STM32 DMA->內(nèi)存到內(nèi)存

基于STM32 F401 Discovery板：

DMA2在AHB1總線上

步驟一：使能DMA

#defineDMA_STREAM_CLOCKRCC_AHB1Periph_DMA2

RCC_AHB1PeriphClockCmd(DMA_STREAM_CLOCK,ENABLE);

步驟二：reset DMA Stream register:

/*ResetDMAStreamregisters(fordebugpurpose)*/

DMA_DeInit(DMA_STREAM);

步驟三：

/*CheckiftheDMAStreamisdisabledbeforeenablingit.

NotethatthisstepisusefulwhenthesameStreamisusedmultipletimes:

enabled,thendisabledthenre-enabled...Inthiscase,theDMAStreamdisable

willbeeffectiveonlyattheendoftheongoingdatatransferanditwill

notbepossibletore-configureitbeforemakingsurethattheEnablebit

hasbeenclearedbyhardware.IftheStreamisusedonlyonce,thisstepmight

bebypassed.*/

while(DMA_GetCmdStatus(DMA_STREAM)!=DISABLE)

{

}

步驟四：初始化DMA 結(jié)構(gòu)體

/*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--》外設(shè)地址，可以選擇USART,I2C,ADC等

DMA_Memory0BaseAddr-》memory地址，用于外設(shè)和內(nèi)存的數(shù)據(jù)傳輸

DMA_DIR -》傳送方向，分別有外設(shè)到內(nèi)存，內(nèi)存到外設(shè)，內(nèi)存到內(nèi)存

DMA_BufferSize -》傳輸?shù)腷uffer size

DMA_PeripheralInc -》外設(shè)地址是否自加

DMA_MemoryInc -》內(nèi)存地址是否自加

DMA_PeripheralDataSize -》外設(shè)每個data的size，分別有1byte，半字，全字

DMA_MemoryDataSize -》內(nèi)存的每個data的size，如上

DMA_Mode -》DMA mode，分別是傳輸完了是否循環(huán)還是正常

步驟四：DMA使能中斷：

DMA_ITConfig(DMA_STREAM,DMA_IT_TC,ENABLE);

其中DMA有發(fā)送完成中斷，完成一半中斷，和錯誤中斷等

步驟五：開始傳輸

/*DMAStreamenable*/

DMA_Cmd(DMA_STREAM,ENABLE);