外设到DMA怎么实现

Eternal单人行 · 发表于 2017-5-4 15:03:25

楼主想实现外设数据传输到DMA上，楼主简单的更改了下原子哥的例程，先将数据通过串口发送给USART1，USART1收到数据后，启动DMA传给数组USART_RX_BUF(作为寄存器)，再由串口读取寄存器的数据（楼主的开发板没有LCD）

[mw_shl_code=c,true]//DMA配置
MYDMA_Config(DMA2_Stream5,DMA_Channel_4,(u32)&USART1->DR,(u32)USART_RX_BUF,SEND_BUF_SIZE);
//while循环
if(USART_RX_STA&0x8000)
{
len=USART_RX_STA&0x3fff;
USART_DMACmd(USART1,USART_DMAReq_Rx,ENABLE);
MYDMA_Enable(DMA2_Stream5,len);
   while(1)
{
LED1=0;
if(DMA_GetFlagStatus(DMA2_Stream5,DMA_FLAG_TCIF5)!=RESET)
{
DMA_ClearFlag(DMA2_Stream5,DMA_FLAG_TCIF5);
break;
}
}
USART_RX_STA=0;
｝

//DMA配置函数
void MYDMA_Config(DMA_Stream_TypeDef *DMA_Streamx,u32 chx,u32 par,u32 mar,u16 ndtr)
{

DMA_InitTypeDef  DMA_InitStructure;

if((u32)DMA_Streamx>(u32)DMA2)
{
   RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2,ENABLE);

}else
{
   RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1,ENABLE);
}
DMA_DeInit(DMA_Streamx);

while (DMA_GetCmdStatus(DMA_Streamx) != DISABLE){}

  DMA_InitStructure.DMA_Channel = chx;
  DMA_InitStructure.DMA_PeripheralBaseAddr = par;
  DMA_InitStructure.DMA_Memory0BaseAddr = mar;
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
  DMA_InitStructure.DMA_BufferSize = ndtr;
  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Enable;
  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Disable;
  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
  DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
  DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;
  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_Streamx, &DMA_InitStructure);

} [/mw_shl_code]