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?