[{It!ie \'a m6 ph(')l1g Tl"en Ihlfc te, h¢ mo phlmg d nh ky dQc c:.'le I¢p chua t,ie d6ng Ueh 110<.,11 il1'.Kh vii kel 11(1'p eac sI,r ki¢n 1'.li d Ll vi\O \'(')"i de slj ki~n duoc sinh ra Imng qLl<i Ir]nh hm,lt d(lIlg ella m'.Kh. Them vi\O do. ngoili ui.e s~r ki¢n sinh ra :-'L.r t[nh 1O,ln e,ie t!i{1 Iri Ifll 11i¢ll lrung m'.Kh. lrang k5' Ihu,-~I IIlll hlBh hoa klgic h~ Ihong 1116 ph('lllg e(lll eo 1[1l( Ihelll dc sl! ki~]] dieu khien qll{1 trlnh. Oie SLX kl¢n 10'-,li n~IY khbi 1,.10 C{IC hm,lt t(>ng kh:.ie nhau clla llli teh lai de Ihi)'i diem Ihai giall X,1e djnh. Du6'i d,ly lit ml)1 s6 t,1e dl)llg eLla cic sl.r ki¢n di~u khien: lIien th! gi,i Irj ella n[1I1'ng tin hi¢ll xae djnh: Kicm Ira giil. Iri ella dc tin hi¢u cy th~ V:I c() Ihe citIng qUlt 11"'ll1h Illl) phung llC'U c(l sai sol lrong qua Irlnh Ifnll lo,in. Dc mCl I,"t 1"0 qu,i Irinil llll) hlnh ho,\ lClgic d nH) phllllg hu6ng sV ki~il. ehulIg la ql Ihe ho,i Ihw)1 lo,in mtl ph('lllt! iurtmg s~r kl¢n nhu '>all. \fe,'ll k)' hi¢u I,)p hup de c;)p "gi,i Il"j lin [lIl'll - du6ng truyclI lin hll'U Ihay dl)i l'i Ih<\i diem Ihi)'i glan hi¢n I' Ii" h,'lI1g V(I viI 1[lp [Wp de C(lp "gi,i Irj Ifn hl¢U - dLrh'ng IrLlycn lIn hi¢u Ihay dcii dLrt'l'i I,ie dl.lng ella V(I" h,\ng VI' Khi do Ihu:II lo;in m(l hlllh ht'la i(lglC [urt'l'llg s~r ki¢n Ihy-c hi('ll Iheo Irluh I~!' nlur : au: I. Thie-I [(1[1 hai I,)p hqp Va \,~I VI> \'ll gCln a+ O , b + J 2. '1'11112'1 1(lp gia Irj ella Ir'.lIlg Ih:ti ban thlu cua nwch. J. Doc dc gi,i Irj chlu vilo. X01 de c1UOllg lin hi¢u Ill~l Iren c16 xut!1 hi~n dte s~r ki¢n ( sl! Ihay doi gi:l Irj tin hi~u ). celc gia Iri elm s~!' ki¢n x'.y ra [](IY dune ghl \'(10 Wp hqp Va' -L KJ\,;m Ira I,)p hqp V". nC'll V. , I"llllg Iii quay \'e bLr6c J: neu Va kh6ng dlllg, Illl,rc hil'n ilw)'c 5. 5. Thuc llI~[] 1ll(J hinh h6a il'lgie d,)i \'6i c,ie gia Ifj trong 1<)p hap V,,: cile dll'Cing Lilt lt~'u Irl'll d6 .'\u:II 11l¢n slf ki¢ll V~l gia Ifi ella ehung du'qe ghi \'(10 V h . 6. uem a+ I . b + 0 . Yell tl"() clla V" \'(1 VI> Ihay doi. Kieln Ira s~r X-+1 C d b X 1 xutll hi¢n dao d(lng lrong mach. !\ell khong co dao d(lIlg, quay \'t~ hu6c 4. NIH!' V(ly, chung ta Ihtly pllLKing ph;ip mo hinh ho,.1. logic huang st! ki¢n kh{LC \'6i phl10ng pilap m6 hillh h(xi tx\ng hiell djch (1 eho: la khong crln t1wc hi~n vi¢c phrm h'.lllg cae ph,[11 Ill'. Them \'(10 <16 wii s~r co m(11 cui.! \ lmg 1(lp. la eo Ihe Ilwc 113 111011 \'lCC 11111 hll1h h6a vO'i dQ phuc t<.lp tuy y. Vi d~l, la 1110 hlnb hoa qu,i Irlnh ho'.lt d(lng coa trigl1 RS: \. B \ : Thiel 1;IP V,\ va V II ( A ~ 0 , B ~ 1) ; 2. B2: Do 1l"i.lI1g Ih<.ii ban dau ella mq.ch khong x.k djnh, gi.:i trj trcn t,fl ci UtC throng tin hi~u dU'l,K g<in btl11g 'X'; 3. B3: D(ll de giu Ir\ dflll vilo : a = 0, b = I. 6 d£IY ta co V" = I ( a, 0 ), ( h, I ) I; 4. B4: Ta thay t,~p hq'p Vo khong rang, la ehuy~n sang buoe 5. 5. B5: Gia Irj Iren duang tIn hi¢u ra c thay doi IU 'X' sang 'I', tilP hqp V I = ! ( c, 1 ) !; 6. B6: (,dn VI vao Vo. T(lp hqp VI) nh,~n giu Ir! Vo = I (c, I) ! va qUil)' l\li bu6c 4. 7. B-J.: Ta IllSy tZlp IWp Vo khong rang ta cl1Uy~n toi buoc 5. 8. B5: Gia Irj lin hi¢u Iren dLfong d chuyc'n Ilr 'X' S.'Ulg '0'. V,= I (d,O) I 9. D6: (hill V\ V;'\O VO' T;lp hqp VI) nhi~n gia Ir! Vo = { (d. 0) I \'21 quay v~ bU'O'l' -to 10. B4: Ta IhAy t(lp hqp VII kh(lllg dmg. ta sang bLf6e 5. 85: Do kh6ng ell lin hi¢u V,\O va kh6ng co tfn hieu Ihay doi khi (\=0, V1=0. 11. 86: Ta g,in \' 1 V;'1O VII' khi d6 V 0 = 0 va ehuyen sang bu6e 4. 12. B4: Ta tha'y t.'~p hqp Vo rang nen quay v~ buCtc 3. 13. B3: Dqc cae gia If! li~p Iheo 6 dau vao. l'\hu v,)y \'oi gil Ir! d'-Iu V~\O a = '0', b = '1', ta nh(1I1 duqe de gill Ifj drill ra e = 'I', d = '0'. I\bu v~ly chung ta dJ. Il1fty nguyen Iy eua phumlg ph,ip m6 blllh hOii hUtl'ng sl! ki¢n. Trang Iru0ng hl.1P can ph,ii Ifnh 16"i anh Illrong cua Iham s6 tho'i gian tn~ clla cae uk phfln Ill', la kh6ng Ihe: chi SLr dyng hai trang th,ii Vi), VI . Trong truong hqp nay la co tht dVa them vao qUi\. trinh m6 pht'lllg cae Iran" thai V. tuon" tIn" \'oi cac gia tri thai "ian tr~ va S{lp xcp then Irlnh ILf . b .I ~ ~ . c . e<lc trt~ng thai Vi' 114 §5.4. Mo hlnh hoa qua trinh tre tin hi~u trong cae phan hI Im.tch Khi chung ta Ihl;IC hi¢n mo hinh hoa logic va 1110 phong ho< \t O~)llg clla ll1i;lch trcn Il1lrC cac phfin tlr It)gic, m9t nhi'm to quyct ltjnh muc 09 chinh xac cua 1Il0 hinh so voi m'.lCh thvc te lit tham s6 thui gian tn~ cua cac phiin tll" logic. NC"u chung la bieu dicn hOi;lt d(mg ella m~lch khong lUong ung v6'i nhG"ng Gnh hu6ng thlfc te se dien ra trong d.c ph[ill tlf logic. khi d6 SC XU[lt hi~n Sl.t khong chinh x<ic Irong cae mo hinh hO<.11 d()ng eua milch chu )"C'"u Iheo nhG"ng quail h~ vc Ihi)i gian. Khi tlwc hi~n qwi Irlnh mo hlnh h('ia huont! W ki~n Iheo so' d6 lrong mL.lC 5.3 ( 11111h 5.16 ) chung la co the' nh(l11 duO"(: llhiIng bien Iht eua thu(11 10,.'In. Slf kh,IC nh<'1ll dn 11<'m trong nhG"ng biC~n the 06 plW IhU(lC chtl yell vao cae 11l() hlllh tre tin Ill¢U lu"tmg lmg V(ij ho< \t d(mg ella nhung ph tll IV logic tham gia vno m~\eh, Vi~e me) hlnh h()a qu,l. trlnh Irc tin hi~u Iii. nili'm t6 co 11<\n trang vi~c x,ic dinh tinh chinh xac eLla mo 1I111h m,.teh va I1lUC 09 phuc t':lP cua Ihu,~t tOiln mo hlnh hoa. 1. Mtl hinh hoa qua trinh trt' tin hi~u (Ilia dlc plutH tl~ lugic Moi ph[in IU logic deu lac (h)ng len ellc tin hi~u vito v2\ 121111 Ire de tin hi~u cia. Trang k5' thU(lt, ta IhU(':ing sU' ul,lng hal mo hinh Ire qua dc phan IU IllgLC: il1() hlnh Ire Ian truyen va m6 hlnh tn~ qu,l.n tlnh. Ngoai hai 1000~i tre n6i tr2n. trong 111[,)t so tru'(tng IWp de me) Iii oU'l)"c hOi 11 o(mg eua mi lch, ngudi ta con :-'If dl,lllg dc md hinh tre ngtlu nillen. Trc Ian truycn: 121 Sl.! Ire tin hi~'Ll pl:cil sinh kill ta cho lin hi~u di qua ph:in tu m \ch. Tr~ lju,in tlnh: I~t s~r Ire tin hi.:u g:1l1 lien voi n[mg luqng de; klch hOi lt ph{in IU mi.,lch. 3. Trc Ian truyclI Thai ~ian tre Ian truycn 121 th6i gian ma tfn hi¢u ra eua In,.tell ch(lln pita ,0 vCii tin hi¢u \,~IO llwch, M6 hlnh tre Ian lruy~n l~\ 1116 hlnh co b'LLI, Irong de) xac dinh khOi.lng thCti gian .0 T each bi¢1 giG"a de sV kit;n .xU,·\1 hi¢n tai (hill ra voi de SL.f ki¢n xuiit hi¢n t'.li dau vao sinh ra chlmg. Dc dun gi,'tn, tmng c,ic liS Ihu;lI luan m(l hlnh boa \'~l mo phong, gia Irj thfmg so thi)i gian Ir~ sl.f (iL,mg trollg m(l pJl('lJlg la dc s6 nguyen. Trong m(ll s6 tnrang hqp. khi mo hinh hoa mi tch ta khong tinh den th(\i giall II"':: lin hi2u khi di qua dc pbun IV. Luc d6, chung la COL Ihai gian Ire: cua phan IiI btlllg kh6ng. Nhu V~ly trong Iwang hQ'p nay. chung til sir dung mo hinh \'oi Iho'i gian tre tin hi~u bang kh6ng. Phuang ph:lp tn(l hlnh hoa I(lgic d m6 ph,'mg hAng bien djch sv dl,lng ma hinh Ihu(lC tinh Ire nay. M6 hlnh de phfin ILr v6i Ih0i gian tn~ btll1g kh6ng chi daqe Sl'j' dl,lJlg de: m() hlnh hoa de gia Irj 16gie Irong nhLr!lg nwch 16 hap va m;.lch lu{in Il.f dong be). Ml) hlnh ct'la 111;,ICh Irong do Ih(1i gian Ire CLJa HIt ca de phfil1 Ill' logic d h E IHllh 5.IS VI' (111,0 (161));.1('11 cho Inrill1;C 110p Ir~ liluilll nil[!1 \'i\ ln~ pil,ill l,in_ b;l.ng nlHlu gQi lit mo hlnh "oi thuc)e !lnh tn~ IhuAI1 nh:Yt. Do de ph[in ILl' logic c6 Ihai gJan Ir~ kh,ic kh6ng. nhU \,~IY chung la e6 kh;i nang mo hlnh h6a va XLI Iy dc m'.lch khang dong bc) co ph,in I}(::)i. M() hinh 11::IY hi m() hlnh ch(fa Ih{lIlg s(i Ir~ dcm gi<.in nhS!. Trollg tru6"ng hQ'p nilY, la co Ihe chqn gia III th(mg so Ire EII~1 dan vj \'o-i I)' I¢ 111()1. Nhu \',)y. chung la C() ma hlllh Ire gqi Iii lllO hlnh Ire don \'i. Trong ll"U'lmg hop tong qUill, dc phfln tu- cua mach c6 Ihe nh~1II nhlrng 1~,61~gi~l~k~II~.~lh~h~4~lri~~h~~h~ L __ _ -, ~ -, OL J' -, L_r ~- lilnh 5.19 Hoal cltmg ella mach Iren hlnh 5 I g \ 6i m{l hlnh Ire Ihu~in uhi!!. 116 _b __ ~~ __ _ ' ___ ,-L- __ _ -b ~ ~- e L.J - 9 "S L Hinh 5.20 I[oal dong ella mach tren ilillh 5.1 g \'oi m(i lilnh Ire ph:m I,ill_ .';,,~'"\ ' ' 2. lren nhling. pilallilf kh.ic.\ ",. J d6ng ella nwch. ta Slt' dl,lng don VI thai gian oe 00 gia Ir; thCHlg 'i6 Ih(\i glan Ire 1~1 u6c s6 chung 16n nh[lt !'.I' Cll<l de IhOng so thai gian Ire Ire]) dlC ph~lll tLI' va ph:1Il ph6i cae giu tr! thong so Ihai gian In~ Iheo ty I~ lU'o'ng Ll'ng \'(J'i AT ' Mo hlnh d(l g91 la rno hlnh hm.11 d¢ng v6i Ihong so Ihai gian tre pilftn t{lI1. Mo hloh la m6 hlnh pht,) bi61 d~ bieu die:n cae thut?e tfnh tre Ian IruyC;Il. Vi JI,l, d6i v6i m<',lCh tn:n hinh 5.18. He'u ta thLfc hi¢n mo hinh h6a Ilwch v6i m(l hlnh qw.i Idnh In>: tin hi~u \"6i Ihong so Ihoi giall tre thuiLll nilal, 1<.1 .~c nh(Ul dU'(Jc sd 06 hm.11 d(lng theo thai gian nhu tn~n hlllh 5.19, KIll Ih6ng 'i6 thoi gian tre cua GtC ph[in tll" H va E btlllg 2. nhiJ"ng phfin tu con 1~li llh~ll1 c6 Ih6ng 'itl tho'i gwn tr~ bang I, ta e6 so d6 hm.1t d()ng clla m'.lch Ihen thi\i gian th~ hien tren hinh 5.20, Khi m6 hlnh hoa hanh vi eLla cac cae ph[in tu logic. chung ta thlrC1"l1g phtlll tach ehue nang tinh toan logic va cd chc di~u ph6i thai gian ella chung. Hinh 5.21 r "16 hln11 rh[lllilich chl'rc nang logIC \'il Ihuoc tinh In!. l\'hu v 1.y, 111()1 ph,-I.n Ilr voi thong s6 thai gian trc hi !'.·I sc tLTo'ng ung vl'ii phfin IV 16gic voi thong so thoi gian tn": bling kh6ng va phitn tV trc co Ih(mg so thoi gian tre l~l AI' Trong quil trlnh 1116 hlnh hoa hunh vi eua phi.ln tV 16gie, dilu li0n phtin Ill" bj Klch hO',11 sc dlfqe tfnh to<l.n theo ehuc nang 16gic, sau do cae thu<)e linll lo!:c se dlrqc tfnh toan V~l the hi¢n qua qua trlnh dieu phoi Ihoi gian. Vi¢e chi ra giii tri duy nhat eua thong so Ihoi gian tn~ eoa phan IV rat b .0.~,=2 ,.0. 111 = I .I1. c c tnnh 5.22 Sv Xllal hien gi,i Iri khong x,ic (lin!! 'u' trong hoat d¢llg Clla phall Ilr AND veil mo hlnh qUiltrlnh Ire tin hicu v6i thai gian tre nrc dai ' nrc liC:u. phlre ti.IP C<l tren khla «.mh diu true 11l<;lch vii Irell khla Ci,lI1h san xuJi Ta co the tlure hi¢n do d~lC trve liep tren cae m~lch thl;l·c. nlnrng d6i vai nhilng l11i;lch dLH;JC thiet ke Judi (h.mg d.e m~ch tich h9'P VLSI thl khi\ n[mg do IrLfc tiep la khong Ihe c6 duqe. Trang truong h~}p nay de ntlllg eao linh ehinh xae ella qua trlnh rno hlnh hoa va mo phung. ta chi ra khoiing bien thien ella thong so thai gian tre. Mo hlnh qua trlnh tre till hi¢u nay duqe g9i 1,1 rn6 hinh ycji thai gian u'e: kh6ng xae d~nh. Ne~u Uung mo hinh v6i thai 117 gian tre kh6ng xac d\nh, chung la chi r6 gia Irj clfc di.\[ ~~l va gia Ifj cl.re ti~u !-,., cua thong so thai gian tre, mo hlnh sc duqc gQi la rno hlnh vai thai gian In:: q!C d,~i - cue litu. Vi dl;!. thong so Ihi:ri gian tn~ cua m(ll lOi li phan lu NAND Cll tht bien Ihien trong khoang tir 5 ns d6n 10 ns, nhu Vi))' doi vai IOi).i ph{in ll'I NAND nay, All, = 5 ns va A~l= 10 ns. De khao Si\t ma hlnh nay. ta c6 the' XLJl1 xet lux.lt d(lIlg ella phan tu AND c6 hai drill vao ( hlnh 5.22 ). Trong d d~l nay. ph,in tu AND c6 gia trj thoi gian Ire clfc d<'.li - clfc ti~u: ~~I = 2, ~'n = 1. Ta Ih[1y lin hicu tn~n duang c chuycn lir tr,.mg Ih,l.i '0' sang tn.lIlg thai' I' khi lin hi~ll Iren dau vao a chuycn IiI '0' sang' 1'. Ta thAy dmg lrong khoang Ihai gian Ini(K !' ,n tfnh IiI Ih(\i diem xual hi~n sl! ki¢ll tren dui:mg a. Iren duong c khong Ct) slf Ihay d6i glil. tr! lin hi¢u. Cilng wang II!, sau khoang thai gu.ll1 A\I tinh Ill' Ihlri dicm xufil hi9n slf ki¢n tren dU'ang (I, tren dlrang c thiel l(\p gia tf! '1'. Nhu v~y. trong khOi.lng thai gian lu ~1l1 d~n ~tl sau klll xUiil hi¢n Sl! ki¢I1 tr~n duang u, tin hi¢u Iren duang c iJ kh6ng xac djnh, la sc dung gia trj 'U' de bieu Ih! gi,i trj lin hi¢u. Tom li.~i. khi la SLr d~ll1g m6 hlnb Ire kh6ng xae djnh hO(lc mo hlnh Ire elfc d'.li - elfc lieu. Irong lio".lt dt)ng eua 111 \Ch sc xuAt hi¢n nhG:ng hi:lI1h vi khong x~c d!nh va bieu Ill! qua nhling giii tr! 'U'. mnh 5.23 Anh huang ub mll hlnh Ire cuc dai ClIC tl~lI !en qu.i trinh 1110 plK'lIlg hOi.lt dong ella m<.tch. , ~ b) b ttl , IlYE:kiJ 9 c) a) ~ b !IJj , - dJ Iw , 9 n V oi rno hlnh Ire ClfC d~i - clfe li~u, la co the m6 hinh hoa phfin Ian d.c twang hqp phuc tQ.p xUiil hi~n trong hO~1 dt)ng cua mi.lch Ir~n tlwc t6. Nhung Irong m6 hlnh nay neu chung la gia Ihiet khoang bicn thien eua thr.lj gian Ire Ian. lrong qua trlnh mo hil1h hoa la co Ih~ t uy~n lohn C,Ie gia tr~ 'U' hO(lC 118 trang 111' ICh co the xui'll hi¢n nhung d',\Ilg tIn hi¢u khong co lrong <.;(1 (t(i IltIfC. D~ minh h(:m vfin de n~IY, chlltlg ta xet sa d6 In;:n hlnh 5.23. (rli't illl.:"t rang cae pldn tlf m' Ich co Ih6ng so thai gian Ire 0.~1 = 3 va L\, = 2. '!hco :-;0 d('j logic ta phiii co gii\. Irj In::n duong tin hi¢u g luon btltlg '0'. Neu bat dau qu;.i trlnh mo phimg III duong tin hi¢u lI. ta nh:1t1 dW)'c giil. Irj tren duong lin hi~u g se htmg 'U' ( thea hlnh 5.2:I.c ). VI gi;\ Irj tin hiGu tren duang g luon bang '0'. do do sL.r xuftt 111\:'11 gi:1 tri 'tJ" co ngh!,1 1a gi<i tr! c16 e6 the: lil '!' ho~e '0'. Sl,l' xufit hi¢n gi'l. lri 'I' tren duang g co nghl:il l:t trong mi.leh co Iht xiiy ra sy- (ri. Dieu nil),' Ch1~K qua trinh \TIO hinh hOi\. d\.f doan, nhung trong lhy-c Ie kh6ng hao gio xiiy ra. Neu bat (hiu qua trinh m6 phong tiI duemg tin hi¢u c, 1<1 SC I1h(\I1 dum: g = 0 ( thea hinh 5.23.b), boi VI dQ tre e\.fe tieu tfen duo'ng lill hi¢u c - d - (' co gia tr! hang 4, Irong khi d6 dQ Ire c~rc d,.u 1n':n throng c -fbang 3. Nhu V~\y, 1ren hai duang tin hi¢u e vilfkhang: bao gio' c6 cung gia tr! '1' dong tho'i va dieu d(l co nghl<.l ia duong g lut'Hl nh~lll gia tr! '0'. Khi ta m6 hinh hoa mi lch voi mo hinh tre khong xac djnh wong ling voi mnh 5.24 Hien IlrciIlg ll1a fQllg mi.!ll gi,i lri 'U· khi ~lr oVng mobll\h Ire khong xac d!llh. - -'' ''<'-f-' a Q a -l 1 b Q ,,-, __ L J L __ ~ Q , - .~ truong h<;1p xuu nhat, moi khi tin hi¢u di qua mi~ch, mien gia trj 'U' co th~ sc bi m6' r(mg. Ta hay xct hO<~t c1qng eua m':,lch Iriga RS voi hai phil.n tu NAND e6 cung thong so thai gian tre ( hinh 5.24 ). Ta SLr dl.mg mo hlnh tre c\.fc di).i - c\.fe ti~u voi t ~\ = 2 va L\, = 1. Oi;i thie'l, tr~ng thai ban (h\u Q = '0' . Q = '1' va a = b = '1'. Trang tn10ng htJP khi gia tf! tr~n duang a lhay doi tu '1'~ '0'. Khi a thay doi, a dau ra Q xuat hi~n gia Ir! 'U'. Gia tr! 'U' nay - - sc sinh fa gii hi 'U' t<!-i (Mu ra Q. Vi¢c liep t~c qua Irinh tl1'11 loan voi de gia tri 'U' dan t6i tinh tri).ng sau: bat dau tiI mQt thoi diem nao do. gia trj cua Q \,J Q tr/1 thanh 'U'. Nhl1 v~y mo hinh tn~ khong xac djnh khong th~ <l.p dyng dlIqc Irong trlIcmg hqp nay. Trong de m~ch so, vi~e tinh gia tri thong so thai gian Ire se phy thuQc 119 . _ -, ~ -, OL J' -, L_r ~- lilnh 5.19 Hoal cltmg ella mach Iren hlnh 5 I g 6i m{l hlnh Ire Ihu~in uhi!!. 116 _b __ ~~ __ _ ' ___ ,-L- __ _ -b ~ ~- e. ~lr oVng mobllh Ire khong xac d!llh. - -& apos;' ''<'-f-' a Q a -l 1 b Q , ,-, __ L J L __ ~ Q , - .~ truong h<;1p xuu nhat,. dQ tre e.fe tieu tfen duo'ng lill hi¢u c - d - (' co gia tr! hang 4, Irong khi d6 dQ Ire c~rc d,.u 1n':n throng c -fbang 3. Nhu V~y, 1ren hai duang tin hi¢u