usart dma 接收无数据--done

只看该作者 · 2021-5-21 00:10

本帖最后由 muyichuan2012 于 2021-5-24 11:31 编辑

请教 AT32F421 USART DMA 接收不定长数据，空闲中断正常，能正常进入，但设置的接收内存RxBuffer数据全为0，找不到原因，不知怎么回事？

代码如下：

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void USART1_DMA(void)
{

      DMA_InitType DMA_InitStructure;

  DMA_Reset(DMA1_Channel3);
  DMA_DefaultInitParaConfig(&DMA_InitStructure);
  DMA_InitStructure.DMA_PeripheralBaseAddr = 0x40013804;
  DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)RxBuffer;
  DMA_InitStructure.DMA_Direction = DMA_DIR_PERIPHERALSRC;
  DMA_InitStructure.DMA_BufferSize = LENGTH;
  DMA_InitStructure.DMA_PeripheralInc = DMA_PERIPHERALINC_DISABLE;
  DMA_InitStructure.DMA_MemoryInc = DMA_MEMORYINC_ENABLE;
  DMA_InitStructure.DMA_PeripheralDataWidth = DMA_PERIPHERALDATAWIDTH_BYTE;
  DMA_InitStructure.DMA_MemoryDataWidth = DMA_MEMORYDATAWIDTH_BYTE;
  DMA_InitStructure.DMA_Mode = DMA_MODE_NORMAL;
  DMA_InitStructure.DMA_Priority = DMA_PRIORITY_VERYHIGH;
  DMA_InitStructure.DMA_MTOM = DMA_MEMTOMEM_DISABLE;
  DMA_Init(DMA1_Channel3, &DMA_InitStructure);
}

void usart1_init( uint32_t BaudRate, uint32_t USART_Parity )
{
GPIO_InitType GPIO_InitStructure;
NVIC_InitType NVIC_InitStructure;
USART_InitType USART_InitStructure;

/* Enable GPIO clock */
RCC_AHBPeriphClockCmd( RCC_AHBPERIPH_GPIOA, ENABLE );

/* Enable USART1 Clock */
RCC_APB2PeriphClockCmd( RCC_APB2PERIPH_USART1, ENABLE );
/* Connect PXx to USART1_Tx */
GPIO_PinAFConfig( GPIOA, GPIO_PinsSource9, GPIO_AF_1 );
/* Connect PXx to USART1_Rx */
GPIO_PinAFConfig( GPIOA, GPIO_PinsSource10, GPIO_AF_1 );
/* Configure USART1 Tx/Rx */
GPIO_InitStructure.GPIO_Pins = GPIO_Pins_9 | GPIO_Pins_10;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_MaxSpeed = GPIO_MaxSpeed_50MHz;
GPIO_InitStructure.GPIO_OutType = GPIO_OutType_PP;
GPIO_InitStructure.GPIO_Pull = GPIO_Pull_NOPULL;
GPIO_Init( GPIOA, &GPIO_InitStructure );


USART_InitStructure.USART_BaudRate = 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_Rx | USART_Mode_Tx;
/* Configure USARTx */
USART_Init( USART1, &USART_InitStructure );

/* Enable the USART1 Interrupt */
NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init( &NVIC_InitStructure );

      USART1_DMA();

      USART_Cmd(USART1, ENABLE);
      USART_INTConfig(USART1, USART_INT_IDLEF, ENABLE);
   USART_DMACmd(USART1, USART_DMAReq_Rx, ENABLE);

   DMA_ChannelEnable(DMA1_Channel3, ENABLE);

}

void USART1_IRQHandler(void)
{

      u8 i;

if(USART_GetITStatus(USART1, USART_INT_IDLEF) != RESET)
{

                     i =USART1->STS;
                     i =USART1->DT;
                     DMA_ChannelEnable(DMA1_Channel3, DISABLE);                                                                      //关闭DMA
                     get_len = LENGTH - DMA_GetCurrDataCounter(DMA1_Channel3);             //获取字符长度

                     DMA_SetCurrDataCounter(DMA1_Channel3,LENGTH);                                                                                                                      //设置DMA字符长度
                     DMA_ChannelEnable(DMA1_Channel3, ENABLE);                                                                               //开启DMA

}
}

只看该作者 · 2021-5-21 17:42

DMA时钟好像没开

只看该作者 · 2021-5-22 23:23

hoop 发表于 2021-5-21 17:42
DMA时钟好像没开

多谢，已经试好了，就是DMA时钟问题