博客

程序使用DMA传输，需要使用DMA传输完成中断，程序如下：

void DMA2_Stream7_IRQHandler(void)
{
	static u16 cnt = 0 ;
	if(DMA_GetITStatus(DMA2_Stream7,DMA_FLAG_TCIF7)==SET) //检查DMA传输完成中断
	{
	DMA_ClearITPendingBit(DMA2_Stream7,DMA_FLAG_TCIF7);  //Clear the IT flag
	}
		
}

ITStatus DMA_GetITStatus(DMA_Stream_TypeDef* DMAy_Streamx, uint32_t DMA_IT)
{
  ITStatus bitstatus = RESET;
  DMA_TypeDef* DMAy;
  uint32_t tmpreg = 0, enablestatus = 0;

  /* Check the parameters */
  assert_param(IS_DMA_ALL_PERIPH(DMAy_Streamx));
  assert_param(IS_DMA_GET_IT(DMA_IT));
 
  /* Determine the DMA to which belongs the stream */
  if (DMAy_Streamx < DMA2_Stream0)
  {
    /* DMAy_Streamx belongs to DMA1 */
    DMAy = DMA1; 
  } 
  else 
  {
    /* DMAy_Streamx belongs to DMA2 */
    DMAy = DMA2; 
  }

  /* Check if the interrupt enable bit is in the CR or FCR register */
  if ((DMA_IT & TRANSFER_IT_MASK) != (uint32_t)RESET)
  {
    /* Get the interrupt enable position mask in CR register */
    tmpreg = (uint32_t)((DMA_IT >> 11) & TRANSFER_IT_ENABLE_MASK);   
    
    /* Check the enable bit in CR register */
    enablestatus = (uint32_t)(DMAy_Streamx->CR & tmpreg);
  }else 
  {
    /* Check the enable bit in FCR register */
    enablestatus = (uint32_t)(DMAy_Streamx->FCR & DMA_IT_FE); 
  }
 
  /* Check if the interrupt pending flag is in LISR or HISR */
  if ((DMA_IT & HIGH_ISR_MASK) != (uint32_t)RESET)
  {
    /* Get DMAy HISR register value */
    tmpreg = DMAy->HISR ;
  }
  else
  {
    /* Get DMAy LISR register value */
    tmpreg = DMAy->LISR ;
  } 

  /* mask all reserved bits */
  tmpreg &= (uint32_t)RESERVED_MASK;

  /* Check the status of the specified DMA interrupt */
  if (((tmpreg & DMA_IT) != (uint32_t)RESET) && (enablestatus != (uint32_t)RESET))
  {
    /* DMA_IT is set */
    bitstatus = SET;
  }
  else
  {
    /* DMA_IT is reset */
    bitstatus = RESET;
  }

  /* Return the DMA_IT status */
  return  bitstatus;
}```

发现DMA传输完成后，if内程序无法进入处理。逐步调试发现其函数 DMA_GetITStatus(DMA_Stream_TypeDef* DMAy_Streamx, uint32_t DMA_IT)中传递的参数DMA_FLAG_TCIF7存在问题，现将问题记录如下：

函数内其中DMA_IT传递的是DMA_IT_TCIF7，如下

DMA_IT: specifies the DMA interrupt source to check.
  *          This parameter can be one of the following values:
  *            @arg DMA_IT_TCIFx:  Streamx transfer complete interrupt
  *            @arg DMA_IT_HTIFx:  Streamx half transfer complete interrupt
  *            @arg DMA_IT_TEIFx:  Streamx transfer error interrupt
  *            @arg DMA_IT_DMEIFx: Streamx direct mode error interrupt
  *            @arg DMA_IT_FEIFx:  Streamx FIFO error interrupt

其在stm32F4XX.h文件中的定义如下：

#define DMA_FLAG_FEIF0                    ((uint32_t)0x10800001)
#define DMA_FLAG_DMEIF0                   ((uint32_t)0x10800004)
#define DMA_FLAG_TEIF0                    ((uint32_t)0x10000008)
#define DMA_FLAG_HTIF0                    ((uint32_t)0x10000010)
#define DMA_FLAG_TCIF0                    ((uint32_t)0x10000020)
#define DMA_FLAG_FEIF1                    ((uint32_t)0x10000040)
#define DMA_FLAG_DMEIF1                   ((uint32_t)0x10000100)
#define DMA_FLAG_TEIF1                    ((uint32_t)0x10000200)
#define DMA_FLAG_HTIF1                    ((uint32_t)0x10000400)
#define DMA_FLAG_TCIF1                    ((uint32_t)0x10000800)
#define DMA_FLAG_FEIF2                    ((uint32_t)0x10010000)
#define DMA_FLAG_DMEIF2                   ((uint32_t)0x10040000)
#define DMA_FLAG_TEIF2                    ((uint32_t)0x10080000)
#define DMA_FLAG_HTIF2                    ((uint32_t)0x10100000)
#define DMA_FLAG_TCIF2                    ((uint32_t)0x10200000)
#define DMA_FLAG_FEIF3                    ((uint32_t)0x10400000)
#define DMA_FLAG_DMEIF3                   ((uint32_t)0x11000000)
#define DMA_FLAG_TEIF3                    ((uint32_t)0x12000000)
#define DMA_FLAG_HTIF3                    ((uint32_t)0x14000000)
#define DMA_FLAG_TCIF3                    ((uint32_t)0x18000000)
#define DMA_FLAG_FEIF4                    ((uint32_t)0x20000001)
#define DMA_FLAG_DMEIF4                   ((uint32_t)0x20000004)
#define DMA_FLAG_TEIF4                    ((uint32_t)0x20000008)
#define DMA_FLAG_HTIF4                    ((uint32_t)0x20000010)
#define DMA_FLAG_TCIF4                    ((uint32_t)0x20000020)
#define DMA_FLAG_FEIF5                    ((uint32_t)0x20000040)
#define DMA_FLAG_DMEIF5                   ((uint32_t)0x20000100)
#define DMA_FLAG_TEIF5                    ((uint32_t)0x20000200)
#define DMA_FLAG_HTIF5                    ((uint32_t)0x20000400)
#define DMA_FLAG_TCIF5                    ((uint32_t)0x20000800)
#define DMA_FLAG_FEIF6                    ((uint32_t)0x20010000)
#define DMA_FLAG_DMEIF6                   ((uint32_t)0x20040000)
#define DMA_FLAG_TEIF6                    ((uint32_t)0x20080000)
#define DMA_FLAG_HTIF6                    ((uint32_t)0x20100000)
#define DMA_FLAG_TCIF6                    ((uint32_t)0x20200000)
#define DMA_FLAG_FEIF7                    ((uint32_t)0x20400000)
#define DMA_FLAG_DMEIF7                   ((uint32_t)0x21000000)
#define DMA_FLAG_TEIF7                    ((uint32_t)0x22000000)
#define DMA_FLAG_HTIF7                    ((uint32_t)0x24000000)
#define DMA_FLAG_TCIF7                    ((uint32_t)0x28000000)

其中：/* Get the interrupt enable position mask in CR register */

tmpreg = (uint32_t)((DMA_IT >> 11) & TRANSFER_IT_ENABLE_MASK); 中TRANSFER_IT_ENABLE_MASK为0x001E，主要要获得当前中断是否被设置（参加数据手册），设置在CR寄存器的低4位。


，好决定在语句if (((tmpreg & DMA_IT) != (uint32_t)RESET) && (enablestatus != (uint32_t)RESET))是否返回。以为的目的就是是的中断标识的置位段处于低四位。我使用的是DMA2_Stream7,从头文件定义可以看出DMA_FLAG_TCIF7>>11后，根本不会得到想要的结果，其他DMA中断也会一样。

由于不想修改系统库文件，所以采用寄存器操作

    void DMA2_Stream7_IRQHandler(void)
{
	static u16 cnt = 0 ;
	if(DMA2->HISR & 0x08000000) //检查DMA传输完成中断
	{
	DMA_ClearITPendingBit(DMA2_Stream7,DMA_FLAG_TCIF7);  //Clear the IT flag
		
}

则中断可以正常处理了。