芯片：N32G401系列

宏定义如下：使用串口1，如需使用其他串口，修改宏定义即可。

注意引脚复用号，同一个串口可以使用不同的引脚，复用号没对上

本人在使用中就遇到一个问题，使用串口4，PB0和PB1引脚，没有看手册直接查看头文件使用 GPIO_AF6_UART4 复用号，最终发现怎么配置串口都不生效，最后查看手册发现同一个串口下的不同引脚对应不同的复用号，串口4的PB0和PB1引脚对应复用号7，大家不要踩坑了。

#define USARTy            USART1
#define USARTy_CLK        RCC_APB2_PERIPH_USART1
#define USARTy_GPIO       GPIOA
#define USARTy_GPIO_CLK   RCC_AHB_PERIPH_GPIOA
#define USARTy_RxPin      GPIO_PIN_10
#define USARTy_TxPin      GPIO_PIN_9
#define USARTy_Rx_GPIO_AF GPIO_AF5_USART1
#define USARTy_Tx_GPIO_AF GPIO_AF5_USART1
#define USARTy_APBxClkCmd RCC_APB2_Peripheral_Clock_Enable
#define USARTy_IRQn       USART1_IRQn
#define USARTy_IRQHandler USART1_IRQHandler

使能对应时钟

    /* Enable GPIO clock */
    RCC_AHB_Peripheral_Clock_Enable(USARTy_GPIO_CLK | USARTz_GPIO_CLK);
    /* Enable USARTy and USARTz Clock */
    USARTy_APBxClkCmd(USARTy_CLK);
    USARTz_APBxClkCmd(USARTz_CLK);

初始化引脚并配置中断

     GPIO_InitType GPIO_InitStructure;
     NVIC_InitType NVIC_InitStructure;

    /* Initialize GPIO_InitStructure */
    GPIO_Structure_Initialize(&GPIO_InitStructure);
   
    /* Configure USARTy Tx as alternate function push-pull and pull-up */
    GPIO_InitStructure.Pin            = USARTy_TxPin;    
    GPIO_InitStructure.GPIO_Mode      = GPIO_MODE_AF_PP;
    GPIO_InitStructure.GPIO_Alternate = USARTy_Tx_GPIO_AF;
    GPIO_InitStructure.GPIO_Pull      = GPIO_PULL_UP;
    GPIO_Peripheral_Initialize(USARTy_GPIO, &GPIO_InitStructure);

    /* Configure USARTz Tx as alternate function push-pull and pull-up */
    GPIO_InitStructure.Pin            = USARTz_TxPin;
    GPIO_InitStructure.GPIO_Alternate = USARTz_Tx_GPIO_AF;
    GPIO_Peripheral_Initialize(USARTz_GPIO, &GPIO_InitStructure); 

    /* Configure USARTx Rx as alternate function push-pull and pull-up */
    GPIO_InitStructure.Pin            = USARTy_RxPin;
    GPIO_InitStructure.GPIO_Alternate = USARTy_Rx_GPIO_AF;
    GPIO_Peripheral_Initialize(USARTy_GPIO, &GPIO_InitStructure);    

    /* Configure USARTz Rx as alternate function push-pull and pull-up */
    GPIO_InitStructure.Pin            = USARTz_RxPin;
    GPIO_InitStructure.GPIO_Alternate = USARTz_Rx_GPIO_AF;
    GPIO_Peripheral_Initialize(USARTz_GPIO, &GPIO_InitStructure);     


    NVIC_Priority_Group_Set(NVIC_PER2_SUB2_PRIORITYGROUP);
    /* Enable the USARTy Interrupt */
    NVIC_InitStructure.NVIC_IRQChannel                   = USARTy_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority           = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd                = ENABLE;
    NVIC_Initializes(&NVIC_InitStructure);

    /* Enable the USARTz Interrupt */
    NVIC_InitStructure.NVIC_IRQChannel                   = USARTz_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority           = 1;
    NVIC_InitStructure.NVIC_IRQChannelCmd                = ENABLE;
    NVIC_Initializes(&NVIC_InitStructure);

  

初始化串口

    USART_InitType USART_InitStructure;
   
 /* USARTy and USARTz configuration ----------------------------------------------*/
    USART_Structure_Initializes(&USART_InitStructure);
    USART_InitStructure.BaudRate            = 115200;
    USART_InitStructure.WordLength          = USART_WL_8B;
    USART_InitStructure.StopBits            = USART_STPB_1;
    USART_InitStructure.Parity              = USART_PE_NO;
    USART_InitStructure.HardwareFlowControl = USART_HFCTRL_NONE;
    USART_InitStructure.Mode                = USART_MODE_RX | USART_MODE_TX;

    /* Configure USARTy and USARTz */
    USART_Initializes(USARTy, &USART_InitStructure);

    /* Enable USARTy Receive and Transmit interrupts */
    USART_Interrput_Enable(USARTy, USART_INT_RXDNE);

    /* Enable the USARTy and USARTz */
    USART_Enable(USARTy);
 
    void USART1_IRQHandler(void)
    {
        if(USART_Flag_Status_Get(USART1,USART_FLAG_RXDNE) ==  SET)
        {
            USART_Flag_Clear(USART1,USART_FLAG_RXDNE);
        }


    }