Iren dilu ra eLla mach t6 hCJP e6 Iht Ihay doi \'a lac d<,)ng vito nU.lch nht'5 de: Ihay clui tn.my th.:ii ella m~lch. Nhu \'~\y e6 mOt kho,'lllg Ihdi gian chuye:n tiep eLla cae gi<.i. 11") In':n dfiu ra eLla 11l<.lch luan tl,l' kh6ng d1l<.io<in (hI0C. ClU Ink kh(mg dong b() cLla mach tll<hl It! dLIQ"C hieu dicn tr~n hlnh 3.36. Dc khtlc phuc 11nh trang hfil c1inh lJ d:iu I"a ella m !ch t".li nhu11g th(1i diem chuyt:n tn.l!1g th,\1, nglf('5i ta them \,,10 llli Kh mol h¢ m<'lch nh6 n6i Ink tier nh6 -, , I I I I I ~ I ' TIn h1211 I c10ng l~() tHI\ fa nl1(j (\[iu 1"<1 -~ Tin lllCU dOllg 00 IJinh 3.:\7 C;llIlnk mach tu£ill II! clOII)!: b() hinl1 th:tllh (bll ra (king bo. \'O'i dil.u ra clla Illi.\ch lurin ILJ. ll¢ 111:.ICh nh6 n:lY Ct'l tk d~ll1g lUll giu gl,i Iri d:lU ra n'1<l m;'.leh lU:in IU" khi 111;lCh dang. 11' ~i,ll doan hlnh 111211111 Iraug. Ih{li m{l"i. Khi m'.lch d,1 ('y Ir".lng. thiii l~n d(nh ll11"l"i. e.ll· gi,i Ir) d iu ra mtl'i dul.l·c tinh 10{1I1. Sal! \ hl to~1.1l hI) qU{1 Irlnh chuyen Ir mg. Ih,ii \,,\ hiJlh Ihilnh gi;i Ir) ra m6i kct lillie. dur'l"i t,ic dl.lng eLla till hi¢u dong bl) llwcll nha sc ghi gia If! m6i \':1 dna gi,i tr! (\('1 t6i (t.tu f.:l. Khi tin hi¢u dung bl) IfIt, m<'leh nha 6 Ir'.lJlg th(li lUll Iru def lieu \,;1 mach ';an sang \!llye 11l¢n die than lac mtl'i. 6. Tui thic'u hmi Cal' h<ing chu)'cn tr<:lng th.ii ella C.lc uUlInat Trong qua tfLnh x:ly dl,rng de Jl1<.lch Wiin ILJ. s(j luqng de tfang Ihai clla c;.le ol(lll1U1 ;illh hUl5ng r~{1 l6n 16i ell') phu:e 1".lp cua ll1i.lch. Trnng. nhieu Inl"(\ng lwr cae ot(lll1at cll(l"a nhO"ng tn.ll1)}, th{li dlf thil'a, do d6 m(n Irnng nhiJng blJ"O"C q~an It"\mg trong khi thi6t ke cae ()tom{1t 1~1 lui Ihic'lI hO{l so luqng de 11 lng Ihal ella olomal. Qua Irinh lui thieu hoa In.lI1g Ih,ii t!ll.rc hi~l\ btlllg. deh n116111 hai 1I0(lC nhicu tr'.l11g thai IUOl1g (hrong eLla aloma\. De Illite hit;ll dicu nay ehuno ta Slf dun" ban" ehu)''':·n Iran" thaI - m()t each bicu dicll \U'O'11 0 co .0 0 .0. C" duung \'6i sU do ehuyen Ir:'.l11g thai eua 61l'lmal. Mbi dong cLla h,'lng ChUYCll 1n.1l1g Ihai IlIong ung \'oi Im)1 tn.tIlg thai, moi Cl)1 eLla bang se xac u\llh gia If! 64 Trang th;ii D<:1.U vao 0 51, O/S, SI O!S~ S, I/SII S, O/S, S, O/S" S, O/S, S6 I/S" S, O/S, S, 1/Sp I O/S, O/S, 2/S" O/S, I/S" O/S" 2/S" I/~, 2/S p dfiu ra vit tn.mg thai tiep theo eLla otCllllat Wong vng voi gia trj drill \":to dang xcI. Oic tr<.:ng th'li tuong duang cLla (l\()1nal e(l the dU9C d!llh nghiil nill!" sau. llai Ir'.lI1g thai S, va 51 dw.x coi Iii tuang d ,rang neu voi 1l19t chuG I tin hi¢u vao brl"t kS' 1{1e d(lllg vao (Jt{Hl1al kili 6t()Il1,lt dang (] tn.lI1g thai 5, 110.)c SJ chung Ii.l ciltlg nh,)n (lLrqe Im)l ehuoi tin hl2u ra nhu nhau. Djnh nghia n~IY ell m()t )' I1ghl:t tlWe t6 :\,le djnil boi VI n0"u ta quail s,it 616111((1 tll: ben ngoai ta chi tim nhflll dU0c c,le tin hi~u ra. Dieu ki~n dll clla s~r tHong dU'ong cae tn.lI1g thai dW,K biet den nhtr di~lJ kl~n ColdWell. Tuong (rrlg v6i dieu kicn nay. lwi dong hAl k5' "dfiu rLi / tn.m!,!: Ih,li tie"p ';<.IU" glong nhau dUQ"c eoi n tU·(.1ilg dll"Ong. Trong hlnh 3.39. cac tn.mg thiil S2' SI,' S~ thoa man di~ll ki0n ColdWell \"~l do d6 dUQ"e eoi la tuong duong. Nhung th(\1n chi c<.t khi nhu"tlg. tn.lI1g Ihai tic"p sau phaJ1 bi~1 Hllung I\li la wong duong thl hai dong cung duo'c COl IiI wong duong. r :lnr \'(1)' t.1 phai Ihlfe hien nhling buoe kiel1l Iw tlnl1 tU'(Jllg dm1i1g clla d.e tr'.lIlg thai trang bang thl.:o nhi1"ng buoe t(lp. va slr d~lIlg tlnl1 h()i tL.I ella thll tlle ki~1l1 Ira. lIlllh 3 39 So do chuytn lrang lluii (Lla 6t6mallll'lJllg lIng v6i b,lng chuy!'!!) Ir.m)!: Ill;il tr~n hlnh 3.3X. Phuong pilar ph:in nhom de 1rang Ih,ii. Ck tieu churin ColdWcH co the du'<.;iC chi a tam Iwi c1i6u ki¢n. Di6u ki¢n tuong thleh c1fiu w. Dieu ki¢1l nay HI lien quyel. Dieu kl~n trlll1g h0P eLLa nhung tn.mg thai liep Sall. 65 QUo! trlllh ph~m nhom cae d.e dong trong b.ing ehuyclI tn~lIg thai dLfqc tlure hi¢n nhU' sau: 66 l'\h6m de dong trong bang chuyen tr< lI1g thi\i theo dc tfn hi~u ra de nh;)n dll'Q"e cae phfm nhom. Vi dl;!. trong hlnh 3.1R. cae ph.ln nhom thea tin hicu ra se l~: G, = I (S", S" S,' S,), (S,. S,,' S,), (S" S,)}. Ta thfiy e'l the hi~n nht'ill1 eae tn.mg thai t<;iO ra nhung gia trj tin hi~u ra nhu nhau vdi duy tin hi~u v~o e6 de) (Eli mOt. Cae tl"i mg th.ii S4 v~ 5, 115m trong cling IT1Qt nb6m hai \'1 vui dfiu V;:IO '0'. S4 chuyen vc Sf, ctll1 S7 ehuytn vc S~. nlllt'Ilg SI> va s~ li li n;\m trang eung lTI9t nhom tU'O"ng duang: veli (hiu vaa , 1 '. S4 vii S) cling ehuycn v~ tn.mg th,ii So. Kigm tra sLf trung hqp ella nillIng tr~lllg thai r!i thl)'i diem tiep doi n)'j eile trail" thill ()- tron" tll'll(1 . e e e nhom. Cae tn.lllg th,ll tie'p th-:o phai nAm trotH! eung m6t nh6m. :"Jc'u de dieu kl~n n;:.)' khClllg tho:. mdn thl nh6m Sl; dUCJe ph:m chia nllc). Trong "i dy. twue. nh6m thu- nhrit ella G I tu (S". SI' Sl' S,J ehu'a cae tl"i lI1g thai SI va S,. Cae tn,mg thai nuy chuyen \'(' nhung nh6m giong nhau: klli tin hi~u vao t3 '0'. h¢ thong se chuycn ve cac tr~ng Tl"i lI1g thJi t),lu vao () 1 So O/S. o/s" SI' O/S" o/s" .• S. o/s" 0/S')7 S2i>~ 1/ S I1 2/S 11 S')7 OIS'('K 1/ S n Hinh 3.40 Ballg chuyell Irang th,ii sau khi elil t6i thi~lI hmi ella (WlI1JallrCIl hillh .L19. I-linh 3.41 Sa ela ot()mallrCIl hl1111 3.39 ~all khi dJ 16i lhlfu hu;i. thai {rang nh6m {hd ha. S, va S,: khi {in hieu van b '1', he {h6ng se ehu),cn \'c tl"i l1lg thai trong nh6m thu hai: Sl va Sf,' C[IC tn~lIg thai kh,!c chuyen vao nhO"ng nh6m khae nhau. Do d6 nllom ( SII' \. S;, S, ) se dwl'C pi1O:1n chia thanh cae nh6m ( SI> ), ( SI' S, ), ( S1 ), Ok nh6m con 1<,li clla (i I khong phan t,ich dLfCJC. Cuoi eung chung ta nh(1Il duqe phan nhom tlftl'ng duang nhu sau: (i, ~ \ (,~,), ( S,' S, ), (S, ), ( S" S,,' s, ), ( s,' S, ) I, - - Phtm nllom nay (tU~iC kicm tra v6i c{tC chuoi driu VilO c6 dl) d~li hai. Thll 1~IC vira trlnh bi:'y d tren se dU'qc l~\p h,ll cho 16i klli d'.lt duQ'c sV hQi t~. Chung ta kh6ng the tiep t~c phan uhom O 2 , do d6 kc"\ qua nhan duqc co Ih0 (lLr~1C coi !u Ill'j gi;.i.i hai loan t6i thi6u h<xl. §3.6. Nhllng ,,"an de khi thi(;t kc eric m~ch tuan tJ! 1. Hi¢n tu~mg c~nh tranh trong de mach tufin tt! Kh<.lc \'6i de mach \t; hop, tn.l1lg lha! eua de m,.teh lU,111 h.r duqc xac djnh kh6ng chi tv cae IIIl hi¢u \'~\O ma (,')\1 phl;! thw.)c vao de tn~llg IhJi trude do cua m<.\Ch. Vi¢c luu ira cae tr~l11g thai trude do eua l11<.\ch dlfO'C (111)'c hi~n trcn cae phfin III nh6 nhu thanh gilL trigo, ." Nhu v(\y mi lell luan tl! c6 the bieu dicn bang nhung 6t6mat co so ln~ng th,h hl1u Iwo. V i~c phan 1fch va t6ng h<;1p cae dt6mat \.1 m()t pban quan tn;mg s Q Q r llinll JA2 !\l;\Ch !riga RS. trong I)' thuyet 6t6mat. Trong I1we nay r - Q lnnh 3.43 Anh huong eua c.mil trallh trong phein tLr trigu RS. chung ta chi de e.~p tai m91 so vi.l'n d~ khi thiet ke eil.c 61omat. Trang cae 6t6nlilt, do ilnh huang cl.\a thai gian tre tin hi¢u tren cae phfil1 tu mi.lCb, nguai ta quan sat thuy nhung tr<.tng thai trung gian chuytn tiep gina d.e trt.l11g thai trong Ihiet ke. Nhilng t··<).ng th,ii chuytn tiep ni\y c6 i.lnh hu6"ng Ion den hm.lt dOng eua mach. SLf qnh 1r<111h trong que\ trlnh truY~11 tfn hi¢u 67 gifra d.c ph:'ln Ill' lE'.ICh e6 th~ dan (iCn vi~e thiet I~p nhiIng tri ll1g Ih,\i sai clla d.c philu III uh6. do 06 co the d:ln 1.16'n hO'.11 uqng sai eua 111i ICh. Khi thi~t kc Ci\c ot6mat .';~r canh Iranh lrong cac ph,in tll: Im.lch phi.li dut)'c lo'.li IrlL Chung la khtlo S,tl i.lnh hui1ng cua sL! qllh tranh gii1a cae phuH Ill' llli leh lrung \"i dl,l don gi,in \'~ hO'.11 d(Jng cua triga RS. Ta 11Mn IhAy, neu S = R = I, Iri"o "iG: nouyen trang ihai va oia tri tren hai l1uonu tin hl~U ra ee C,.~ e, e. Q vii Q ugu'{,l'c nhau. Vi dl,l, khi Q = 1 Ihl hai dfiu vao cLla phi.ln ILl' NA: JD? se nh(1l1 gi'l. Ir! '1', khi u6 gia Irl (!:iu ra Q ~iS btmg '0'. (iia Ir\ '0' n~ly ,,,C duy Iri giii tn '1' li.li d[iu ra Q. Kh<.i. nilng nhCj clla ph,in tll uUge duy 11'1 bl1i \"()ng ph,'\ll h6i IJ'l~n hal phiin III NA; JD. - - :-J6u cllC dell! \"(10 S = '0' . R = '1', Gi<i Ir~ dc Jeiu ra s0 1a Q = '1', - - Q = '0'. Cic gd Irj nay dut)c duy lri ngay Ci.l, ,au khi S = '1'. DietL na~ clIng xiiy ra wang tl! khi R = '0', S = 'I', de dl10'llg tin hi¢u raQ~'O', Q~T. - - Trang th<.i1 khi S = '0' . R = '0' li1. trang thai cAm. Tn.mg Ih[li n;\y kh(lllg lilt slr dung duge \'1 khi cae gi,i 11'! In~n hai dau vao S , IZ chuyen sang nh(\rl - - cac gii.l. Irj S = '\' , R = '1', kc'\ qu,'t siS phu thu(lC VlIO SU' C<,l11h Iranh giiJa - - hai ph,\n Iv: I'\Al'.'D] \'(1 NA0JD,. Ta nhfl1l lha'y khi S = '0' . R::::: '0'. hai dAu ra Q \'it Q cling nhtuJ gi{l Irj Q = 'I' , Q = '1'. Tr~l11g thai n~ly iiI Ir'.lllg Ihai x;ic dinh mac dll n6 pha vo quan he QI\\r-1J:~ = Q:-nr-]l:' Nhung khi triga clllly~n ra khai Ir,.mg Ihai do btlllg de gia Irl S.=' I' . R = 'I', lJU[l Irlnh ChU),Cll Irang Ill,ii sC di~ll ra !lIm Irl'l1 hillh ~.34. Sau khi c~ie gialri '1' xu{\t hi¢1l Iren hai ctiiu \'au cllil ph,·in Ill' trigo, tr~n hai dfill V~IO clIa hai ph,i.n Ill' NA~D, va NAt\D: siS nh~n dong thoi hai gia Iri 'I'. Nhl! V~ly hai (\flU ra sc ph'li cLing nh(1l1 gi,i Irj '0', Nhung oitu do kh6ng Ihe xay ra. hdi VI ~V xuftt hi~ll gia Irj '0' 6 1TI91 (Hiu ra se lam eho dau ra con h.li nh(l.l1 gi,i Irj 'I' vii tn.ll1g thai nay sc dL1gc duy Ir!. Nhu v(\y 111~)t trong hai phiin IU NAND sC th.:lng 1iung CWlc dua va tn.mg thai sc x,le djnh Iheo phall IU NAND do. Vi du, neu tl1(\i gian tn~ ella phiin tu NANDI lOll han Ihai gian tn~ clIa pll<ln ILl' ~AND2' Idl > Idc' lin hi¢u '0' se xual hi~n Ct dau ra Cllil ph tn tll' NAt\D, tnftl'C V'1. Ir".ll1g thai sC: dl1(/c Ihi0't li~p se Iii Q = 'I' , Q = '0'. Trang lrU'ong hVp, neu lei I < t,12' Ihl cile gia tf! ra se btmg Q = '0' , Q = '1'. M~I khae gia II'! Ihlii gian tn~ la ITIQt di.li lU'9ng ng,lu I1hien do do co th~ ket lu~n r<'tng trong truO'ng hqp n~ly gia tri dClu ra kh6ng xae djnh. Dieu nay lam eho e(lp gia tr~ S = '0'. - R = '0' lit cae gia trj cam. 6X Trong nhicu tnrong IWp eo ehe c,-,mh tranh trong de m~teh lu[in IV x:IY ra nlHI' sal!. Ok tn,mg th,-Ii ella 6Wmat, do cae tin hi~u thiet 1~lp thay L1Cii h,li phl} thU(K vito tri,mg Ih{li cua cic phAn tli nh(1. Do hi¢n tutjug Ir~ lin hi¢u trong die ph[in tli logic. sl! thle! 1~IP d.e gla tri ella 6 nh6 kh6ng xilY ra (1t)ng thlii. Uieu L10 co tlH~ <'mh huang t6i tin hi¢u thiet 1~lp ella cae ph[il1 ILl' k\J,\c Vi) do dlS co the cHin dcn nhQng tn,lI1g Ihai khong luong truoe. Phu'(lIlg phap quan trQng de" ng,-ln eMn hi¢n tUQ'ng canh lr"nil gii:i'a e{lc ph[in tLI' trang m',teh la ~U dl,l11g eiic ehe" d<) d6ng h(l. Trong dH.: chc de) n~IY. \'i¢e nh(\l1 cae gia tI") tin hi¢u vao cae 6 nha viI dua cae gia Ir! d6 l(ii cHiu ra eluQe tlH,rc hi¢1l do nhilng thCii di6m xac dinh sau khi cae qua trlnh qua do Irong nweh ket thue. Trcn quail diem v6 to ehue cae qua trlnh thai gian d.C I1Weh SIS co the' chia thanh de mi lell dong hO va cae m'.Ieh khong ddng hi). Trong nhung thiel hi kh6ng dong hi), qua trinh chuycn !)1i.lch CUiI cae ph{in tu xay ra kh6ng theo Sl! di~u khi6n IiI' ben ngoili. Toe d<) IhU'e hl~n ella cae phep toan trang d,e thiet hi d6 ph~ thuQe \'~tO thl':ii gian tre ella cae ph[in tu v,\ IiI nbiin~ d\\i Iw:mg ngau nhicn. 00 thoi gian truyen tin hi¢u trong cae dO~1i1 Jl1~lch khc'lng dUQe biet tru6e. dieu d6 nun eho van de gi,-li quyc't C<.l11h tranh giGa dte phan tu m~teh trd nen kha phtic t' Ip. Nhung phu'O"ng phap giai quyet e',lI1h tranh hi¢11 e6 kha phu:e t'.IP va kh6ng dUQC lhlg d~ll1g rOng rai trang ky thu,~t. Tr6n thlJc t2' ehi eo m()t s6 phan nlll) ella m~lCh dlrqe lillIe hi~n theo ehe: d¢ khong dtll1g hr>. Trang nhlIng thict hj dong h<), qua trlnh xU: I)' thong tin duqe StlP xcp then thl1i gian be':ii nhling til1 hi¢u dong h6 do nhl1'ng thiet bi phat xung clong 116 1' 10 ra.Vi~c nh(U1 dcr li~u vao cae phlin tV nh6 dunc tlWe hien \'.Ii nhl1'ng thai dic:m thai gian xac dinh, sau khi cae lin hiGu t,-~i (bu vao cac phan tV nh6 d,~1 dLIq"e gi{l 11"[ xae h~p. NhiIng gii.i tri xac Ii~p n;)y do eo ehe hG<;lt c1~lI1g eua nweh xae d[nh. Trong nhlrng m':,lch dong h¢. tin hi¢u dong h6 du'qe t,-~o ra sau nhung kboAng thai gian eo dinh voi d,? dai du 16'n M eho eae qua tdnh qua d¢ Irong d,e dm,lI1 Im~eh ket tluk ngay d trong trlIo'ng hQ'p thai gian tn~ tin hi¢u clle ct.li. Tren thl!e Ie cae qua tflnh qua dQ trong pb'ln JOn d,c pb,in lU m' leh ket thlie s6'm hon dl.t tlnh, do d6 trang toan bi) et(> dai nia tin hi~u. dong ht). cae phan ttl nweh 0- tr,~ng thai "nghi". Di~u nay lit ke"1 qUi'l clla qua trlnh eha dqi kho;ing thoi gian dong hO ket thuc tinh eho truong hqp X;1U nh[it khi Ih,1i giaJ1 tre trong m~leh el,fe 1\li. MCTe eI¢ kh6ng sU: dyng het t6e dt) ella phan Ill' 1l1'.lcb ph~ thU(K ,\,'ao sll pbaJ1 Lin tham so thoi gian tre tren cae rhein Ill' va 69 dLH;C xac dinh bai I)' so giua gia Ir! Ihoi gian tn~ elfe d",i va gia tr! trung blnh eLla chung. 2. Thief kc nhu:ng ITI<;ll:h luan tl! dong bl) ~ ·lc_C_'i_C ~g~i'_\ _tl_"'-l "''U="' j I Gia Irj r "O_-t c dUll \·ao 1 ~~= + Gla tfj 0 dfill fa I +-___t-~___t 2 II = +-oc +-~ 1 Cae tl"i.~ng f-_~S"-"-_i "O-Q.Q~~ thai __ S:,-"_-+_-,O",O,,I_ j S, 010 Illnh 3.44 r li'i hoa nhi phan cae giu tri vilo. gia Ir! ra va cae Irang thai. Dc c6 Ihe xuy dlfng cac oloma! Ill" dc so d6 chuyen t!"';lng th,\i ho~\C hi.lng chuytn tri;lng thai, ta can plUll mil hoa nhj phun eho cae gia tri dfiu vao, (Uiu fa va cae II"i.lllg thai. M91 so nhj phi.1.11 11 hit c6 the bieu dien 2" gia trj dau \,~IO, d<.l.u ra va Ir<;lng thai. Doi voi 6t()mat d~ toi thicu hoi.l. trong lllJ,lc truck (hlnh 3.40, 3.41) eac gli.l trj eHi.u vao, d,lu ra va trt.lllg thai se dlIQC mil hoa nhu sau. d dfty chung ta chu )' rang, khi ma hoa eac gia Irj dfiu fa, dau vao va d~c bi¢1 la cac lri Hlg 11uii, la cfin ehQn nhiing t6 hQp ma sao ellO khoang each ma gilJ"a hai trt.mg IMi ehuyen tier Ia il nha!. N6i each khi.ic, ta dn phAi ma hoa de tl"i lI1g thai S, V;I SJ sao eho khi ehuycn Ilr tn.H1g tiuii S, vao tf<;lng thai SI thea sa do ehuycn Ii"i mg Ihai, so hfQ"ng bit can phai ehuyen Ir~ng Ihai la il nhf{t. Chung ta eoi nlng slf ehuyen tr,~ng thai xae djnh voi 11l9i dau vao. Tren thlle Ie, trang cae m<;leh tUitl1 II!, e6 the xiiy 1"<.1 eac truo·ng hQ"p khi gi,l Ir~ eua dau ra va tn.H1g tluii tiep thea kh.6ng x,ic d!nh voi m9i gii.l trj driu vao. NhlI \'~y, trang l11,!-ch sc xu,]"1 hi¢n tlnh Ir<;lng kh6ng xac djnh. Trang nhung truong hqp nay, ding giong nhu dc m<.lch 10 hQP, chung ta c6 the dan gi<ll1 hoa ehue nang hO':1l d9ng eua tn<;leh, nhung khi de la kh6ng the Slr dlJng phuong phi.lp lai thieu ho,\. Ir~U1g thai thea cal: lieu chuill ColdWell nhu lrang myc *3.5.6. Ngu·oi ta Ihuang Slr dJ,lng de phuong phap dlfa tren kinh nghi¢m. 70 . _tl_"'-l "''U="' j I Gia Irj r "O_-t c dUll ·ao 1 ~~= + Gla tfj 0 dfill fa I +-_ __t-~___t 2 II = +-oc +-~ 1 Cae tl"i.~ng f-_~S" ;-& quot ;-_ i. IJ'l~n hal phiin III NA; JD. - - :-J6u cllC dell! " (10 S = '0' . R = '1', Gi<i Ir~ dc Jeiu ra s0 1a Q = '1', - - Q = '0'. Cic gd. +-_ __t-~___t 2 II = +-oc +-~ 1 Cae tl"i.~ng f-_~S" ;-& quot ;-_ i "O-Q.Q~~ thai __ S: ,-& quot; _-+ _-, O",O,,I_ j S, 010 Illnh 3.44 r li'i hoa nhi phan cae giu tri vilo.