stm32u575vgt, usart DMA rX , rx_buff was not changed by DMA.

[simonkoo]

Post edited by ST moderator. In next time please use </> to share your code. Thank you for your understanding.

hi, I am using stm32U5's uasrt2 DMA RX ,  DMA interrupt coming, usart idle int coming, ROR value right, but rx_buffer was not refreshed by DMA, here is my part of code.

/* USER CODE BEGIN PV */
uint8_t loop_TX = 0xaa;
uint8_t loop_RX = 0x0f;
/* USER CODE END PV */
.............................


/* MPU Configuration--------------------------------------------------------*/
  MPU_Config();

  /* 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();
  /* GTZC initialisation */
  MX_GTZC_Init();

  /* USER CODE BEGIN SysInit */
  delay_init();
  HAL_Delay(100);
  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_GPDMA1_Init();
  MX_SPI2_Init();
  MX_USB_OTG_FS_PCD_Init();
  MX_UCPD1_Init();
  MX_I2C4_Init();
  MX_LPUART1_UART_Init();
  MX_USART2_UART_Init();
  MX_USART3_UART_Init();
  MX_I2C3_Init();
  MX_FLASH_Init();
  MX_TIM2_Init();
  MX_USART1_UART_Init();
  MX_ICACHE_Init();

  /* Initialize interrupts */
  MX_NVIC_Init();
 HAL_Delay(100);
while (1) {
    /* First transmit data, then start DMA receive */
    if (loop_TX < 0xFF) {
      loop_TX++;
      HAL_UART_Transmit(&huart2, &loop_TX, 1, 100);
      HAL_Delay(100);
      /* Start DMA receive with IDLE detection */
      HAL_UARTEx_ReceiveToIdle_DMA(&huart2, &loop_RX, 1);
      /* Wait for DMA transfer to complete */
      HAL_Delay(500);
      /* Flush cache to ensure DMA data is visible to CPU */
      //SCB_InvalidateDCache_by_Addr(&loop_RX, sizeof(loop_RX));
      printf("[MAIN] TX: %02X, RX: %02X\r\n", loop_TX, loop_RX);
    }
  }
void USART2_IRQHandler(void)
{
  /* USER CODE BEGIN USART2_IRQn 0 */
  if (__HAL_UART_GET_FLAG(&huart2, UART_FLAG_IDLE)) {
   
    __HAL_UART_CLEAR_IDLEFLAG(&huart2);

    uint16_t dma_cntr = __HAL_DMA_GET_COUNTER(huart2.hdmarx);
   
    /* Flush cache to ensure DMA data is visible to CPU */
    //SCB_InvalidateDCache_by_Addr(&loop_RX, sizeof(loop_RX));
   
    printf("[USART2] IDLE, DMA CNDTR=%u, RX=%02X, RDR=%02X\r\n",
           dma_cntr, loop_RX, huart2.Instance->RDR);
  }
  /* USER CODE END USART2_IRQn 0 */
  HAL_UART_IRQHandler(&huart2);
  /* USER CODE BEGIN USART2_IRQn 1 */
  /* USER CODE END USART2_IRQn 1 */
}
void GPDMA1_Channel4_IRQHandler(void)
{
  /* USER CODE BEGIN GPDMA1_Channel4_IRQn 0 */
  /* USER CODE END GPDMA1_Channel4_IRQn 0 */
  HAL_DMA_IRQHandler(&handle_GPDMA1_Channel4);
  /* USER CODE BEGIN GPDMA1_Channel4_IRQn 1 */
  printf("[GPDMA1_Channel4] DMA done, CNDTR=%u\r\n",
         __HAL_DMA_GET_COUNTER(&handle_GPDMA1_Channel4));
  printf(
      "[GPDMA1_Channel4] DMA buf: %02X %02X %02X %02X %02X %02X %02X %02X\r\n",
      g_oas1200.rx_buffer[0], g_oas1200.rx_buffer[1], g_oas1200.rx_buffer[2],
      g_oas1200.rx_buffer[3], g_oas1200.rx_buffer[4], g_oas1200.rx_buffer[5],
      g_oas1200.rx_buffer[6], g_oas1200.rx_buffer[7]);

  /* USER CODE END GPDMA1_Channel4_IRQn 1 */
}

here is some print result :

[MAIN] loop_RX addr=0x20000029

[GPDMA1_Channel0] DMA done, CNDTR=0, CSAR=0x40004424, CDAR=0x20000029, CTR1=0x00000000

[MAIN] TX: B4, RX: 0F

[USART2] IDLE, DMA CNDTR=0, RX=0F, RDR=B5

[MAIN] loop_RX addr=0x20000029

[GPDMA1_Channel0] DMA done, CNDTR=0, CSAR=0x40004424, CDAR=0x20000029, CTR1=0x00000000

[MAIN] TX: B5, RX: 0F

[USART2] IDLE, DMA CNDTR=0, RX=0F, RDR=B6[MAIN] loop_RX addr=0x20000029

[GPDMA1_Channel0] DMA done, CNDTR=0, CSAR=0x40004424, CDAR=0x20000029, CTR1=0x00000000

I connect usart2 TX and RX pin to do the test , the RX value should be  equal to TX, I have no idea what is wrong ....

[Gyessine · Accepted solution]

Hello @simonkoo 
Here are some ideas that might help you troubleshoot and solve your issue.
First, I noticed that you have

  MX_GTZC_Init();

Are you using the secure zone intentionally? If yes, verify that you handle it correctly. If it is not mandatory, consider using a nonsecure world project to simplify manipulation.

Second, do you really need all these peripherals?

MX_GPIO_Init();
  MX_GPDMA1_Init();
  MX_SPI2_Init();
  MX_USB_OTG_FS_PCD_Init();
  MX_UCPD1_Init();
  MX_I2C4_Init();
  MX_LPUART1_UART_Init();
  MX_USART2_UART_Init();
  MX_USART3_UART_Init();
  MX_I2C3_Init();
  MX_FLASH_Init();
  MX_TIM2_Init();
  MX_USART1_UART_Init();
  MX_ICACHE_Init();

If not, create a project with only the required peripherals, such as USART1 and GPDMA. Clear pinouts when the .ioc file opens.

-I also recommend enabling the destination address increment.

Finally, I have attached a project that echoes a "hello world" buffer transmitted through USART1_TX to USART1_RX using HAL_UART_Receive_DMA and prints it in a buffer named rx_buffer. You can visualize rx_buffer using live expression. Wire the TX pin to the RX pin. Use this project as a reference to identify issues in your project.

BR
Gyessine

[simonkoo]

thanks a lot , it really was caused by  

  MX_GTZC_Init();

I used memory management tool in MX which set the GTZC enable 

Thanks !!!

BR

Simon