那位师兄有利用串口的DMA发送的例子

只看该作者 · 2008-9-9 17:25

我试了几次没有成功，望指教，给个例子参详

只看该作者 · 2008-9-9 17:52

只看该作者 · 2008-9-10 10:26

只看该作者 · 2008-9-10 10:56

我都不知道该什么弄。不理解。串口每次只能收发一个数据，如何用DMA

只看该作者 · 2008-9-10 11:05

u8 test[2]={6,9};
//-------------------DMA设置---------
DMA_Cmd(DMA_Channel4,DISABLE);
  DMA_DeInit(DMA_Channel4);    DMA_InitStructure.DMA_PeripheralBaseAddr=USART1_BASE+USART_Mode_Tx;
    DMA_InitStructure.DMA_MemoryBaseAddr=(u32)test;
    DMA_InitStructure.DMA_DIR = eripheralDST;
    DMA_InitStructure.DMA_BufferSize = 2;
    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_M2M = DMA_M2M_Disable;
    DMA_Init(DMA_Channel4,&DMA_InitStructure);
    DMA_Cmd(DMA_Channel4,ENABLE);
    while(!DMA_GetFlagStatus(DMA_FLAG_TC4));
//--------------------------串口-------------------------------
USART_InitStructure.USART_BaudRate = 115200;//250000;
  USART_InitStructure.USART_WordLength = USART_WordLength_8b;
  USART_InitStructure.USART_StopBits = USART_StopBits_1;
  USART_InitStructure.USART_Parity = USART_Parity_No;
  USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
  USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
  USART_InitStructure.USART_Clock = USART_Clock_Disable;
  USART_InitStructure.USART_CPOL = USART_CPOL_Low;
  USART_InitStructure.USART_CPHA = USART_CPHA_2Edge;
  USART_InitStructure.USART_LastBit = USART_LastBit_Disable;
  USART_Init(USART1, &USART_InitStructure);
USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
USART_DMACmd(USART1,USART_DMAReq_Tx, ENABLE);
  USART_Cmd(USART1, ENABLE);
//---------------------开DMA时钟---------------------------
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA,ENABLE);
发不出去不用DMA就可以