STM32F205串口工作在 DMA 模式下有时接收异常

int main(void)

{

...

USART_Config();

...

while (1)

{

/* Clear Buffers */

Fill_Buffer(RxBuffer, TXBUFFERSIZE);

Fill_Buffer(CmdBuffer, 2);

DMA_DeInit(USARTx_RX_DMA_STREAM);

DMA_InitStructure.DMA_Channel = USARTx_RX_DMA_CHANNEL;

DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;

/************* USART will receive the the transaction data ****************/

/* Transaction data (length defined by CmdBuffer[1] variable) */

DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)RxBuffer;

DMA_InitStructure.DMA_BufferSize =10;// (uint16_t)CmdBuffer[1];

DMA_InitStructure.DMA_Mode =DMA_Mode_Normal;//DMA_Mode_Circular;

DMA_Init(USARTx_RX_DMA_STREAM, &DMA_InitStructure);

NVIC_InitStructure.NVIC_IRQChannel = DMA1_Stream1_IRQn;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);

/* Enable DMA Stream Transfer Complete interrupt */

DMA_ITConfig(USARTx_RX_DMA_STREAM, DMA_IT_TE|DMA_IT_DME|DMA_IT_FE, ENABLE);

/* Enable the DMA Stream */

DMA_Cmd(USARTx_RX_DMA_STREAM, ENABLE);

/* Enable the USART Rx DMA requests */

USART_DMACmd(USARTx, USART_DMAReq_Rx , ENABLE);

// USART_Cmd(USARTx, ENABLE);

// while(SET ==USART_GetFlagStatus(USARTx,USART_FLAG_ORE))

// {

// Tmp =USART_ReceiveData(USARTx);

// }

while ((DMA_GetFlagStatus(USARTx_RX_DMA_STREAM, USARTx_RX_DMA_FLAG_TCIF) ==

RESET)

{

}

/* Clear all DMA Streams flags */

DMA_ClearFlag(USARTx_RX_DMA_STREAM, USARTx_RX_DMA_FLAG_HTIF |

USARTx_RX_DMA_FLAG_TCIF);

/* Disable the DMA Stream */

DMA_Cmd(USARTx_RX_DMA_STREAM, DISABLE);

/* Disable the USART Rx DMA requests */

USART_DMACmd(USARTx, USART_DMAReq_Rx, DISABLE);

//handle the RxBuffer data...

//...

}

}

static void USART_Config(void)

{

USART_InitTypeDef USART_InitStructure;

GPIO_InitTypeDef GPIO_InitStructure;

/* Peripheral Clock Enable -------------------------------------------------*/

/* Enable GPIO clock */

RCC_AHB1PeriphClockCmd(USARTx_TX_GPIO_CLK | USARTx_RX_GPIO_CLK, ENABLE);

/* Enable USART clock */

USARTx_CLK_INIT(USARTx_CLK, ENABLE);

/* Enable the DMA clock */

RCC_AHB1PeriphClockCmd(USARTx_DMAx_CLK, ENABLE);

/* USARTx GPIO configuration -----------------------------------------------*/

/* Connect USART pins to AF7 */

GPIO_PinAFConfig(USARTx_TX_GPIO_PORT, USARTx_TX_SOURCE, USARTx_TX_AF);

GPIO_PinAFConfig(USARTx_RX_GPIO_PORT, USARTx_RX_SOURCE, USARTx_RX_AF);

/* Configure USART Tx and Rx as alternate function push-pull */

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;

GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;

GPIO_InitStructure.GPIO_Pin = USARTx_TX_PIN;

GPIO_Init(USARTx_TX_GPIO_PORT, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = USARTx_RX_PIN;

GPIO_Init(USARTx_RX_GPIO_PORT, &GPIO_InitStructure);

/* USARTx configuration ----------------------------------------------------*/

/* Enable the USART OverSampling by 8 */

USART_OverSampling8Cmd(USARTx, ENABLE);

USART_InitStructure.USART_BaudRate = 1408000;//3750000;

USART_InitStructure.USART_WordLength = USART_WordLength_8b;

USART_InitStructure.USART_StopBits = USART_StopBits_1;

/* When using Parity the word length must be configured to 9 bits */

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(USARTx, &USART_InitStructure);

/* Configure DMA controller to manage USART TX and RX DMA request ----------*/

DMA_InitStructure.DMA_PeripheralBaseAddr = USARTx_DR_ADDRESS;

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_FIFOMode = DMA_FIFOMode_Enable;

DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;

DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;

DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;

/* Here only the unchanged parameters of the DMA initialization structure are

configured. During the program operation, the DMA will be configured with

different parameters according to the operation phase */

/* Enable USART */

USART_Cmd(USARTx, ENABLE);

}

...

/* Enable the DMA Stream */

DMA_Cmd(USARTx_RX_DMA_STREAM, ENABLE);

/* Enable the USART Rx DMA requests */

USART_DMACmd(USARTx, USART_DMAReq_Rx , ENABLE);

while(SET ==USART_GetFlagStatus(USARTx,USART_FLAG_ORE))

{

Tmp =USART_ReceiveData(USARTx);

}

...

...

/* Enable the DMA Stream */

DMA_Cmd(USARTx_RX_DMA_STREAM, ENABLE);

/* Enable the USART Rx DMA requests */

USART_DMACmd(USARTx, USART_DMAReq_Rx , ENABLE);

USART_Cmd(USARTx, ENABLE);

...