本文采用第3種方式.在波特率576000下大數(shù)據(jù)包沖擊證明可行.

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

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

//---------------------串口功能配置---------------------
//打開串口對應(yīng)的外設(shè)時鐘
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 , ENABLE);
//串口發(fā)DMA配置
//啟動DMA時鐘
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
//DMA發(fā)送中斷設(shè)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);
//外設(shè)地址
DMA_InitStructure.DMA_PeripheralBaseAddr =(u32)(&USART1->DR);
//內(nèi)存地址
DMA_InitStructure.DMA_MemoryBaseAddr =(uint32_t)Uart_Send_Buffer;
//dma傳輸方向單向
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
//設(shè)置DMA在傳輸時緩沖區(qū)的長度
DMA_InitStructure.DMA_BufferSize = 100;
//設(shè)置DMA的外設(shè)遞增模式，一個外設(shè)
DMA_InitStructure.DMA_PeripheralInc =DMA_PeripheralInc_Disable;
//設(shè)置DMA的內(nèi)存遞增模式
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
//外設(shè)數(shù)據(jù)字長
DMA_InitStructure.DMA_PeripheralDataSize =DMA_PeripheralDataSize_Byte;
//內(nèi)存數(shù)據(jù)字長
DMA_InitStructure.DMA_MemoryDataSize =DMA_PeripheralDataSize_Byte;
//設(shè)置DMA的傳輸模式
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
//設(shè)置DMA的優(yōu)先級別
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
//設(shè)置DMA的2個memory中的變量互相訪問
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
//啟動DMA時鐘
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
//DMA1通道5配置
DMA_DeInit(DMA1_Channel5);
//外設(shè)地址
DMA_InitStructure.DMA_PeripheralBaseAddr =(u32)(&USART1->DR);
//內(nèi)存地址
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)Uart_Rx;
//dma傳輸方向單向
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
//設(shè)置DMA在傳輸時緩沖區(qū)的長度
DMA_InitStructure.DMA_BufferSize = UART_RX_LEN;
//設(shè)置DMA的外設(shè)遞增模式，一個外設(shè)
DMA_InitStructure.DMA_PeripheralInc =DMA_PeripheralInc_Disable;
//設(shè)置DMA的內(nèi)存遞增模式
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
//外設(shè)數(shù)據(jù)字長
DMA_InitStructure.DMA_PeripheralDataSize =DMA_PeripheralDataSize_Byte;
//內(nèi)存數(shù)據(jù)字長
DMA_InitStructure.DMA_MemoryDataSize =DMA_MemoryDataSize_Byte;
//設(shè)置DMA的傳輸模式
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
//設(shè)置DMA的優(yōu)先級別
DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;
//設(shè)置DMA的2個memory中的變量互相訪問
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA1_Channel5,&DMA_InitStructure);

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

//初始化參數(shù)
//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發(fā)送中斷,TC傳輸完成中斷,RXNE接收中斷,PE奇偶錯誤中斷,可以是多個
//USART_ITConfig(USART1,USART_IT_RXNE,ENABLE);

//中斷配置
USART_ITConfig(USART1,USART_IT_TC,DISABLE);
USART_ITConfig(USART1,USART_IT_RXNE,DISABLE);
USART_ITConfig(USART1,USART_IT_IDLE,ENABLE);

//配置UART1中斷
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_3);
NVIC_InitStructure.NVIC_IRQChannel =USART1_IRQn;//通道設(shè)置為串口1中斷
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority =2;//中斷占先等級0
NVIC_InitStructure.NVIC_IRQChannelSubPriority =1;//中斷響應(yīng)優(yōu)先級0
NVIC_InitStructure.NVIC_IRQChannelCmd =ENABLE;//打開中斷
NVIC_Init(&NVIC_InitStructure);

//采用DMA方式發(fā)送
USART_DMACmd(USART1,USART_DMAReq_Tx,ENABLE);
//采用DMA方式接收
USART_DMACmd(USART1,USART_DMAReq_Rx,ENABLE);
//啟動串口
USART_Cmd(USART1, ENABLE);

//串口1接收中斷
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標(biāo)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];
//啟動串口狀態(tài)機
usart_state_run();
}

//設(shè)置傳輸數(shù)據(jù)長度
DMA_SetCurrDataCounter(DMA1_Channel5,UART_RX_LEN);
//打開DMA
DMA_Cmd(DMA1_Channel5,ENABLE);
}

__nop();
}