STM32 DMA->内存到内存

基于STM32 F401 Discovery板：

DMA2在AHB1总线上

步骤一：使能DMA

#defineDMA_STREAM_CLOCKRCC_AHB1Periph_DMA2

RCC_AHB1PeriphClockCmd(DMA_STREAM_CLOCK,ENABLE);

步骤二：reset DMA Stream register:

/*ResetDMAStreamregisters(fordebugpurpose)*/

DMA_DeInit(DMA_STREAM);

步骤三：

/*CheckiftheDMAStreamisdisabledbeforeenablingit.

NotethatthisstepisusefulwhenthesameStreamisusedmultipletimes:

enabled,thendisabledthenre-enabled...Inthiscase,theDMAStreamdisable

willbeeffectiveonlyattheendoftheongoingdatatransferanditwill

notbepossibletore-configureitbeforemakingsurethattheEnablebit

hasbeenclearedbyhardware.IftheStreamisusedonlyonce,thisstepmight

bebypassed.*/

while(DMA_GetCmdStatus(DMA_STREAM)!=DISABLE)

{

}

步骤四：初始化DMA 结构体

/*ConfigureDMAStream*/

DMA_InitStructure.DMA_Channel=DMA_CHANNEL;

DMA_InitStructure.DMA_PeripheralBaseAddr=(uint32_t)SRC_Const_Buffer;

DMA_InitStructure.DMA_Memory0BaseAddr=(uint32_t)DST_Buffer;

DMA_InitStructure.DMA_DIR=DMA_DIR_MemoryToMemory;

DMA_InitStructure.DMA_BufferSize=(uint32_t)BUFFER_SIZE;

DMA_InitStructure.DMA_PeripheralInc=DMA_PeripheralInc_Enable;

DMA_InitStructure.DMA_MemoryInc=DMA_MemoryInc_Enable;

DMA_InitStructure.DMA_PeripheralDataSize=DMA_PeripheralDataSize_Word;

DMA_InitStructure.DMA_MemoryDataSize=DMA_MemoryDataSize_Word;

DMA_InitStructure.DMA_Mode=DMA_Mode_Normal;

DMA_InitStructure.DMA_Priority=DMA_Priority_High;

DMA_InitStructure.DMA_FIFOMode=DMA_FIFOMode_Disable;

DMA_InitStructure.DMA_FIFOThreshold=DMA_FIFOThreshold_Full;

DMA_InitStructure.DMA_MemoryBurst=DMA_MemoryBurst_Single;

DMA_InitStructure.DMA_PeripheralBurst=DMA_PeripheralBurst_Single;

DMA_Init(DMA_STREAM,&DMA_InitStructure);

其中：
DMA_PeripheralBaseAddr--》外设地址，可以选择USART,I2C,ADC等

DMA_Memory0BaseAddr-》memory地址，用于外设和内存的数据传输

DMA_DIR -》传送方向，分别有外设到内存，内存到外设，内存到内存

DMA_BufferSize -》传输的buffer size

DMA_PeripheralInc -》外设地址是否自加

DMA_MemoryInc -》内存地址是否自加

DMA_PeripheralDataSize -》外设每个data的size，分别有1byte，半字，全字

DMA_MemoryDataSize -》内存的每个data的size，如上

DMA_Mode -》DMA mode，分别是传输完了是否循环还是正常

步骤四：DMA使能中断：

DMA_ITConfig(DMA_STREAM,DMA_IT_TC,ENABLE);

其中DMA有发送完成中断，完成一半中断，和错误中断等

步骤五：开始传输

/*DMAStreamenable*/

DMA_Cmd(DMA_STREAM,ENABLE);