跑马灯实验操作寄存器代码，简单的控制小灯的程序，通过操作寄存器来实现功能很大程度上缩小了代码，而且有利于对硬件的理解(Marquee experiment operation register code, control lights simple procedures, through the operation of the register to realize the function of a large extent reduce the code, but also conduci