【正文】
new type of electronic clock because of its convenient, intuitive also got social wele, occupies a considerable part of the market in the munity. Digital electronic clock is a mon tool in the daily life, large airports and other public places time screen, small to our watches, alarm clocks and timekeeping function, but also has provided convenience for people, therefore, to understand the working principle of the time electronic clock is very necessary, but also very interesting, so I choose this subject the whole point timekeeping digital clock. Road and trigger, these are our most basic electronic students to master the knowledge, through practice can deepen the understanding of textbook knowledge, can deal with the real situation, so the number of electrical design courses, I chose this topic of digital electronic clock, although this is very mon in our daily life, seemed more simple, but contains a lot of learning. In this project, the school is a very important module, not only to be the normal school, but not the disturbance to the time counting display module, and the time display is relatively simple, familiar with the chip can be done, the teacher said, on chip and other ponents of the understanding to the general hands to mobilize force, master chip function, will have the initiative. In the curriculum design topic the whole point timekeeping digital clock, can not only deepen our understanding of the digital electronic technology course, ability can also solve the problem to improve their practical ability and practical problems, to cultivate interest in digital electronic technology.Keywords:Sequential logic circuit。Combinational logic circuit。The trigger。II 1 設(shè)計(jì)目的 數(shù)字鐘是一種用數(shù)字電路技術(shù)實(shí)現(xiàn)時(shí)、分、秒計(jì)時(shí)的裝置,與機(jī)械式時(shí)鐘相比具有更高的準(zhǔn)確性和直觀性,且無機(jī)械裝置,具有更更長的使用壽命,因此得到了廣泛的使用。數(shù)字鐘從原理上講是一種典型的數(shù)字電路,其中包括了組合邏輯電路和時(shí)序電路。 因此,我們此次設(shè)計(jì)與制作數(shù)字鐘就是為了了解數(shù)字鐘的原理。2 設(shè)計(jì)要求1)設(shè)計(jì)一個(gè)數(shù)字鐘。要求用六位數(shù)碼管顯示時(shí)間,格式為00:00:00。2)具有60進(jìn)制和24進(jìn)制(或12進(jìn)制)計(jì)數(shù)功能,秒、分為60進(jìn)制計(jì)數(shù),時(shí)為24進(jìn)制(或12進(jìn)制)計(jì)數(shù)。3)有譯碼、七段數(shù)碼顯示功能,能顯示時(shí)、分、秒計(jì)時(shí)的結(jié)果。4)設(shè)計(jì)提供連續(xù)觸發(fā)脈沖的脈沖信號發(fā)生器,5)具有校時(shí)單元、鬧鐘單元和整點(diǎn)報(bào)時(shí)單元。6)確定設(shè)計(jì)方案,按功能模塊的劃分選擇元、器件和中小規(guī)模集成電路,設(shè)計(jì)分電路,畫出總體電路原理圖,闡述基本原理。3 仿真軟件Multisim