基于 PC 机的8253实验设计

摘要

Intel 8253是典型的定时计数器芯片，有着广泛的应用。要掌握其工作原理和编程方式，实验是必不可少的环节。设计了一个新颖的基于普通PC机的8253发声程序实验。发声程序需要音调和音长两个参数。音长一般通过软件延时实现，但软件延时存在不能精确定时的问题。针对该问题提出了一种利用DOS系统功能调用获取精确音长的方法。该实验既可以独立设为实验，也可以作为基于实验箱的实验的有益补充。%Intel 8253 is a typical timer/counter chip, which has extensive application.Experiment is necessary for students to grasp the working principle and control method of 8253.A novel sound-producing program experiment of 8253 based on PC was designed.The sound -producing program needed two parameters: tone and sound duration.The sound duration is generally generated by the time delay using software which, however, is not very precise.A method that could generate precise sound duration by using DOS system call was put forward.The designed experiment can be treated either as a separate one or as a supplement to the experiment based on experimental box.