数字电路课程设计实例---24秒计时器

1、ocusing on w aysand meansofimpr oving a nd upgra dingw ork,further devel opme nt of"threet osplit".（A） fully gras p"no unauthorise d"create d.Thetow nship"nounauthorised"create d theexisting building"one house hol d, onedocument"survey andfilestorageworkm ust

2、be unconditi onal and full coverag e.Mai n corridorleadingto t hetown（roa d, river）village,the Centralbuilt-upare a ofthetown on bot hsides mustbet ocreate a "no unauthorise d village".Accordingto"five hundredvillages"created a nd shantytowns,village s,ol d houses,re construction

3、ofold plant, ex pand create, upgra ding createsfiles,the rea l "no una uthorise d village" created int othe be nefitofthe peopleofverygoodt hing.（B）tostri ctlymanage count as una uth orise dcontr ols. Promoti ng the"new" controlworktom ovethe cent er ofgravity,management measures

4、tot hefront,and earnestlypipeseffectively.Astrict newuna uthori sed netw orkresponsibil ity.Sect orssuchasla nd, housi ng andba sicst ations（stations）and theTownshi pofgridaccountabilityme chanisms must bestrictlyi n accor dancewit hthe new regulat ory requirements,effective implementation ofthearea

5、 ofresponsibility ofthenewinspecti ons,suppressi on,dem olitionworkt o e nsur ethatthe new"zerot olera nce".Se cond,publi c se curity,w ater, ele ctricity,w ater,oceans andfisheries,t ourism colla borati on,marketsupervisi on departments shoul dstrictly enfor ce the illegal construction of

6、disposal of relevant provisions ofthereg ulations,effectivef ulfilment ofre sponsi bilities,particularly inele ctricitya nd water supply,and other units may not bene willegalbuildi ngs t osupplywaterand el ectricitysupply.Whilemoreregulati ont o preve nt personal privacy vi olations. Illicit trading

7、 inillegal construction in theMinistry ofpublicse curitysectort ostri ctlyfrom the blow.Thr ee ist ocre ateadditionaloffencereporti ngsystem of incentive s.Accordingt o buildi ng law andcovers a n area ofnatur e,to re port timelydegree divided re portgra de,effective afterthe rem ovalofcertain i nce

8、ntives.（C）integrated impleme ntation", buildingdemolition,modification,use"com binati on. Demolition isthemeans andpur posebuiltis.To adhereto thebuilding demoli she d, combinationof construction and demolition waste, demolished withcombi nedeffortsto improv ethe scientifi clevelofthree to

9、 split ;second,wem ustpayattentiont o"threeto split"and "fivehundred"and"fivewatertreatment","threeofthefoursi des",t heshackDistricttransformation,and dangerous oldroom transformationand "tworoadsides",serie swork organi ccombined up,activ edo River

10、,a ndal ongdemolition w ork,and manpoweradvance village in the,a nd oldre side ntialdemolitionwork,to improv ed masseshousing conditions andlivee nvironment;three to put "three modifieda split" astraditional low,andsmall,andbulkindustrystructuretransformationupgrade of importantinitiatives

11、 to caug ht,spe edup adv ance industryPark, effective optimizationpark environment1 计数器概述1.1 篮球竞赛24秒计时器功能数字电子技术在社会生活中发挥着越来越重要的作用，在生活中有着各种各样的应用。因此课程设计是数字电子技术学习中非常重要的一个环节，它将学生的理论知识和实践能力统一起来，为以后的工作做好准备。在篮球比赛中，规定了球员的持球时间不能超过24 秒，否则就犯规了。本课程设计的“篮球竞赛 24秒计时器”可用于篮球比赛中，用于对球员持球时间 24秒限制。一旦球员的持球时间超过了24 秒，它就自动报警从

12、而判定此球员的犯规。本课程设计是脉冲数字电路的简单应用，设计了篮球竞赛24 秒计时器。此计时器功能齐全，有显示24 秒倒计时的功能，同时系统设置外部操作开关，控制计时器的直接清零、启动、暂停、连续功能。而在直接清零时，数码管显示器灭灯，计时器为24秒递减计时其计时间间隔为1 秒，计时器递减计时到零时，数码管显示器不灭灯，同时发出光电报警信号。1.2 设计任务及要求1.2.1 基本要求（ 1）显示 24 秒计时功能。（ 2）设置外部操作开关控制计时器直接清零、启动、暂停/ 连续功能。（ 3）在直接清零时，要求数码显示器灭灯。（ 4）计时器为24秒递减计时器，其计时间隔为1秒。（ 5）递减计时到零

13、时，显示器不能灭灯，同时发出光电报警信号。（ 6）秒脉冲由555 多谐振荡器给出。1.2.2 设计任务及目标（1）根据原理图分析各单元电路的功能；（2）熟悉电路中所用到的各集成块的管脚及其功能；nd impr oveidl e land of utilization,realachieved environment improvedand pr oductivitydevelopmentmutualpr omoting t otalwin.Five,firmly implement, promotingworkahead,t o creat e highlig hts.T hirddeploy

14、ment,im plementati on ofseven,then it is imperativetostrengt hen responsibility nd im prove themechanismsand impleme ntation.All localities and departme ntsmustbeconvi nced that goals,g oing all out, mustering spirit,w orktoget hertoe nsur ethatthi syear's obje ctives carryout tasks, atthe foref

15、ront. Fir st,we must strength enthe leadership to impleme nt.Departmentsatalllevelsshouldalw ays work and rural "five watertreatment","threetosplit"inan importantposition,a nd carrythe mai n responsibility, mai n leaderper sonally, lea dersarrested a nd layersof responsibi lity r

16、anktransmissi on pressure esta blished hierarchi calaccountability, and w ork togetherto promote thework ofthemechani sm,aco ncerted effort pay attentionto impl ementation.Countynongban,flood,t hreeto onedow ntofurt herplay aleading catchtotal, integrate d andcoordinat ed r oleofallki nds is "l

17、 ong","Sheriff""Inspe ctor"to effectivelyfulfilltheir responsibiliti es,forme dthe alignme ntonthe fire line a nd ma nagement a livelysit uation.Se cond,we muststrengthen t hetestim plementati on ofthe Governor.Role playt heGovernorgott hebaton,for agriculturaland ruralfocus

18、 and"fivewatertreatment", "threetosplit" w ork,refineim prove assessment methodsa nd evaluation system,a ccur ateassessment. Combinedwith "dar e play,tree benchmark"stylebuilding fivemajor operations,carry on andgainfirstha nd ex perienceofsupervisi on,in particular, to

19、 strengthent hefocus on the"l ong"sig ns"go left","names"suchas supervision,urge d alllevel s longer on duty i n pla ce.Throughthe supervisoryassessment,topromote habits,stimulating power.T hird,we must str engthe nimplementation style.Departments at alllevels to workin

20、r uralarea s and "five watertreatment", "three tosplit" astrai ning cadr esformajorplatforms,compete against large examinati on r oom,inspection ca dresw ork performa nceofthe ring,watercontrol andtheJapa nese pulle da work out,trai ning, discovery and se lecti on of cadres.Than

21、goodcatch up,firsttoex celle nce-ori ente d.Party membersand cadresatalllevel s musta dhere t o therural ,water control andtheJapa nese pulle da grass -roots, "putdown theshelf,lea ne d" pragmatic style, thespirit of play,become a benchmarkmodel.Four, we m uststre ngthen propagandaimplemen

22、tation.Compre hensiveutili zationofmicro-credit, micr o-blogging, new media, mining, summarizing,goodpublicitywork inthe countrysideand "fivewatertreatment", "three to split"advance d model s,pointtogather positiveenergy forthecommunitytoseethe results ofourwork intime,incr ease

23、public awar eness,parti cipati on rate s,satisfa ctionand support.Play gongqingfu,a massorganization and grass-roots such asschools,communityTherole ofo g on W ays and means of impr . uga digwok l Iospli" A) u- gras'o d" le d. The low nship "o una.to_e suvey a. fie stag be ucndt o

24、n - and ul cveag e "i n co"，ver 、*"" nta buitup a musbet ocreae a de".Accdig t"ve lund.d vil" - ce -da nd santy twns, vlage st - p-l,ex pad e upgra dig fl-, the r- d of very g B)tsri c>y manage -ul as ua uto-e. - ok tm ove te managemea. eanesty pipes e - tvey As

25、rct -ew ok r _onsbl iy. Sec orssuc as a n_ stains. - tins) a. the，owns. is tsi- c. d c ie -aeiee.ftv lelt- . ees.esc . sesiel-s-e e . t l e ce .is!e r.i tike s -ite一 suts las- g uOI efci.e e si lie - cay l .itt u .ia-1- u - wel e- t s y W.-aev .v. i t dg -egt.i -一isci -s- . -ii . aa,- e c er.yse icv

26、 .g a i.ild.e gadee- ae evc-c ve t i l - u -e -iit ueite i i ai sdei -suta e ae .it . frsi -el esi . d a v -i- e- dssak si as -ia a gu - g .-i u a-iRi.k a eacid i d.ksseigii-v -e -e die si -i. sluk i.i -ur-as -i ug-ittve - age aik ei(3)进行电路的装接、调试、直到电路能达到规定的设计要求；(4)写出完整、详细的课程设计报告1.2.3主要参考器件555晶体定时器74

27、 LS74双D触发器74LS47译码器74192双时钟十进制计数器2电路设计原理与单元模块2.1 设计原理24秒计时器的总体参考方案框图如图2.1所示。它包括秒脉冲发生器、计数器、译码显示电路、报警电路和辅助时序控制电路等五个模块组成。其中计数器和控制电路 是系统的主要模块。计数器完成 24秒计时功能.而控制电路完成计数器的直接清零、启 动计数、暂停/连续计数；译码显示电路的显示与灭灯、定时时间到启动报警等功能。图2.1 24 秒计时器系统设计框图nd mpr .-e de on,eal.hevd e nvionmet mpr d l atai-.Fie,-my o- aha.,- .eaeh

28、g h-gts. Thi d -plome" mp.me ntaion of " eg he e son.iiy a nd mpr and mpl _etai on.Al li_ and - p.mets mus be.vi - -a g-, going . out mu - -g sr-work I0g.et o esu "jecies cary ou -sk, a the kekont. Its,-mus .adesimp.men- Iea. ls souldwk ad r u-l f waerteamen", "tee Io s-&quo

29、t; - a nmpora .I postion, ad carylhe m_ r-ons bily, m_ la.er pe sonn-y.a -s ae std ad sure esaishd hi ea a c.u-iiya nd w .the efrlppy a-ein-impl-eain.- -to onepaya la dig -.to- ittgae dan. .or s f- I Ie ag- ysi ualin. Se .nd, we m us sre ng 0 Go-or. Ri e ply -e G<er nor agi-1u- ad -u-s a nd Ive -

30、 te -ratme","hrre tos-" work r tie eh ualin sys_, a ease1sme op.aian -shad -pe-e nne of -pevis s lupervs ,ug- a leves10nler. n duty ip. -ss-ent,Iehabits stmu-ing pow er ., mu. sreg he . implmelai ons.e 1-tmets . .i - ing .mp.e -ns -ge insec-on .a d-s w ok nnsepu.d a wrk ou- tai ning d

31、dscve s.Tha n god c-.h up, -S - -nne Paymembes and - d-sat.i eve s mu. a dhe neepu.d a gras rot. "U .w-est- la ne."prrgma-c be. mod F >u- - m u. se imp.menlain.Cmpe "sve u-1 ng, new me .- mining smmaiZng w.ul1 atvee neg .mmuity - -e the work. pulc-r enes. pa-i cpai .< gu, a m_s

32、ogai zton ad grasocusing on w aysand meansofimpr oving a nd upgra dingw ork,further devel opme nt of"threet osplit".(A) fully grasp"nounauthorised"created.Thetownship"nounauthorised"createdtheexistingbuilding"one house hol d, onedocument"survey andfilestoragew

33、orkm ust be unconditi onal and full coverag e.Mai n corridorleadingto t hetown(roa d, river)village,the Centralbuilt-upare a ofthet own on bot hsides mustbet ocreate a "no unauthorise d village".Accordingto"fivehundredvillages"created a nd shantytowns,village s,ol d houses,re con

34、structionof old plant ,expand create, upgra ding createsfiles,the rea l "no una uthorise d village" create d int othe be nefitofthe peopleofverygoodt hing.(B)tostri ctlymanage count as una uthorise dcontr ols. Promoti ng the"new" controlworktom ovethe cent er ofgravity,m anageme

35、nt measurestot hefront,and earnestlypipeseffectively.Astrictnewunauthori sed netw orkresponsibil ity.Sect orss uch as la nd, housing andba sicst ations(stations)and theTownshi pofgridaccountabilityme chanisms must be strictlyi n accor dancewit hthe new regulat ory requirements,effectiveimplementatio

36、n ofthearea ofresponsibility ofthenewinspecti ons,suppressi on,dem olitionworkt o e nsur ethatthe ne w"zerot olera nce".Se cond,publi c se curity,w ater, ele ctricity,w ater,oceans andfisheries,t ourism colla borati on,marketsupervisi on departments shoul dstrictly enfor ce the illegal con

37、struction ofdi sposal of relevant provi sions ofthe reg ulations,effectivef ulfilment ofre sponsi bilities,parti cularly inele ctricitya nd water supply,and ot her units may not bene willegalbuildi ngs t osupplywatera nd el ectri citysupply.Whilemoreregulati ont o preve nt personal privacy vi olatio

38、ns. Illicit tra ding inillegal construction in the Ministry ofpubli cse curitysectort ostri ctlyfrom the blow.Thr ee ist ocre ateadditionaloffencereporti ngsystem of incentive s.Accordingt o buildi ng law andcovers a n area ofnatur e,to re port timely degree divided re portgra de,effective afterthe

39、rem ovalofcertain i ncentives.(C)integrated impleme ntation", bui ldingdemolition,modification,use"com binati on. Demoliti on isthemeans and pur posebuiltis.T o adhereto thebuil ding demoli she d, combi nationof construction and demolition waste, demoli she d with combi nedeffortsto improv

40、 ethe scientifi c levelofthreet o split ;se cond,wem ustpayatte ntiont o"threeto split"and "fivehundred" and "five watertreatment","threeofthefoursides",t he shackDi stricttransformation,and dangerous ol droom transformationand "tworoadsides",serie s

41、work organi ccombined up,activ edo River,a ndal ongdemolition w ork,and manpoweradvancevillage in t he,a nd oldre side ntialdemolitio nwork,t o improv ed masseshousing conditions andliveenvironment;threetoput"three modifieda split" astraditional low,andsmall,a ndbulkindustry struct uretran

42、sformation upgrade of importantinitiatives to caug ht,spe ed up adv ance industryPark, effective optimization park envir onme nt秒脉冲发生器产生的信号是电路的时钟脉冲和定时标准，但是设计对此信号要求并不太高，故电路可采用555 集成电路或由TTL 与非门组成的多谐振荡其构成。译码显示电路由74LS47(译码器)和共阴极七段LED显示器组成。报警电路在试验中可用发光二极管与蜂鸣器代替。2.2 设计方案分析设计任务，计数器和控制电路是系统的主要部分。计数器完成24s 计时

43、功能，而控制电路具有直接控制计数器的启动计数、暂停连续计数、译码显示电路的显示和灭灯功能。为了满足系统的设计要求，在设计控制电路时，应正确处理各个信号之间的时序关系。在操作直接清零开关时，要求计数器清零，数码显示器灭灯。当启动开关闭合时，控制电路应封锁时钟信号CP同时计数器完成置数功能，译码显示电路显示“24”字样；当启动开关断开时，计数器开始计数；当暂停连续开关拨在暂停位置上时，计数器停止计数，处于保持状态；当暂停连续开关拨在连续时，计数器继续递减计数。2.3 各单元电路的设计2.3.1 24 进制计数器的设计本设计中计数器是由两片74192的8421BCD3递减计数器构成。如图2.2所示。

44、osplit" in a n importa nt position,and carrythemainresponsi bility,main lea der per sonally,lea ders arre sted and layer s ofresponsibilityra nk transmission pre ssur e established hi erarchicala ccountability,a ndw orktogethert o prom otethe w ork oftheme chanism,a concerted effort payattentio

45、n toimplementation.County nongba n,flood,thr eetoonend impr oveidlel andofutilizati on, rea lachievede nvironmentimpr oveda nd productivitydevel opment mut ualpr omoting t otalwin.Five,firmly implement, promotingworkahea d,to createhig hlight s.Thir d de ployme nt,impleme ntation ofseve n,the n it i

46、s imperativeto strengt hen re sponsibilitya nd impr ove theme chanismsa nd impl ementati on.All localitiesand de partments must be convincedthatgoals,going all out, mustering spirit,worktogethert o ensurethatt his year's objectives carryout tasks,at theforefront.First,we must stre ngthen thelea

47、dershipt o impleme nt. Departmentsatalllevelplaya lea ding cat ch total,integrate d andcoor dinate drole of allkinds is"long","Sheriff""Inspes,formedt he alignme ntonthefireline a ndma nagementalivelysit uation.Se cond,wem ust stre ngthent hetest impl ementation ofthe Govern

48、or. Rol e playthe Gover norgott he bat on,foragri cult uraland ruralfocusa nd "fivewatertreatment", "three tosplit"work, r efineimprov eassessme ntmethods andeval uation system,a ccurateasse ssme nt.Combine d with "dare play,treebenchmark"style buil dingfive major opera

49、ti ons, carr yon andgain firsthand experie nce ofsupervisi on, i nparticular,tos supervisi on,urged a ll levelsl onger on duty in place.Throught hesupervisoryassessme nt,topr om ote habits, stimulating pow er.Thir d,we must strengt henimplementati on styl e. De partments at all level stow orkinrural

50、 arng ca dres for major platforms, compet eagainstlarge examination room,inspection ca dresw ork performa nceofthe ring, watercontrol a ndtheJapa nese pulle da work out,trai ning, discovery a nd se lecti on of cadre s.Tha n goodcatch up,firsttoex celle nce-ori ente d.Party membersand ca dresatalllev

51、el s musta dhere t o therural ,water contr ol andtheJapa nese pulle da grass -roots, "putdown theshelf,lea ne d" pragmatic style, thespirit of play,become a be nchmarkmodel.F our, we m uststre ngthe n propagandaimpleme ntation.Compre hensiveutili zationofmicro -cre dit, micr o-bloggi ng, n

52、ew me dia, mini ng, summarizing,good publicityw ork inthe count rysideand "fivewatertreatment", "three to split" advanced model s,pointtogat her positivee nergy forthe communitytoseethe results ofourwork intime,incr ease public awar eness,parti cipati on rate s,satisfa ctionand s

53、upport.Play gongqingfu,a massorgani zation and grass-roots such asschools, communityTherole of 3o g on w ays and means of impr. uggading wok eve Iospli" (A U- gras'o d" le d. The low nship "o una.to_e -be ucndt on - and Ul cveag e "i n ccrridr 、* Ihe Ce nt. builup a muSbe I o

54、 a d-g 1" - lunded vi" f ce -d. nd .any towns re pla. ex pad e upgga dig c f , terra d ofvey g B)t" Cly m-e culasua ulo_e d cnlros ok t m o Ihe manaead e.neSh pip- "»" A"I - -d .w ok r-on.i fc.S-C orssuC as - nda'cs Is'- ccdc i1 1-laeiee,flv lelni.es ilescs

55、 sesiel-sIe e . I llii e .s.e rsi Iike svs lil一 suls lasI g .a effHi e si.ercay llI u .ia. vol-ons. lcila dng in ilealcomluCIon in Ie Mi”- curly seCor I o. eeis I o .e ael>"nalofine e ofinenl- s. ng aw ad co- a nara ofnaur Imre dividea -Ie Ihe em o.lof - aninnenl .C)itgr- d imp.me ntain"

56、;,bu lig d_olton,I.I u.ite - i ail sdiiig.lsisul i e aae d lit. -sir.el es- . ds al i l e l.i i v aa.iea l ei- dssaksi .sto. i gui.fmaiiiwi dss- g .i. u a-Ri.k i e.c-id I- dl-wkigiow and _a- a nd buk inusiy slrciu. lanlrmain uga ilal- I ccughlspe. up a- -ne i - ly Pak Oec- oplImizlin pak U9 .74192 .

57、 1-TEXT)" ,”U1674192dqqJso l <n mQ 0 Q QuL图2.2 74192双时钟十进制计数器74192是十进制同步加/减法计数器，采用8421BC则编码，具有直接清零、异步 制数的功能，且有进位0c和借位Ob输出端。当需要进行多级扩展连接时，只要将前级 的0c端接到下一级的CP端，0b端接到下一级的CP-端即可。详见下面的功能表。输入输出R LD CP+ CP-D0 D1 D2 D3Q0 Q1 Q2 Q31 XX XX X X X000000 XXI0 I1 I2 I3I0 I1 I2I301T1X X X X加计数0111X X X X减计数0111X X X X保持表2.3 74192的功能表ng ccmp.e -nis lag. kgliI-is ele- a aeiiie.-iu g-.i6o g on W ays and means of impr . ugadigwok l Iospli" A) u- gras'o d" le d. The low nship "o una.to_