⒈ 了解交通灯管理的基本工作原理

⒉ 熟悉8259A中断控制器的工作原理和应用编程

⒊ 熟悉8255A并行接口的各种工作方式和应用

⒋ 熟悉8253计数器/定时器的工作方式及应用编程，掌握利用软硬件相结合定时的方法

-⒈ understand traffic lights management familiar with the basic working principle of ⒉ 8259A interrupt controller of the working principle and application programming 8255A ⒊ familiar parallel interface various working methods and applications ⒋ familiar with the 8253 counter/timer of the working methods and application programming, master regular use of a combination of hardware and software approach