STM32F103VET6的USART是如何利用DMA收发数据的

直接上代码

#define SENDBUFF_SIZE 128
#define RECEBUFF_SIZE      128
#define USART1_DR_Base  0x40013804

uint8_t SendBuff[SENDBUFF_SIZE];
uint8_t RecvBuff[SENDBUFF_SIZE];

void DMAUart1Tx_Init()
{
    DMA_InitTypeDef DMA_InitStructure;
    NVIC_InitTypeDef NVIC_InitStructure;
        
     RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);   
   
     /* Configure one bit for preemption priority */
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
  
    NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel4_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
    DMA_InitStructure.DMA_PeripheralBaseAddr = USART1_DR_Base;      
    DMA_InitStructure.DMA_MemoryBaseAddr = (u32)SendBuff;
        
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;   
   
    DMA_InitStructure.DMA_BufferSize = SENDBUFF_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_Normal ;     
   
    DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;  
   
    DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
   
    DMA_Init(DMA1_Channel4, &DMA_InitStructure);        
   
     DMA_Cmd (DMA1_Channel4,ENABLE);                    
    // DMA_ITConfig(DMA1_Channel4,DMA_IT_TC,ENABLE);  
}

void DMAUsar1Rx_Init()
{
    DMA_InitTypeDef   DMA_InitStructure;   
      
    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);                        
    DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)(&USART1->DR);            
    DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)RecvBuff;                  
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;                        
    DMA_InitStructure.DMA_BufferSize = RECEBUFF_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_Normal;                              
    DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;                     
    DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;                              
    DMA_Init(DMA1_Channel5,&DMA_InitStructure);   
  
    DMA_Cmd(DMA1_Channel5,ENABLE);   
    USART_DMACmd(USART1,USART_DMAReq_Rx,ENABLE);     
}


void USART1_Init(u32 My_BaudRate)
{

    GPIO_InitTypeDef  GPIO_InitStructure ;

    USART_InitTypeDef  USART_InitStructure ;

    NVIC_InitTypeDef  NVIC_InitStructure ;
   
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_USART1 | RCC_APB2Periph_AFIO , ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA,&GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING ;
    GPIO_Init(GPIOA,&GPIO_InitStructure);
   
    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn ;        
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;      
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE ;         
    NVIC_Init(&NVIC_InitStructure);


    USART_DeInit(USART1);
    USART_InitStructure.USART_BaudRate = My_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_Tx | USART_Mode_Rx ;
    USART_Init(USART1, &USART_InitStructure);
   
    USART_ITConfig(USART1, USART_IT_IDLE, ENABLE);
    DMAUart1Tx_Init();
    DMAUsar1Rx_Init();
   
    USART_Cmd(USART1 , ENABLE);
}



void USART_SendData(USART_TypeDef* USARTx, uint16_t Data)
{
  /* Check the parameters */
  assert_param(IS_USART_ALL_PERIPH(USARTx));
  assert_param(IS_USART_DATA(Data));
   
  /* Transmit Data */
  USARTx->DR = (Data & (uint16_t)0x01FF);
}

void Usart_SendString(USART_TypeDef *USARTx, uint8_t *str, uint16_t len)
{
    unsigned short count = 0;
   
    for(; count < len; count++)
    {
        USART_SendData(USARTx, *str++);                                    
        while(USART_GetFlagStatus(USARTx, USART_FLAG_TC) == RESET);        
    }
}

void MYDMA_Enable(DMA_Channel_TypeDef*DMA_CHx, uint16_t len)
{
    DMA_Cmd(DMA_CHx, DISABLE );
    DMA_SetCurrDataCounter(DMA_CHx, len);
    DMA_Cmd(DMA_CHx, ENABLE);  
}

uint16_t uart_read( uint8_t* buf, uint16_t read_len)
{
        uint16_t Usart1_Rec_Cnt = 0;
    if(USART_GetITStatus(USART1, USART_IT_IDLE) != RESET)
    {
      USART_ReceiveData(USART1);
      Usart1_Rec_Cnt = RECEBUFF_SIZE - DMA_GetCurrDataCounter(DMA1_Channel5);
      Usart_SendString(USART1, RecvBuff, Usart1_Rec_Cnt);
      memcpy(buf, RecvBuff, Usart1_Rec_Cnt);
       USART_ClearITPendingBit(USART1,USART_IT_IDLE);
       MYDMA_Enable(DMA1_Channel5, RECEBUFF_SIZE);              
    }
        return Usart1_Rec_Cnt;
}

void USART1_IRQHandler(void)               
{
    uart_read(RX1_Receive, RX1_Receive_LEN);
}

uint16_t uart_puts(const uint8_t *src, uint16_t len)
{
    const uint8_t *pstr_tmp = src;
    uint16_t len_temp = len;
    MYDMA_Enable(DMA1_Channel4, len_temp);
    for(int i = 0;i < len_temp; i++)
  {
            SendBuff     = *pstr_tmp++;
  }
    USART_DMACmd(USART1, USART_DMAReq_Tx, ENABLE);
}

int main(void)
{   
    SystemInit();
    USART1_Init(9600);
    for(;;)
    {

    }
}