该代码实现了一个基于Wishbone总线协议的DMA控制器，由于SOC可集成的模块越来越多，本文设计的DMAC包含了31个可编程的DMA通道，能够处理多个DMA传输请求。由于数据在Wishbone总线上传输，在总线接口方面，本文设计的DMAC提供了两个既可以作为主机接口又可以作为从机接口的Wishbone接口。当有多个外设同时发出DMA请求时，本文设计的DMAC采用循环优先级和动态优先级相结合的方式，实现了通道仲裁器二级仲裁的功能。为了提高传输效率，本文设计的DMAC不仅支持数据块的传输，还支持高效的分散/集中DMA传输方式。(In this thesis, after in-depth understanding of Wishbone bus protocol and DMA technology, present a design concept of a DMAC integrated into a Wishbone bus based SOC. The DMAC designed in this thesis contains thirty-one programmable DMA channels, which can handle multiple DMA transfer request. As the data is transmitted over the Wishbone bus, the DMAC provides two Wishbone interfaces that can act as a host interface or as a slave interface. When several peripherals issue DMA transfer request at the same time, the DMAC adopts the combination of cyclic priority and dynamic priority to realize the secondary arbitration function of channel arbiter. In order to improve the transmission efficiency, the DMAC not only supports the transmission of data blocks, but also supports efficient scatter/gather DMA transfer mode.)