毫秒计、信号源、测频仪等是中、高等院校的常用实验教学仪器,但目前这类仪器大多功能单一,精度低,体积大,成本高.我们利用单片机技术研制成功的多功能程控测试仪克服了这些缺点,而且自动化程度高,操作简单.1 电路组成系统原理图如图1所示.这里简要介绍部分电路的功能.(1)8253电路 Millisecond meter, signal source, frequency meter and so on are common experimental teaching instruments in colleges and universities, but most of these instruments are mostly single-function, low precision, large volume and high cost. We use the single-chip technology to develop successful multi-function program control Tester to overcome these shortcomings, but also a high degree of automation, simple operation .1 circuit components system schematic shown in Figure 1. Here is a brief description of some of the circuit functions. (1) 8253 circuit