stm32f429 uart dma空闲中断接收不正常

312011 提问时间：2018-6-15 09:05 /

本帖最后由 312011 于 2018-6-15 09:23 编辑

/*
* uart1 dma rx idle intrrupt process
*/
void Addedto_USART1_IRQHandler(void)
{
      if(__HAL_UART_GET_FLAG(&huart1,UART_FLAG_IDLE)!=RESET) //uart1 dma rx idle intrrupt
      {
            static  uint32_t rxdatanum,temp;

            __HAL_UART_CLEAR_IDLEFLAG(&huart1);       //clear uart1 dma rx idle intrrupt flag
            temp =huart1.Instance->SR;
            temp =huart1.Instance->DR;
            temp=huart1.hdmarx->Instance->NDTR;
//             CLEAR_BIT(huart1.Instance->CR3, USART_CR3_DMAR);
//             HAL_DMA_Abort(huart1.hdmarx);
            __HAL_DMA_DISABLE(huart1.hdmarx);
            rxdatanum=UART_DMA_RX_SIZE-(__HAL_DMA_GET_COUNTER(huart1.hdmarx));

            /* Enable the DMA transfer for the receiver request by setting the DMAR bit
in the UART CR3 register */
SET_BIT(huart1.Instance->CR3, USART_CR3_DMAR);
            /* Enable the Peripheral */
__HAL_DMA_ENABLE(huart1.hdmarx);

            osMessagePut(Queue_EventUart,(rxdatanum +((uint32_t )EVENT_UART1_RX<<16)),0);//send rx event
      }

}

/**
* @brief This function handles USART1 global interrupt.
*/
void USART1_IRQHandler(void)
{
  /* USER CODE BEGIN USART1_IRQn 0 */

  /* USER CODE END USART1_IRQn 0 */
  HAL_UART_IRQHandler(&huart1);
  /* USER CODE BEGIN USART1_IRQn 1 */
      Addedto_USART1_IRQHandler();
  /* USER CODE END USART1_IRQn 1 */
}
为什么这样第一次无法正确接收，需要发两次甚至更多次才能收到上一次的数据？中断停在这个空闲中断处理函数里的sMessagePut函数，发现rxdatanum和temp值不正确，什么原因？