STM32 standard firmware library function name (I)

• Operation register CRH and CRL To configure the IO Mode and speed of port

  void GPIO_Init(GPIO_TypeDef* GPIOx, GPIO_InitTypeDef* GPIO_InitStruct);
  

• operation IDR Register read IO Port data is through GPIO_ReadInputDataBit Functionally implemented

  GPIO_ReadInputData(GPIO_TypeDef * GPIOx)
  uint8_t GPIO_ReadInputDataBit(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin)
  

  The return value is 1(Bit_SET) perhaps 0(Bit_RESET);

• Set... In the firmware library ODR Register value to control IO The output state of the port is through the function GPIO_Write To achieve

  GPIO_WriteBit(GPIO_TypeDef * GPIOx, uint16_t GPIO_Pin, BitAction BitVal)
  GPIO_Write(GPIO_TypeDef* GPIOx, uint16_t PortVal);
  

• adopt BSRR and BRR Set register GPIO The port output is through the function GPIO_SetBits() And the function GPIO_ResetBits() To complete .

  void GPIO_SetBits(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin);
  void GPIO_ResetBits(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin);
  

• peripherals （ A serial port ） Clock enable

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1);
  

• Serial reset

  void USART_DeInit(USART_TypeDef* USARTx);
  

• Initialization of serial port parameters

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

  The first parameter is the serial port name , The second parameter is the structure pointer containing initialization parameters

• Data sending and receiving

  void USART_SendData(USART_TypeDef* USARTx, uint16_t Data);
  uint16_t USART_ReceiveData(USART_TypeDef* USARTx);
  

• Serial port status

  The serial port status can be through USART Of SR Register view

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  Fifth RXNE（read external not enpty） When this bit is set 1 When , It indicates that data has been received , And you can read it . At this time, all we have to do is read it as soon as possible USART_DR, By reading USART_DR This bit can be cleared , You can also write... To this bit 0, Direct removal .

  Sixth place TC（transaction complete） When the bit is set , Express USART_DR The data in has been sent . If the interrupt of this bit is set , An interrupt is generated . There are also two ways to clear this bit ：1） read USART_SR, Write USART_DR.2） Write directly to this bit 0.

  Read the serial port status function ：

  FlagStatus USART_GetFlagStatus(USART_TypeDef* USARTx, uint16_t USART_FLAG);
  

  The first parameter is the serial port name , The second parameter is the status to view , For example, the second parameter can be USART_FLAG_RXNE, USART_FLAG_TC wait .

• Serial port enable

  USART_Cmd(USART_TypeDef * USARTx, FunctionalState NewState)
  

  The first parameter is needless to say , The options for the second parameter are ENABLE , DISABLE.

• Serial port interrupt configuration , What situations can be configured （ Such as Count overflow , Data received , Completion of data transmission, etc ） Can trigger an interrupt

  // Serial port interrupt configuration 
  USART_ITConfig(USART_TypeDef * USARTx, uint16_t USART_IT, FunctionalState NewState)
  

  The second entry parameter of this function is to indicate the type of enable serial port , That is, what kind of interrupt is enabled , Because there are many interrupt types of serial port . For example, when receiving data （RXNE The read data register is not empty ）, We need to generate interruptions , So the way we turn on the interrupt is ：

  USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
  

  At the end of sending data （TC, Send complete ） To generate interrupts , So the way is ：

  USART_ITConfig(USART1,USART_IT_TC,ENABLE);
  

  For more interrupt enable types, please refer to STM32 In the Chinese reference manual USART_CR register

• Get the corresponding interrupt status

  If enabled, interrupt , When an interrupt occurs, a bit change will occur in the corresponding status register , We can know whether an interrupt has occurred by reading this bit

  USART_GetITStatus(USART_TypeDef * USARTx, uint16_t USART_IT)
  

change , We can know whether an interrupt has occurred by reading this bit

```
USART_GetITStatus(USART_TypeDef * USARTx, uint16_t USART_IT)
```

 The return value is SET , RESET,set Represents an interruption ,RESET Represents that there is no interruption .