数字电子技术讲义实验一.doc

专业好文档实验一、门电路的功能测试一、实验目的1. 学会对门电路逻辑功能进行测试。2. 掌握门电路闲置输入端的处理。3. 掌握门电路的灵活运用二、实验仪器设备和器件1. 实验仪器1) dlc1数字电子技术实验箱2) 万用表 示波器2. 实验器件74ls0074ls0274ls8674ls20 三、实验原理1常用逻辑门电路有与、或、非、与非、或非、与或非和异或门电路，它们所完成的逻辑功能分别为：、。2逻辑门电路分为ttl电路和cmos电路两大类示（请查阅相关资料）。3闲置输入端一般不能悬空，闲置输入端视逻辑功能可采取接地、接电源、或与信号输入端并联使用等方法进行处理。（1）对于与非门（与门）多余的输入端：应接高电平，依据是a1=a；或与有用的输入端相连（依据是aa=a）,绝对不能接低电平。（2）对于或非门（或门）多余的输入端：应接低电平，依据是a+0=a； 或与有用的输入端相连（依据是a+a=a）绝对不能接高电平。 4门电路逻辑功能的测试方法 （1）对集成电路供电 （2）按真值表给输入端输入信号，观察和测量输出端逻辑值 （3）与理论值比较是否一致。四、实验内容及步骤（一）门电路逻辑功能的测试（20分）1测试与非门的逻辑功能（74ls00）74ls00是二输入四ttl与非门，其管脚排列如下图74ls00引脚排列选用第一个与非门，按下图接线，测试与非门的逻辑功能并填入测试表格。测试表格一输入端(逻辑值)输 出 端a b 理论逻辑值y实测电位(v)实测逻辑值y0 0 0 1 1 0 1 1 比较上表中理论逻辑值y和实际逻辑值y是否相同，结果说明了什么问题？2测试74ls02的逻辑功能74ls02是二输入四ttl或非门，其管脚排列如下图74ls02引脚排列仿照测试表格一画出74ls02的测试表格并测试（预习时画出测试表格）（二）闲置输入端的处理（30分）与非门闲置输入端处理 74ls20是四输入端二与非门，管脚排列如下图 74ls20引脚排列 选用其中的一个与非门，完成的逻辑功能。（预习时说明闲置输入端如何处理？依据是什么？） 测试逻辑功能,填入下表。输入端(逻辑状态)输 出 端a b c d理论逻辑值y实测电位(v)逻辑状态y0 0 0 0 0 1 0 1 0 0 1 1 1 0 01 0 11 1 01 1 1 根据上述真值表写出逻辑函数式，从而验证该电路是否完成要求的逻辑功能。（三）观察门电路对脉冲信号的控制作用（30分） 设计一个用与非门（74ls00）来控制输出信号的无触发点开关，将与非门的输入端a接入1khz的连续方波脉冲信号，另一输入端b接数据开关，电路如下图。当输入端b分别为“0”和“1”两种情况下，（预习时用multisim仿真，并画出z端的输出波形），实验时用示波器同时观察输入和输出波形，并对控制结果加以说明。 （四）基本设计（30分）1用74ls86构成一个非门（完成的逻辑功能），（预习时说明理论依据），实验时验证。2用现有的门电路构成一个与门，（预习时说明理论依据并画出电路），实验时验证。3轿车有四个门，只有当四个门全部关好后，发动机才可以点火。当门关上时逻辑值为1，否则为0；发动机能点火逻辑值为1，否则为0。（预习时画出电路），实验时验证。五、注意事项1. 实验时要正确选择集成电路的型号，芯片的位置别插错。2. 接线时输出端不能直接接电源或地。3. 实验时注意电源管脚和极性，不能将芯片的电源端接反。4. ttl电路的电源电压为5v10%。千万不能接成12v。六、预习要求按讲义中加粗字体要求作好预习七、报告要求1.整理实验数据，填写实验表格，并分析结果。2.回答思考题中提出的问题八、思考题1.与非门什么情况下输出高电平?什么情况下输出低电平，与非门中不用的输入端应如何处理?2.与或非门在什么情况下输出高电平?什么情况下输出低电平?与或非门中不用的输入端应如何处理?其它门电路资料74ls86是四ttl异或门，其管脚排列如下图74ls51是二路32输入与或非门，其引脚排列如下图winger tuivasa-sheck, who scored two tries in the kiwis 20-18 semi-final win over england, has been passed fit after a lower-leg injury, while slater has been named at full-back but is still recovering from a knee injury aggravated against usa.both sides boast 100% records heading into the encounter but australia have not conceded a try since josh charnleys effort in their first pool match against england on the opening day.aussie winger jarryd hayne is the competitions top try scorer with nine, closely followed by tuivasa-sheck with eight.but it is recently named rugby league international federation player of the year sonny bill williams who has attracted the most interest in the tournament so far.the kiwi - with a tournament high 17 offloads - has the chance of becoming the first player to win the world cup in both rugby league and rugby union after triumphing with the all blacks in 2011.id give every award back in a heartbeat just to get across the line this weekend, said williams.the (lack of) air up there watch mcayman islands-based webb, the head of fifas anti-racism taskforce, is in london for the football associations 150th anniversary celebrations and will attend citys premier league match at chelsea on sunday.i am going to be at the match tomorrow and i have asked to meet yaya toure, he told bbc sport.for me its about how he felt and i would like to speak to him first to find out what his experience was.uefa hasopened disciplinary proceedings against cskafor the racist behaviour of their fans duringcitys 2-1 win.michel platini, president of european footballs governing body, has also ordered an immediate investigation into the referees actions.cska said they were surprised and disappointed by toures complaint. in a statement the russian side added: we found no racist insults from fans of cska. baumgartner the disappointing news: mission aborted.the supersonic descent could happen as early as sunda.the weather plays an important role in this mission. starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. the balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. it will climb higher than the tip of mount everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. as he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.the balloon will slowly drift to the edge of space at 120,000 feet ( then, i would assume, he will slowly step out onto something resembling an olympic diving platform.they blew it in 2008 when they got caught cold in the final and they will not make the same mistake against the kiwis in manchester.five years ago they cruised through to the final and so far history has repeated itself here - the last try they conceded was scored by englands josh charnley in the opening game of the tournament.that could be classed as a weakness, a team under-cooked - but i have been impressed by the kangaroos focus in their games since then.they have been concentrating on the sort of stuff that wins you tough, even contests - strong defence, especially on their own goal-line, completing sets and a good kick-chase. theyve been great at all the unglamorous stuff that often goes unnoticed in the stands but not by your team-mates.it is as though their entire tournament has been preparation for the final.in johnathan thurston, cooper cronk, cameron smith and either billy slater or greg inglis at full-back they have a spine that is unmatched in rugby league. they have played in so many high-pressure games - a priceless asset going into saturday.the kiwis are a lot less experienced but winning a dramatic match like their semi-final against england will do wonders for their confidence.they defeated australia in the four nations final in 2010 and the last world cup, and know they can rise to the big occasion.winger tuivasa-sheck, who scored two tries in the kiwis 20-18 semi-final win over england, has been passed fit after a lower-leg injury, while slater has been named at full-back but is still recovering from a knee injury aggravated against usa.both sides boast 100% records heading into the encounter but australia have not conceded a try since josh charnleys effort in their first pool match against england on the opening day.aussie winger jarryd hayne is the competitions top try scorer with nine, closely followed by tuivasa-sheck with eight.but it is recently named rugby league international federation player of the year sonny bill williams who has attracted the most interest in the tournament so far.the kiwi - with a tournament high 17 offloads - has the chance of becoming the first player to win the world cup in both rugby league and rugby union after triumphing with the all blacks in 2011.id give every award back in a heartbeat just to get across the line this weekend, said williams.the (lack of) air up there watch mcayman islands-based webb, the head of fifas anti-racism taskforce, is in london for the football associations 150th anniversary celebrations and will attend citys premier league match at chelsea on sunday.i am going to be at the match tomorrow and i have asked to meet yaya toure, he told bbc sport.for me its about how he felt and i would like to speak to him first to find out what his experience was.uefa hasopened disciplinary proceedings against cskafor the racist behaviour of their fans duringcitys 2-1 win.michel platini, president of european footballs governing body, has also ordered an immediate investigation into the referees actions.cska said they were surprised and disappointed by toures complaint. in a statement the russian side added: we found no racist insults from fans of cska. baumgartner the disappointing news: mission aborted.the supersonic descent could happen as early as sunda.the weather plays an important role in this mission. starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. the balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. it will climb higher than the tip of mount everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. as he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.the balloon will slowly drift to the edge of space at 120,000 feet ( then, i would assume, he will slowly step out onto something resembling an olympic diving platform.they blew it in 2008 when they got caught cold in the final and they will not make the same mistake against the kiwis in manchester.five years ago they cruised through to the final and so far history has repeated itself here - the last try they conceded was scored by englands josh charnley in the opening game of the tournament.that could be classed as a