STM32N6: DCMIPP

Clyasenth · ‎2025-06-10

Hello,

I want to use the TW9992 NTSC/PAL Video Decoder for STM32N6 to transfer an NTSC camera (720x480 resolution) to the MCU via MIPI-CSI and display it on the screen. I have attached the code below.

static void MX_DCMIPP_Init(void)
{
 
  /* USER CODE BEGIN DCMIPP_Init 0 */
 
  /* USER CODE END DCMIPP_Init 0 */
 
  DCMIPP_CSI_PIPE_ConfTypeDef pCSI_PipeConfig = {0};
  DCMIPP_CSI_ConfTypeDef pCSI_Config = {0};
  DCMIPP_PipeConfTypeDef pPipeConfig = {0};
 
  /* USER CODE BEGIN DCMIPP_Init 1 */
 
  /* USER CODE END DCMIPP_Init 1 */
  hdcmipp.Instance = DCMIPP;
  if (HAL_DCMIPP_Init(&hdcmipp) != HAL_OK)
  {
    Error_Handler();
  }
 
  /** Pipe 0 Config
  */
  pCSI_PipeConfig.DataTypeMode = DCMIPP_DTMODE_DTIDA;
  pCSI_PipeConfig.DataTypeIDA = DCMIPP_DT_RGB565;
  pCSI_PipeConfig.DataTypeIDB = DCMIPP_DT_RGB565;
  if (HAL_DCMIPP_CSI_PIPE_SetConfig(&hdcmipp, DCMIPP_PIPE0, &pCSI_PipeConfig) != HAL_OK)
  {
    Error_Handler();
  }
  pCSI_Config.PHYBitrate = DCMIPP_CSI_PHY_BT_1600;
  pCSI_Config.DataLaneMapping = DCMIPP_CSI_PHYSICAL_DATA_LANES;
  pCSI_Config.NumberOfLanes = DCMIPP_CSI_ONE_DATA_LANE;
  if (HAL_DCMIPP_CSI_SetConfig(&hdcmipp, &pCSI_Config) != HAL_OK)
  {
    Error_Handler();
  }
  pPipeConfig.FrameRate = DCMIPP_FRAME_RATE_ALL;
  pPipeConfig.PixelPipePitch = 1440;
  pPipeConfig.PixelPackerFormat = DCMIPP_PIXEL_PACKER_FORMAT_RGB565_1;
  if (HAL_DCMIPP_PIPE_SetConfig(&hdcmipp, DCMIPP_PIPE0, &pPipeConfig) != HAL_OK)
  {
    Error_Handler();
  }
  HAL_DCMIPP_CSI_SetVCConfig(&hdcmipp, 0U, DCMIPP_CSI_DT_BPP16);
  /* USER CODE BEGIN DCMIPP_Init 2 */
 
  /* USER CODE END DCMIPP_Init 2 */
 
}

if (HAL_DCMIPP_CSI_PIPE_Start(&hdcmipp, DCMIPP_PIPE0, DCMIPP_VIRTUAL_CHANNEL0 ,
      AXISRAM4_ADDRESS, DCMIPP_MODE_CONTINUOUS) != HAL_OK)
  {
    Error_Handler();
  }

while(1){
    /* Start DMA2D transfer*/
    if(HAL_DMA2D_Start_IT(&hdma2d,
                          (uint32_t)AXISRAM4_ADDRESS, /* camera data */
                          (uint32_t)BUFFER_ADDRESS,    /* LCD frame buffer address */
                          FRAME_WIDTH,
                          FRAME_HEIGHT) != HAL_OK)
    {
      Error_Handler();
    }
  }

Is the parameter pCSI_Config.PHYBitrate = DCMIPP_CSI_PHY_BT_1600; correct for the camera used in our application?

pPipeConfig.PixelPipePitch = 1440;

HAL_DCMIPP_CSI_SetVCConfig(&hdcmipp, 0U, DCMIPP_CSI_DT_BPP16);

When using 16-bit, does it become 720 or 1440?

Also, Pipe 1 has an ISP, but we don't need to use it (the camera has its own ISP). Therefore, we chose Pipe 0 so what would you recommend about it?

Best regards,

Egemen Aksoy

Clyasenth · ‎2025-06-12

Hello,

Is there any progress?

Clyasenth · ‎2025-06-17

Hello,

Sadly, still there is no any response.

Could you please help for this topic. It is a bit urgent.

Best regards,

Egemen Aksoy

Ch_JE · ‎2025-06-19

Hello ,

The PIPE0 can be used directly to dump data from the sensor without any post-processing. In this case, the PixelPipePitch value has no impact (it is mandatory only for Pipe 1 and Pipe 2).

Please ensure that the data format is properly aligned for both CSI and DCMIPP; otherwise, no data will be dumped. You can use Pipe 0 with pCSI_PipeConfig.DataTypeMode = DCMIPP_DTMODE_ALL to directly dump all the data sent from the sensor.

Finally, ensure that the synchronization signals (HSYNC, VSYNC) from the TW9992 are properly connected and configured in DCMIPP.

Could you please share the behavior you are observing with the current configuration? Also, verify that the sensor is correctly configured with the selected virtual channel.

Regards,

Clyasenth · ‎2025-06-20

Hello,

Init code:

static void MX_DCMIPP_Init(void)
{
 
  /* USER CODE BEGIN DCMIPP_Init 0 */
 
  /* USER CODE END DCMIPP_Init 0 */
 
  DCMIPP_CSI_PIPE_ConfTypeDef pCSI_PipeConfig = {0};
  DCMIPP_CSI_ConfTypeDef pCSI_Config = {0};
  DCMIPP_PipeConfTypeDef pPipeConfig = {0};
 
  /* USER CODE BEGIN DCMIPP_Init 1 */
 
  /* USER CODE END DCMIPP_Init 1 */
  hdcmipp.Instance = DCMIPP;
  if (HAL_DCMIPP_Init(&hdcmipp) != HAL_OK)
  {
    Error_Handler();
  }
 
  /** Pipe 0 Config
  */
  pCSI_PipeConfig.DataTypeMode = DCMIPP_DTMODE_ALL;
  pCSI_PipeConfig.DataTypeIDA = DCMIPP_DT_RGB565;
  pCSI_PipeConfig.DataTypeIDB = DCMIPP_DT_RGB565;
  if (HAL_DCMIPP_CSI_PIPE_SetConfig(&hdcmipp, DCMIPP_PIPE0, &pCSI_PipeConfig) != HAL_OK)
  {
    Error_Handler();
  }
  pCSI_Config.PHYBitrate = DCMIPP_CSI_PHY_BT_1000;
  pCSI_Config.DataLaneMapping = DCMIPP_CSI_PHYSICAL_DATA_LANES;
  pCSI_Config.NumberOfLanes = DCMIPP_CSI_ONE_DATA_LANE;
  if (HAL_DCMIPP_CSI_SetConfig(&hdcmipp, &pCSI_Config) != HAL_OK)
  {
    Error_Handler();
  }
  pPipeConfig.FrameRate = DCMIPP_FRAME_RATE_ALL;
  pPipeConfig.PixelPipePitch = 1440;
  pPipeConfig.PixelPackerFormat = DCMIPP_PIXEL_PACKER_FORMAT_RGB565_1;
  if (HAL_DCMIPP_PIPE_SetConfig(&hdcmipp, DCMIPP_PIPE0, &pPipeConfig) != HAL_OK)
  {
    Error_Handler();
  }
 
  /* USER CODE BEGIN DCMIPP_Init 2 */
  HAL_DCMIPP_CSI_SetVCConfig(&hdcmipp, 0U, DCMIPP_CSI_DT_BPP8);
  /* USER CODE END DCMIPP_Init 2 */
 
}

In main.c

if (HAL_DCMIPP_CSI_PIPE_Start(&hdcmipp, DCMIPP_PIPE0, DCMIPP_VIRTUAL_CHANNEL0 ,
             /*CAMERA_BUF_ADRESS*/BUFFER_ADDRESS, DCMIPP_MODE_CONTINUOUS) != HAL_OK)
{
Error_Handler();
}

With this configuration I see double images in the screen. What could be wrong with it?

pCSI_Config.PHYBitrate = DCMIPP_CSI_PHY_BT_1000;

How should we configure this parameter (Bit rate)?

Best regards,

Ch_JE · ‎2025-06-20

Hello,

Please attach a screenshot of the screen or the display configuration. The issue is more likely related to the display rather than the DCMIPP or the sensor.

(No overrun on dcmipp or any other error ? frames received correctly ?)

Best regards.

Clyasenth · ‎2025-06-20

Hello,

Display output looks like this.

For the display side LCD 24bit RGB interface

  pLayerCfg.WindowX0 = 0;
  pLayerCfg.WindowX1 = 720;
  pLayerCfg.WindowY0 = 0;
  pLayerCfg.WindowY1 = 480;
  pLayerCfg.PixelFormat = LTDC_PIXEL_FORMAT_RGB565;//todo fix
  pLayerCfg.Alpha = 255;
  pLayerCfg.Alpha0 = 0;
  pLayerCfg.BlendingFactor1 = LTDC_BLENDING_FACTOR1_CA;
  pLayerCfg.BlendingFactor2 = LTDC_BLENDING_FACTOR2_CA;
  pLayerCfg.FBStartAdress = BUFFER_ADDRESS;
  pLayerCfg.ImageWidth = 720;
  pLayerCfg.ImageHeight = 480;
  pLayerCfg.Backcolor.Blue = 0;
  pLayerCfg.Backcolor.Green = 0;
  pLayerCfg.Backcolor.Red = 0;
  if (HAL_LTDC_ConfigLayer(&hltdc, &pLayerCfg, 0) != HAL_OK)
  {
    Error_Handler();
  }

But we initialize RGB565 to display camera output directly to the display.

LCD resolution is 800x480.

Also I added an error counter in to the code and run the code many times but there is no error received.

Best regards,

Ch_JE · ‎2025-06-20

Hello,

It looks correct ,

while(1){
    /* Start DMA2D transfer*/
    if(HAL_DMA2D_Start_IT(&hdma2d,
                          (uint32_t)AXISRAM4_ADDRESS, /* camera data */
                          (uint32_t)BUFFER_ADDRESS,    /* LCD frame buffer address */
                          FRAME_WIDTH,
                          FRAME_HEIGHT) != HAL_OK)
    {
      Error_Handler();
    }
  }

What is the purpose of this function? It seems you might not be managing the memory correctly, which could cause the display to show incorrect data.

The DCMIPP is used to dump data directly in the memory , allowing you to use the same frame address for display."

Ch_JE · ‎2025-06-20

You are not using a secod pipe ?

Clyasenth · ‎2025-06-20

Hello,

Normally our image format ARGB8888 we used RGB565 format for displaying camera.

Currently this code is commented and not used.