STM32 DMA数据转运-优快云博客

首先要进行DMA的初始化

1：DMA开启时钟，DMA在AHB总线控制下

2：DMA结构体初始化，配置DMA结构体的各个成员，然后初始化结构体

3：DMA开启

uint16_t MyDMA_Size;

void MyDMA_Init(uint32_t AddrA, uint32_t AddrB, uint16_t Size)
{

MyDMA_Size = Size;
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
   DMA_InitTypeDef DMA_InitStructure;
   DMA_InitStructure.DMA_PeripheralBaseAddr = AddrA;
   DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
   DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Enable;
   DMA_InitStructure.DMA_MemoryBaseAddr = AddrB;
   DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
   DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
   DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
   DMA_InitStructure.DMA_BufferSize = Size;
   DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
   DMA_InitStructure.DMA_M2M = DMA_M2M_Enable;
   DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;
   DMA_Init(DMA1_Channel1, &DMA_InitStructure);

   DMA_Cmd(DMA1_Channel1, DISABLE);
}

开启DMA转运有三个条件，一是传输计数器值不为零，二是有触发源，无论是硬件触发还是软件触发，但必须有一个触发源，三是DMA_Cmd，开启DMA;

void MyDMA_Transfer(void)
{
   DMA_Cmd(DMA1_Channel1, DISABLE);
   DMA_SetCurrDataCounter(DMA1_Channel1, MyDMA_Size);
   DMA_Cmd(DMA1_Channel1, ENABLE);

   while (DMA_GetFlagStatus(DMA1_FLAG_TC1) == RESET); //TCIF1置1,表示通道1转运完成
   DMA_ClearFlag(DMA1_FLAG_TC1);
}
对于DMA的传输计数器的值，不能够在DMA使能的情况下赋值，要先把DMA失能，再赋值，然后使能DMA。

还有就是如果正常的在主函数定义的变量，一般存储再0x2000 0000后，如果变量前有const修饰，那么这个变量会存储到flash中，地址一般在0x8000 0000后

下面的代码时DMA+AD多通道的代码：

uint16_t AD_Value[4];

void AD_Init(void)
{
   RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
   RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
   RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

   RCC_ADCCLKConfig(RCC_PCLK2_Div6);

   GPIO_InitTypeDef GPIO_InitStructure;
   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
   GPIO_Init(GPIOA, &GPIO_InitStructure);

   ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_55Cycles5);
   ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 2, ADC_SampleTime_55Cycles5);
   ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 3, ADC_SampleTime_55Cycles5);
   ADC_RegularChannelConfig(ADC1, ADC_Channel_3, 4, ADC_SampleTime_55Cycles5);

   ADC_InitTypeDef ADC_InitStructure;
   ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
   ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
   ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;
   ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
   ADC_InitStructure.ADC_ScanConvMode = ENABLE;
   ADC_InitStructure.ADC_NbrOfChannel = 4;
   ADC_Init(ADC1, &ADC_InitStructure);

   DMA_InitTypeDef DMA_InitStructure;
   DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&ADC1->DR;
   DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
   DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
   DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)AD_Value;
   DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
   DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
   DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
   DMA_InitStructure.DMA_BufferSize = 4;
   DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
   DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
   DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;
   DMA_Init(DMA1_Channel1, &DMA_InitStructure);

   DMA_Cmd(DMA1_Channel1, ENABLE);
   ADC_DMACmd(ADC1, ENABLE);
   ADC_Cmd(ADC1, ENABLE);

   ADC_ResetCalibration(ADC1);
   while (ADC_GetResetCalibrationStatus(ADC1) == SET);
   ADC_StartCalibration(ADC1);
   while (ADC_GetCalibrationStatus(ADC1) == SET);

   ADC_SoftwareStartConvCmd(ADC1, ENABLE);
}