摘要:目前，单片机广泛应用于各个领域，随着各种单片机类型地发展，单片机的功能也在逐渐完善，其中AT89S51单片机可实现ISP在线编程功能，即可直接在目标系统或电路板上烧录程序，并且可以反复烧录，无需购置专用编程器等优点。利用这一特点可以大大减少在实时检测和自动控制的单片机应用系统中的工作量，再根据它的具体结构，然后再对具体应用对象特点的软件结合来进行开发设计。

　　　本文首先对单片机的研究意义和研究现状进行了分析，还对单片机特别是AT89S51单片机的结构特点和重要引脚功能进行了介绍，同时对AT89S51单片机在线编程器进行了详细的设计及分析，最后进行了各个电路的程序设计及调试，以保障设计的单片机各个功能能够正常运行。

关键词： AT89S51单片机　ISP　设计及调试

ABSTRACT:At present, SCM is widely used in various fields, along with a variety of microcontroller type development, the function of MCU are also gradually improved, AT89S51 to achieve ISP online programming function, can be burned directly in the target system or circuit board, and can be repeated burning, the advantages of no purchase special programmer etc.. Use this feature can be greatly reduced in the MCU application system for real-time detection and automatic control of the workload, then according to its specific structure, and then the specific characteristics of the target application software to design.

　　　Firstly, the research significance and the research status of SCM is analyzed, and puts forward some improvement methods. Based on SCM especially the structure characteristics of AT89S51 single chip and pin function is introduced, and a detailed analysis of the design of AT89S51 single chip microcomputer online programmer, the end of the program design and debugging of the circuit, in order to ensure the design of each single machine function to the normal operation of. 

Keywords：AT89S51 microcontroller；ISP；designing and debugging