407开发板照相实验问题咨询

sougasouga33 · 发表于 2016-1-5 17:32:46

   407开发板照相机实验章节//OV2640拍照jpg图片
//返回值:0,成功
// 其他,错误代码

函数：
u8 ov2640_jpg_photo(u8 *pname)
{
.....
DCMI_DMA_Init((u32)jpeg_buf0,(u32)jpeg_buf1,jpeg_dma_bufsize,DMA_MemoryDataSize_Word,DMA_MemoryInc_Enable);//DCMI DMA配置(双缓冲模式)
.....
}

DCMI_DMA_Init()函数调用了：
[mw_shl_code=c,true]void DCMI_DMA_Init(u32 DMA_Memory0BaseAddr,u32 DMA_Memory1BaseAddr,u16 DMA_BufferSize,u32 DMA_MemoryDataSize,u32 DMA_MemoryInc)
{
.......

  /* 配置 DMA Stream */
  DMA_InitStructure.DMA_Channel = DMA_Channel_1;  //通道1 DCMI通道
  DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)&DCMI->DR;//外设地址为

CMI->DR
  DMA_InitStructure.DMA_Memory0BaseAddr = DMA_Memory0BaseAddr;//DMA 存储器0地址
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;//外设到存储器模式
  DMA_InitStructure.DMA_BufferSize = DMA_BufferSize;//数据传输量
  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;//外设非增量模式
  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc;//存储器增量模式
  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;//外设数据长度:32位
  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize;//存储器数据长度
  DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;// 使用循环模式
  DMA_InitStructure.DMA_Priority = DMA_Priority_High;//高优先级
  DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Enable; //FIFO模式
  DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;//使用全FIFO
  DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;//外设突发单次传输
  DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;//存储器突发单次传输
  DMA_Init(DMA2_Stream1, &DMA_InitStructure);//初始化DMA Stream

if(DMA_Memory1BaseAddr)
  {
DMA_DoubleBufferModeCmd(DMA2_Stream1,ENABLE);//双缓冲模式
   DMA_MemoryTargetConfig(DMA2_Stream1,DMA_Memory1BaseAddr,DMA_Memory_1);//配置目标地址1
DMA_ITConfig(DMA2_Stream1,DMA_IT_TC,ENABLE);//开启传输完成中断
.........
}

}

[/mw_shl_code]

DMA_MemoryTargetConfig(DMA2_Stream1,DMA_Memory1BaseAddr,DMA_Memory_1);//配置目标地址1

这里的DMA_Memory_1的宏定义为
#define DMA_Memory_1                   ((uint32_t)0x00080000)

照相机JPAG图形采集实验数据是从相机到外部SRAM，然后再拷贝到SD卡，为什么这里DMA_Memory_1不是外部SRAM地址，而是0x00080000？请教下，谢谢