STM32F429 DMA串口数据发送

串口数据配置

void macUART4_Config(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
  USART_InitTypeDef USART_InitStructure;

    RCC_AHB1PeriphClockCmd(macUART4_RX_GPIO_CLK|macUART4_TX_GPIO_CLK,ENABLE);
  RCC_APB1PeriphClockCmd(macUART4_CLK, ENABLE);

  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;  
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_Pin =  macUART4_TX_PIN  ;  
  GPIO_Init(macUART4_TX_GPIO_PORT, &GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_Pin =  macUART4_RX_PIN;
  GPIO_Init(macUART4_RX_GPIO_PORT, &GPIO_InitStructure);

GPIO_PinAFConfig(macUART4_RX_GPIO_PORT,macUART4_RX_SOURCE,macUART4_RX_AF);
  GPIO_PinAFConfig(macUART4_TX_GPIO_PORT,macUART4_TX_SOURCE,macUART4_TX_AF); 

  USART_InitStructure.USART_BaudRate = macUART4_BAUDRATE;
  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_Init(macUART4, &USART_InitStructure); 
  USART_Cmd(macUART4, ENABLE);
}

DMA配置函数，请和DMA串口接收数据配置函数对比

void DMA_Config(void)
{
    DMA_InitTypeDef DMA_InitStructure;                //
    RCC_AHB1PeriphClockCmd(macUART4_DMA_CLK, ENABLE); //
    DMA_DeInit(macUART4_TX_DMA_STREAM);               //

  while (DMA_GetCmdStatus(macUART4_TX_DMA_STREAM) != DISABLE){
  } 

    DMA_InitStructure.DMA_Channel = macUART4_TX_DMA_CHANNEL;             //
  DMA_InitStructure.DMA_PeripheralBaseAddr = macUART4_DR_BASE;         //
  DMA_InitStructure.DMA_Memory0BaseAddr = (u32)SendBuff;               //

  DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral;                //
  DMA_InitStructure.DMA_BufferSize = macUART4_SEND_BUFF_SIZE;          //
  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;     //
  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;                //
  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;   //
  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;        //
  DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;                        //
  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(macUART4_TX_DMA_STREAM, &DMA_InitStructure);                   //     
  DMA_Cmd(macUART4_TX_DMA_STREAM, ENABLE);                                 

    while(DMA_GetCmdStatus(macUART4_TX_DMA_STREAM) != ENABLE)
  {
  }
}

主函数，调试串口和UART４同时发送数据，相互并不影响

int main(void)
{
    int i;
    SysTick_Init();
    NVIC_Configuration();
    Debug_USART_Config();
    macUART4_Config();
    DMA_Config();
    printf("Hello World!\n\n");

    for(i=0;i'A';
  }

    USART_DMACmd(macUART4, USART_DMAReq_Tx, ENABLE);

    while(1)
    {
        printf("Hello World!\n");
    }
}

该程序中没有涉及中断程序，DMA的使用本应该尽量避免使用中断。