STM32 serial port register library function configuration method

1. References

      "STM32F1 Development Guide - Library Function Version" - 5.3 usart serial port folder introduction

                                    - Chapter 9 Serial Port Experiment

      "STM32 Chinese Reference Manual V10" - Chapter 25 Universal Synchronous Asynchronous Receiver Transmitter (USART)

2. Basic principles of serial communication

        Commonly used serial port related registers

           USART_SR status register

           USART_DR data register

           USART_BRR baud rate register

   Serial port operation related registers (entry parameters omitted):

      void USART_Init(); //Serial port initialization: baud rate, data word length, parity check, hardware flow control and transmit and receive enable

            void USART_Cmd(); //Enable serial port

            void USART_ITConfig(); //Enable related interrupts

            void USART_SendData(); //Send data to the serial port, DR

            uint16_t USART_ReceiveData(); //Receive data and read the received data from DR

            FlagStatus USART_GetFlagStatus(); //Get the status flag

            void USART_ClearFlag(); //Clear status flag

            ITStatus USART_GetITStatus(); //Get interrupt status flag

            void USART_ClearITPendingBit(); //Clear interrupt status flag

   Status Register (USART_SR)

      FlagStatus USART_GetFlagStatus(USART_TypeDef* USARTx, uint16_t USART_FLAG);

   Data register (USART_DR)

      void USART_SendData(USART_TypeDef* USARTx, uint16_t Data);

            uint16_t USART_ReceiveData(USART_TypeDef* USARTx);

Baud Rate Register (USART_BRR)

     void USART_Init(USART_TypeDef* USARTx, USART_InitTypeDef* USART_InitStruct);

   Baud rate calculation method

Hardware Connection

PA9, PA10 (serial port 1) are connected to the USB serial port circuit

3. General steps for serial port configuration

  ①Serial port clock enable, GPIO clock enable: RCC_APB2PeriphClockCmd();

        ②Serial port reset: USART_DeInit(); This step is not necessary

        ③GPIO port mode setting: GPIO_Init(); mode is set to GPIO_Mode_AF_PP

        ④Serial port parameter initialization: USART_Init();

        ⑤ Enable interrupts and initialize NVIC (this step is required only if interrupts need to be enabled)

              NVIC_Init();

              USART_ITConfig();

        ⑥ Enable the serial port: USART_Cmd();

        ⑦Write interrupt handling function: USARTx_IRQHandler();

        ⑧Serial port data transmission and reception:

        void USART_SendData(); //Send data to the serial port, DR

        uint16_t USART_ReceiveData(); //Receive data and read the received data from DR

        ⑨Serial port transmission status acquisition:

        FlagStatus USART_GetFlagStatus(USART_TypeDef* USARTx, uint16_t USART_FLAG);

        void USART_ClearITPendingBit(USART_TypeDef* USARTx, uint16_t USART_IT);