关于APM32F407配置串口DMA收发没有数据的问题记录

一.问题环境

​ 整活了一套APM32F407的板子，用了APM32F4xx_SDK_V1.4的标准外设库，正在搭建移植底层BSP框架串口部分，BSP底层配置逻辑是从STM32F407移植过来的。DMA发送时才使能通道及配置外设地址及缓存大小。

​ 串口1DMA配置过程如下：

static USART_DMAConfig_t USART_ComDmaTx(DMA_ChannelType_t channel,DMA_StreamType_t stream,uint32_t peripheralBaseAddr,uint8_t IRQChannel,uint32_t dmaFlag)
{
   
   
	USART_DMAConfig_t dmaConfig = {
   
   0};
	 
	dmaConfig.channel = channel;
	dmaConfig.stream = stream;
 
	dmaConfig.dma.channel = channel;
	dmaConfig.dma.peripheralBaseAddr = peripheralBaseAddr;			//DMA外设地址：USART数据寄存器地址
	dmaConfig.dma.memoryBaseAddr = (uint32_t)0;									//内存地址，使用时再配置
	dmaConfig.dma.dir = DMA_DIR_MEMORYTOPERIPHERAL;									//外设地址为目的地址
	dmaConfig.dma.bufferSize = (uint32_t)0;										//传输时缓冲区大小，使用时再配置
	dmaConfig.dma.peripheralInc = DMA_PERIPHERAL_INC_DISABLE;					//外设地址固定，不递增
	dmaConfig.dma.memoryInc = DMA_MEMORY_INC_ENABLE;								//内存地址递增
	dmaConfig.dma.peripheralDataSize = DMA_PERIPHERAL_DATA_SIZE_BYTE;				//外设数据格式为字节
	dmaConfig.dma.memoryDataSize = DMA_MEMORY_DATA_SIZE_BYTE;						//内存数据格式为字节
	dmaConfig.dma.loopMode = DMA_MODE_NORMAL;										//工作在正常模式，不循环
	dmaConfig.dma.priority = DMA_PRIORITY_HIGH;									//DMA传输优先级为高（VeryHigh/High/Medium/Low）
	dmaConfig.dma.fifoMode = DMA_FIFOMODE_DISABLE;										//禁能DMA的两个Memory中变量相互访问
	
	dmaConfig.dma.peripheralBurst = DMA_PERIPHERALBURST_SINGLE;						
	dmaConfig.dma.fifoThreshold = DMA_FIFOTHRESHOLD_QUARTER;
	dmaConfig.dma.memoryBurst = DMA_MEMORYBURST_SINGLE;
	
	dmaConfig.nvic.NVIC_IRQChannel = IRQChannel;
	
	dmaConfig.nvic.NVIC_IRQChannelPreemptionPriority = 6;							//抢占优先级
	dmaConfig.</