a. Bi~u dien kien true thco h~lfih vi Bie'u dien kicn truc ella thl!e tlH!f thea himh vi Iii ma IiI chue n£ing elw h¢ thong wong tlJ' nhu d.e chuang tdnh phan mem btng cae qua tfrnh tinh to{lIl. Trong bieu dien nay la khong cung ctip chi tict \'i~c thl!e hi~n ,hiel ke. Trong ngon ngli V HDL, de bicu dicn kicn true theo hanh vi, diu true ehfnh eua htlI1h vi sc Iii qmi lrinh. M9t qUii tdnh c6 the eoi nhu Iii rnQl chuang 11'll1h va dW1e xiy dl!ng lu nhU'ng cau true thu IJ,lC va co Ihe: eho phep gC)i cae chuang tftnh can gi6ng nhu lrong cae ngon ngO' qp trlnh truy~n Ihong. Ta hay xet vi d~l rno ta kien true cua m ~eh ct)ng mOt bit bang hanh vi. Trang m6 lit chua m¢l qua lrrnh voi ba tham s6 iu cae tfn hicu A. 8, Cin. etc tin hi¢u mi.y ctuQ'e chua trong danh saeh cae tin hi¢u t<k d9ng 'laO qua trlnh. Vi~c thl!c hi¢n qua tdnh sc dung l~i neu khong eo de Sl.t ki¢n x<iy tra Iren de tfuong tin hi~u xuiit hi¢n tmng danh siich hay noi mQt each kh{IC 1;1 cac tin hi¢u lrong danh siich di.e tin hi~u tae dQng khong thay doi gia Ir!_ Moi khi c6 mQI slJ' ki¢n x:'y fa lfen cac duong tin hi¢u, qua trlnh siS dU'<)'e kieh ho~1t va d.c cau I¢nh ben trang cau trlie se duqe thl!c hi~n tuan II!. 142 architecture BEHAVIOR of FULL_ADDER is begin process ( A, 13, Cin ) begin if ( A = '0' and B = '0' and C = '0' ) then Sum <:::: '0' : Caul <:::: '0' ; elsif (A:::: '0' and il :::: '0' and Cin :::: '1' ) or (A:::: '0' and il:::: 'I' and Cin::::: '0' ) or ( A :::: 'I' and B:::: '0' and Cin :::: '0' ) then Sum <::::'J' ; Cout <:::: '0' ; clsif ( A :::: '1' and 13 :::: 'I' and Cin = 'I' ) then Sum <:::: 'J' : end if end process; end BEHA VIOR; Cout <:::: '1'; A B J C,n • F.A -·c '"' • S S=A8JB8JC m C,,", = (A 8J Fl)C m + AFl A __ t \0~~! B ___ I -:L./ II ~r,.i \:;:-~ :: ' }"/'j S::: A(fJB ex: mnh 6.5 ('[ill (rllc viI hilllh VI b6 con)?: lll('lt bit. .,' I , ',j II C ,n I _____ J c\~ C ::: "" out· J ) ~_/ M¢I qu<i trlnh m6 d. h;mh vi ella mQt phau ho~c tOlln b(l thiet ke. Qua trlnh xuc uinh d.c khoi rna l~nh luan tv uQc l~p. Cae khoi nay co the duq'C klch hOi.~t ling voi cae bien u6i tr~ng thai eua lin hi~u. Khi co nhicu han 1l1l)t qua trinh trang kien true thl nhung qua trlnh do tIm;)'c tlwc hi911 u6ng thai. i. Mu hinh hanh vi Thie'! ke' so dU<;1c md hinh hoa nhu mQt nhum cae phep lOan lac d¢ng len cae gia Ir! du li~u truy~n qua h¢ thong. Trang ma hlnh htll1h vi ella VHDL Qua trinh i Qua trinh k ._- ~ I tin hleu -L /' ~~ 'Tc \ )- I '- II i tic h;" I· ._ I ~~ ~ tic h;', r "" ~ rL ~ ~ I tin hi$u L- _ Qua trinh j I M6 hinh cua qua trinh II'inh 6.6 }'fo hlllh hoa! d(ll1g cua mot qua Irlllh process. 143 mOL phcp loAn dugc gOi I~l mOl qua trlnh va cac gia tr~ du li~u di qua h¢ Ihting duO·c gOi Iii. tin hi~u. Mot M thong c6 the coi ia trip hqp cac qua tdnh \'~l cac qu<.l trinh tucmg tac voi nhau thong qua cae tin hi~u. Tilt d. cae qu,i trinh trong mo hinh tlwc hi~n dong thai va cac tin hi~u Olf(jC oung ot dlnh vi cae qua trinh song song. Chung ta co the coi vi¢c thlie hi¢n mt?t qwi trinh nhl1 I119t vi:mg i~p vo iwn. Y DOg \~p nay bAt driu tli vi¢c tlwc hi¢n oong l¢nh dilU tien. Lil) lugt den dong l¢nh thu hai, tht'r ba, eho den oong \¢nh cuoi ClHlg va li.li quay trt)· Ii ti d{)ng \¢nh driu tien. Yi~c tlwc hi~n cae diu I¢nh tmng qua tdnh duqc th!!c hi¢n cho dc'n khi g0P dIU l~nh wait. Khi bj dling 10-1. qua trlnh e6 th~ duqc tkp tl]c tlwc hi¢n tra Jai. Di~u kl~n de qua trlnh thl.!C hicn Ira L ti phl] thuQc vao tho·i gian thai gian ngung cl.!c di.~i tmng ctlU l¢nh wait tn)i qua. Trang ohicu tnIang hgp qu;.l trlnh c6 the dU(jC kich hOQ.l tr6 1;.\1 ILl)' thu~)C \'~I.U sl.! thay dbi tqmg thai clla d.c tin hi~u tac d9ng ho~c khi cac dieu ki9n d~t Ia dugc thoa man. Ngoo ngu- YHDL cung dip kha nang ml'i t~i. nhung tin hi¢u tac d¢ng vao GtC qua tdnh bang oanh sach cUc tin hi~u tac dtjng. Khi gl<.1 tri Clia dc tin hi¢u trong danh sach tac di;mg hi thay d6i. qua trinh dlf()"C kich hm'lt va biit ddu tlll!c hi~n. 1'r011 hinh 6.6 ta C(S 1116 hinh kien true clla h¢ thong gom ba qua trinh i,.I, k. Moi qua trlnh i va.i e6 hai tin hi~u tic d()ng con qua trlnh k ch"! c6 m(l\. tXiu fa cua qua trillh i n6i voi duu van eua qua trinh k va dau ra n\a quci.lr1nh .i noi Vl1·i dAu \,~lO clla qua trinh i. Ca ba qua trlnh clmg tlll.fc hi~n dong tlll1"i \'it de tin hi¢u tac dl)ng dung de kiem soat tien trinh t1wc hi(:n cae qua trinh. 51.! thay doi gia tr! tin hi~u t,~i llhung thai dic·m tho-i gian X<l.C d~nh duqc the bi9n qua "thai diem mo ph(·mg" eoa h~ th6ng. Thoi di6m ml'i phong trong ngon ngu YHDL la thoi (hem tQ i do C() cae sl.! ki~n xuat hiQn tfen duang tin hi¢u. Khii ni¢m th0i diem m6 phong tren thue te la khac voi kh<ii ni¢m Iho·i gian dflng ho I1Qi ti li. CJc qua t1"il1h lrong YHDL dW1c kich ho~.lt l<'.li moi hhi e6 slJ thay doi gia lr\ cua tin hi¢u trong danh sil.eh tin hl~u tac d(mg. Khi qua tr"hlh t,~o nen gla Iri eho tin hi¢u (Uu fa, hl' thong m() phong se chi oinh luqng ttl th(11 gi<l11 trU"tl'c khi gia p.' dU(K gih ra dau ra. LLie do ta noi rhng h~ mo phong th~rc hi¢n vi¢e d~nh c IUC1l1g trillh ch,) glao tac sau thai diem ma phong xac dinh. H¢ thong ma pho,tg clla YHDL cling cho phep dinh chuang tdnh 144 cilo tn()l s{i btll k5' de glao lac d6i \,()'i duO'ng tin ilJ(~u ra. T(lp hqp t[11 d dc giao tac d6i v6i tin hi¢u Irollg llH)1 qUi' Irll1h gql hi VI-IDL eung cf\p m6 illnh hal giai do"m: elm Irinh tnt) phong. Trang giai doan 1: gia Ir~ Cllil c,ic 1111 111~u "t:; lIme 1112n giao dich lrong thi)'i gl<ln hi¢n t',li dune Illln 1116i Trong gi<li do'.HI 2: nhilng process nh(ll1 I'h(mg lin tai Ilhung till hicu laC d()ng sc tIme hi¢n Ilnll tn,in ello leii khi bi Lreo. Kel thue gJai aat crall rna phung Chu trinll rna phong GI8i doan mot crlp nh~t tin 'hieu Giai do~n tlai Thlle !lIen Ifnh toan Di~u khie';n tieh trinh cae qiao dich Ket thue rna phong C lIinh 6.7 ChUll'inh m() r1l(ing ell;! qu~i lrlilh. dO<,lII 2. Iht)'i diem me) phl'Hlg se nh:ln gJ<.l tq m(ti va eilu tdnh tll\rc IH¢n h.li. Nh:1 thie't kl:' co Ihe chi dinh tho'j gian tinh ILr thlJi di~m hi~n tho"j 1l1~\ gi<i Ir! SC du\l'C glri It'li tin hi¢u ra trong dc du I~nh g(m lin hi¢u. l\eu lrong du 12nl1 giin lin hicu kh{)ng chi r6 gl(1 Iri IhO'i gJan tn: hofle gi:.i Iri ni:IY b{lng '()' thi Ihi.'!'i giaD Ire lll~\c dPlh delta eua bO nH) ph('lI1g ,,~ duqc sir ciL,mg d~ dillh J.ich Irinh cho Ihao 1<IC. Thb'i gian Ir~ nay khong thay doi thai di~m :,\u(t't hl¢n tin 11l¢u d(ing 11<.) 1110 ph(lllg nhulIg dUo'e ~Lr dung d~ kel Ihlic m()t rilu Ir'1I1h mll phong \':1 btll (till m(ll elm trillh 1116i. :.Jc'u gia Irj mai duqc g<ln cho 1111 hi¢u kll,ic \'6i gi;t If! cu. Ircn dU'CI1l2 lin hi¢u XU~ll hi¢n s~r ! icn. Phong deh me) 1<\ kic'n true th("o dim!; liCf lil:u dfIC III 11¢ th6ng nluf Gil' hi~u di~l1 song ~ong Clla Ci\c dim!;! du h¢u Vi:I dilllg dc tin hi¢u dicu khi~l1. Then plllMng ph,ip ni:l)' cbllng ta 1116 1:'1 dc cii:Jng th6ng lin. h.lnl1 vi lUiln ehuy0n e:.ie dong dCr licu 1hen Ihtl'i gian eua dc hi:lln 16gic 10 hlJP nlw 1\1i.lCh e(lllg. mi,leh so ~iinh. m'.lch gi,'li ma V~I de pld.n ILr IC)gic eo S()'. Vi du, la et'l th0 hi~u lilcn kic'n Irue cua n1<.lch C(Hlg FULL_ADDER then phong dell dClllg dO- li¢u nhu "'-Ill. 145 architecture DATAFLOW of FUll_ADDER is signal S : BIT ; begin S <:::: A xo I3: Sum <:::: S xur Cil1 alTer IOns: COlli <= ( A and I3 ) or (S and Gn ) affer.5 I1S : end DATAFLOW: Trong yf dl,! nay la co ba bicu illl.Ic gall lIn hi¢u song song. Moi hicu IhLIe g,;in nay c6 Ihe: hieu nhllll1QI qua Irlnh ,,6i lIn hi¢u "c' ben ph,ii ella phcp g,ill !~l cae lin hi¢u ntnll Irong danh sach dc lin hi~u Ik d¢ng eua qu,i Irlnh. Vi cll,l, Imng phcp gan IhLI ni1{l\' duang lin hieu S se nh(lIl giJ If! A xur B sau khl c6 Slf h211 XU.r1 hi¢n tfell c1u())1g A, ho~e Iren du(mg B hO~le IreB cil hai dUi\ng A \",1 B. 6 dily chung la kh6ng d~t gi<.i. Ir~ tLrO'ng minh ella IhO'i glan Ire. Do do de 111l) phong tic'n lrlnh thVe hi¢n qua Irinh theo thai giall, he thong Sll (h.ll1g Ih(:1i glan tre m(lC dinh delta. Trong phep g{1l1 thu' haL duung tIn hi¢u Sum nh;)n gi<.1 tri hic'u thu'C S xur Cin sau IOn" so v{ii Ihi:J'i dIem c{l cae Sl! ki¢n Ircn uic d£ill "ao S V~\ On cu,\ phfill tll XnL Cling tU'C5ng tu nhu v(ly. dueing lin hi¢Ll COlli ,,is nh.)n gi:1 Irj « A and B) or (S and Cil1) sau :'i noS ",0 y6i Ihbi diem co sl.r ki¢n treB cae throng lill hi¢u A, 11. S ho,)c Cill. Cic htlllg sC:i co sa eo the dvqc dung nhu cae Iham so Ire. Trong vi d~l Illty, ehting ta Ih[iy cae khai bao ella tham so tre cua ph:in khai bao tlwc tile \'ll vi¢e slr dl,!ng chung lrong kicn Irllc. 14G VI dl.l. entity FULL_ADDER is generic ( K TIME := 5 n.'i )~ port (A. 11. Cin ; in I3IT; Sum, COlli: uut BlT)~ end r-ULLADDER; architecture DATAf-lOW or FeLL_ADDER is signal S: BIT: heg,in S <=A xUI'll : SUI11 <= S xor Cill Hiler 2*N : Cout <= (A Hnd il) or ( S Hnd Cm ) affer N ; end DATAFLOW, e. meu dien ki,Yn truc hang cau true Phong e:."teh 1116 t:.t kie'll truc th6ng lJua c:lu tr(ie x,ie d.illh call true eua thue th~ ~U' d~l11g e:le khai 0,10 ella c:."te pldn tt! thlll1h ph[ill \'il cae phicn b,111 eua cae phiin tu thill1h phan. Cue mel hi cau true eh{ra danh ",:.\.ch eae philll tu hO<)t d<)ng c[{)ng thoi Vi:l licll ket giil"a ule ph:ln tu do, Vi Ul,J, khi ta m6 1<"1 C:'\U truc cua m<wh c<)ng m(ll bit FULL_ADDER. M:'.lch feLL_ADDER dti'(/e Ihi6"1 ke tren co' s('j c:te thLll1h pllan Ii:I HALf< _ADDER viI OR_GATE. Clu true dlfl/e thie't he' ella m:.lch e~)ng I1H)t oit chua hai m:.lch nt'ra tong \'il llH)t phiin tU'logie eo ball l~l OICGalc, C.i.c phiin tu nily licn kc"t voi nhau btmg e.:ie tin hicu. I ~ '0 ~N3 HA2 Sum ~ > - i c '" Il"Ilih 6.N CIU In.k (', lillIe kitn (nk ell~l m;.lch C011i! 1l1(1( bit ell<! h,1I till hitu. architecture STRUCTURE of f<ULL ADDER is component IIALF _ADDER }lort ( L ILl: in BIT; Carry,Sum : out BIT ); end compunent: compunent OR_GATE 147 hegin port ( LJ. L2: in nIT; 0: uut IllT ): end component signal N l,N2.N3 : BIT; HA I : HALF_ADDER port map ( A, 13, N L 1\2 ); HA2: HALP _ADDER port map ( N2. Cin. N3. Sum ): ORI : OICC;ATE port map (NL N3. Cout): end STRUCfURE; Khi d(l phlie li.\P ella thie"1 ke' lang iC:n. ni1a thiet ke tlllIong ph[m Uieh h¢ th6ng th~l!lh nhung h¢ thong con. eie h¢ Ih6ng con Ilay li~n kc"t ch(lt ehe theo ehCre n[lllg lrong thanh phiin eua h¢ thong t6ng the. Moi h¢ thong con le.ti Cl) th(~ dtfqe pilan tach thimh nhu'ng phan h¢ 6 111ue th,rp h<Jn niJa. Trong ngoll ngu' VHDL o' mCfe eao nh:;t eua Ihie"t ke nguai la slf dl;lIlg m6 hinh kicn tnk theo ['hong deh du true eua tlWe Ih~. Ciu true nay se g01l1 t;)p hqp phi":n lxin eua de ['him h~ ke"! noi v0i nhau bang de dU'ung Illl hi¢u. Moi phien bi111 ella Ih;'lllh phiin mi.lCh du\l"C m6 t.i b,\ng de h(lp den trong hicu lhell e[iu true \"(5i e<.te licil klYt cUu v;:\O V~I lien kc"! (bu ra du"U"c 1116 Iii ro rimt-!. eic phien IX"1ll thilnil ph:in ph li lUang thfch \'6i e.te t1We th':. Cic time the ni\y ;0 mi.) lei de chu'e nimg eua Ih~lJ1h plliln mach btmg cae mil hlllh ki61 Iruc theo bi':u dl~n e{lu Irue hO(1( h~lllh vi. Vi du, d6i \"()'i m< \Ch u)ng m(ll bit ella hili tin iliell. ta co m'.leh eQng "i,: dU"eJe X[IY dvng tu Iwi 1n'.lCh !lila tClng "il In(lt phrin tu OR. Khi d6 theo de m() 1,\ kicn true ella cae Ihve the bang e.ie m(l t,i cAu true. thve the H;LL_ADDER c1uqe t,.\O b()'i hili lime the HALf_ADDER V~I lll(lt tlH.re the Ol-COATE. Trong d{l tlwc til': HALF_ADDER co the c1w;/C xtty dL.rng til cae philn tu XOR V~l AND. \IJ{) t.l th~re th~ HALf_ADDER theo cflu Irue tu de rlltin Ill" AND "i\ XDR, 148 entity HALf_ADDER is purt ( 10, I I : in BIT: S, CO : out IllT ); end HALf-_ ADDER; an:hitecturc STRUCTURE of HALf_ADDER is component XOR_GATE port ( III. I I: in IlIT; 0: uut IllT ); . qUi' Irll1h gql hi VI-IDL eung cfp m6 illnh hal giai do"m: elm Irinh tnt) phong. Trang giai doan 1: gia Ir~ Cllil c,ic 11 11 11 1~u "t:; lIme 11 12n giao dich lrong. rilu Ir'1I1h mll phong ' :1 btll (till m(ll elm trillh 11 16i. :.Jc'u gia Irj mai duqc g<ln cho 11 11 hi¢u kll,ic '6i gi;t If! cu. Ircn dU'CI1l2 lin hi¢u. ni:l)' cbllng ta 11 16 1: &apos ;1 dc cii:Jng th6ng lin. h.lnl1 vi lUiln ehuy0n e:.ie dong dCr licu 1hen Ihtl'i gian eua dc hi:lln 16 gic 10 hlJP nlw 1 1i.lCh e(lllg.