Associate III

Question

Problem with DCMI FRAME interrupt ?

Forum|Forum|12 years ago
July 22, 2014
5 replies
984 views

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 ?

This topic has been closed for replies.

Tesla DeLorean

Guru

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);

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zeros_and_ones1991Author

Associate III

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

Guru

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.

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zeros_and_ones1991Author

Associate III

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

Guru

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?

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