使用F103 USART3 DMA接收不定长数据

ajianyes · 发表于 2018-12-3 23:02:00

最近在使用F103的usart3接收不定长数据时候，发现问题，进入IDLE中断之后，只接受到了一个数据

biglu · 发表于 2018-12-3 23:02:01

http://www.openedv.com/forum.php ... d=284146&extra=

ajianyes · 发表于 2018-12-3 23:03:25

static void USART3_GPIO_CONFIG(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
  USART_InitTypeDef USART_InitStructure;
  NVIC_InitTypeDef NVIC_InitStructure;

  /* config USART3 clock */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO , ENABLE);

  /* USART1 GPIO config */
  /* Configure USART3 Tx (PB.11) as alternate function push-pull */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
  /* Configure USART3 Rx (PB.10) as input floating */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
  GPIO_Init(GPIOB, &GPIO_InitStructure);

  NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//抢占优先级3
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //子优先级3
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道使能
  NVIC_Init(&NVIC_InitStructure); //根据指定的参数初始化VIC寄存器

  USART_InitStructure.USART_BaudRate = 115200;/* USART3 mode config */
  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(USART3, &USART_InitStructure);

  USART_ITConfig(USART3, USART_IT_IDLE, ENABLE);//开启空闲中断
  USART_ClearFlag(USART3, USART_FLAG_IDLE);
  USART_Cmd(USART3, ENABLE);
}

static void USART3_DMA_CONFIG(void)
{
  DMA_InitTypeDef DMA_InitStructure;
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1,ENABLE);

  DMA_DeInit(DMA1_Channel2);/* USART3_Tx_DMA_Channel (triggered by USARTy Tx event) Config */
  DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&USART3->DR;
  DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)0x0000;
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
  DMA_InitStructure.DMA_BufferSize = 0;
  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_Channel2, &DMA_InitStructure);

  DMA_DeInit(DMA1_Channel3);/* USART3_Rx_DMA_Channel*/
  DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)(&USART3->DR);
  DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)g_UsartRxBuf;
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
  DMA_InitStructure.DMA_BufferSize = USART_RX_LEN_MAX;
  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_Channel3, &DMA_InitStructure);

  DMA_Cmd(DMA1_Channel2,DISABLE);//Disable Tx DMA
  DMA_Cmd(DMA1_Channel3,ENABLE);//Enable RX DMA
  USART_DMACmd(USART3, USART_DMAReq_Tx, ENABLE);
  USART_DMACmd(USART3, USART_DMAReq_Rx, ENABLE);

  DMA_ClearFlag(DMA1_FLAG_TC2 | DMA1_FLAG_TC3);
  USART_ClearFlag(USART3, USART_FLAG_TXE | USART_FLAG_RXNE | USART_FLAG_IDLE);
}

中断处理程序
void USART3_IRQHandler(void)
{
  u8 clear = 0;
  if(USART_GetITStatus(USART3, USART_IT_IDLE) != RESET) //接收中断(接收到的数据必须是0x0d 0x0a结尾)
  {
clear =  USART3->DR;
clear =  USART3->SR;
DMA_Cmd(DMA1_Channel3,DISABLE);
g_Usart_Rec_Cnt = USART_RX_LEN_MAX - DMA_GetCurrDataCounter(DMA1_Channel3);
g_Usart_Rx_OverFlag = 1;
DMA1_Channel3->CNDTR = USART_RX_LEN_MAX;
DMA_Cmd(DMA1_Channel3,ENABLE);
  }
}