Introduction - If you have any usage issues, please Google them yourself
Based on DMA send and receive data through the UART example, attention DMA_0 accepted channels, DMA_1 to send the channel. Can, of course dma' s read_master and writer_master the same time even in the uart_0 and sdram_0 from the port, it can both read and write on using a dma operation, but can not simultaneously do two-way transmission.