摘 要

20世紀末，電子技術(shù)獲得了飛速的發(fā)展，在其推動下，現(xiàn)代電子產(chǎn)品幾乎滲透了社會的各個領(lǐng)域，有力地推動了社會生產(chǎn)力的發(fā)展和社會信息化程度的提高，同時也使現(xiàn)代電子產(chǎn)品性能進一步提高，產(chǎn)品更新?lián)Q代的節(jié)奏也越來越快。
現(xiàn)代生活的人們越來越重視起了時間觀念，可以說是時間和金錢劃上了等號。對于那些對時間把握非常嚴格和準確的人或事來說，時間的不準確會帶來非常大的麻煩，所以以數(shù)碼管為顯示器的時鐘比指針式的時鐘表現(xiàn)出了很大的優(yōu)勢。數(shù)碼管顯示的時間簡單明了而且讀數(shù)快、時間準確顯示到秒。而機械式的依賴于晶體震蕩器，可能會導(dǎo)致誤差。
數(shù)字鐘是采用數(shù)字電路實現(xiàn)對“時”、“分”、“秒”數(shù)字顯示的計時裝置。數(shù)字鐘的精度、穩(wěn)定度遠遠超過老式機械鐘。在這次設(shè)計中，我們采用LED數(shù)碼管顯示時、分、秒，以24小時計時方式，根據(jù)數(shù)碼管動態(tài)顯示原理來進行顯示，用12MHz的晶振產(chǎn)生振蕩脈沖，定時器計數(shù)。在此次設(shè)計中，電路具有顯示時間的其本功能，還可以實現(xiàn)對時間的調(diào)整。數(shù)字鐘是其小巧，價格低廉，走時精度高，使用方便，功能多，便于集成化而受廣大消費的喜愛，因此得到了廣泛的使用。
關(guān)鍵字：數(shù)字電子鐘 單片機


Abstract
At the end of the 20th century, electronic technology has experienced rapid growth, the modern electronic products, almost permeated the various sectors of society, and promoted the development of social productive forces and the social informatization level, but also improve the modern electronic products to further improve the performance, product update rhythm also more and more quickly.
Modern life of people pay more and more attention to the concept of time, money and time on the hospital. For those in time and accurately grasp the very strict about or inaccurate, time will bring great trouble, so as to displays clock digital tube than the pointer clock showed a lot of advantages. Digital pipe display time is simple and accurate readings, time to seconds. And mechanical dependent on crystal oscillators, may cause errors.
A digital clock is used in digital circuit ", "" points" and "second" digital display timer. A digital clock accuracy and stability than old mechanical clock. In this design, we adopt LED digital display tube, minutes and seconds, when in 24 hours time, according to the principle of dynamic display of digital tube to show, with the crystals 12MHz produce oscillation pulses, timer count. In this design, the circuit has its time, still can realize the function of the time. A digital clock is its small, inexpensive, high precision, easy to use and when, the function is much, facilitate integration by vast consumption, so it has been widely used.
Key words: digital electric clock microcontroller

目 錄
第一章 緒論
1.1 數(shù)字電子鐘的背景…………………………………………………………………5
1.2 數(shù)字電子鐘的意義…………………………………………………………………5
1.3 數(shù)字電子鐘的應(yīng)用…………………………………………………………………5
第二章 整體設(shè)計方案
2.1 單片機的選擇…………………………………………………………………………2
2.2 單片機的基本結(jié)構(gòu)……………………………………………………………………4
第三章 數(shù)字鐘的硬件設(shè)計
3.1 最小系統(tǒng)設(shè)計…………………………………………………………………………12
3.2 LED顯示電路…………………………………………………………………………14
3.3 鍵盤控制電路…………………………………………………………………………16
第四章 數(shù)字鐘的軟件設(shè)計
4.1 系統(tǒng)軟件設(shè)計流程圖…………………………………………………………………18
4.2 數(shù)字電子鐘的原理圖…………………………………………………………………22
4.3中斷子程序 ……………………………………………………………………………23
4.4 延時子程序……………………………………………………………………………23
4.5 主程序和定時器中斷子程序…………………………………………………………23
4.6 LED顯示子程序………………………………………………………………………24
4.7 按鍵控制子程序………………………………………………………………………26
第五章 系統(tǒng)仿真
5.1 PROTUES軟件介紹……………………………………………………………………29
5.2 電子鐘系統(tǒng)PROTUES仿真……………………………………………………………29
第六章 調(diào)試與功能說明
6.1 系統(tǒng)性能測試與功能說明……………………………………………………………30
6.2 系統(tǒng)時鐘誤差分析……………………………………………………………………30
6.3 軟件調(diào)試問題及解決…………………………………………………………………30
結(jié)束語. ………………………………………………………………………………………31
參考文獻………………………………………………………………………………………32
致謝……………………………………………………………………………………………33