Problem with DCMI FRAME interrupt ?

[zeros_and_ones1991]

Posted on July 22, 2014 at 19:02

Hullo guys , I 'm trying to get my OV7670 cam working with STM32F207zg , and I have set up all required configurations , I want to get snapshot , transfer the frame to external SRAM , but the FRAME interrupt is never generated , while LINE interrupt is working fine , also the DMA flags r not set , HC/TC/ or even FIFO error , here is my code ,

    // Enable the Clck of the DCMI module

    RCC_AHB2PeriphClockCmd (RCC_AHB2Periph_DCMI , ENABLE);

    // Reset the DCMI Registers

RCC_AHB2PeriphResetCmd(RCC_AHB2Periph_DCMI, ENABLE);

   RCC_AHB2PeriphResetCmd(RCC_AHB2Periph_DCMI, DISABLE);

    //

    // Configure the DCMI

    DCMI_Struct.DCMI_CaptureMode=DCMI_CaptureMode_SnapShot;

    DCMI_Struct.DCMI_CaptureRate=DCMI_CaptureRate_All_Frame;

    DCMI_Struct.DCMI_ExtendedDataMode=DCMI_ExtendedDataMode_8b;

    DCMI_Struct.DCMI_HSPolarity=DCMI_HSPolarity_Low;

    DCMI_Struct.DCMI_PCKPolarity=DCMI_PCKPolarity_Rising;

    DCMI_Struct.DCMI_VSPolarity=DCMI_VSPolarity_High ;

    DCMI_Struct.DCMI_SynchroMode=DCMI_SynchroMode_Hardware;

    DCMI_Init(&DCMI_Struct);

// Enable the DCMI Interrupts

    DCMI_ITConfig(DCMI_IT_VSYNC, ENABLE);

  DCMI_ITConfig(DCMI_IT_LINE, ENABLE);

  DCMI_ITConfig(DCMI_IT_FRAME, ENABLE);

  DCMI_ITConfig(DCMI_IT_ERR, ENABLE);    //

    //

    // Enable the NVIC for the DCMI

    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);

    NVIC_DCMI.NVIC_IRQChannel=DCMI_IRQn;

    NVIC_DCMI.NVIC_IRQChannelCmd=ENABLE;

    NVIC_DCMI.NVIC_IRQChannelPreemptionPriority=1;

    NVIC_DCMI.NVIC_IRQChannelSubPriority=1;

    NVIC_Init(&NVIC_DCMI);

    //

    // Enable NVIC for DMA2 , Stream 1

    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);

    NVIC_DCMI.NVIC_IRQChannel=DMA2_Stream1_IRQn;

    NVIC_DCMI.NVIC_IRQChannelCmd=ENABLE;

    NVIC_DCMI.NVIC_IRQChannelPreemptionPriority=0;

    NVIC_DCMI.NVIC_IRQChannelSubPriority=1;

    NVIC_Init(&NVIC_DCMI);

    //

   

    //

    // Enable DMA2 Clock

     RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);  

    // Configure the DMA

     DMA_DCMI.DMA_Channel = DMA_Channel_1;  

  DMA_DCMI.DMA_PeripheralBaseAddr = DCMI_DR_ADDRESS;  // (0x50050028)

  DMA_DCMI.DMA_Memory0BaseAddr = 0x64000000; // Address of external SRAM

  DMA_DCMI.DMA_DIR = DMA_DIR_PeripheralToMemory;

  DMA_DCMI.DMA_BufferSize = 640*480*2/4;

  DMA_DCMI.DMA_PeripheralInc = DMA_PeripheralInc_Disable;

  DMA_DCMI.DMA_MemoryInc = DMA_MemoryInc_Enable;

  DMA_DCMI.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;

  DMA_DCMI.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;

  DMA_DCMI.DMA_Mode = DMA_Mode_Normal;

  DMA_DCMI.DMA_Priority = DMA_Priority_High;

  DMA_DCMI.DMA_FIFOMode = DMA_FIFOMode_Enable;         

  DMA_DCMI.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;

  DMA_DCMI.DMA_MemoryBurst = DMA_MemoryBurst_Single;

  DMA_DCMI.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;

    DMA_Init(DMA2_Stream1, &DMA_DCMI);

    DMA_ITConfig(DMA2_Stream1 , DMA_IT_TC , ENABLE);

    DMA_ITConfig(DMA2_Stream1 , DMA_IT_FE  , ENABLE);

    

    // Enable the Capture mode

    DCMI_Cmd(ENABLE);

    DCMI_CaptureCmd(ENABLE);

    

    DMA_Cmd(DMA2_Stream1, ENABLE);

//

//

Any ideas ?

[Tesla DeLorean]

Posted on July 22, 2014 at 19:29

Is the DMA faulting?

The DMA is only capable of doing 65535 transactions. Perhaps you have a sequencing issue?

/* Enable DMA2 stream 1 and DCMI interface then start image capture */
DMA_Cmd(DMA2_Stream1, ENABLE);
DCMI_Cmd(ENABLE);
/* Insert 100ms delay: wait 100ms */
Delay(200);
DCMI_CaptureCmd(ENABLE);

[zeros_and_ones1991]

Posted on July 22, 2014 at 19:44

Thx for ur reply Clive , well its less than 65535 transactions (640*480*2/4) / (4-word transaction) , and the DAM is not generating any fault , like i said above not even generating anything , i tried the delay , but its not working still .

[Tesla DeLorean]

Posted on July 22, 2014 at 22:19

(640*480*2/4) = 153600

DMA_BufferSize is a count, not a size in bytes

If you get no DMA operations, it's kind of indicative there isn't a clock somewhere. You should look at all the interface clocks, and perhaps put the bus on an analyzer.

[zeros_and_ones1991]

Posted on July 23, 2014 at 01:39

all clocks r working clive , i can write to the various peripherals , well i could see that im kinda getting an image to the memory (due to the correlation between the pixels values in the external SRAM) .

When i use the continuous mode of the DCMI , and change the DMA to circular mode , all i get is just noise on the LCD (of course the Memory address was changed to the LCD address , also memory and peripheral increment are disabled) .

I hope the Silicon is ok , cuz some people said there is some fault with the DCMI module .

i also have confusion about the DMA_SxNDTR Reg in the DMA .... what does the number of data items mean? ... bytes or word or 4-word transaction ?

[Tesla DeLorean]

Posted on July 23, 2014 at 04:06

The F205 doesn't have DCMI, pretty sure the F207 does, but you can review the errata.

The Transfer Count for the DMA is 16-bit, and can represent 65535 transactions of 1, 2 or 4 BYTE. So with 32-bit words, a maximum of just shy of 256KB

Is any of the buffer filling with data? If you fill the buffer with a known pattern you should be able to discern how much. What if the buffer is internal SRAM?