电子万年历中英文翻译.doc

Design of the digital Perpetual Calendar based on real-time clock chip Abstract:This Electronic calendar uses the AT89S52 microcontroller as the core for the control. Time Circuit which is constituted by Dallass DS12C887A real-time clock chip achieved a time and date display, it increased functionality for the temperature display and the whole point timekeeping. This paper discusses the hardware circuit of the system, principle in detail,and gives the flow chart of the software design and the major source code. keywords:microcontroller; real-time clock; Temperature measurement 1 Introduction E-calendar-bedroom at home,schools,stations and more and more extensive use of plaza for peoples lives,study,work great convenience. Electronics calendar for the past need to re-adjust after power-off time and date,and time is a big error. Designed the system using real-time clock chip (DS12C887A) as a timer parts,the chip comes with an internal crystal oscillator,so that effectively guarantee the accuracy of the time and hang own internal battery power makes the situation will continue to update the time information . This design uses AT89S52 as the main controller,in order to improve the practicality of the circuit add temperature measurement circuit,timekeeping and alarm functions. 2 System hardware design Schematic circuit shown in Figure 2: System architecture diagram 2.1 Power Supply Circuit In order to reduce circuit costs,the system power supply circuit by the transformer transformer,three-terminal integrated regulator (L7805 circuit 5V, has a simple,reliable, inexpensive and so on. 2.2 Host Controller Host controller using ATMELs latest MCU Products AT89S52. Apart from the single-chip microcomputer has a MCS-51 series single-chip all the benefits of things,also has 8KB of internal in-system programmable FLASH memory,free and low-power brown-out mode, greatly reducing the power circuit . In addition,also has a watchdog circuit,a reliable job fo