学习板stm32技术全常见问题中usartdma实现

对于没玩过DMA的朋友,这里简单说一下DMA,用自己的语言说吧,那就是,从某个位置DMACPUDMAAB,搬到哪里去;C;D:DMA.CPUDMA_InitStructure.DMA_MemoryInc=FLASHDMAUSART1->DRu8USART1_DMA_Buf1[512512DMA断（通道5）在这里修改DMA的内存写入u8USART1_DMA_Buf2[512];，同时标记下次的_Buf_No=BUF_NO1;与Buf_Ok=TRUE;证明已有数据准备完成。这时CUPUSART1_DMA_Buf1FLASH.DMABUF1BUF1DMABUF2,BUF125F080DMABUF2DMABUF1,此时a.DMABUF1断,此时切换DMA的目标缓冲为BUF2,而且切换的过程必须在新的串口数据溢出之前完成.b.DMABUF1BUF225F080,USARTFLASH#defineSRC_USART1_DR(&(USART1->DR))u8USART1_DMA_Buf1[512];u8BUF_NO_Buf_No;//空闲的BUF号typedefenumDMA_InitTypeDefDMA_InitStructure;voidUSART_DMAToBuf1(void){DMA_InitStructure.DMA_PeripheralBaseAddr=(u32)SRC_USART1_DR;//BUF既是(&(USART1-DMA_InitStructure.DMA_MemoryBaseAddr(u32)USART1_DMA_Buf1BUF/DMA_InitStructure.DMA_PeripheralInc=DMA_PeripheralInc_Disable;//外设地址寄存器不递增DMA_InitStructure.DMA_MemoryInc=DMA_MemoryInc_Enable;//内存地址递增DMA_InitStructure.DMA_PeripheralDataSize=DMA_PeripheralDataSize_Byte;//外设字节为单位DMA_InitStructure.DMA_MemoryDataSize=DMA_PeripheralDataSize_Byte;//内存字节为单位DMA_InitStructure.DMA_Mode=DMA_Mode_Circular;//工作在循环缓存模式DMA_InitStructure.DMA_Priority=DMA_Priority_High;//4DMA_InitStructure.DMA_M2MDMA_M2M_Disable;道1寄存器DMA_ITConfig(DMA1_Channel5,DMA_IT_TCENABLE/DMA5_Buf_No=BUF_NO2;DMA_InitStructure.DMA_MemoryBaseAddr(u32)USART1_DMA_Buf1;Buf_Ok=FALSE;//此时没有数据准备完成当然FALSEDMA_Cmd(DMA1_Channel5ENABLE}//u16DexternDMA_InitTypeDefvoid{GL{//Dounter=DMA_GetCurrDounter(DMA1_Channel5);//获取剩余长度,一般都为0,调试用DMA_ClearITPendingBit(DMA1_IT_GL5);//清除全部中断标志//转换可操作BUF{DMA_InitStructure.DMA_MemoryBaseAddr=(u32)USART1_DMA_Buf1;DMA_Init(DMA1_Channel5,&DMA_InitStructure);}{DMA_InitStructure.DMA_MemoryBaseAddr=(u32)USART1_DMA_Buf2;DMA_Init(DMA1_Channel5,&DMA_InitStructure);}Buf_Ok=TRUE;}}{{LED1_ON;Buf_Ok=FALSE;//操作了准备好的数据{}Timer1=5000;}{}}FlagStatusITStatusDMADMA_IT