了解8255A芯片的结构、功能及工作原理。
2、　掌握8086CPU与8255接口扩展方法，及通过8255A并行口传输数据的方法。
3、　握8255A初始化编程、及应用程序设计方法。

,Understanding of the 8255A chip structure, function and working principle. 2, master 8086CPU interface with the 8255 expansion method, and transmission through the parallel port 8255A data. 3, grip initialization 8255A programming, design methodology and applications.