HAL Library

void MX_USART1_UART_Init(void)
{

  huart1.Instance = USART1;
  huart1.Init.BaudRate = 9600;
  huart1.Init.WordLength = UART_WORDLENGTH_8B;
  huart1.Init.StopBits = UART_STOPBITS_1;
  huart1.Init.Parity = UART_PARITY_NONE;
  huart1.Init.Mode = UART_MODE_TX_RX;
  huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart1.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart1) != HAL_OK)
  {
    Error_Handler();
  }

}

STD Library

void uart_init(u32 bound)
{
	GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	
	RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA,ENABLE); //使能GPIOA時鐘
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1,ENABLE);//使能USART1時鐘
 
	//串口1對應引腳復用映射
	GPIO_PinAFConfig(GPIOA,GPIO_PinSource9,GPIO_AF_USART1); //GPIOA9復用為USART1
	GPIO_PinAFConfig(GPIOA,GPIO_PinSource10,GPIO_AF_USART1); //GPIOA10復用為USART1
	
	//USART1埠配置
  	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_10; //GPIOA9與GPIOA10
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//復用功能
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;	//速度50MHz
	GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽復用輸出
	GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; //上拉
	GPIO_Init(GPIOA,&GPIO_InitStructure); //初始化PA9，PA10

   //USART1 初始化設定
	USART_InitStructure.USART_BaudRate = bound;//波特率設定
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;//字長為8位資料格式
	USART_InitStructure.USART_StopBits = USART_StopBits_1;//一個停止位
	USART_InitStructure.USART_Parity = USART_Parity_No;//無奇偶校驗位
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//無硬體資料流控制
	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;	//收發模式
  USART_Init(USART1, &USART_InitStructure); //初始化串口1
	USART_Cmd(USART1, ENABLE);  //使能串口1 
}