[STM32F4xx] UART1 DMA Receive Test (s/w test)

지난 번의 IDLE IT 를 사용한 DMA 테스트는 UART2에서 한 테스트였고,

이번에는 UART1 에서 테스트를 해 봤다.

수정할 내용만 적어 보면 다음과 같다.

UART1 인터럽트함수의 코드는 다음과 같다.

void USART1_IRQHandler(void)
{
  /* USER CODE BEGIN USART1_IRQn 0 */
    /* Check for IDLE flag */
    if (USART1->SR & UART_FLAG_IDLE) {         /* We want IDLE flag only */
        /* This part is important */
        /* Clear IDLE flag by reading status register first */
        /* And follow by reading data register */
        volatile uint32_t tmp;                  /* Must be volatile to prevent optimizations */
        tmp = USART1->SR;                       /* Read status register */
        tmp = USART1->DR;                       /* Read data register */
        (void)tmp;                              /* Prevent compiler warnings */
        __HAL_DMA_DISABLE(&hdma_usart1_rx);
    }    
    return;
  /* USER CODE END USART1_IRQn 0 */
  HAL_UART_IRQHandler(&huart1);
  /* USER CODE BEGIN USART1_IRQn 1 */
 
  /* USER CODE END USART1_IRQn 1 */
}

 

UART1 의 DMA 인터럽트는 DMA2_Stream2_IRQHandler 함수를 사용한다.

코드는 다음과 같다.

void DMA2_Stream2_IRQHandler(void)
{
  /* USER CODE BEGIN DMA2_Stream2_IRQn 0 */
    size_t len, tocopy;
    uint8_t* ptr;
    
    /* Check transfer complete flag */
    if (DMA2->LISR & DMA_FLAG_TCIF2_6) {
        DMA2->LIFCR = DMA_FLAG_TCIF2_6;           /* Clear transfer complete flag */
        
        /* Calculate number of bytes actually transfered by DMA so far */
        /**
         * Transfer could be completed by 2 events:
         *  - All data actually transfered (NDTR = 0)
         *  - Stream disabled inside USART IDLE line detected interrupt (NDTR != 0)
         */
        len = DMA_RX_BUFFER_SIZE - DMA2_Stream2->NDTR;
        tocopy = UART_BUFFER_SIZE - Write;      /* Get number of bytes we can copy to the end of buffer */
        
        /* Check how many bytes to copy */
        if (tocopy > len) {
            tocopy = len;
        }
        
        /* Write received data for UART main buffer for manipulation later */
        ptr = DMA_RX_Buffer;
        memcpy(&UART_Buffer[Write], ptr, tocopy);   /* Copy first part */
                
        
        /* Correct values for remaining data */
        Write += tocopy;
        len -= tocopy;
        ptr += tocopy;
        
        /* If still data to write for beginning of buffer */
        if (len) {
            memcpy(&UART_Buffer[0], ptr, len);      /* Don't care if we override Read pointer now */
            Write = len;
        }
        
        /* Prepare DMA for next transfer */
        /* Important! DMA stream won't start if all flags are not cleared first */
        //DMA2->HIFCR = DMA_FLAG_DMEIF1_5 | DMA_FLAG_FEIF1_5 | DMA_FLAG_HTIF1_5 | DMA_FLAG_TCIF1_5 | DMA_FLAG_TEIF1_5;
        DMA2->LIFCR = DMA_FLAG_DMEIF2_6 | DMA_FLAG_FEIF2_6 | DMA_FLAG_HTIF2_6 | DMA_FLAG_TCIF2_6 | DMA_FLAG_TEIF2_6;
        DMA2_Stream2->M0AR = (uint32_t)DMA_RX_Buffer;
        DMA2_Stream2->NDTR = DMA_RX_BUFFER_SIZE;
        __HAL_DMA_ENABLE(&hdma_usart1_rx);
        //DMA1_Stream5->CR |= DMA_SxCR_EN;            /* Start DMA transfer */
    }
    return;
  /* USER CODE END DMA2_Stream2_IRQn 0 */
  HAL_DMA_IRQHandler(&hdma_usart1_rx);
  /* USER CODE BEGIN DMA2_Stream2_IRQn 1 */
 
  /* USER CODE END DMA2_Stream2_IRQn 1 */
}

main() 함수 코드 내용은 다음과 같습니다.

int main(void)
{
 
  /* USER CODE BEGIN 1 */
  /* USER CODE END 1 */
 
  /* MCU Configuration----------------------------------------------------------*/
 
  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();
 
  /* USER CODE BEGIN Init */
 
  /* USER CODE END Init */
 
  /* Configure the system clock */
  SystemClock_Config();
 
  /* USER CODE BEGIN SysInit */
 
  /* USER CODE END SysInit */
 
  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_DMA_Init();
  MX_USART1_UART_Init();
 
  /* USER CODE BEGIN 2 */
    __HAL_UART_ENABLE_IT(&huart1,UART_IT_IDLE);
    HAL_UART_Receive_DMA(&huart1,DMA_RX_Buffer,DMA_RX_BUFFER_SIZE);
  /* USER CODE END 2 */
 
  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
  /* USER CODE END WHILE */
 
  /* USER CODE BEGIN 3 */
        if (Read != Write)
        { 
            __wfi();    // or __wfe();
            //__HAL_UNLOCK(&huart2);
            //__HAL_LOCK(&huart2);
            while (!(USART1->SR & USART_SR_TXE));   /* Wait till finished */
            USART1->DR = UART_Buffer[Read++];
            //HAL_UART_Transmit(&huart2,(uint8_t *)UART_Buffer[Read++],1,1);
            //while (!(USART2->SR & USART_SR_TC));   /* Wait till finished */
            //while (!(__HAL_UART_GET_FLAG(&huart2, UART_FLAG_TXE))){};
                    
                    
            if (Read > UART_BUFFER_SIZE) /* Check buffer overflow */
            {     
                    Read = 0;
            }
        }
        //while(HAL_GPIO_ReadPin(B1_GPIO_Port,B1_Pin) == GPIO_PIN_RESET);
        //while(HAL_GPIO_ReadPin(B1_GPIO_Port,B1_Pin) == GPIO_PIN_SET);
        
  }
  /* USER CODE END 3 */
 
}