ADC用DMA,分配16K的BufferSize不能有效分配

只看该作者 · 2008-12-27 00:03

用STM32F103VET6的芯片,分配16K的空间用做ADC1的DMA缓存尺寸,初始化是可以的,使能DMA函数后,
  DMA_DeInit(DMA1_Channel1);
  DMA_InitStructure.DMA_PeripheralBaseAddr = ADC1_BASE + 0x4c ;  //base + 0x4c
  DMA_InitStructure.DMA_MemoryBaseAddr = (u32)&ADCConvertedValue;
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
  DMA_InitStructure.DMA_BufferSize = 0x2000;                    //64 * 256;
  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
  DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
  DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;
  DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
  DMA_Init(DMA1_Channel1, &DMA_InitStructure);
  /* Enable DMA1 channel1 */
  DMA_Cmd(DMA1_Channel1, ENABLE);

运行的DMA_Init函数 DMA_CNDTR1 0x2000

运行DMA_Cmd函数后 DMA_CNDTR1 变成一个随机的数,但总不是0x2000