AbstractIn the daily life and the work, the means which the housing and department's safe guard, unit's document file, the financial report form as well as some individual material preservation many locks solves.If use tradition mechanical key unblanking, the people often must carry many the key, the use is not extremely convenient, after also the key loses the security namely to sell at a discount greatly.Unfolds unceasingly along with the science and technology, in people's is more and more high to daily life safe insurance component request.In order to satisfy the people blockage the operation requirements, increases its security, replaces the key with the password the password lock to arise at the historic moment.The password locking device kto prevent going in has the security high, the cost low, the power loss low, easy to operate and so on the merits.This article introduced manufactures the design system using at89S51 monolithic integrated circuit which a simple password locks.In the article first introduced this design design mentality and the design proposal, it mainly divides into three big modules: Keyboard control module, nixietube demonstration module, password comparison module.Then has made the detailed introduction to the main chip.Finally narrated the system hardware part comprehensively, the software part.This system uses the C language to carry on the software design, and enclosed detailed programming diagram, flow chart, concrete procedure.This design may realize its function, causes the system to have the practical application, the user friendly, the intellectualization.Key word：Monolithic integrated circuit;；Password lock；STC89C521. 绪论1.1 课题背景随着社会物质财宝的日益增长，安全防盗已成为社会问题...
