STM32H7的摄像头接口DCMI配套的函数HAL_DCMI_Start_DMA非常不错，支持大分辨率直接传输

eric2013

函数HAL_DCMI_Start_DMA封装的通用定时器DMA1，DMA2。使用这个定时器的特点是限制单轮最大65535次传输，这样使用大分辨率摄像头非常不方便。

使用这个函数的话，解决了这个问题，程序里面做了一个处理，对于需要大于65536次传输的情况，使用了双缓冲，不断动态调整地址，直到一帧传输完毕后会使能DCMI的帧中断

1. /**
   
2.   * @brief  Enables DCMI DMA request and enables DCMI capture  
   
3.   * @param  hdcmi:     pointer to a DCMI_HandleTypeDef structure that contains
   
4.   *                    the configuration information for DCMI.
   
5.   * @param  DCMI_Mode: DCMI capture mode snapshot or continuous grab.
   
6.   * @param  pData:     The destination memory Buffer address (LCD Frame buffer).
   
7.   * @param  Length:    The length of capture to be transferred.
   
8.   * @retval HAL status
   
9.   */
   
10. HAL_StatusTypeDef HAL_DCMI_Start_DMA(DCMI_HandleTypeDef* hdcmi, uint32_t DCMI_Mode, uint32_t pData, uint32_t Length)
    
11. {  
    
12.   /* Initialize the second memory address */
    
13.   uint32_t SecondMemAddress = 0;
    
14. 
    
15.   /* Check function parameters */
    
16.   assert_param(IS_DCMI_CAPTURE_MODE(DCMI_Mode));
    
17. 
    
18.   /* Process Locked */
    
19.   __HAL_LOCK(hdcmi);
    
20.   
    
21.   /* Lock the DCMI peripheral state */
    
22.   hdcmi->State = HAL_DCMI_STATE_BUSY;
    
23. 
    
24.   /* Enable DCMI by setting DCMIEN bit */
    
25.   __HAL_DCMI_ENABLE(hdcmi);
    
26.   
    
27.   /* Configure the DCMI Mode */
    
28.   hdcmi->Instance->CR &= ~(DCMI_CR_CM);
    
29.   hdcmi->Instance->CR |=  (uint32_t)(DCMI_Mode);
    
30. 
    
31.   /* Set the DMA memory0 conversion complete callback */
    
32.   hdcmi->DMA_Handle->XferCpltCallback = DCMI_DMAXferCplt;
    
33. 
    
34.   /* Set the DMA error callback */
    
35.   hdcmi->DMA_Handle->XferErrorCallback = DCMI_DMAError;
    
36. 
    
37.   /* Set the dma abort callback */
    
38.   hdcmi->DMA_Handle->XferAbortCallback = NULL;
    
39. 
    
40.   /* Reset transfer counters value */
    
41.   hdcmi->XferCount = 0;
    
42.   hdcmi->XferTransferNumber = 0;
    
43.   
    
44.   if(Length <= 0xFFFF)
    
45.   {
    
46.     /* Enable the DMA Stream */
    
47.     HAL_DMA_Start_IT(hdcmi->DMA_Handle, (uint32_t)&hdcmi->Instance->DR, (uint32_t)pData, Length);
    
48.   }
    
49.   else /* DCMI_DOUBLE_BUFFER Mode */
    
50.   {
    
51.     /* Set the DMA memory1 conversion complete callback */
    
52.     hdcmi->DMA_Handle->XferM1CpltCallback = DCMI_DMAXferCplt;
    
53. 
    
54.     /* Initialize transfer parameters */
    
55.     hdcmi->XferCount = 1;
    
56.     hdcmi->XferSize = Length;
    
57.     hdcmi->pBuffPtr = pData;
    
58.       
    
59.     /* Get the number of buffer */
    
60.     while(hdcmi->XferSize > 0xFFFF)
    
61.     {
    
62.       hdcmi->XferSize = (hdcmi->XferSize/2);
    
63.       hdcmi->XferCount = hdcmi->XferCount*2;
    
64.     }
    
65. 
    
66.     /* Update DCMI counter  and transfer number*/
    
67.     hdcmi->XferCount = (hdcmi->XferCount - 2);
    
68.     hdcmi->XferTransferNumber = hdcmi->XferCount;
    
69. 
    
70.     /* Update second memory address */
    
71.     SecondMemAddress = (uint32_t)(pData + (4*hdcmi->XferSize));
    
72. 
    
73.     /* Start DMA multi buffer transfer */
    
74.     HAL_DMAEx_MultiBufferStart_IT(hdcmi->DMA_Handle, (uint32_t)&hdcmi->Instance->DR, (uint32_t)pData, SecondMemAddress, hdcmi->XferSize);
    
75.   }
    
76.   
    
77.   /* Enable Capture */
    
78.   hdcmi->Instance->CR |= DCMI_CR_CAPTURE;
    
79. 
    
80.   /* Release Lock */
    
81.   __HAL_UNLOCK(hdcmi);
    
82. 
    
83.   /* Return function status */
    
84.   return HAL_OK;
    
85. }

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DMA传输完成中断里面的关键地方：

1. /**
   
2.   * @}
   
3.   */
   
4. /* Private functions ---------------------------------------------------------*/
   
5. /** @defgroup DCMI_Private_Functions DCMI Private Functions
   
6.   * @{
   
7.   */
   
8.   /**
   
9.   * @brief  DMA conversion complete callback.
   
10.   * @param  hdma: pointer to a DMA_HandleTypeDef structure that contains
    
11.   *                the configuration information for the specified DMA module.
    
12.   * @retval None
    
13.   */
    
14. static void DCMI_DMAXferCplt(DMA_HandleTypeDef *hdma)
    
15. {
    
16.   uint32_t tmp = 0;
    
17. 
    
18.   DCMI_HandleTypeDef* hdcmi = ( DCMI_HandleTypeDef* )((DMA_HandleTypeDef* )hdma)->Parent;
    
19. 
    
20.   if(hdcmi->XferCount != 0)
    
21.   {
    
22.     /* Update memory 0 address location */
    
23.     tmp = ((((DMA_Stream_TypeDef *)(hdcmi->DMA_Handle->Instance))->CR) & DMA_SxCR_CT);
    
24.     if(((hdcmi->XferCount % 2) == 0) && (tmp != 0))
    
25.     {
    
26.       tmp = ((DMA_Stream_TypeDef *)(hdcmi->DMA_Handle->Instance))->M0AR;
    
27.       HAL_DMAEx_ChangeMemory(hdcmi->DMA_Handle, (tmp + (8*hdcmi->XferSize)), MEMORY0);
    
28.       hdcmi->XferCount--;
    
29.     }
    
30.     /* Update memory 1 address location */
    
31.     else if((((DMA_Stream_TypeDef *)(hdcmi->DMA_Handle->Instance))->CR & DMA_SxCR_CT) == 0)
    
32.     {
    
33.       tmp = ((DMA_Stream_TypeDef *)(hdcmi->DMA_Handle->Instance))->M1AR;
    
34.       HAL_DMAEx_ChangeMemory(hdcmi->DMA_Handle, (tmp + (8*hdcmi->XferSize)), MEMORY1);
    
35.       hdcmi->XferCount--;
    
36.     }
    
37.   }
    
38.   /* Update memory 0 address location */
    
39.   else if((((DMA_Stream_TypeDef *)(hdcmi->DMA_Handle->Instance))->CR & DMA_SxCR_CT) != 0)
    
40.   {
    
41.     ((DMA_Stream_TypeDef *)(hdcmi->DMA_Handle->Instance))->M0AR = hdcmi->pBuffPtr;
    
42.   }
    
43.   /* Update memory 1 address location */
    
44.   else if((((DMA_Stream_TypeDef *)(hdcmi->DMA_Handle->Instance))->CR & DMA_SxCR_CT) == 0)
    
45.   {
    
46.     tmp = hdcmi->pBuffPtr;
    
47.     ((DMA_Stream_TypeDef *)(hdcmi->DMA_Handle->Instance))->M1AR = (tmp + (4*hdcmi->XferSize));
    
48.     hdcmi->XferCount = hdcmi->XferTransferNumber;
    
49.   }
    
50. 
    
51.   /* Check if the frame is transferred */
    
52.   if(hdcmi->XferCount == hdcmi->XferTransferNumber)
    
53.   {
    
54.     /* Enable the Frame interrupt */
    
55.     __HAL_DCMI_ENABLE_IT(hdcmi, DCMI_IT_FRAME);
    
56.    
    
57.     /* When snapshot mode, set dcmi state to ready */
    
58.     if((hdcmi->Instance->CR & DCMI_CR_CM) == DCMI_MODE_SNAPSHOT)
    
59.     {  
    
60.       hdcmi->State= HAL_DCMI_STATE_READY;
    
61.     }
    
62.   }  
    
63. }

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hpdell

研究的很深啦

sblpp

谢谢分享！

jgmms

楼主你好，我使用STM32H723的DCMI的HAL_DCMI_Start_DMA（）函数，程序会跑到 hdcmi->DMA_Handle->XferErrorCallback = DCMI_DMAError;不知道是什么问题请指教

eric2013

jgmms 发表于 2022-5-10 17:06
楼主你好，我使用STM32H723的DCMI的HAL_DCMI_Start_DMA（）函数，程序会跑到 hdcmi->DMA_Handle->XferError ...

直接使用我们的代码，测试是否正常。