1、洛阳理工学院毕业设计（论文） 1 外文资料翻译 LED using digital tube digital display its high-brightness, indicating the advantages of intuitive intelligence is widely used in areas such as equipment and household appliances. AT89C52This article describes a single-chip microcomputer as the core, to a total of anode high-
2、brightness LED L ED as a display composed of seven figures show that the practical design of multi-function electronic clocks, the clock shows a week, hour, minute, second, it can be switched to year, month, day showed that the whole point of music at the same time and from time to time the alarm ti
3、me and other functions can also be used for electronic stopwatch. Clock circuit is the heart of the computer, which controls the rhythm of the work of the computer is through the completion of complex sequential circuits function in different directions. Clock, since it was invented that day on, peo
4、ples lives has become an indispensable tool, especially in this era of efficient, the clock is in the human production and living, learning and other fields is widely. However, with the passage of time, people not only to the requirements of the clock is getting higher and higher precision, and func
5、tional requirements for the clock more and more, the clock has not only a tool used to display time, in many practical applications It also needs to be able to achieve more other functions. Features such as alarm clock, calendar display, temperature measurement function, humidity measurements, volta
6、ge measurements, frequency measurements, have been under-voltage alarm function. Digital clocks to the peoples production and life has brought great convenience, but also greatly expands the time feature the original clocks. Such as regular auto-alarm, Automatic time-ling, time process automation, f
7、rom time to time broadcast, from closed-circuit automatic lights, oven timer switch, on-off power equipment, electrical and even a variety of timing is automatically enabled, all of which are based on digital clocks and watches based. It can be said that the design of the significance of multi-funct
8、ion Digital Clock Digital Clock is not just itself, 洛阳理工学院毕业设计（论文） 2 a greater significance of the multi-function digital clock in a number of real-time control systems. In many practical applications, as long as the digital clock circuit of the programs and hardware to a certain degree of modificat
9、ion could be useful for real-time 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
10、 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. High-precision, multifunction, small size, low power consumption, is the development trend of the modern clock. In this trend, digital clock, multi
11、function clock has become the modern design of the production of research-led direction. This article is based on this design direction for the control of a single-chip core design requirements of a multi-function indicators in line with the digital clock. The design is based on the principle of sin
12、gle-chip technology to chip AT89C52single-chip microcomputer as the core controller, through the production of hardware and software procedures for the preparation, design to produce a multi-functional digital clock system. The clock system mainly by clock module, alarm module, the ambient temperatu
13、re detection 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, 24-hour system), may be time
14、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 single-chip features, most of the functions through software progra
15、mming to achieve, the circuit is simple and clear, high system stability. At the same time, the clock system also has the power of small, low cost, and highly practical. System components as a result of less use, single-chip occupied by the I / O port not 洛阳理工学院毕业设计（论文） 3 more than, the system has a
16、 certain degree of scalability. Clock design is no theory of discrete logic, programmable logic, or using full-custom 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 temperature, voltage deviation or the
17、 manufacturing process will result in the case wrong, and debugging difficult, spending a lot. In the design of FPGA / CPLD clock when several types of commonly used. Clock can be divided into the following four types: global clock, clock gating, multi-level logic clock clock and volatility. Multi-c
18、lock system to include the above-mentioned four types of any combination of the clock. No matter what methods are the real circuit clock tree can not achieve the ideal assumption that the clock, so we must be based on an ideal clock, the clock real work to build a model to analyze the circuit, so as
19、 to make the circuit performance and the practical work as expected . Clock in the actual model, we have to consider the spread of clock-tree skew, vertical jump and absolute bias and other uncertainties. To register, the clock was working along the arrival of the data terminal when it should have b
20、een stable, so as to ensure that the work along the sampling clock to the accuracy of the data, this data preparation time that we call set-up time (setup time). Data should also be working along the clock to maintain over a period of time, this period of time known as the hold time (hold time). Glo
21、bal clock for a design project, the global clock (or clock synchronous) is the simplest and most predictable clock. In the PLD / FPGA design of the clock the best options are: by a dedicated global clock input pins of a single master clock-driven clock design projects to each flip-flop. As long as p
22、ossible should be used in the design of global clock projects. PLD / FPGA has a dedicated global clock pins, the device is directly connected to each register. Global clock to provide such a device in the shortest possible delay to the output clock. Clock-gated in many applications, the entire design of the overall use of
