【正文】 a greater significance of the multifunction digital clock in a number of realtime control systems. In many practical applications, as long as the digital clock circuit of the programs and hardware to a certain degree of modification could be useful for realtime control system, which applied to the actual work and production to. Thus, digital clock and to expand its applications, has a very practical significance. With the development of human civilization, science and technology, there is the request of the clock continues to improve. Clock has not only seen as a tool to display the time, in many practical applications also need to be able to achieve more other functions. Highprecision, multifunction, small size, low power consumption, is the development trend of the modern clock. In this trend, digital clock, multifunction clock has bee the modern design of the production of researchled direction. This article is based on this design direction for the control of a singlechip core design requirements of a multifunction indicators in line with the digital clock. The design is based on the principle of singlechip technology to chip AT89C52singlechip microputer as the core controller, through the production of hardware and software procedures for the preparation, design to produce a multifunctional digital clock system. The clock system mainly by clock module, alarm module, the ambient temperature detectio n module, liquid crystal display module, control module and the keyboard signal prompted module. System is simple and clear user interface that can 4V ~ 7V DC power under normal operation. Able to accurately display time (display format hh: mm: seconds seconds, 24hour system), may be time to adjust at any time, with clock time settings, alarm on / off, only to make functions, where the clock to measure the ambient temperature and displayed. Hardware and software design into the guiding ideology, give full play to the singlechip features, most of the functions through software programming to achieve, the circuit is simple and clear, high system stability. At the same time, the clock 畢業(yè)設(shè)計(jì)（論文） 3 system also has the power of small, low cost, and highly practical. System ponents as a result of less use, singlechip occupied by the I / O port not more than, the system has a certain degree of scalability. Clock design is no theory of discrete logic, programmable logic, or using fullcustom silicon devices of any digital design, in order to successfully operate and reliable clock is crucial. Poor design of the clock in the limits of temperat