本文采用第3种方式.在波特率576000下大数据包冲击证明可行.

源代码:
//串口接收DMA缓存
#define UART_RX_LEN 128
extern uint8_t Uart_Rx[UART_RX_LEN];

//串口接收DMA缓存
uint8_t Uart_Rx[UART_RX_LEN] = {0};

//---------------------串口功能配置---------------------
//打开串口对应的外设时钟 
   RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 , ENABLE);
//串口发DMA配置 
//启动DMA时钟
   RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
//DMA发送中断设置
NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel4_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 3;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
//DMA1通道4配置
DMA_DeInit(DMA1_Channel4);
//外设地址
DMA_InitStructure.DMA_PeripheralBaseAddr =(u32)(&USART1->DR);
//内存地址
DMA_InitStructure.DMA_MemoryBaseAddr =(uint32_t)Uart_Send_Buffer;
//dma传输方向单向
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
//设置DMA在传输时缓冲区的长度
DMA_InitStructure.DMA_BufferSize = 100;
//设置DMA的外设递增模式，一个外设
DMA_InitStructure.DMA_PeripheralInc =DMA_PeripheralInc_Disable;
//设置DMA的内存递增模式
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
//外设数据字长
DMA_InitStructure.DMA_PeripheralDataSize =DMA_PeripheralDataSize_Byte;
//内存数据字长
DMA_InitStructure.DMA_MemoryDataSize =DMA_PeripheralDataSize_Byte;
//设置DMA的传输模式
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
//设置DMA的优先级别
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
//设置DMA的2个memory中的变量互相访问
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA1_Channel4,&DMA_InitStructure);
DMA_ITConfig(DMA1_Channel4,DMA_IT_TC,ENABLE);

//使能通道4
//DMA_Cmd(DMA1_Channel4, ENABLE);

//串口收DMA配置 
//启动DMA时钟
   RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
//DMA1通道5配置
DMA_DeInit(DMA1_Channel5);
//外设地址
DMA_InitStructure.DMA_PeripheralBaseAddr =(u32)(&USART1->DR);
//内存地址
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)Uart_Rx;
//dma传输方向单向
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
//设置DMA在传输时缓冲区的长度
DMA_InitStructure.DMA_BufferSize = UART_RX_LEN;
//设置DMA的外设递增模式，一个外设
DMA_InitStructure.DMA_PeripheralInc =DMA_PeripheralInc_Disable;
//设置DMA的内存递增模式
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
//外设数据字长
DMA_InitStructure.DMA_PeripheralDataSize =DMA_PeripheralDataSize_Byte;
//内存数据字长
DMA_InitStructure.DMA_MemoryDataSize =DMA_MemoryDataSize_Byte;
//设置DMA的传输模式
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
//设置DMA的优先级别
DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;
//设置DMA的2个memory中的变量互相访问
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA1_Channel5,&DMA_InitStructure);

//使能通道5
DMA_Cmd(DMA1_Channel5,ENABLE);

 
   //初始化参数 
   //USART_InitStructure.USART_BaudRate =DEFAULT_BAUD; 
   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_BaudRate = DEFAULT_BAUD;
//初始化串口
   USART_Init(USART1,&USART_InitStructure); 
   //TXE发送中断,TC传输完成中断,RXNE接收中断,PE奇偶错误中断,可以是多个  
   //USART_ITConfig(USART1,USART_IT_RXNE,ENABLE);

//中断配置
USART_ITConfig(USART1,USART_IT_TC,DISABLE);
USART_ITConfig(USART1,USART_IT_RXNE,DISABLE);
USART_ITConfig(USART1,USART_IT_IDLE,ENABLE); 

//配置UART1中断 
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_3);
   NVIC_InitStructure.NVIC_IRQChannel =USART1_IRQn;              //通道设置为串口1中断 
   NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority =2;      //中断占先等级0 
   NVIC_InitStructure.NVIC_IRQChannelSubPriority =1;             //中断响应优先级0 
   NVIC_InitStructure.NVIC_IRQChannelCmd =ENABLE;                //打开中断 
   NVIC_Init(&NVIC_InitStructure);  
       
//采用DMA方式发送
USART_DMACmd(USART1,USART_DMAReq_Tx,ENABLE);
//采用DMA方式接收
USART_DMACmd(USART1,USART_DMAReq_Rx,ENABLE);
   //启动串口 
   USART_Cmd(USART1, ENABLE);

//串口1接收中断  
void USART1_IRQHandler(void)                              
{  
uint32_t temp = 0;
uint16_t i = 0;

if(USART_GetITStatus(USART1, USART_IT_IDLE) != RESET)
    {
    //USART_ClearFlag(USART1,USART_IT_IDLE);
    temp = USART1->SR;
    temp = USART1->DR; //清USART_IT_IDLE标志
    DMA_Cmd(DMA1_Channel5,DISABLE);

temp = UART_RX_LEN - DMA_GetCurrDataCounter(DMA1_Channel5);
for (i = 0;i < temp;i )
{
Data_Receive_Usart = Uart_Rx[i];
  //启动串口状态机
usart_state_run();
}

//设置传输数据长度
DMA_SetCurrDataCounter(DMA1_Channel5,UART_RX_LEN);
    //打开DMA
DMA_Cmd(DMA1_Channel5,ENABLE);
    }

__nop();
}