我的芯片是M4内核的，因为项目需要设置USART3的RX为DMA接收，采用的是双缓存模式。
DMA配置信息如下
[mw_shl_code=c,true]void DMA_RX_Configuration(void) { DMA_InitTypeDef DMA_InitStructure; RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1,ENABLE);//DMA1时钟使能       DMA_DeInit(DMA1_Stream1);        DMA_InitStructure.DMA_Channel = DMA_Channel_4; //USART3-RX 是数据流1,通道4       DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&USART3->DR;//外设地址 DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)temp_rx_buf0;//内存基地址,默认memory0的地址 DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory; DMA_InitStructure.DMA_BufferSize = 8;//接收8个字节满     DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;//外设地址不递增 DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; //内存地址递增 DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte; DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte; DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;//双缓冲模式下,这个默认也是循环 DMA_InitStructure.DMA_Priority = DMA_Priority_Medium; DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable; DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full; DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;//单次突发 DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;//???è??·????????? //下面这个第二个参数是第二个缓存区的地址,参数3是指定的当前缓存区 DMA_DoubleBufferModeConfig(DMA1_Stream1, (uint32_t)temp_rx_buf1,DMA_Memory_0); DMA_DoubleBufferModeCmd(DMA1_Stream1, ENABLE); //启动双缓存模式 DMA_Init(DMA1_Stream1, &DMA_InitStructure); DMA_Cmd(DMA1_Stream1,ENABLE); DMA_ITConfig(DMA1_Stream1, DMA_IT_TC, ENABLE); //开启传送完成中断 DMA_ClearITPendingBit(DMA1_Stream1,DMA_IT_TCIF1); while (DMA_GetCmdStatus(DMA1_Stream1) == DISABLE);//等待启动完成 } [/mw_shl_code] [mw_shl_code=c,true]这个是中断服务函数[/mw_shl_code] [mw_shl_code=c,true]void DMA1_Stream1_IRQHandler(void) { uint32_t tmp; if(DMA_GetITStatus(DMA1_Stream1,DMA_IT_TCIF1) == SET) { DMA_ClearITPendingBit(DMA1_Stream1,DMA_IT_TCIF1); [mw_shl_code=c,true] //下面这个地方存在问题,有时候第一次进来是0,有时候是1,初始化是指定的0为第一个[/mw_shl_code] tmp = DMA_GetCurrentMemoryTarget(DMA1_Stream1); if(tmp == 0)//get current memory target used by double buffer transfer { DMA_MemoryTargetConfig(DMA1_Stream1,(uint32_t)temp_rx_buf1,DMA_Memory_1); //switch to memory 1 rt_sem_release(&dma_sem0); //memory0 is full,release sem }else { DMA_MemoryTargetConfig(DMA1_Stream1,(uint32_t)temp_rx_buf0,DMA_Memory_0);//switch to memory 0 rt_sem_release(&dma_sem1); //memory1 is full,release sem } } }[/mw_shl_code]

现在的遇到的问题有两个,1是在没有数据发送给串口的时候,也就是USART3没有接收的时候,还是进入中断,而且两个缓存区都没有数据。
2.在初始化后第一次进入中断服务函数的时候， [mw_shl_code=c,true]tmp = DMA_GetCurrentMemoryTarget(DMA1_Stream1);[/mw_shl_code] 这个函数得到的值有时候是0,有时候是1,但是在设置的时候不是由这个函数 [mw_shl_code=c,true]DMA_DoubleBufferModeConfig(DMA1_Stream1, (uint32_t)temp_rx_buf1,DMA_Memory_0); [/mw_shl_code] 设置的DMA_Memory_0吗？   大神们 帮忙看看哪里配置有问题吗？