chuang trlnh VHDL. cac nha thiet kc can cung cap t~p hqp cac gi,i tl\ thu: nghi¢m t<;ti nhfrng thai diem rna phong xac dinh. 3. Tong hqp m~ch T6ng iWp m<:tcJlla qua trlnh xay dtfng cae ma tii. thiet ke tlr Ill,)t muc trlI'u tvqng nao do sang O1(1t rnue tI'lru wqng thap han. Qua trinh nZiy c6 the' lao SlJ bien d6i tlr hanh vi nay sang hanh vi khac ho~e til hanh vi sang cau true. Qua trlnh bien d6i nay wang ttf nhu qua trlnh bien dieh chuang tdnh phan m~m viet tren nie ngon ngu b~e eao sang cac ma assembly. Cae dau vao CUll eae eang Cl,l h6 trq thict k€ thL1i1ug 13 cac mo t3 tren cae ngon ngu HDL, d.c ca ehe di~u khi~n thai gian, d.c rnl,lc tieu toi uu, cae thu vi~n ky thu~t. Dau ra ella h~ thong h6 trq thict ke iii. cae danh saeh m;:.mg iWli da toi uu, eae hi~u nang ella m<;leh, di~n tfeh eua thiet k6 duqe xay dlfJlg. Sau dfty chung ta mo tii. ngan g9n ve qua trlnh t6ng hqp hanh vi, tong hqp 6 mile thanh ghi truy~n d<;lt va t6ng hqp logie. - Tong hqp h~l.Ilh vi ia qua trinh bien doi cae m6 til. bang nhfrng ngan ngfr thu tl}-e sang cae rno t1 6 mile thanh ghi truy~n c1<;lt. Thiet k€ 6 mile thanh ghi truy~n d,!.t thuang bao gam cae duang truy~n dfr Ii~u, cae mf,leh nha va cae b9 di~u khicn. Qua trlnh tong hqp hil.llh vi thuang 'duqe gQi Ia qua trinh tong hqp (j mile eao hay eon gQi Iii. tong hqp kien true. Buoe nay thuang baa gom tong hqp eae duang du li~u, t6ng hqp cae m,!-eh nh6 va tong hqp eae rn;:~eh di~u khi~n. Tong hqp a mile thanh ghi truy~n d,!-t Ia qua trlnh li,lO ra eau tnk m~ng eha cae m<;teh tuan tlJ tu t~p hQP cae ham truy~n d~t thanh ghi. Cae tr~ng th;:h wang lIng v6i ehe'd(l dong ho cung duqe xac d~nh a mue nay. Gie thao tae a mue thanh ghi truyen d<;tt co the m6 tii. h<lng cae 6tomat ·hfru h~n ha~e t~p hap cae phuong trinh truyen d<:J.t a mue thanh ghi. Cae thanh phau ella qua trlnh bao gam: t6i uu hoa tr'.lng thai, rna hoa tr<,tng thai, toi ~ hoa logic, anh x<;t eang ngh~. T6ng hQP logic la qua trlnh ehuycn cae bieu dicn il1'.lch bltng cae bieu thde lOgic sang cae m<!-ch logic. Qua trlnh t6i uu hoa mi,leh lOgic thiet ke' duqc chia Hun hai giai do~n: cae qua trlnh tai uu flTli,leh kh6ng phl! thUt?c van eong ngh¢; va cae anh x<;t cae sa do 135 va cae phD.n tLr vaa cae lien ket ella cae phall tu rna la trang h¢ tim vi~n. Nhu vav chuno ta d5 lhav ohlinu kh,ij nicm chuna ve n06n ngu VHDL va • ., '" • I:> • I:> c- cae giai do,-~n trang qwi tdnh thiet k€ Slr dl;lIlg cae ngon ngu m6 1,1 phan cung. §6.2. Cae cau true ca S(1 trong VHDL Moi m¢1 h~ thong nwch so duqc thief k€ nhu Il1(Jt h¢ phan cap cae m6dun. M6i modun luang ling voi m¢t tlwe the' ella thie't kc trcn ngon ngu YHDL. llwc the' thiet kc th~ hi~n mQt doi tuqng ella thiet ke phiin cung. Doi lUqng nay c6 cae dau vao va dau ra dU'qc xac djnh r6 riing, dong thai thvc th6 thie't kc cOng plul.i chi fa duqc chue nang eua doi tLfQTlg thOng qua cae phep toan duqc d!oh nghla truDe. M6i thl!c tht thiet k€ g6m c6 hai phiio: phan khai Mo tlWe tht va kien true tlwe the'. Phall khai bao thl!c th6 1116 ta d<:lllg ben ngoai ella lhL!c tht, cac giao dien clla thL!C th~ voi cac thL!c th~ khac. Giao di¢n nay ctuqe the hi¢1l qua d.c c(jng vao va cdng ra clla thllc th~. Kien true tiwc the' ma ta nhung thanh phan ben trong cua th1:l'c th~. Ngoai ra chung ta con c6 th~ dung cac g6i ti~n feh de h6 trq thiet ke. Cae g6i ti¢n feh xac djnh dc thong tin chung CUi] m(H so thl;fC the. Ctic tlwc the con c6 dc cau hll1h. cau hinb Iii. d.c d"U1g ttrcmg duang cua thiet kc. VI dl,l nhu rn~ch mIa Idng eo the coi lit IllQt thy'C the thiet ke. llwe the nay co the duqe xfly dL!llg trell cac phan til NAND Ii.O~lC tren de phan til NOR. Khi d6 ta noi thL!c the: nay co hai cflu hlnh. Cac cau hll1h eha phcp ta khao sat cac bien the khae nhau ella thict kc va lL!a ehQI1 nhung bQ thiet bi t6i lID. Cae thu vi~n iii. t~p hqp nhiing thL!e th~ dUQ'c rna ta SaIl. Cae thlle the nay duqc bien djch va llID tril thuang trl.fc. cac thL!c the' trong thu vi~n se duqe str dl,lt1g tuy thea muc dl) quan tn:mg trong thiet ke. Cac cau truc co sa cua ngon ngO' VHDL bao g6m: 136 Cae tlwc the' (entity) Oic kien true (architecture) Cac goi (package) Cac nlu hlnh (configuration) Cac thu vi~11 (library) 1. !\to fa cae thl!c th~ Cie khai b,io thl!e the eho ta cai nhin d6i vai phiin ttr tnQ.ch din dUQ'c 1116 ta tir m(lt ben ngoai. Bing de khai b,-lo tlwe the, phan tu lTIi;leh sc dUQ'e ma t,l bang so lUQ'ng \'a eh(re nang ella de eang giao tiep va de tll1h ehat eua clU ii~u t, ti c;1e ecing nay theo phuong di¢n tu ngo~li v~lO. Cie khai baa thl/e th~ khan" eho ChllflO la thtl)' eaeh thue x,!.\' dun o phan tu mach. o 0 •. L>. Ng6n ngCi' VHDL duC)'e m6 ta thea nhO:ng quy tAe eu ph<.ip. Doi vai cae m6 ta t1wc the, eu phap c6 d<.mg nhu sau. entit)' {('II~th//c_'h/is I begin [ I ~Jllh _ klulI'_!Jclo _generic ] [ cac-'II~/t_t<lI'_cU'lJg I 1 ('(Ie thdllliy!/(In kIwi buo tlll/c tlii I - - - - - C(lc_t hanh y/uJII_billl_Illli'c_t III/C_lhi/ I end l tell_tll/fe_lh"']; L¢nh khai baa generic dung de khai b,to cae tham s6 dUQ'e Slr dl,ll1g d~ kicm soat diu true hO~lC h~U1h vi ella thlfc the. eie hing s6 nay gQi Ii cae tham s6 chung. Cae tham so chung co ph'.llTI vi su dy.ng trong tO~lil b9 thve the. cttu I~nh generic co ell phap nhu sau, generic ( lell)ICllIg: kid'lI_ COil [ : = gia _11"; _J.://(fi_tWJ ] 1; tell_hung: kie'II_COIl l := gici_IILkluJ'i _/~IO 11 ); tell_h/ing: 1a ten eua {ham so ehung. kh;'ll: kieu dO: li¢u eua tham so. gicl_lnJI/(;'i_t~lO: gia tr~ khoi ti;lo ella tham s6. eie 1u(lt e6ng d~c tii eho cae kcr giao tiep ella {iwc the va e6 quy tac ell phap nhu sau. port ( tdllJ61lg: l mode] kill/_con [ := gi(I_'ILkhd( t~/() ] 137 I; rCII_cd'lIg: [mot/l! 1 kt(]H_COIi [ ': g/(l_fll_klul! taol \ ): tell cdng: ten cna c6ng dU0c rna ta, mode: chi huang eua tin hi~u I~i eong. ki/lI_con: ki~u dCf. h~u Ii ll cbng ho~c d.c tham so chung. gi6 _tiL khrii_t(lO: ,gia tr~ khai t<;'o cho cong, Trang phAn khai bao, thl,fc th~ va cae cbng eua thl,fC the luon duqe d~t ten hOi!-c danh djnh danh, Ten, djnh danh lrong ngan ngu- VHDL khang phan bi~t ehu- hoa va thuang. M¢t s6 dinh danh lil cae lU khoa eua ngan ngu nhu: entity. port, is. end •. ,. NhG:ng tit nay co y nghia e6 dinh va kh6ng th~ thay d6i trong loan b¢ ngan ngu Cie ebng la cae tin hi~u k€t n6i tlH!c Ih~ vai de thl,fc the' khac Nhung tin hi¢u ti,li eong duqc di!-l tuO'ng ung 'vai de d~ng: in. out. buller, iRout v,\ de kieu dCf li¢u. Y nghla cua d.e d~ng eong nl1l1 sau. 138 Cong co d\ll1g in Iii. eong chi dung d€: dge, Trong cae rn~eh s6 cae eong d<;,ng in chi dueye :'iii dl,ll1g lam eong tin hi~u vao. Cong d<;lng out lil cong chi d€: gan cac gia trj. Trang thie'! ke rn~\ch. eong d\mg out chi str dy-n,g lam eong tin hi¢u ra. Cong d\mg buffer HI e6ng Co th~ eho phcp d hai thao lac dge va gan dCi' li~u. Nhung trong tung ngCf cimh eong chi e6 the: nh0.n m('ll trang hai ehue nang d9C ho~e gao du li~u. Vi dl,l vc edng d'.mg huffer HI hai duong tin hi¢u ra Q va Qcua RS trigO'. Doi' vai tlWe tht trigo, hal dUo-ng tin hi9U nay Iii. hal tin hi¢u ra. Nhung doi vai hai phan Itr NAND heyp thanh trigo, de duang tin hi¢u nay Hi cac tin hi¢u vao. Trang cae ehuong trinh tren ngon ng[r VHDL, cac tin hi¢u d~ng buffer Ihuang duqc sU d~lJ1g trong cae truong hqp khi ta muon d9c va ghi dll li¢u 6 ben trong chuang tdnh nhung tlr ben ngoai chuang trinh thi chi co the dQe dCf Ji¢u rna khong the ghi vao duong tin hi~u nay. Cong d~ng inout Ia e6ng co th~ Vlra dQc va Vlra gan gi,i Irj. Cae cbng lo~i nay eho phep c6 nhieu dieu khien dCf li¢u d6ng thoi trong rnQi ngu dnh. Cae VI dl:l v~ cbng d<,lng inout co the 1a cae tuyen dCf li¢u vao/ra eua h9 xU- ly, Trong phan c(I(·_thd/Jh~)I/(i/J_kh(Ji_b(io _III/fe_tin;;" ella lhl!c the cht"ra khai h,lo cae hang so, d.c kicu ho~c tin hi¢u co the Slr dyng trang qua ldoh xay . dl!ng IIwc the. Phfin crlc_thdJJIJylullI_hii/u_tlllfc _tll//e_thl chua cae biC:u lhue thl!c hi¢11 dong thai. Cae bicu thue oily dLfqc A A Slr dyng de kicm tra cae dieu ki~n rang bUQc cae I ~ phcp toal1 trong hanh vi eua thl,1'C the can thict kc. J~ -, Ta hay xct vi dlJ !lI0 ta lm~ch c(log lTI¢t hit. C I c out ~ ,n M<.Kh cQng co ten la FULL_ADDER va co ha 1 c6ng vao lit A. 13 va Cillo Hai cong fa ella Jm~ch I I c9~g HI. Sum va Coul. Cae cong vao va fa deu co ~ , ~ .Sum kieu tin hi~u lit BIT, trong d6 kieu mT Iii tn¢t kicu duqc djnh nghii1 truoe ella ng6n ngO' VHDL. Dm.lI1 chuang trlnh rna tii" tlwc the tm~ch cQn£ m¢t bit duqc viet nhu sau. Hinh 6.2 Bic'u dicn ella bo cong !l1(JI bit. entity FULLADDER is port ( A, B, Cin : in BIT; SUlll, Cout : out mT); end FULL_ADDER A(3) 6(3)A(2) B(2)A(1)B(1) A(O)B(O) Chung ta co th~ ki~m soar cau true va che d¢ dtnh thai gian clla tlwc th~ bang each su dl,mg cac tham so chung. V f dl,l, ne"u chung ta muon x<-ly d~ng m,-~ch cQng N bit, ta sc dung tham so chung N de chi so bit clm m<;lch c(mg va tham so chung M de d~e tfU'ng cho hanh vi thea dien bien thai gian clla th~c th6. Trang truling hqp mo ta b¢ I' L'J I· I I~_I I ,-_I l, C out I I C m ' 1-' ,[- S3 I S2 !S1 Iso Hillh 6.3 nl~u dien cua bb cQllg b5n bit. c¢ng bon bit, ban dau N dUQc k:hoi t<;1o gia tri 4. Trang qua trinh ma phong ho~lC tong hqp m~ch gia tri th~c clla C,i . tham so chung co the: thay doi tuy thea nhu duo D0<;1n chuo'I1g trlnh VHDL sau cho la vf dl,l me ta m~ch c(mg bon bit. 139 entity ADDER is generic ( N : INTEGER := 4; M : TIME := 10 ns ); port ( A, B: in BIT_VECTOR ( N - 1 duwnto 0); Cin: in BiT; SUM: uut BlT_ VECTOR( N - 1 duwntu 0); Cout : out BIT ) ; end ADDER; 2. Cae kie'n true Sau khi cae phan tir Im.teh <lllCJe mo tA III m~H ngoai b[mg cae khai hao tbl!e the, 1l1(:l1 hO~le nhifu c;J.eh tlwe hi¢n phfin tu sc dvqc mo ta hang cae kien true. Trong ngon ngu VHDL. cae kicn truc eung eap cai nhin ben trung eua tlllse th0. Kicn true eua tlWe tlH~ xac <linh m6i quan h~ giUa cae driu vao V~l cae driu ra etla Ihl;fe Iht: va eo the bieu dicn thea hanh vi, then dong v~n ehuyen ria li~u hO(K theo etiu true. Kien true xac d~nh cae eh(re nang eua tbl!e tht, Kicn Irue ehu'a phfin khai b<.io, trong do hao gom cae khai bao eua tfn hi¢u, khai bao kieu, khai bao htmg, khai bao cae th~lI1h philn va cae ehvong trlnh COIL Theo sau phfin khai h;.lo la phan than eua kie'n true, Trong phan than eua kien true chua ei.l.c eau ket diu thl!c hi~n dong thai. Cic kct c[iu thl!c hi¢n <long thai eo the ia: eae khoi gan tin hi¢u song song, cae kh6i Cil'u true va de thanh phan khai t\lO, Cac kG't cAli tlwe hi¢11 dong thai the hi~n tinh chat thve hi¢n <long tho'i ella cae thi:tnh phan pilan e(fng !rong thie't kc"khi e6 Sl.f thay doi tn mg thi.ii tin hi~u tae d¢ng vao ITIi leh. Cae kCI cau thl;fc hi~n dclng thai tuang tae v6"i nhau thong 4ua cac tin hi¢u. Moi kct c[iu tlwe hi¢n dong thai xae d!nh ITI'.)t phdn tu t[nh tmin. PhAn tu nay ctQe tin hi~u. tlWe bien cae phcp loan t["en cae tin hi¢u Va gan !lhling gia trj tinh dUlje eho tin hi¢u. Cae kct du nity hieu di~n e,k kh6i phan cling va deh Ihuc lien kct giD"a l'hClllg theo di.\llg diu truc ho~c theo dang htUlh \'i. Btl11g cal 11 do de ket e<:iu thl!c hi~n d6ng thai SC 1110 ta tdng the nYu true va hAnh \'i eua thVe th~ dl(0C thier ke. Cic ket efiu dong tho'i duqe tlwe hi¢n song song khong pill;! thuQe vao trlnh tl! xu[tt hi~n eua ehung trong mo ti kie'n true. Kicn true dU'qc mo ti.l theo quy tae eu phap sau, 140 architecture (('/I kh'll (nle of {('II flllfe fhc'" is - { plul'lI_ kiwi _/l(fO _ 0;(/ Ji61_fnic 1 begin \ dC_AC"_uill_tIIllC_'IICII_J{JI1I; fh/ii) end [ fhl_ki(lll" fnie ]; Trong do. f('/I_f!t(i'C_fh/ la ten eua d6i lUq'ng sc xay dl,mg. Ten nay phili trung vai ten eua tlll,rc the: luong ung vai kien true cia khai ban trong phiin khai ban thl,rc the:, Phan khai bilo plu/l1_ f.:.flw'_/)(IO JI';(I __ f.:.i6/_fnic ehu:a nhling khai bao trong tna ttt kicn true. Hai uau \ 1 eo nghla la eo th6 kh6ng chua ll1l)t khai bao nao ho.;te eo chua nhicu khai bao. Phiin flam gina hai IV kho i begin va end, ('(Ic_UI_uill_tlll./'('_hi(;/I_d/mg_fhrfi xae dinh d,e kh6i phlln eLrng Iheo di,lt1g eau true ho(\e hanh vi. Cae Ihanh phall signals dl:lllg de ket n6i nhii'ng klloi rieng bi~t eua kien Irue, Moi tfn hi~u lUang ung vai m()t kieu dO- lieu. Cae kieu do x,ic dinh d~mg eua dfr li~u duQ'c Iruycn Iren de dlfong lin hi¢u. M¢t thl!c th~ eo the co nhicu kien Irue, Nh~1 thict ke co the Xlly ch;l'ng m6 hlnh thet k6 SLr dl:lng eac pbuong phar thl!C hi¢n kh<ie nhau theo cae gae d() 4uan sat khae nhau hO~le 6 cae IT1UC ell) trvu tI1<;mg khac nhau. Th6ng thlfll'Jlg, ta eo the bieu dien kien true cua m(H thl,l'e the: d ba phuong di¢n: phlfong di¢n hanh \'i, phuong di~1l dong dfr li~u va phuong di¢n ciiu tnk. ~101 kiell truc cung c6 tilt eo hon hQ'p d ha phucmg ui¢n bieu dien thiet ke. Ta h~IY xct \'i dl! bieu dicn kien true thiet ke eua 1TI' lCh e()]Ig 1m)t bit. Theo h~U1h vi. m' lch cQng eo the UU'(1C hi~u dicn nhlf mc)! h~ ham Il'lgie t<ic ch)ng lcn ba bi(Yn d()e Itlp la A. I3 va Cin de hlnh thanh cae tin hi¢u ra la Sum va COUI. Then deh bi~Ll dlcn bill1g dbllg dO- li~u, mi lch ct)ng Ilwe hien c[le tac d()ng. A J ,Sum ~, ; 69 C9 n 9 J ,c'e' Hanh vi 4-/ r~~OCeSS(A, B. G m ) Begin End ~ -~ Dong dCr I lieu T IS<=Axors! Sum <= S xor C1n I after 5ns ~l<=(A&B)V(S&C,~) ___ ~au true ll'inh 6.4 ~16 1.\ tllLIe the mach e6n.Q; va cae kic·nlrUc. _.J \4\ . _ klulI'_!Jclo _generic ] [ cac-'II~/t_t<lI'_cU'lJg I 1 ('(Ie thdllliy!/(In kIwi buo tlll/c tlii I - - - - - C(lc_t hanh y/uJII_billl_Illli'c_t. va cae cbng eua thl,fC the luon duqe d~t ten hOi!-c danh djnh danh, Ten, djnh danh lrong ngan ngu- VHDL khang phan bi~t ehu- hoa va thuang. M¢t s6 dinh danh lil cae lU khoa eua. th6. Trang truling hqp mo ta b¢ I' L'J I· I I~_I I ,-_ I l, C out I I C m ' 1-& apos; , [- S3 I S2 !S1 Iso Hillh 6.3 nl~u dien cua bb cQllg b5n bit. c¢ng