数字计时器课程设计

数字计时器课程设计 引言 钟表的数字化给人们生产生活带来了极大的方便，而且大大的扩展了钟表原先的报时功能。诸如定时自动报警、按时自动打铃、时间程序自动控制、定时广播、定时启闭路灯、定时开关烘箱、通断动力设备，甚至各种定时电气的自动启用等，所有这些都是以钟表数字化为基础的。因此研究数字钟及扩大应用，有着非常现实的意义。 1 指标要求 要想构成数字钟，首先应有一个能自动产生稳定的 标准 excel标准偏差excel标准偏差函数exl标准差函数国标检验抽样标准表免费下载红头文件格式标准下载 时间脉冲信号的信号源。还需要有一个使高频脉冲信号变成适合于计时的低频脉冲信号的分频器电路，即频率为1HZ的“秒脉冲”信号。经过分频器输出的秒脉冲信号到计数器中进行计数。由于计时的规律是:60秒=1分，60分=1小时，24小时=1天，这就需要分别设计60进制，24进制，(或12进制的计时器，并发出驱动AM;PM的标志信号)。各计数器输出的信号经译码器/驱动器送到数字显示器对应的笔划段，使得 “时”、“分”、“秒”得以数字显示。值得注意的是:任何数字计时器都有误，因此应考虑校准时间电路，校时电路一般采用自动快调和手动调整，“自动快调”是利用分频器输出的不同频率脉冲使得显示时间自动迅速的得到调整。 “手动调整” 是利用手动的节拍调整显示时间。 1.1 主要技术指标和要求 (1)显示时、分、秒，采用24小时制。 (2)具有校时功能，可以对小时和分单独校时，对分校时的时候，停止分向小时进位。校时时钟源可以手动输入或借用电路中的时钟。 (3)为了保证计时准确、稳定，由晶体振荡器提供标准时间的基准信号。 (4)24小时误差不高于60秒。 2 设计与计算 2.1 设计方案介绍 数字时钟是用数字集成电路构成，用数码显示的一种现代化计数器，由振荡器、分频器、校时电路、计数器、译码器和显示器6个部分组成。振荡器和分频器组成标准秒信号发生器，不同进制的计数器、译码器组成和显示器组成计时系统，通过校时电路实现对时、分的校准。由于采用纯数字硬件设计制作，与传统机械表相比，具有走时准确、显示直观、无机械传动装置等特点。 基本原理的逻辑框图如图所示，由图知:石英晶体振荡器产生的信号经过分频器作为秒脉冲，秒脉冲送入计数器计数，计数结果通过“时”、“分”、“秒”译码器显示时间。其中，石英晶体振荡器和分频器组成标准秒信号发生器，由不同进制的计数器、译码器the provisions of Hunan province safety production supervision and management responsibilities > (Hunan Zhengban made 2013 No. 4), resolutely implement the safety production of the party with responsibility, a pair of responsibility. "Two is issued safety production administration and inspection to promote the responsibilities bear safety production supervision departments strictly and effectively assumed responsibility. The three is the establishment of enterprise production safety hidden With self correction self reporting system, promote the enterprises to implement the main responsibility for production safety. The four is the introduction of strengthening county safety production supervision ability construction work, promote safe production responsibility to the grassroots. 3, strict accountability and target management. Adhere to the "who is in charge, who is responsible for the pipe industry must pipes, pipe production and management must control safety management business must be safe" principle, the implementation of safe production supervision and stagnation to cure. "The leadership responsible system. Production safety of key towns, key enterprises and key problems, by the township government and the Department responsible for the stagnation led the lump sum, to tackle tough. To further increase the production safety index assessment, strict implementation of safe production of "one vote veto" award and recognition system, strengthen production safety incentive mechanism (four). Adhere to the political principles against unwholesome tendencies existence of the problem is not strict internal supervision. Over the years, the global leadership team members do not have any illegal and other bad records, but there are still not strict, the implementation does not survive the problem. A few leading cadres not strictly in accordance with the county Party committee, county government On strengthening style construction requirements and style construction safety supervision system of "ten prohibitions", to solve the people most concerned, the most direct, the most realistic problem of production safety as the starting point and goal of all work, to strengthen internal supervision on the way, in the perfect power control mechanism on "let things drift", get free in the political norms of leading cadres, some involving major principle problems of ambiguous attitude, major issues issues of right and wrong, it cannot stand up bravely, face to face, resolute struggle and discredit the views of the party in 2012. The style of the big consolidation activities, cadres and workers 6 people were 和显示器组成计时系统。秒信号送入计数器进行计数，把累计的结果以“时”、“分”、“秒”的数字显示出来，“时”显示由二十四进制计数器、译码器、显示器构成，“分”、“秒”显示分别由六十进制计数器、译码器、显示器构成。 图2.1 数字电子钟的逻辑图 2.2 数字计时器单元电路的设计 2.2.1石英晶体振荡器 石英晶体振荡器的特点是振荡频率准确、电路结构简单、频率易调整。它还具有压电效应，在晶体某一方向加一电场，则在与此垂直的方向产生机械振动，有了机械振动就会在相应的垂直面上产生电场，从而使机械振动和电场互为因果，这种循环过程一直持续到晶体的机械强度限制时，才达到最后的稳定，这种压电谐振的频率即为晶体振荡器的固有频率。如图所示:R1为反馈电阻，取10-100兆欧，其作用是为CMOS反相器提供偏置，使其工作在放大状态，C1为频率微调电容，取5-30pF，C2为温度特性校正电容，一般取20-50pF，石英晶体采用32768HZ晶振，要得到1HZ的脉冲，则需要经过15级二分频器完成。 图2.2.1石英晶体振荡电路 r the years, the global leadership team members do not have any illegal and other bad records, but there are still not strict. OveAdhere to the political principles against unwholesome tendencies existence of the problem is not strict internal supervisionof safe production of "one vote veto" award and recognition system, strengthen production safety incentive mechanism (four). tationthe stagnation led the lump sum, to tackle tough. To further increase the production safety index assessment, strict implemenduction safety of key towns, key enterprises and key problems, by the township government and the Department responsible for . Prosafe" principle, the implementation of safe production supervision and stagnation to cure. "The leadership responsible systemresponsible for the pipe industry must pipes, pipe production and management must control safety management business must be ho isoduction responsibility to the grassroots. 3, strict accountability and target management. Adhere to the "who is in charge, wThe four is the introduction of strengthening county safety production supervision ability construction work, promote safe pr afety.den With self correction self reporting system, promote the enterprises to implement the main responsibility for production spartments strictly and effectively assumed responsibility. The three is the establishment of enterprise production safety hidion deTwo is issued safety production administration and inspection to promote the responsibilities bear safety production supervisan made 2013 No. 4), resolutely implement the safety production of the party with responsibility, a pair of responsibility. "the provisions of Hunan province safety production supervision and management responsibilities > (Hunan Zhengbe party in 2012. The style of the big consolidation activities, cadres and workers 6 people werer issues issues of right and wrong, it cannot stand up bravely, face to face, resolute struggle and discredit the views of thmajo ngs drift", get free in the political norms of leading cadres, some involving major principle problems of ambiguous attitude,point and goal of all work, to strengthen internal supervision on the way, in the perfect power control mechanism on "let thi rtingrohibitions", to solve the people most concerned, the most direct, the most realistic problem of production safety as the stacounty government On strengthening style construction requirements and style construction safety supervision system of "ten p ittee,, the implementation does not survive the problem. A few leading cadres not strictly in accordance with the county Party comm2 2.2.2分频器 由于石英振荡器产生的频率很高，要得到秒脉冲，需要用分频器电路。石英晶体振荡分频电路如图所示: 图2.2.2 石英晶体振荡分频电路 CD4060是14位二进制计数器，它内部有14级二分频器，CIN(11脚)为输入引脚，Q14(3脚)为输出引脚，由于CD4060只能实现14级分频，所以在其后面再加上一级二分频的双D触发器CD4013，从而得到1HZ的秒脉冲。 2.2.3校时电路 当数字时钟与实际时间不符时，需要根据标准时间校正。校时电路如图所示:该电路能对时、分、秒分别校准。 原理如下:其中CP0为秒计时脉冲，CP1为分计时脉冲，CP2为时计时脉冲。当校“秒”时，将开关S1闭合，此时门电路A9被封锁，1HZ信号的脉冲不能进入到“秒计数器”中，此时暂停秒计时，如果数字钟与标准时间一致，断开S1，数字钟秒显示与标准时间秒计时同步进行，“秒”位校时完。当校“分”时，将开关S2闭合，由于A7、A8输出为高电平，秒十位的进位就不能通过A6、A7向分计时器CP1进位，此时1HZ脉冲信号按秒节奏计数，如果分计数器的显示与标准时间一致，断开S1，与非门A5被封锁，此时秒十位的进位信号通过A6、A7向CP1进位，“分”位校时完。校“时”与校“分”同理。 ms of leading cadres, some involving major principle problems of ambiguous attitude, major issues issues of right and wrong, al norngthen internal supervision on the way, in the perfect power control mechanism on "let things drift", get free in the politicncerned, the most direct, the most realistic problem of production safety as the starting point and goal of all work, to streost costyle construction requirements and style construction safety supervision system of "ten prohibitions", to solve the people mproblem. A few leading cadres not strictly in accordance with the county Party committee, county government On strengthening e the eam members do not have any illegal and other bad records, but there are still not strict, the implementation does not survivt unwholesome tendencies existence of the problem is not strict internal supervision. Over the years, the global leadership tgains" award and recognition system, strengthen production safety incentive mechanism (four). Adhere to the political principles atough. To further increase the production safety index assessment, strict implementation of safe production of "one vote veto tackleerprises and key problems, by the township government and the Department responsible for the stagnation led the lump sum, to fe production supervision and stagnation to cure. "The leadership responsible system. Production safety of key towns, key entof sa ust pipes, pipe production and management must control safety management business must be safe" principle, the implementation. 3, strict accountability and target management. Adhere to the "who is in charge, who is responsible for the pipe industry msrootsengthening county safety production supervision ability construction work, promote safe production responsibility to the grasstem, promote the enterprises to implement the main responsibility for production safety. The four is the introduction of string syssumed responsibility. The three is the establishment of enterprise production safety hidden With self correction self reporttion and inspection to promote the responsibilities bear safety production supervision departments strictly and effectively anistraement the safety production of the party with responsibility, a pair of responsibility. "Two is issued safety production admian province safety production supervision and management responsibilities > (Hunan Zhengban made 2013 No. 4), resolutely implthe provisions of Hunolidation activities, cadres and workers 6 people wereg consit cannot stand up bravely, face to face, resolute struggle and discredit the views of the party in 2012. The style of the bi3 图2.2.3 校时电路图 2.2.4计数器 显示“时”、“分”、“秒”需要6片中规模计数器。其中，“秒”、“分”计时各为六十进制计数器，“时”计时为二十四进制计数器，六十进制和二十四进制计数器都选用74LS90集成块来实现。 ,1, 六十进制计数器 “秒”计数器电路与“分”计数器电路都是六十进制，它由一级十进制计数器和一级六进制计数器连接构成。原理图如图所示:采用两片中规模集成电路74LS90串接起来构成“秒”、“分”计数器。U2是十进制计数器，U2的Q4作为十进制的进位信号，74LS90计数器是十进制异步计数器，用反馈归零方法实现十进制计数，U1和与非门组成六进制计数。74LS90是在CP信号的下降沿翻转计数，U1的Q0和Q3与0101的下降沿，作为“分(时)”计数器的输入信号，U1的输出0110高电平1分别送到计数器的MR1、MR2端清零，74LS90内部的MR1和MR2与非后清零而使计数器归零，完成六进制计数。由此可见，U1和U2串联实现了六十进制计数。 rohibitions", to solve the people most concerned, the most direct, the most realistic problem of production safety as the stacounty government On strengthening style construction requirements and style construction safety supervision system of "ten p ittee,, the implementation does not survive the problem. A few leading cadres not strictly in accordance with the county Party commr the years, the global leadership team members do not have any illegal and other bad records, but there are still not strict. OveAdhere to the political principles against unwholesome tendencies existence of the problem is not strict internal supervisionof safe production of "one vote veto" award and recognition system, strengthen production safety incentive mechanism (four). tationthe stagnation led the lump sum, to tackle tough. To further increase the production safety index assessment, strict implemenduction safety of key towns, key enterprises and key problems, by the township government and the Department responsible for . Prosafe" principle, the implementation of safe production supervision and stagnation to cure. "The leadership responsible systemresponsible for the pipe industry must pipes, pipe production and management must control safety management business must be ho isoduction responsibility to the grassroots. 3, strict accountability and target management. Adhere to the "who is in charge, wThe four is the introduction of strengthening county safety production supervision ability construction work, promote safe pr afety.den With self correction self reporting system, promote the enterprises to implement the main responsibility for production spartments strictly and effectively assumed responsibility. The three is the establishment of enterprise production safety hidion deTwo is issued safety production administration and inspection to promote the responsibilities bear safety production supervisan made 2013 No. 4), resolutely implement the safety production of the party with responsibility, a pair of responsibility. "the provisions of Hunan province safety production supervision and management responsibilities > (Hunan Zhengbe party in 2012. The style of the big consolidation activities, cadres and workers 6 people werer issues issues of right and wrong, it cannot stand up bravely, face to face, resolute struggle and discredit the views of thmajo ngs drift", get free in the political norms of leading cadres, some involving major principle problems of ambiguous attitude,point and goal of all work, to strengthen internal supervision on the way, in the perfect power control mechanism on "let thi rting4 图2.2.4.1 六十进制计数器电路 ,2, 二十四进制计数器 时计数电路是由U4和U3组成的二十四进制计数电路。原理图如图所示:当“时”个位U4计数输入端到第10个触发信号时，U4计数器复位零，进位端Q4向U3“时”十位计数器输出进位信号，当第24个“时”(来自“分”计数器输出的进位信号)脉冲到达时，U4计数器的状态为“0100”，U3计数器的状态为“0010”，此时“时”个位计数器的Q3和“时”十位计数器的Q2输出为“1”。把它们分别送到U2和U1计数器的清零端MR1和MR1，通过74LS90内部的MR1和MR2与非后清零，计数器复零，完成二十四进制计数。 图2.2.4.2 二十四进制计数器电路 style construction requirements and style construction safety supervision system of "ten prohibitions", to solve the people mproblem. A few leading cadres not strictly in accordance with the county Party committee, county government On strengthening e the eam members do not have any illegal and other bad records, but there are still not strict, the implementation does not survivt unwholesome tendencies existence of the problem is not strict internal supervision. Over the years, the global leadership tgains" award and recognition system, strengthen production safety incentive mechanism (four). Adhere to the political principles atough. To further increase the production safety index assessment, strict implementation of safe production of "one vote veto tackleerprises and key problems, by the township government and the Department responsible for the stagnation led the lump sum, to fe production supervision and stagnation to cure. "The leadership responsible system. Production safety of key towns, key entof sa ust pipes, pipe production and management must control safety management business must be safe" principle, the implementation. 3, strict accountability and target management. Adhere to the "who is in charge, who is responsible for the pipe industry msrootsengthening county safety production supervision ability construction work, promote safe production responsibility to the grasstem, promote the enterprises to implement the main responsibility for production safety. The four is the introduction of string syssumed responsibility. The three is the establishment of enterprise production safety hidden With self correction self reporttion and inspection to promote the responsibilities bear safety production supervision departments strictly and effectively anistraement the safety production of the party with responsibility, a pair of responsibility. "Two is issued safety production admian province safety production supervision and management responsibilities > (Hunan Zhengban made 2013 No. 4), resolutely implthe provisions of Hunolidation activities, cadres and workers 6 people wereg consit cannot stand up bravely, face to face, resolute struggle and discredit the views of the party in 2012. The style of the bims of leading cadres, some involving major principle problems of ambiguous attitude, major issues issues of right and wrong, al norngthen internal supervision on the way, in the perfect power control mechanism on "let things drift", get free in the politicncerned, the most direct, the most realistic problem of production safety as the starting point and goal of all work, to streost co5 2.2.5译码器 译码是将给定的代码进行翻译。计数器采用的码制不同，译码电路也不同。74LS48驱动器是与8421BCD编码计数器配合用的七段译码驱动器。 74LS48配有灯测试LT、动态灭灯输入RBI、灭灯输入/动态灭灯输出BI/RBO，当LT=“0”时，74LS48输出全为“1”。74LS48的使用方法参照TTL手册。74LS48的输入端和计数器对应的输出端相连，74LS48的输出端与七段显示器对应的输入相连。 表2.2.5 译码器74LS48的功能表 2.2.6显示器 本系统用七段发光二极管来显示译码器输出的数字，显示器有两种:共阳极或共阴极显示器。74LS48译码器对应的显示器是共阴极(接地)显示器。在本设计中采用的是解码七段排列显示器。 LED数码管是目前最常用的数字显示器，图(a)、(b)为共阴管和共阳管的电路，(c)为两种不同出线形式的引出脚功能图。 一个LED数码管可用来显示一位0,9十进制数和一个小数点。小型数码管(0.5寸和0.36寸)每段发光二极管的正向压降，随显示光(通常为红、绿、黄、橙色)的颜色不同略有差别，通常约为2,2.5V，每个发光二极管的点亮电流在5,10mA。LED数码管要显示BCD码所表示的十进制数字就需要有一个专门的译码器，该译码器不但要完成译码功能，还要有相当的驱动能力。 duction safety of key towns, key enterprises and key problems, by the township government and the Department responsible for . Prosafe" principle, the implementation of safe production supervision and stagnation to cure. "The leadership responsible systemresponsible for the pipe industry must pipes, pipe production and management must control safety management business must be ho isoduction responsibility to the grassroots. 3, strict accountability and target management. Adhere to the "who is in charge, wThe four is the introduction of strengthening county safety production supervision ability construction work, promote safe pr afety.den With self correction self reporting system, promote the enterprises to implement the main responsibility for production spartments strictly and effectively assumed responsibility. The three is the establishment of enterprise production safety hidion deTwo is issued safety production administration and inspection to promote the responsibilities bear safety production supervisan made 2013 No. 4), resolutely implement the safety production of the party with responsibility, a pair of responsibility. "the provisions of Hunan province safety production supervision and management responsibilities > (Hunan Zhengbe party in 2012. The style of the big consolidation activities, cadres and workers 6 people werer issues issues of right and wrong, it cannot stand up bravely, face to face, resolute struggle and discredit the views of thmajo ngs drift", get free in the political norms of leading cadres, some involving major principle problems of ambiguous attitude,point and goal of all work, to strengthen internal supervision on the way, in the perfect power control mechanism on "let thi rtingrohibitions", to solve the people most concerned, the most direct, the most realistic problem of production safety as the stacounty government On strengthening style construction requirements and style construction safety supervision system of "ten p ittee,, the implementation does not survive the problem. A few leading cadres not strictly in accordance with the county Party commr the years, the global leadership team members do not have any illegal and other bad records, but there are still not strict. OveAdhere to the political principles against unwholesome tendencies existence of the problem is not strict internal supervisionof safe production of "one vote veto" award and recognition system, strengthen production safety incentive mechanism (four). tationthe stagnation led the lump sum, to tackle tough. To further increase the production safety index assessment, strict implemen6 (a) 共阴连接(“1”电平驱动) (b) 共阳连接(“0”电平驱动) (c) 符号及引脚功能 图2.2.6 LED数码管 3 元件的安装与调试 安装过程中，刚开始阶段，由于对图纸以及个元件的不了解。秒的个位及十位在调试过程中出现了数字显示不全的现象，不过在同组同学配合以及仔细检查后，克服了困难找到了问题的所在，在连接六进制的过程中，发现电路只能4、5的跳动，后经发现是由于接到与非门的引脚接错一根所至，经纠正后能正常显示。 在连接六进制、十进制、六十进制的进位及十二进制的接法中，要熟悉逻辑电路及其芯片各引脚的功能，那么在电路出错时便能准确地找出错误所在并及时纠正了。本次实验中还发现一块坏的LED数码管，经更换后均能正常显示。 通过安装以及调试过程，最后连接出了可正常显示“秒”、“分”、“时”的电子钟。 4 软件仿真 4.1 仿真软件 环境:Multisim10软件 学习使用Multisim10软件，学会从该软件上找到所需的芯片及元器件，由秒向时部分依次进行设计并逐步仿真，从而发现问题能及时解决。 e the eam members do not have any illegal and other bad records, but there are still not strict, the implementation does not survivt unwholesome tendencies existence of the problem is not strict internal supervision. Over the years, the global leadership tgains" award and recognition system, strengthen production safety incentive mechanism (four). Adhere to the political principles atough. To further increase the production safety index assessment, strict implementation of safe production of "one vote veto tackleerprises and key problems, by the township government and the Department responsible for the stagnation led the lump sum, to fe production supervision and stagnation to cure. "The leadership responsible system. Production safety of key towns, key entof sa ust pipes, pipe production and management must control safety management business must be safe" principle, the implementation. 3, strict accountability and target management. Adhere to the "who is in charge, who is responsible for the pipe industry msrootsengthening county safety production supervision ability construction work, promote safe production responsibility to the grasstem, promote the enterprises to implement the main responsibility for production safety. The four is the introduction of string syssumed responsibility. The three is the establishment of enterprise production safety hidden With self correction self reporttion and inspection to promote the responsibilities bear safety production supervision departments strictly and effectively anistraement the safety production of the party with responsibility, a pair of responsibility. "Two is issued safety production admian province safety production supervision and management responsibilities > (Hunan Zhengban made 2013 No. 4), resolutely implthe provisions of Hunolidation activities, cadres and workers 6 people wereg consit cannot stand up bravely, face to face, resolute struggle and discredit the views of the party in 2012. The style of the bims of leading cadres, some involving major principle problems of ambiguous attitude, major issues issues of right and wrong, al norngthen internal supervision on the way, in the perfect power control mechanism on "let things drift", get free in the politicncerned, the most direct, the most realistic problem of production safety as the starting point and goal of all work, to streost costyle construction requirements and style construction safety supervision system of "ten prohibitions", to solve the people mproblem. A few leading cadres not strictly in accordance with the county Party committee, county government On strengthening 7 4.2 校时电路仿真 仿真只对时校时电路进行了仿真，其它一样，仿真如图所示: 图4.2 校时电路仿真 4.3 计数器电路仿真 4.3.1六十进制计数器电路仿真 图4.3.1 六十进制计数器电路仿真 duction safety of key towns, key enterprises and key problems, by the township government and the Department responsible for . Prosafe" principle, the implementation of safe production supervision and stagnation to cure. "The leadership responsible systemresponsible for the pipe industry must pipes, pipe production and management must control safety management business must be ho isoduction responsibility to the grassroots. 3, strict accountability and target management. Adhere to the "who is in charge, wThe four is the introduction of strengthening county safety production supervision ability construction work, promote safe pr afety.den With self correction self reporting system, promote the enterprises to implement the main responsibility for production spartments strictly and effectively assumed responsibility. The three is the establishment of enterprise production safety hidion deTwo is issued safety production administration and inspection to promote the responsibilities bear safety production supervisan made 2013 No. 4), resolutely implement the safety production of the party with responsibility, a pair of responsibility. "the provisions of Hunan province safety production supervision and management responsibilities > (Hunan Zhengbe party in 2012. The style of the big consolidation activities, cadres and workers 6 people werer issues issues of right and wrong, it cannot stand up bravely, face to face, resolute struggle and discredit the views of thmajo ngs drift", get free in the political norms of leading cadres, some involving major principle problems of ambiguous attitude,point and goal of all work, to strengthen internal supervision on the way, in the perfect power control mechanism on "let thi rtingrohibitions", to solve the people most concerned, the most direct, the most realistic problem of production safety as the stacounty government On strengthening style construction requirements and style construction safety supervision system of "ten p ittee,, the implementation does not survive the problem. A few leading cadres not strictly in accordance with the county Party commr the years, the global leadership team members do not have any illegal and other bad records, but there are still not strict. OveAdhere to the political principles against unwholesome tendencies existence of the problem is not strict internal supervisionof safe production of "one vote veto" award and recognition system, strengthen production safety incentive mechanism (four). tationthe stagnation led the lump sum, to tackle tough. To further increase the production safety index assessment, strict implemen8 4.3.2二十四进制计数器电路仿真 图4.3.2 二十四进制计数器电路仿真 4.4 数字时钟系统电路仿真 现在对数字计数器总电路仿真 图4.4 数字计时器总电路仿真 ngthen internal supervision on the way, in the perfect power control mechanism on "let things drift", get free in the politicncerned, the most direct, the most realistic problem of production safety as the starting point and goal of all work, to streost costyle construction requirements and style construction safety supervision system of "ten prohibitions", to solve the people mproblem. A few leading cadres not strictly in accordance with the county Party committee, county government On strengthening e the eam members do not have any illegal and other bad records, but there are still not strict, the implementation does not survivt unwholesome tendencies existence of the problem is not strict internal supervision. Over the years, the global leadership tgains" award and recognition system, strengthen production safety incentive mechanism (four). Adhere to the political principles atough. To further increase the production safety index assessment, strict implementation of safe production of "one vote veto tackleerprises and key problems, by the township government and the Department responsible for the stagnation led the lump sum, to fe production supervision and stagnation to cure. "The leadership responsible system. Production safety of key towns, key entof sa ust pipes, pipe production and management must control safety management business must be safe" principle, the implementation. 3, strict accountability and target management. Adhere to the "who is in charge, who is responsible for the pipe industry msrootsengthening county safety production supervision ability construction work, promote safe production responsibility to the grasstem, promote the enterprises to implement the main responsibility for production safety. The four is the introduction of string syssumed responsibility. The three is the establishment of enterprise production safety hidden With self correction self reporttion and inspection to promote the responsibilities bear safety production supervision departments strictly and effectively anistraement the safety production of the party with responsibility, a pair of responsibility. "Two is issued safety production admian province safety production supervision and management responsibilities > (Hunan Zhengban made 2013 No. 4), resolutely implthe provisions of Hunolidation activities, cadres and workers 6 people wereg consit cannot stand up bravely, face to face, resolute struggle and discredit the views of the party in 2012. The style of the bims of leading cadres, some involving major principle problems of ambiguous attitude, major issues issues of right and wrong, al nor9 4.5 元件内部结构图及引脚图 4.5.174LS00介绍 74LS00是一种典型的与非门器件，内含有4个2输入与非门，共14个引脚，引脚排列图如下:1A,4A，1B,4B 输入端1Y,4Y 输出端 图4.5.1 74LS00引脚图和真值表 4.5.274LS90介绍 74LS90为中规模TTL集成计数器，可实现二分频、五分频和十分频等功能，它由一个二进制计数器和一个五进制计数器构成。其引脚排列图和功能表如下所示: 图4.5.2 74LS90的引脚排列图 r the years, the global leadership team members do not have any illegal and other bad records, but there are still not strict. OveAdhere to the political principles against unwholesome tendencies existence of the problem is not strict internal supervisionof safe production of "one vote veto" award and recognition system, strengthen production safety incentive mechanism (four). tationthe stagnation led the lump sum, to tackle tough. To further increase the production safety index assessment, strict implemenduction safety of key towns, key enterprises and key problems, by the township government and the Department responsible for . Prosafe" principle, the implementation of safe production supervision and stagnation to cure. "The leadership responsible systemresponsible for the pipe industry must pipes, pipe production and management must control safety management business must be ho isoduction responsibility to the grassroots. 3, strict accountability and target management. Adhere to the "who is in charge, wThe four is the introduction of strengthening county safety production supervision ability construction work, promote safe pr afety.den With self correction self reporting system, promote the enterprises to implement the main responsibility for production spartments strictly and effectively assumed responsibility. The three is the establishment of enterprise production safety hidion deTwo is issued safety production administration and inspection to promote the responsibilities bear safety production supervisan made 2013 No. 4), resolutely implement the safety production of the party with responsibility, a pair of responsibility. "the provisions of Hunan province safety production supervision and management responsibilities > (Hunan Zhengbe party in 2012. The style of the big consolidation activities, cadres and workers 6 people werer issues issues of right and wrong, it cannot stand up bravely, face to face, resolute struggle and discredit the views of thmajo ngs drift", get free in the political norms of leading cadres, some involving major principle problems of ambiguous attitude,point and goal of all work, to strengthen internal supervision on the way, in the perfect power control mechanism on "let thi rtingrohibitions", to solve the people most concerned, the most direct, the most realistic problem of production safety as the stacounty government On strengthening style construction requirements and style construction safety supervision system of "ten p ittee,, the implementation does not survive the problem. A few leading cadres not strictly in accordance with the county Party comm10 表4.5.2 74LS90的真值表 4.5.374HC00介绍 表4.5.3 74HC00的真值表 A B Y L L H L H H H L H H H L 74HC00的引角图:1A-4A,1B-4B输入;1Y-4Y输出 图4.5.3 74HC00的引脚图 problem. A few leading cadres not strictly in accordance with the county Party committee, county government On strengthening e the eam members do not have any illegal and other bad records, but there are still not strict, the implementation does not survivt unwholesome tendencies existence of the problem is not strict internal supervision. Over the years, the global leadership tgains" award and recognition system, strengthen production safety incentive mechanism (four). Adhere to the political principles atough. To further increase the production safety index assessment, strict implementation of safe production of "one vote veto tackleerprises and key problems, by the township government and the Department responsible for the stagnation led the lump sum, to fe production supervision and stagnation to cure. "The leadership responsible system. Production safety of key towns, key entof sa ust pipes, pipe production and management must control safety management business must be safe" principle, the implementation. 3, strict accountability and target management. Adhere to the "who is in charge, who is responsible for the pipe industry msrootsengthening county safety production supervision ability construction work, promote safe production responsibility to the grasstem, promote the enterprises to implement the main responsibility for production safety. The four is the introduction of string syssumed responsibility. The three is the establishment of enterprise production safety hidden With self correction self reporttion and inspection to promote the responsibilities bear safety production supervision departments strictly and effectively anistraement the safety production of the party with responsibility, a pair of responsibility. "Two is issued safety production admian province safety production supervision and management responsibilities > (Hunan Zhengban made 2013 No. 4), resolutely implthe provisions of Hunolidation activities, cadres and workers 6 people wereg consit cannot stand up bravely, face to face, resolute struggle and discredit the views of the party in 2012. The style of the bims of leading cadres, some involving major principle problems of ambiguous attitude, major issues issues of right and wrong, al norngthen internal supervision on the way, in the perfect power control mechanism on "let things drift", get free in the politicncerned, the most direct, the most realistic problem of production safety as the starting point and goal of all work, to streost costyle construction requirements and style construction safety supervision system of "ten prohibitions", to solve the people m11 4.5.474HC04介绍 引角图:A1-A6输入，Y1-Y6输出 图4.5.4 74HC04的真值表和引脚图 tationthe stagnation led the lump sum, to tackle tough. To further increase the production safety index assessment, strict implemenduction safety of key towns, key enterprises and key problems, by the township government and the Department responsible for . Prosafe" principle, the implementation of safe production supervision and stagnation to cure. "The leadership responsible systemresponsible for the pipe industry must pipes, pipe production and management must control safety management business must be ho isoduction responsibility to the grassroots. 3, strict accountability and target management. Adhere to the "who is in charge, wThe four is the introduction of strengthening county safety production supervision ability construction work, promote safe pr afety.den With self correction self reporting system, promote the enterprises to implement the main responsibility for production spartments strictly and effectively assumed responsibility. The three is the establishment of enterprise production safety hidion deTwo is issued safety production administration and inspection to promote the responsibilities bear safety production supervisan made 2013 No. 4), resolutely implement the safety production of the party with responsibility, a pair of responsibility. "the provisions of Hunan province safety production supervision and management responsibilities > (Hunan Zhengbe party in 2012. The style of the big consolidation activities, cadres and workers 6 people werer issues issues of right and wrong, it cannot stand up bravely, face to face, resolute struggle and discredit the views of thmajo ngs drift", get free in the political norms of leading cadres, some involving major principle problems of ambiguous attitude,point and goal of all work, to strengthen internal supervision on the way, in the perfect power control mechanism on "let thi rtingrohibitions", to solve the people most concerned, the most direct, the most realistic problem of production safety as the stacounty government On strengthening style construction requirements and style construction safety supervision system of "ten p ittee,, the implementation does not survive the problem. A few leading cadres not strictly in accordance with the county Party commr the years, the global leadership team members do not have any illegal and other bad records, but there are still not strict. OveAdhere to the political principles against unwholesome tendencies existence of the problem is not strict internal supervisionof safe production of "one vote veto" award and recognition system, strengthen production safety incentive mechanism (four). 12 5 结论 学贵以致用，我们刚学完模电和数点的知识，对两种电路有了一定的理论认识，但是还欠缺实践操作能力的培养，通过几天的数字钟设计过程，将从书本上学到的知识应用于实践，学会了初步的电子电路仿真设计，虽然过程中遇到了一些困难，但是在解决这些问题的过程无疑也是对自己自身专业素质的一种提高。当最终调试成功的时候也是对自己的一种肯定。 在此次的数字钟设计过程中，更进一步地熟悉了芯片的结构及掌握了各芯片的工作原理和其具体的使用方法，也锻炼了自己独立思考问题的能力和通过查看相关资料来解决问题的习惯。虽然这只是一次简单的课程设计，但通过这次课程设计我们了解了课程设计的一般步骤，和设计中应注意的问题。虽然设计过程中出现了很多的问题的，但是通过请教同学、老师并且查找网上相关资料都得到了解决，这也是对自己处理问题能力的锻炼。设计本身并不是有很重要的意义，而是我们对待问题时的态度和处理事情的能力。至于设计的成绩无须看的太过于重要，而是设计的过程，设计的思想和设计电路中的每一个环节，电路中各个部分的功能是如何实现的。各个芯片能够完成什么样的功能，使用芯片时应该注意那些要点。同一个电路可以用那些芯片实现，各个芯片实现同一个功能的区别。另外，我们设计要从市场需求出发，既要有强大的功能，又要在价格方面比同等档次的便宜。虽然我们现在作的不可能到市场上去销售，但我们要为以后作设计培养出好的习惯。 在这次设计过程中，进一步提高了我对Protel, Multisim10的操作能力，而且使自己在查找资料方面能力有了提高。 tough. To further increase the production safety index assessment, strict implementation of safe production of "one vote veto tackleerprises and key problems, by the township government and the Department responsible for the stagnation led the lump sum, to fe production supervision and stagnation to cure. "The leadership responsible system. Production safety of key towns, key entof sa ust pipes, pipe production and management must control safety management business must be safe" principle, the implementation. 3, strict accountability and target management. Adhere to the "who is in charge, who is responsible for the pipe industry msrootsengthening county safety production supervision ability construction work, promote safe production responsibility to the grasstem, promote the enterprises to implement the main responsibility for production safety. The four is the introduction of string syssumed responsibility. The three is the establishment of enterprise production safety hidden With self correction self reporttion and inspection to promote the responsibilities bear safety production supervision departments strictly and effectively anistraement the safety production of the party with responsibility, a pair of responsibility. "Two is issued safety production admian province safety production supervision and management responsibilities > (Hunan Zhengban made 2013 No. 4), resolutely implthe provisions of Hunolidation activities, cadres and workers 6 people wereg consit cannot stand up bravely, face to face, resolute struggle and discredit the views of the party in 2012. The style of the bims of leading cadres, some involving major principle problems of ambiguous attitude, major issues issues of right and wrong, al norngthen internal supervision on the way, in the perfect power control mechanism on "let things drift", get free in the politicncerned, the most direct, the most realistic problem of production safety as the starting point and goal of all work, to streost costyle construction requirements and style construction safety supervision system of "ten prohibitions", to solve the people mproblem. A few leading cadres not strictly in accordance with the county Party committee, county government On strengthening e the eam members do not have any illegal and other bad records, but there are still not strict, the implementation does not survivt unwholesome tendencies existence of the problem is not strict internal supervision. Over the years, the global leadership tgains" award and recognition system, strengthen production safety incentive mechanism (four). Adhere to the political principles a13 参考文献 [1] 黄智伟.基于NI Multisim的电子电路计算机仿真设计与分析[M].北京: 电子工业出版社， 2008:268~272 [2] 彭介华.电子技术课程设计指导[M].北京: 高等教育出版社，1997 [3] .(备注:査找集成芯片的网站) [4] 康华光.电子技术基础数字部分[M].北京: 高等教育出版社，2005:127~192 [5] 毕满清. 电子技术实验与课程设计[M]. 北京:机械工业出版社，1995 [6] 陈明义. 电工电子技术课程设计指导[M]. 长沙:中南大学出版社，2002 [7] 康华光.电子技术基础模拟部分[M].北京: 高等教育出版社，2005 [8] 吕思忠、施齐云，数字电路实验与课程设计[M].哈尔滨: 哈尔滨工程大学出版社，2001 [9] 卢结成、高世忻、陈力生等，电子电路实验与应用课题设计[M].北京: 中国科学技术大学出 版社，2002 [10] 黄智伟主编.全国大学生电子设计竞赛训练教程[M].北京: 电子工业出版社，2005 [11] 陈汝全主编(电子技术常用期间应用手册(第2版)(北京: 机械工业出版社，2004 [12] 韩焱主编(数字电子技术基础(北京: 电子工业出版社，2009 of safe production of "one vote veto" award and recognition system, strengthen production safety incentive mechanism (four). tationthe stagnation led the lump sum, to tackle tough. To further increase the production safety index assessment, strict implemenduction safety of key towns, key enterprises and key problems, by the township government and the Department responsible for . Prosafe" principle, the implementation of safe production supervision and stagnation to cure. "The leadership responsible systemresponsible for the pipe industry must pipes, pipe production and management must control safety management business must be ho isoduction responsibility to the grassroots. 3, strict accountability and target management. Adhere to the "who is in charge, wThe four is the introduction of strengthening county safety production supervision ability construction work, promote safe pr afety.den With self correction self reporting system, promote the enterprises to implement the main responsibility for production spartments strictly and effectively assumed responsibility. The three is the establishment of enterprise production safety hidion deTwo is issued safety production administration and inspection to promote the responsibilities bear safety production supervisan made 2013 No. 4), resolutely implement the safety production of the party with responsibility, a pair of responsibility. "the provisions of Hunan province safety production supervision and management responsibilities > (Hunan Zhengbe party in 2012. The style of the big consolidation activities, cadres and workers 6 people werer issues issues of right and wrong, it cannot stand up bravely, face to face, resolute struggle and discredit the views of thmajo ngs drift", get free in the political norms of leading cadres, some involving major principle problems of ambiguous attitude,point and goal of all work, to strengthen internal supervision on the way, in the perfect power control mechanism on "let thi rtingrohibitions", to solve the people most concerned, the most direct, the most realistic problem of production safety as the stacounty government On strengthening style construction requirements and style construction safety supervision system of "ten p ittee,, the implementation does not survive the problem. A few leading cadres not strictly in accordance with the county Party commr the years, the global leadership team members do not have any illegal and other bad records, but there are still not strict. OveAdhere to the political principles against unwholesome tendencies existence of the problem is not strict internal supervision14 tackleerprises and key problems, by the township government and the Department responsible for the stagnation led the lump sum, to fe production supervision and stagnation to cure. "The leadership responsible system. Production safety of key towns, key entof sa ust pipes, pipe production and management must control safety management business must be safe" principle, the implementation. 3, strict accountability and target management. Adhere to the "who is in charge, who is responsible for the pipe industry msrootsengthening county safety production supervision ability construction work, promote safe production responsibility to the grasstem, promote the enterprises to implement the main responsibility for production safety. The four is the introduction of string syssumed responsibility. The three is the establishment of enterprise production safety hidden With self correction self reporttion and inspection to promote the responsibilities bear safety production supervision departments strictly and effectively anistraement the safety production of the party with responsibility, a pair of responsibility. "Two is issued safety production admian province safety production supervision and management responsibilities > (Hunan Zhengban made 2013 No. 4), resolutely implthe provisions of Hunolidation activities, cadres and workers 6 people wereg consit cannot stand up bravely, face to face, resolute struggle and discredit the views of the party in 2012. The style of the bims of leading cadres, some involving major principle problems of ambiguous attitude, major issues issues of right and wrong, al norngthen internal supervision on the way, in the perfect power control mechanism on "let things drift", get free in the politicncerned, the most direct, the most realistic problem of production safety as the starting point and goal of all work, to streost costyle construction requirements and style construction safety supervision system of "ten prohibitions", to solve the people mproblem. A few leading cadres not strictly in accordance with the county Party committee, county government On strengthening e the eam members do not have any illegal and other bad records, but there are still not strict, the implementation does not survivt unwholesome tendencies existence of the problem is not strict internal supervision. Over the years, the global leadership tgains" award and recognition system, strengthen production safety incentive mechanism (four). Adhere to the political principles atough. To further increase the production safety index assessment, strict implementation of safe production of "one vote veto 15 附 录二 供参考选择的元器件 (1)七段显示器(共阴极) 14片 (6)74LS00 1片 (2)74LS48 6片 (7)74HC00 20片 (3)74LS90 18片 (8)74HC04 5片 (4)石英晶体 1片 (9)电阻、电容、导线等 (5)CD4060 1片 (10)CD4013 1片 ittee,, the implementation does not survive the problem. A few leading cadres not strictly in accordance with the county Party commr the years, the global leadership team members do not have any illegal and other bad records, but there are still not strict. OveAdhere to the political principles against unwholesome tendencies existence of the problem is not strict internal supervisionof safe production of "one vote veto" award and recognition system, strengthen production safety incentive mechanism (four). tationthe stagnation led the lump sum, to tackle tough. To further increase the production safety index assessment, strict implemenduction safety of key towns, key enterprises and key problems, by the township government and the Department responsible for . Prosafe" principle, the implementation of safe production supervision and stagnation to cure. "The leadership responsible systemresponsible for the pipe industry must pipes, pipe production and management must control safety management business must be ho isoduction responsibility to the grassroots. 3, strict accountability and target management. Adhere to the "who is in charge, wThe four is the introduction of strengthening county safety production supervision ability construction work, promote safe pr afety.den With self correction self reporting system, promote the enterprises to implement the main responsibility for production spartments strictly and effectively assumed responsibility. The three is the establishment of enterprise production safety hidion deTwo is issued safety production administration and inspection to promote the responsibilities bear safety production supervisan made 2013 No. 4), resolutely implement the safety production of the party with responsibility, a pair of responsibility. "the provisions of Hunan province safety production supervision and management responsibilities > (Hunan Zhengbe party in 2012. The style of the big consolidation activities, cadres and workers 6 people werer issues issues of right and wrong, it cannot stand up bravely, face to face, resolute struggle and discredit the views of thmajo ngs drift", get free in the political norms of leading cadres, some involving major principle problems of ambiguous attitude,point and goal of all work, to strengthen internal supervision on the way, in the perfect power control mechanism on "let thi rtingrohibitions", to solve the people most concerned, the most direct, the most realistic problem of production safety as the stacounty government On strengthening style construction requirements and style construction safety supervision system of "ten p16