low;
USART_ClockInitStructure.USART_CPHA = USART_CPHA_2Edge;
USART_ClockInitStructure.USART_LastBit = USART_LastBit_Disable;

   USART_ClockInit(USART2, &USART_ClockInitStructure);
   USART_Init(USART2, &USART_InitStructure);

   USART_Cmd(USART2, ENABLE);
//
USART_ITConfig(USART2,USART_IT_RXNE,ENABLE);
}
串口发送函数：

void USART1_Putc(unsigned char c)
{
   USART_SendData(USART1, c);
   while(USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET );
}

void USART1_Puts(char * str)
{
   while(*str)
   {
       USART_SendData(USART1, *str++);
       /* Loop until the end of transmission */
       while(USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);
   }
}

串口1接收中断函数：

void USART1_IRQHandler(void)
{
//接收中断
if(USART_GetITStatus(USART1,USART_IT_RXNE)==SET)
{
 USART_ClearITPendingBit(USART1,USART_IT_RXNE);
 Uart1_Get_Data=USART_ReceiveData(USART1);

}

//溢出-如果发生溢出需要先读SR,再读DR寄存器 则可清除不断入中断的问题
if(USART_GetFlagStatus(USART1,USART_FLAG_ORE)==SET)
{
 USART_ClearFlag(USART1,USART_FLAG_ORE); //读SR
 USART_ReceiveData(USART1);    //读DR
}
}