STM32串口通信原理及HAL库代码stm32f1xx

只看该作者 · 2023-9-20 14:57

HAL_StatusTypeDef HAL_UART_Receive_IT(UART_HandleTypeDef *huart, uint8_t *pData, uint16_t Size)
{//串口中断接收函数
  /* Check that a Rx process is not already ongoing */
  if(huart->RxState == HAL_UART_STATE_READY)
  {
if((pData == NULL) || (Size == 0U))
{
   return HAL_ERROR;
}

只看该作者 · 2023-9-20 14:57

/* Process Locked */
__HAL_LOCK(huart);

huart->pRxBuffPtr = pData;//接收的数据缓存指针
huart->RxXferSize = Size;//接收的最大数据量字节数
huart->RxXferCount = Size;//还剩余的要接收的数据量字节数

huart->ErrorCode = HAL_UART_ERROR_NONE;
huart->RxState = HAL_UART_STATE_BUSY_RX;

/* Process Unlocked */
__HAL_UNLOCK(huart);

/* Enable the UART Parity Error Interrupt */
__HAL_UART_ENABLE_IT(huart, UART_IT_PE);//校验错误中断使能

/* Enable the UART Error Interrupt: (Frame error, noise error, overrun error) */
__HAL_UART_ENABLE_IT(huart, UART_IT_ERR);//错误中断使能-帧错误,噪错误，满溢错误

/* Enable the UART Data Register not empty Interrupt */
__HAL_UART_ENABLE_IT(huart, UART_IT_RXNE);//接收中断使能【如果串口收到数据，则进入到串口处理函数HAL_UART_IRQHandler】

return HAL_OK;
}

只看该作者 · 2023-9-20 14:57

else
{
return HAL_BUSY;
}
}

只看该作者 · 2023-9-20 14:57

如果串口收到数据，则进入到串口处理函数HAL_UART_IRQHandler的下面部分执行

if(((isrflags & USART_SR_RXNE) != RESET) && ((cr1its & USART_CR1_RXNEIE) != RESET))
{//打开串口中断，且有数据收到-RXNE被置位
   UART_Receive_IT(huart);
   return;
}

static HAL_StatusTypeDef UART_Receive_IT(UART_HandleTypeDef *huart)
{
  uint16_t* tmp;

  /* Check that a Rx process is ongoing */
  if(huart->RxState == HAL_UART_STATE_BUSY_RX)
  {
if(huart->Init.WordLength == UART_WORDLENGTH_9B)
{//带有校验
   tmp = (uint16_t*) huart->pRxBuffPtr;
   if(huart->Init.Parity == UART_PARITY_NONE)
   {
      *tmp = (uint16_t)(huart->Instance->DR & (uint16_t)0x01FF);
      huart->pRxBuffPtr += 2U;
   }

只看该作者 · 2023-9-20 14:57

else
   {
      *tmp = (uint16_t)(huart->Instance->DR & (uint16_t)0x00FF);
      huart->pRxBuffPtr += 1U;
   }
}
else
{//不带校验
   if(huart->Init.Parity == UART_PARITY_NONE)
   {
      *huart->pRxBuffPtr++ = (uint8_t)(huart->Instance->DR & (uint8_t)0x00FF);//接收数据寄存器RDR被读取【保存数据到接收buf，并指向下一个】，RXNE标志复位。【当下1字节数据8位全部都从接收移位寄存器转移到接收数据寄存器RDR后，RXNE再次被置位，将再次触发RXNE中断，再次到此处执行，如此循环直到收完全部数据】
】

只看该作者 · 2023-9-20 14:58

else
   {
      *huart->pRxBuffPtr++ = (uint8_t)(huart->Instance->DR & (uint8_t)0x007F);
   }
}

if(--huart->RxXferCount == 0U)
{//收完全部数据后
   /* Disable the IRDA Data Register not empty Interrupt */
   __HAL_UART_DISABLE_IT(huart, UART_IT_RXNE);//关闭RXNE中断

   /* Disable the UART Parity Error Interrupt */
   __HAL_UART_DISABLE_IT(huart, UART_IT_PE);//关闭校验错误中断
      /* Disable the UART Error Interrupt: (Frame error, noise error, overrun error) */
      __HAL_UART_DISABLE_IT(huart, UART_IT_ERR);//关闭错误中断

只看该作者 · 2023-9-20 14:58

/* Rx process is completed, restore huart->RxState to Ready */
   huart->RxState = HAL_UART_STATE_READY;

   HAL_UART_RxCpltCallback(huart);//接收完成中断回调函数，用户可以再这里做操作

   return HAL_OK;
}
return HAL_OK;
  }
  else
  {
return HAL_BUSY;
  }
}

只看该作者 · 2024-4-28 18:14

楼主是使用的HAL库进行的开发？

只看该作者 · 2024-4-28 18:14

楼主是使用的HAL库进行的开发？