可用于BF533开发板上的MDMA测试代码，这个代码是我用来点LED灯的方式检测MDMA的工作状态。已添加注释。运行100 正常，实现时需注意时间的控制问题。-BF533 board can be used to develop MDMA test code, the code I use to point the way LED lamp test MDMA' s working condition. Comments have been added. Running 100　normal, implementations should pay attention to the time control problem.