- 1. TrngihcBchkhoaHNi Bmniukhintng Ni dung Tiliutmttbiging 1 MU
................................................................................................................................5H
THNG IU KHIN
NHNG1.11.2Cckhinimvhnhng......................................................................................5Lnhvcngdngcahnhng...........................................................................71.3
cimcngnghvxuthphttrincahnhng .....................................8
(EmbeddedControlSystems) 1.3.1
cimcngngh.....................................................................................8
1.3.2 Xuthphttrinvstngtrngcahnhng
.................................9 TS.LuHngVit1.4
Mcchvnidungmnhc.............................................................................10
2
CUTRCPHNCNGHNHNG........................................................................11
2.1
Ccthnhphnkintrccbn...........................................................................11
2.1.1
nvxltrungtmCPU.....................................................................11
2.1.2 Xungnhpvtrngthitnhiu
..............................................................13
2.1.3
Busach,dliuviukhin............................................................16
2.1.4 Bnh
..........................................................................................................17
2.1.5
Khnggianvphnvngach............................................................21
2.1.6
Ngoivi........................................................................................................21
2.1.7
Giaodin......................................................................................................33
2.2 Mtsnnphncngnhngthngdng(P/DSP/PLA)
...............................37 2.2.1 ChipVixl/Viiukhinnhng
.......................................................37 2.2.2
ChipDSP......................................................................................................39
2.2.3
PAL...............................................................................................................41
3
CSKTHUTPHNMMNHNG....................................................................48
3.1 cimphnmmnhng
..................................................................................48
3.2 Biudinsvdliu
...........................................................................................48
3.2.1
Cchthngcs......................................................................................48
3.2.2 Snguyn
....................................................................................................48
3.2.3
Sduphytnh.........................................................................................50
3.2.4
Sduphyng.......................................................................................51
3.2.5 Mtsphptnhcbn
............................................................................52
3.3 Tplnh
....................................................................................................................55
3.3.1
CutrctplnhCISCvRISC...............................................................55
3.3.2 nhdnglnh
...........................................................................................57
3.3.3 Cckiutruynachtontlnh
.......................................................57 3.3.4
Nguynlthchinpipeline.....................................................................60
3.3.5 Harzard
........................................................................................................61
1http://www.ebook.edu.vn 2
2. 3.4Ngnngvmitrngphttrin
.....................................................................633.4.1
Ngnng.....................................................................................................633.4.2
Bindch
......................................................................................................65
3.4.3 Simulator
.....................................................................................................703.4.4
Emulator
......................................................................................................713.4.5
Thitkhthngbngmytnh
.............................................................71 4
HIUHNHNHNG
...............................................................................................73
4.1Hiuhnh............................................................................................................73
4.2Bnpkhito(Bootloader)
..................................................................................74
4.3Ccyucuchung...................................................................................................76
4.4Hiuhnhthigianthc
..................................................................................77
5 KTHTLPTRNHNHNG
.....................................................................................81
5.1Tcvvqutrnh(process)
..................................................................................81
5.2Lplch(Scheduling)
................................................................................................81
5.2.1
Cckhinim..............................................................................................81
5.2.2 Ccphngphplplchphbin
........................................................82 5.2.3
Kthutlplch
.........................................................................................85
5.3Truynthngvngb.......................................................................................875.3.1
Semaphore
...................................................................................................875.3.2
Monitor
........................................................................................................89
5.4Xlngt
.................................................................................................................90
6 THITKHNHNG:THPPHNCNGVMM.......................................93
6.1Quitrnhphttrin
.................................................................................................93
6.2Phntchyucu.....................................................................................................93
6.3Mhnhhoskinvtcv
..............................................................................936.3.1
PhngphpmhnhPetrinet................................................................936.3.2
QuicbiudinmhnhPetrinet
........................................................946.3.3
MtcctnhhunghotngcbnviPetrinet ............................956.3.4
Ngnngmtphncng(VHDL)
....................................................103
6.4Thitkphnmmiukhin............................................................................1046.4.1
Mhnhthcthibiukhinnhng
.................................................1046.4.2
VdthcthibiukhinPIDs
......................................................106
TILIUTHAMKHO
........................................................................................................108
3 http://www.ebook.edu.vn 4 3. 1M U K nguyn cng ngh mi v ang tip tc
pht trin khng ngng nhm thng
minhhohinihothngsutcchthng.Cthninhdusraivpht
trincahnhngtrctinphiknsraicaccbvixl,viiukhin.
NcnhdubisraicaChipvixlutin4004vonm1971chomc
chtnhtonthngmibimtcngtyNhtbnBusicomvsaucchp
cnhvphttrinvtbcbiInteltrthnhccbsiuxlnhccChipc
ngdngchoPCnhngynay.Thpk80cthccoilkhiimbtuk
nguyncasbngnvphttrincchnhng.Tkhinguncholnsngra
icahnglotccchngloivixlvgnlinlcchnhngthmnhprng
khptrongccngdnghngngycacucsngchngtavdnh,ccthitbin
tsdngchosinhhothngngy(lvisng,TV,tlnh,mygit,iuho...)v
vnphnglmvic(myfax,myin,myinthoi...)...Ccbvixlvphnmm
cngngycngcsdngrngritrongrtnhiucchthngnh.Ccloivix
lcsdngtrongcchthngnhnghinnayvtxasoviPCvslngHnh11:Mtvihnhnhvhnhng
chng loi (chim n 79% s cc vi x l ang tn ti [2] ) v vn cn tip tc pht
trinnhmpngvthomnrtnhiungdngadng.Trongsvncn Hthigianthc? ng dng c cc
Chip vi x l 8 bit, 16 bit v hin nay ch yu vn l 32 bit (chim
Trongccbitoniukhinvngdngchngtarthaygpthutngthigian
khong75%).Gnlinvisphttrinphncng,phnmmcngphttrinvithc.Thigianthccphilthigianphnnhvtrungthccathigianhay
tcnhanhkhngthuakmthmchstngnhanhhnrtnhiutheosphttrin khng? Thi gian
thc c phi l hin th chnh xc v ng b theo ng nh nhp hnhng.ng h m thi
gian hay khng? Khng phi hon ton nh vy! Thc cht,
theocchhiununitrongcchthngkthutcbitcchthngyucukhtkhev 1.1Cc khi nim
v h nhngsrngbucthigian,thigianthcchiulyucucahthngphimbo
Hnhng?thomnvtnhtinnhtronghotngcahthng.Tnhtinnhnilnhnhvi
Trongthgiithccachngtabtkmtthitbhayhthngin/intckh
cahthngthchinngtrongmtkhungthigianchotrchontonxcnh. nng x l thng
tin v iu khin u c th tim n trong mt thit b hay h
Khungthigiannycquytnhbicimhocyucucahthng,cthl nhng, v d nh cc thit
b truyn thng, thit b o lng iu khin, cc thit b
vigiyvcngcthlvinanogiyhocnhhnna.ychngtaphnbit
phcvsinhhothngngynhlvisng,mygit,cameraRtddngcthyu t thi gian gn lin
vi khi nim v thi gian thc. Khng phi h thng thc k ra hng lot cc thit
b hay h thng nh vy ang tn ti quanh ta, chng l h
hinrtnhanhlsmboctnhthigianthcvnhanhhaychmhontonl
nhng.Vyhnhngthcchtlgvnnhiuthnovhnhng?Hinnaycngphp so snh c tnh tng
i v mili giy c th l nhanh vi h thng iu khin
chacmtnhnghanothcsthongcchunhovthanhnrngnhitnhnglilchmiviccitngiukhininnhdng,p.Hnth
richohnhngmvnchlnhngkhinimdintvchngthngquanhngc
nanuchnhanhkhngthchamphimboduytrnnhbngmtc
thchung.Tuynhinychngtacthhiuhnhnglmtphnhthngxl
chhotngtincy.Chnhvvyhthngkhngkimsotchotngcan
thngtinnhngtrongcchthngln,phchpvclpvdnhtrongt,cc(btnh)thkhngthlmththngmbotnhthigianthcmcdhthng
thitbolng,iukhin,truynthngvthitbthngminhnichung.Chnglcthchopngrtnhanh,thmchnhanhhnrtnhiusoviyucutra.
nhngthpcaphncngvphnmmthchinmthocmtnhmchcnng Mt v d minh ho tiu biu
l c ch truyn thng d liu qua ng truyn chuyn bit, c th (Tri ngc vi my
tnh PC m chng ta thng thy c s
chunEthernettruynthng,mcdaicngbittctruynlrtnhanhnhngvn
dngkhngphichomtchcnngmlrtnhiuchcnnghayphcvchungcho
khngphihhotngthigianthcvkhngthomntnhtinnhtrongcch
nhiumcch).PCthcchtlilmththngln,thpcanhiuhthngnhngtruyndliu(cthlrtnhanhvcngcthlrtchmnucscanhtrnhv
vdnhcardmnhnh,mthanh,modem,cng,bnphmChnhiunylm
giaothngngtruynbnghn). chngtadlngtngnuchinnhiuthnovPC,cphilhnhnghay
khng. 5http://www.ebook.edu.vn 6 4.
Ngitaphnralmhailoiivikhinimthigianthclcng(hardrealtime)1.3c im cng
ngh v xu th pht trin ca h nhng
vmm(softrealtime).Thigianthccnglkhihthnghotngviyucutho mn s
rngbuctrong khung thigiancng tclnuviphm ths dnnhot1.3.1c im cng ngh
ngcatonhthngbsaihocbphhu.Vdvhotngiukhinchomt Cc h thng nh vy u c
chung mt s c im nh yu cu v kh nng thi
lphnnghtnhn,nuchmraquytnhcthdnnthmhogyradophngianthc,tincy,tnhclpvhiuqu.Mtcuhitraltisaohthng
ngphn
hchvdnnbngnchthng.Thigianthcmmlkhihthngnhngliphttrinvcphcpmtcchnhanhchngnhhinnay.Cutrli
hotngviyucuthomnrngbuctrongkhungthigianmm,nuviphmv
thcranmccyucutnglnkhngngngtrongccngdngcngnghhin sai lch nm trong
khong cho php th h thng vn c th hot ng c v chp
nay.Mttrongnhngyucucbnl:
nhnc.Vdnhhthngphtthanhtruynhnh,nuthngtintruynittrm pht ti ngi
nghe/nhn chm mt vi giy th cng khng nh hng ng k n
Khnngclpvthngminhho:iunycchrhnthngquamtscc
tnhthiscatinctruynivhontoncchpnhnbingitheodi.thuctnhyucu,cthnh:
tincy
ThctthyrnghuhthnhnglcchthigianthcvhuhtcchthigianKhnngbotrvnngcp
thclhnhng.iunyphnnhmiquanhmtthitgiahnhngvthigian Sphcpvtinsdng
thcvtnhthigianthctrthnhnhmtthuctnhtiubiucahnhng.V anton
vyhinnaykhicpticchnhngngitaunitictnhcbncanlTnhbomt tnhthigianthc. H
thi gian thc Hiuqu:Yucunycthhinthngquamtscccimcahthngnh
sau:Hnhngthi Nnglngtiuth Kchthcvphncngvphnmmgianthc
Hiuquvthigianthchin Kchthcvkhilng H Nhng
GithnhHnh12:Phnbvquanhgiahnhngvthigianthc
Phnhochtcvvchcnngho:Ccbvixltrongcchnhngthngc 1.2 Lnh vc ng dng ca h
nhngsdngmnhimvthchinmthocmtnhmchcnngrtclpvcng
cthchotngphnchcnngcahthnglnmncnhngvo.Vdnh
Chngtacthkracrtnhiuccngdngcahthngnhngangcs
mtvixlthchinmtphniukhinchomtchcnngthuthp,xlvhin
dnghinnay,vxuthscntiptctngnhanh.Mtscclnhvcvsnphm
thcathayhthngiukhinqutrnh.Khnngnylmtngthmschuyn
thtrngrnglncacchnhngcthcnhmnhsau:
bithovchcnngcamththnglnvddnghnchoqutrnhxydng, Ccthitbiukhin
vnhnhvbotr. t,tuin Truynthng
Khnngthigianthc:Cchthngugnlinvivicmnhimmtchcnng Thitbyt
chnhvphicthchinngtheomtkhungthigianquinh.Thngthng Hthngolngthmnh
mtchcnngcahthngphicthchinvhonthnhtheomtyucuthi Tonhthngminh gian nh
trc m bo thng tin cp nht kp thi cho phn x l ca cc chc
Thitbtrongccdytruynsnxut
nngkhcvcthnhhngtrctiptishotngngvchnhxccaton Rbt
hthng.Tuthucvotngbitonvyucucahthngmyucuvkhnng ...
thigianthccngrtkhcnhau. Tuy nhin, trong thc t khng phi h nhng no
cng u c th tho mn tt c
nhngyucunutrn,vchnglktqucasthohipcanhiuyucuviu kin nhm u tin cho
chc nng c th m chng c thit k. Chnh iu ny li7
http://www.ebook.edu.vn8 5.
cnglmtngthmtnhchuynbithocacch/thitbnhngmccthitbaFPGA, PSOC v s t hp
ca chng...Km theo l cc k thut pht trin phn nngkhngthcnhtranhc.
mmchophpmnhimcccbitonyucukhtkhetrncsmtnnphncng hu hn v kh nng x l v
khng gian b nh. Gii quyt cc bi ton thi 1.3.2Xu th pht trin v s tng
trng ca h
nhnggianthcnhphnchiatcvvgiiquytcnhtranhchiastinguynchung.Hin
Vsphttrinhnhnglskthpnhunnhuyngiaphncngvphnmm nay cng c nhiu nh pht
trin cng ngh phn mm ln ang hng vo th
nncngnghgnlinvincngchnhlcngnghkthpgiaccgiiphpchotrnghnhngbaogmcMicrosoft.NgoimtscchiuhnhWindowsquen
phncng vmm.V tnh chuyn bitca cc thit b /h nhng nh giithiuthuc dng
cho PC, Microsoft cng tung ra cc phin bn mini nh WindowsCE,
nnccnnphncngcngcchtoutinpngchochcnnghaynhimWindowsXPEmbeddedvcccngcphttrinngdngkmtheophcvchocc
vcthcayucuthitktra.
thitbnhng,inhnhnhccthitbPDA,mtsthitbiukhincngnghip
nhccmytnhnhng,IPCcaSiemens... Lp h nhng u tin pht trin theo tiu ch
v kch thc nh gn, tiu th nng
lngt,githnhthp.CcchpxlnhngcholphthngngdngthngC th ni h nhng tr thnh
mt gii php cng ngh v pht trin mt cch
yucuvkhnngtnhtonthocvaphinnhuhtcxydngtrncs nhanh chng, ha hn nhiu
thit b nhng s chim lnh c th trng rng ln
bngxl8bt16bithoccnglml32bitvkhnghtrduphyngdos trong tng lai nhm p
ng nhu cu ng dng khng ngng trong cuc sng ca
hnchvdunglngvkhnngtnhton.chngta.ivilnhvccngnghipviukhinvtngho,hnhngcngl
mtgiiphpytimnngvangcngdngrngri.Nrtphhp
Lphnhngutinthcthikhnngxltnhtonvitcthchinnhanh.Ccthcthiccchcnngthngminhho,chuynbittrongcchthngvthitbcng
chpxlnhngchocchthngcngslccChippdngcccngnghcaonghip,tcchthngtptrungncchthngphntn.Giiphphnhngcth
cpvikintrcxlsongsongpngccngtnhtonlnvtcm
thcthitcpthpnhtcahthngcngnghipnhccuchphnhchoncc
ccChipxlachcnngthngthngkhngttic. cpcaohnnhgimstiukhinqutrnh.
Lphthngutinchaitiuchphttrincahailptrn,tclkchthcnh 1.4Mc ch v ni
dung mn hc
gn,mctiuthnnglngthp,tctnhtonnhanh.TutheosthohipgiaHiukhinnhnglmtmnhcminhmcungcpkinthcchosinhvinv
ccyucuvxuthphttrinchnhvvycngkhngcgngcnhinkhichngtakhnngphntchvthitkhthngiukhinvthngminhhohthngtheo
thystntisongsongcartnhiuccChipvixlnhng,viiukhinnhng8chcnngtheogiiphpcngngh.Thitkthcthiiukhintrnnnphncng
bit,16bithay32bitcngviccChpsiuxlkhcvnangcngdngrngnhng. ri cho h
nhng. cng l s kt hp a dng v s ra i ca cc h nhng ni
chungnhmthomnccngdngphttrinkhngngng. Vimi mt nn phn cng nhngthng c
nhngc thringvkm theo mt
giiphpphttrinphnmmtiutngng.Khngcmtgiiphpnochung
vchuntcchottccchnhng.Chnhvvythngthngccnhphttrinv
cungcpphncngcnglichnhlnhcungcpgiiphpphnmmhoccngc pht trin phn mm km
theo. Rt ph bin hin nay cc Chip vi x l hay vi iu
khinuccchphttrin(StarterKithayEmulator)htrchoccnhngdng v xy dng h
nhng vi hiu bit hn ch v phn cng. Ngn ng m ho phn mm cng thng l C
hoc gn ging nh C (Likely C) thay v phi vit hon ton
bnghpngAssembly.iunychophpccnhthitktiuvnginhort
nhiuchobcphttrinvxydnghnhng. Trong xu th pht trin khng ngng v nhm
tho mn c nhu cu pht trin nhanh v hiu qu c rt nhiu cc cng ngh cho
php thc thi cc gii php h
nhng.ngsausphcprngricaccChipvixlviiukhinnhng,DSP phi k n cc cng ngh
cng ang rt c quan tm hin nay nh ASIC, CPLD, 9
http://www.ebook.edu.vn 10 6.
Bgiimchuyni(thngdch)cclnhlutrtrongbmchngtrnhthnh 2CU TRC PHN CNG H
NHNG
ccmmALUcthhiucvthcthi.BtuntcnhimvqunldngdliutraoiquabusdliucaVXL.CcthanhghicsdngCPUlutrtm
2.1Cc thnh phn kin trc c bn
thiccdliuchnhchovicthcthicclnhvchngcththayinidungtrongqutrnhhotngcaALU.HuhtccthanhghicaVXLulccbnhcthamchiu(mapped)vhinhpvikhuvcbnhvcthcsdngnhbtkkhuvcnhkhc.CcthanhghicchcnnglutrtrngthicaCPU.NuccnidungcabnhVXLvccnidungcaccthanhghitimtthiimnoclugiythhontoncthtmdngthchinphnchngtrnhhintitrongmtkhongthi
gian bt k v c th tr li trng thi ca CPU trc . Thc t s lng
ccthanhghivtngicachngcngkhcnhautrongcchVXL/VKvthngdochnh cc nh ch
to qui nh, nhng v c bn chng u c chung cc chc
nngnhnu.Khithtbytetrongbnhcxcnhthngithitkphncngphithc
hinmtsquytnhxemCPUsludliunhthno.CchnycngkhcHnh21:KintrcinhnhcaccchpVXL/VKnhng
nhaututheokintrctplnhcpdng.Cbaloihnhcbn: 2.1.1n v x l trung tm CPU
(1) Kintrcngnxp (2) Kintrcbtchlu (3) KintrcthanhghimcchchungKin trc
ngn xp s dng ngn xp thc hin lnh v cc ton t nhn c
tnhngnxp.Mcdcchnyhtrmtmttvmhnhnginchovicnhgicchthhinchngtrnhnhngngnxpkhngthhtrkhnngtruynhpngunhinvhnchhiusutthchinlnh.KintrcbtchluvilnhmttontngmmcnhchatrongthanhghitchlucthgimcphctpbntrongcacutrcCPUvchophpcuthnhlnhrtnhgn.Nhngthanhghitchluchlnichadliutmthinngiaothngbnhrtln.Kintrcthanhghimcchchungsdngcctpthanhghimcchchungvc
n nhn nh m hnh ca cc h thng CPU mi, hin i. Cc tp thanh ghi
Hnh22:CutrcCPU nhanhhnbnhthngvddngchobbindchxlthcthivcthcs Ngi ta
vn bit ti phn li x l ca cc b VXL l n v x l trung tm CPU
dngmtcchhiuqu.Hnnagithnhphncngngycngcxuthgimng (Central Processing
Unit) ng vai tr nh b no chu trch nhim thc thi cc php
kvtpthanhghicthtngnhanh.Nucchtruynhpbnhnhanhthkintrc tnh v thc hin
cc lnh. Phn chnh ca CPU m nhim chc nng ny l n v
datrnngnxpcthlslachnltng;cnnutruynhpbnhchmth
logictonhc(ALUArthimeticLogicUnit).NgoirahtrchohotngcaALUkintrcthanhghislslachnphhpnht.
cncthmmtsccthnhphnkhcnhbgiim(decoder),btunt(sequencer)
vccthanhghi.Mt s thanh ghi vi chc nng in hnh thng c s dng trong cc
kin trc CPUnhsau: 11http://www.ebook.edu.vn 12 7.
nngtngthchkhicshotngphihpgiaccthitbghpnihaymrngThanhghicontrngnxp(stackpointer):
tronghthng.Thngthngthngtinvccnhpthigianhotngcngnhc Thanh ghi ny lu
gi a ch tip theo ca ngn xp. Theo nguyn l gi tr a ch
tnhkthutchititccungcphocquinhbiccnhchto.
chatrongthanhghicontrngnxpsgimnudliucluthmvongnxp
vstngkhidliuclyrakhingnxp.Mtsctrngvthigiancacctrngthihotngcbncacctnhiuh
thnggmcnhsau:Thanhghichs(indexregister)Thigiantnghocgim
Thanhghichscsdngluachkhimodeachcsdng.NcnThigiantrlantruyntnhiu
cbittivitngilthanhghicontrhaythanhghilachntp(Microchip).Thigianthitlp
ThigiangiThanhghiachlnh/Bmchngtrnh(ProgramCounter)Trcmhotngvtrngthitreo(TriState)
Mt trong nhng thanh ghi quan trng nht ca CPU l thanh ghi b m chng
rngxung trnh. Thanh ghi b m chng trnh lu a ch lnh tip theo ca chng
trnh s Tnsnhpxunghotng cCPUxl.MikhilnhctrtivcCPUxlthnidunggitrca
thanhghibmchngtrnhstnglnmt.ChngtrnhsktthckhithanhghiThigiantnghocgim
PCcgitrbngachcuicngcachngtrnhnmtrongbnhchngtrnh.
Thanhghitchly(Accumulator)
ThanhghitchlylmtthanhghigiaotiptrctipviALU,csdnglu
gicctonthocktqucamtphptontrongqutrnhhotngcaALU.2.1.2Xung nhp v trng
thi tn hiu TrongVXLvccvimchsnichung,hotngcahthngcthchinng
bhocdbtheoccxungnhpchun.Ccnhpclytrctiphocgintip
Hnh24:Mttrngthitnhiulogictngvgim
tmtngunxungchunthnglccmchtoxunghocdaongthchanh. mthotngcahthng,cctn
hiudliuviukhinthngcmtThigiantngcnhnghalkhongthigian
tnhiutngt20%n80%
trngthitheoginthigianvmctnhiunhcchratrongHnh23:Mtmctnhiucnthit.Thigiangimlkhongthigiantnhiugimt80%n
vtrngthitnhiuhotngtrongVXL 20%mctnhiucnthit. Thigiantrlantruyn:
Lkhongthigiantntkhithayitnhiuvochotikhicsthayitnhiu
ura.ctnhnythngdocutovkhnngtruyndntnhiuvtltrongh
thngtnhiu.Hnh23:MtvtrngthitnhiuhotngtrongVXL
McchcavicmttrngthitnhiutheoginthigianvmctnhiulHnh25:Mttrngthivtrlantruyntnhiu
phntchvxcnhchuiskinhotngchitittrongmichukbus.NhvicThigianthitlpvlugi
mtnychngtacthxemxtnkhnngpngthigiancaccskinthc
Khongthigiancnthittnhiutrchmuttimttrngthinnhtrckhi
thitronghthngvthigiancnthitthcthihotngtuntcngnhlkh
nhpxungchunnghthayicgilthigianthitlp.Thigianlugil13
http://www.ebook.edu.vn 14 8. khong thi gian cn thit duy tr tn hiu
trch mu n nh sau khi xung nhpHnh28:Mtchuktnhiu3trngthivcontention
chunnghthayi.Thcchtkhongthigianthitlpvthigianlugilcnrngxungvtnsnhpxungchun
thit m bo tn hiu c ghi nhn chnh xc v n nh trong qu trnh hot
ngvchuynmctrngthi.GinthigiantrongHnh26:Thigianthitlpv
lugiminhhathigianthitlpvlugitronghotngcaTrigerD.
Hnh26:Thigianthitlpvlugi Hnh29:rngvtnsxungnhpchun
Trongtrnghphotngchuyntrngthitnhiukhngngbvkhngm
bocthigianthitlpvlugiscthdnnsmtnnhhaykhngxc2.1.3Bus a ch, d liu v
iu khin nh mc tn hiu trong h thng. Hin tng ny c bit ti vi tn gi l
Busach metastabilit. minh ha cho hin tng ny trong Hnh 27 m t hot ng
li ca Busachlccngdntnhiulogicmtchiutruynachthamchiuti mt Triger khi
cc mc tn hiu vo khng tha mn yu cu v thi thit lp v lu cc khu vc b nh
v ch ra d liu c lu gi u trong khng gian b nh. gi.Trong qa trnh hot
ng CPU s iu khin bus a ch truyn d liu gia cc
khuvcbnhvCPU.Ccachthngthngthamchiuticckhuvcbnhhoccckhuvcvora,hocngoivi.Dliuclucckhuvcthngl8bit(1byte),16bit,
hoc 32bittythucvo cutrctng loi vi x l/vi iu
khin.Huhtccviiukhinthngnhachdliutheokhi8bit.Ccloivixl8bit,16bitv32bitnichungcngucthlmvictraoivikiudliu8bitv16bit.Chngtavnthngcbittikhinimachtruynhptrctip,lkhnngCPUcththamchiuvtruynhptitrongmtchukbus.NuvixlcNbita
chtclncthnhachc2NkhuvcmCPUcththamchiutrctipHnh27:HintngMetastabilittronghotngcaTrigerD
ti.Quiccckhuvccnhachbtutach0vtngdnn2N1.
Chuktnhiu3trngthivcontentionHinnayccvixlvviiukhinnichungchyuvnsdngphbinccbus
dliucrngl16,20,24,hoc32bit.Nunhachtheobytethmtvixl16bit c th nh a
ch c 216 khu vc b nh tc l 65,536 byte = 64Kbyte.
TuynhincmtskhuvcbnhmCPUkhngthtruynhptrctiptitclphisdngnhiunhpbustruynhp,thngthngphikthpviviciukhinphnmm.K
thut nychyu csdng m rng b nh vthng cbit ti vi khi nim nh a ch trang
nh khi nhu cu nh a ch khu vc nhvtquphmvicthnhachtruynhptrctip.V d:
CPU 80286 c 24bit a ch s cho php nh a ch trc tip cho 224 byte
(16Mbyte)nh.CPU80386vccloivixlmnhhnckhnggianach32bitscthnhcti232byte(4Gbyte)achtrctip.
15 http://www.ebook.edu.vn16 9.
BusdliuTrongkintrcvonNeumannkhngphnbitvngchadliuvmchngtrnh.
BusdliulccknhtruyntithngtintheohaichiugiaCPUvbnhhocccC chng trnh v
d liu u c truy nhp theo cng mt ng. iu ny cho
thitbngoivivora.BusdliuciukhinbiCPUchocvitccdphpadliuvovngmchngtrnhROM,vcngcthlumchngtrnh
liuhocmlnhthcthitrongqatrnhhotngcaCPU.rngcabusdliuvovngdliuRAMvthchint.
ni chung s xc nh c lng d liu c th truyn v trao i trn bus. Tc
truynhaytraoidliuthngctnhtheonvl[byte/s].Slngng bit d liu s cho php
xc nh c s lng bit c th lu tr trong mi khu vc
thamchiutrctip.Numtbusdliuckhnngthchinmtlntruyntrong1 s, th bus d
liu 8bit s c bng thng l 1Mbyte/s, bus 16bit s c bng thng l
2Mbyte/svbus32bitscbngthngl4Mbyte/s.Trongtrnghpbusdliu8
bitvichukbuslT=1s(tclstruync1byte/1chuk)thstruync1
Mbytetrong1shay2Mbytetrong2s. Busiukhin
Busiukhinphcvtruynticcthngtindliuiukhinhotngcah
Hnh211:KintrcbnhvonNeumannvHavard thng.Thngthng
ccdliuiukhinbaogmcctnhiuchukngb cc nhp chuyn ng v hot ng ca h thng.
Bus iu khin thng c iu
KintrcHavardtch/phnbitvnglumchngtrnhvdliu.Mchngtrnh
khinbiCPUngbhanhphotngvdliutraoitrnccbus.TrongchcthcluvthchintrongvngchaROMvdliucngchcthlu
trnghpvixlsdngdnknhbusdliuvbusachtclmtphnhoc
vtraoitrongvngRAM.Huhtccvixlnhngngynaysdngkintrcb
tonbbusdliuscsdngchungchiasvibusachthcnmttnhiu
nhHavardhockintrcHavardmrng(tclbnhchngtrnhvdliutch
iukhinphnnhptruynhpchophpchtlutrthngtinachmikhibtbitnhngvnchophpkhnnghnchlydliuratvngmchngtrnh).
umtchu k truyn. Mtv dvcc chu k bus v s ngb
cachngtrongTrongkintrcbnhHavardmrngthngsdngmtslngnhcccontr
hotngcahthngbusachvdliudnknhcchratrongHnh210.lydliutvngmchngtrnhtheocchnhngvotrongcclnhtcthi.
ylhotnginhnhtronghviiukhin8051vnhiuloitngt. Mts Chipviiu khin
nhngtiubiuhinnay s dng cu trc Havardl8031,
PIC,AtmelAVR90S.NusdngChip8031chngtasnhnthyiunythngqua vic truy nhp
ly d liu ra t vng d liu RAM hoc t vng m chng trnh.
ChngtacmtvicontrcsdnglydliuratbnhdliuRAM,
nhngchcduynhtmtcontrDPTRcthcsdnglydliuratvng m chng trnh. Hnh 211 m
t nguyn l kin trc ca b nh von Neumann v Harvard. u im ni bt ca cu
trc b nh Harvard so vi kin trc von Neumann l c hai
knhtchbittruynhpvovngbnhmchngtrnhvdliunhvym
mchngtrnhvdliucthctruynhpngthivlmtngtclung traoivibxl.
Hnh210:Chukhotngbusdnkch2.1.4B nhKintrcbnh
Kintrcbnhcchiaralmhailoichnhvcpdngrngritronghu
htccChipxlnhnghinnaylkintrcbnhvonNeumannvHavard.
17http://www.ebook.edu.vn18 10.
BnhFlashCnggingnhEPROMccutobimtmngtransistorkhtrnhnhngcthxocbnginvchnhvvycthnplichngtrnhmkhngcntchrakhi
nn phn cng VXL. u im ca b nh flash l c th lp trnh trc tip
trnmchcngmnangthcthitrn.Hnh212:Nguynliukhintchknhtruynhpbusachvbusdliu
BnhchngtrnhPROM(ProgrammableReadOnlyMemory)
Hnh214:SnguynlghpniEPROMviVXLVnglumchngtrnh.CbaloibnhPROMthngdngcsdngcho
BnhdliuRAM
hnhngvscgiithiulnltsauy.Vngluhoctraoidliutrunggiantrongqutrnhthchinchngtrnh.
EPROM Baogmmtmngcctransistorkhtrnh.Mchngtrnhscghitrctipvvi x l c th
c ra thc hin. EPROM c th xo c bng tia cc tm v c th
clptrnhli.CutrcvtlcaEPROMcmtnhtrongHnh213. Hnh215:CutrcnguynlbnhRAM
ChailoiSRAMvDRAM Hnh213:NguynlcutovhotngxocaEPROM
19http://www.ebook.edu.vn20 11. dng ph bin trong cc nhim v m xung,
o khong thi gian cc s kin, hoc
nhchukthigianthcthicctcv.Mttrongnhngngdngquantrngcab
nhthigianltonhptbtoxungthchanhchobtruynthngdbanng hot ng. Thc cht l
ng dng thc hin php chia tn s. t c chnhxc,
tnsthchanhthngcchnsaochoccphpchiasnguync thc hin chnh xc m bo cho
tc truyn thng d liu c to ra chnh xc.
Chnhvvyhviiukhin80C51thnghaysdngthchanhctnsdaong
l11.059thayv12MHztoranhphotngtruynthngtcchun9600.
Hnh216:CutrcmtphntnhDRAMHnh218:Bnhthi/bm8bitcaAVRBiukhinngt
Ngtlmtskinxyralmdnghotngchngtrnhhintiphcvthc
thimttcvhaymtchngtrnhkhc.CchngtgipCPUlmtngtcp
ngphcvccskintrongchngtrnhhotngcaVXL/VK.CcVKkhc
nhausnhnghaccnguntongtkhcnhaunhngucchungmtcchhotHnh217:Nguynlghpni(mrng)RAMviVXL
ng v d nh ngt truyn thng ni tip, ngt b nh thi gian, ngt cng, ngt
ngoi...Khi mt s kin yu cu ngt xut hin, nu c chp nhn CPU s lu ct
2.1.5 Khng gian v phn vng a ch
trngthihotngchochngtrnhhintiangthchinvdnhnidungb 2.1.6 Ngoi
vimchngtrnh(contrlnh)ccnidungthanhghiludliuiukhinchng trnh ni chung
thc thi chng trnh phc v tc v cho s kin ngt. Thc cht Bnhthigian/Bm
qu trnh ngt l CPU nhn dng tn hiu ngt, nu chp nhn s a con tr lnh
Huhtccchipviiukhinngynayuctnhtmtbnhthigian/bmc
chngtrnhtrtivngmchachngtrnhphcvtcvngt.Vvymimt
thcuhnhhotnglinhhottheoccmodephcvnhiumcchtrongccngngt u gn vi mt
vector ngt nh mt con tr lu thng tin a ch ca vng b
dngxl,iukhin.Ccbnhthigianchophptoraccchuixungvngt nh cha m chng
trnh phc v tc v ca ngt. CPU s thc hin chng trnh
thigianhocmtheocckhongthigiancthlptrnh.Chngthngcng21
http://www.ebook.edu.vn22 12.
phcvtcvngtnkhinogplnhquaytrvchngtrnhtrcthiims
kinngtxyra.Cthphnra2loingunngt:NgtcngvNgtmm. Ngtmm Ngt mm thc cht
thc hin mt li gi hm c bit m c kch hot bi cc
ngunngtlccskinxuthintbntrongchngtrnhvngoivitchhptrn
Hnh219:Snguynlhotngcabnhthichcanh
Chipvdnhngtthigian,ngtchuyniA/D,Cchngtnycnchiu
lloithchinngbvichngtrnhvnckchhotvthcthiticcthi
imxcnhtrongchngtrnh.Hmcgisthcthichcnngtngngvi
yucungt.Cchmthngctrbimtvectorngtmcnhngha
vgncnhbinhsnxutChip.VdnhhiuhnhcaPCsdngngts
21hexgnchongttruynhpcdliutacngvxutdliuramyin. Ngtcng
Ngtcngcthcxemnhlmtligihmcbittrongngunkchhotl
mtskinntbnngoichngtrnhthngquamtcutrcphncng(thng c kt ni vi th gii
bn ngoi qua cc chn ngt). Ngt cng thng c hiu
hotngtheocchdbvccskinngtkchhottcctnhiungoivibn ngoi v tng i c lp vi
CPU, thng l khng xc nh c thi im kch
hot.KhiccngtcngckchhotCPUsnhndngvthchinligihmthc
thichcnngphcvskinngttngng.
Trongcccchngtkhongthigiantkhixuthinskinngt(cyucuphc
vngt)tikhidchvngtcthcthilxcnhvtuthucvocngnghphn
cngxlcaChip.BnhthichcanhWatchdogTimer Thng thng khi c mt s c xy ra
lm h thng b treo hoc chy qun, CPU s
khngthtiptcthchinngchcnng.cbitkhihthngphilmvicch
vnhnhtngvkhngcscanthiptrctipthngxuynbingivn
hnh.thchincchtgimstvphthinscphnmm,mtsVXL/VK cthmmtbnh
thichcanh.Bnchtlmtbnh thicbitnh ngha mt khung thi gian hot ng bnh
thng ca h thng. Nu c s c phn
mmxyraslmhthngbtreokhibnhthichcanhsphthinvgip h thng thot khi trng
thi bng cch thc hin khi to li chng trnh.
Chngtrnhhotngkhicbnhthiphimboresetntrckhikhungthi
gianbviphm.Khungthigiannycnhnghaphthucvosnhgica ngi thc hin phn mm,
thit lp khong thi gian m bo chc chn h thng
thchinbnhthngkhngcscphnmm. (a) (b)Hnh220:Nguynlhotngbnhthichcanh
CmtscchthchincitbnhthichocanhgimsthotngcahBiukhintruynhpbnhtrctipDMA
thngnhsau: DMA(DirectMemoryAccess)lcchhotngchophphaihaynhiuvixlhoc
ngoivichia sbuschung.Thit b no ang cquyn iu khinbus scthton 23
http://www.ebook.edu.vn24 13.
quyntruynhpvtraoidliutrctipviccbnhnhhthngcmtvixcncmtbcxlquytnhxemthitbnoscnhnquyniukhin
l.ngdngphbinnhtcaDMAlchiasbnhchunggiahaibvixlhoctrongtrnghpcnhiuhnmtthitbcnhucusdngDMA.Thngthng
ccngoivitruyndliutrctipgiathitbngoivivo/ravbnhdliukiuDMAchuknhmcntdliuthngtiniukhin(overhead)nnckhnng
caVXL.traoivitccaonhnglichimnhiuthigiantruynhpbusdotruynckhi
dliuln.iunycthnhhngnhotngcachthngdotrongsut
TruynhpbnhtrctipcsdngpngnhucutraoidliuvoraqutrnhthchinDMAnhm,CPUsbkhoquyntruynhpbnhvkhngth
tc cao gia ngoi vi vi b nh. Thng thng cc ngoi vi kt ni vi h thng x
l cc nhim v khc ca h thng m c nhu cu b nh, v d nh cc dch v
phichiasbusdliuvciukhinbiCPUtrongqutrnhtraoidliu.
ngt,hoccctcvthigianthc... iunylmhnchtctraoi,tngcngtcvloibscanthipca
CPU, c bit trong trng hp cn truyn mt lng d liu ln. C ch hot ng
Chukri(CycleStealing) DMAcmtnhtrongHnh221.Thtccbtubngvicyucuthc
Trong kiu ny DMA s c thc hin trong nhng thi im chu k bus m CPU
hinDMAviCPU.Saukhixl,nucchpnhnCPUstraoquyniukhinkhngsdngbusdokhngcnthchinthtcxlcpphtquyntruynhp
buschongoivivthchinqutrnhtraoidliu.SaukhithchinxongCPUs vthchinDMA.
nhncthngbovnhnliquyniukhinbus.TrongcchDMA,chaicch
truyndliu:kiuDMAchukn,vkiuDMAchuknhm(burst).Huhtccvixlhiniusdnggnnh100%dunglngbnhvbng
thngcabusnnskhngcnhiuthigiandnhchoDMAthchin.titkimvtiutinguynthcncmttrngtiphnxvdliusctruynixpchngtheothigian.NichungkiuDMAdngbursthiuqunhtkhikhongthigiancnthchinDMAtnginh.TrongkhongthigianthchinDMA,tonbbngthngcabusscsdngtiavtonbkhidliusctruynitrong
mt khong thi gian rt ngn. Nhng nhc im ca n l nu d liu
cntruynlnvcnmtkhongthigiandithsdnnvicblockCPUvcthbquavicx l ccs kin
v tc vkhc.ivi DMA chu k n th yu
cutruynhpbnh,truynmttdliuvgiiphngbus.CchnychophpthchintruyninterleavevcbittivitngiinteleavedDMA.KiutruynDMAchuknphhptruyndliutrongmtkhongthigiandimcthigianyucutruynhpvgiiphngbuschomilntruynmttdliu.Chnhvvysgimbngthngtruynhpbusdophimtnhiuthigianyucutruynhpvgiiphngbus.TrongtrnghpnyCPUvccthitbkhcvncthchiasvtruyn
d liu nhng trong mt di bng thng hp. Trong nhiu h thng bus
thchincchxlvgiiquytyucutruynhp(trngti)thngquadliutruynvvycngkhngnhhngnhiuntctruynDMA.DMAcyucukhikhnngiukhincaCPUtruyndliuthchinquchm.DMAcngthcscnghakhiCPUangphithchincctcvkhcmkhngcnnhucutruynhpbus.
Hnh221:NhphotngDMA ICchcnngchuyndngDMAchuknvnhmDAC/ADC
TrongkiuhotngDMAchuknhm,ngoivisnhncquyniukhinv truynkhi d liu ri tr
li quyniu khin cho CPU.Trongc chDMAchuk
nngoivisaukhinhncquyniukhinbuschtruynmttdliuritr
lingayquynkimsotbnhvbusdliuchoCPU.TrongcchthchinDMA25http://www.ebook.edu.vn26
14. Hnh224:SnguynlcutrcADC1754A Hnh222:SnguynlmchchuyniDAC
Hnh223:SnguynlmchchuyniADCVdADC754A
cimkthut:ChtotheocngnghCMOS.Hnh225:SbtrchncaChipADC574A12bitvigiaodintngthchviccloiVXL/VK8,12v16bit.Cthlptrnhhotngchuyni8bithoc12bit.NguynliukhinTn
hiu d liu ra tng thch vi chun TTL v ghp ni thng qua loi cng
ADC574ciukhinbiccchntnhiunhmttrongbngsau:logic3trngthi.Bng1:TnhiuiukhinADC574ADigitrinpuvocthlachnnhcuhnhgitrintrniuvonhnccditnhiu(010)V,(020)V,(5+5)V,v(10+10)V.K
hiunh ngha Chc nngCthmkhnngcungcpngunthamchiuniVref=+10V.Chip
Enable Must be high (1) to either initiate a conversion or read
output data. 0-1 edge may be used toNguncungcpcthl+5V,12V,hoc15V CE
(Pin 6) (active high) initiate a conversion.
Thigianchuyniccil25svithigiantruynhpbusl150ns. Chip SelectMust be
low (0) to either initiate a conversion or read output data. 1-0
edge may be used to CS (Pin 3)(active low) initiate a
conversion.27http://www.ebook.edu.vn28 15. Read/ConvertMust be low
(0) to initiate either 8- or 12-bit conversions. 1-0 edge may be
used to initiate a R / C (Pin 5)(1 = read)conversion.(0 = convert)
Must be high (1) to read output data. 0-1 edge may be used to
initiate a read operation.In the start-convert mode, AO selects
8-bit (AO= 1) or 12-bit (AO= "0") conversion mode.Byte AddressAO
(Pin 4) Short CycleWhen reading output data in two 8-bit bytes, AO=
0 accesses 8 MSBs (high byte) and AO= 1accesses 4 LSBs and trailing
0s (low byte).Data ModeSelectWhen reading output data, 12/8 = 1
enables all 12 output bits simultaneously. 12/8 = 0 will 12 / 8
(Pin 2) (1 = 12 bits) enable the MSBs or LSBs as determined by the
AOline. (0 = 8 bits) (1)
Thitlpchhotng:Modechuyni8bithay12bitcthitlpbi
tnhiuA0.Tnhiunyphicchttrckhinhnctnhiulnhbt uthchinchuyni. (2) Kch
hot qu trnh chuyn i: B chuyn i thc hin chuyn i khi nhn
ctnhiumnhlnhtchcctchntnhiuhocCE/CS,hocR/Cviiu
kincctnhiuiukhinkhccxclp. (3)
Trngthichuyni:TnhiuuraSTATUSbotrngthichuynihin hnh ca ADC; thit lp
mc cao nu ang thc hin chuyn i v mc
thpnuhonthnh.Trongqutrnhchuynicctnhiuiukhinb
khovdliukhngthccvccngtnhiuracchuynsang trngthicaotr. (4) c d liu
ra: Qu trnh c d liu ra c th c thc thi nu cc tn hiu iu khin xc lp
trng thi cho php c v tn hiu STATUS trng thi
thp.Tuthucvomodechuynicthitlpvnhdngdliucra
Hnh226:Ginkhichcnngca82C55A bithptrng 12 / 8
vA0.Chcnngvnghacaccchnonchipca82C55AcmttrongBng2:Chc
Cngsongsongkhtrnh82C55A nngccchnonchipca82C55A. 82C55A l mt giao
din ngoi vi cng song song kh trnh c ch to theo cng
nghCMOS.NlmtthitbngoivivorakhtrnhamcchvcthcsBng2:Chcnngccchnonchipca82C55AdngvinhiuloiVXL/VKkhcnhau.82C55Ac24chnvoraonChipcchia
K hiu Kiu M t chc nngrathnh2nhm,minhm12chnvcthcsdngtheo3chhotng VCC
VCC: The +5V power supply pin. A 0.1F capacitor between VCC and GND
is recommended for decoupling.
khcnhau.Hnh226mtginkhichcnngcachip82C55A. GND GROUND D0-D7 I/ODATA
BUS: The Data Bus lines are bidirectional three-state pins
connected to the system data bus. RESET: A high on this input
clears the control register and all ports (A, B, C) are set to the
inputRESETI mode with the Bus Hold circuitry turned onCHIP SELECT:
Chip select is an active low input used to enable the 82C55A onto
the Data Bus forCS I CPU communications.READ: Read is an active low
input control signal used by the CPU to read status information or
dataRD I via the data bus.WRITE: Write is an active low input
control signal used by the CPU to load control words and data WRI
into the 82C55A.ADDRESS: These input signals, in conjunction with
the RD and WR inputs, control the selection ofA0-A1I one of the
three ports or the control word register. A0 and A1 are normally
connected to the least significant bits of the Address Bus A0, A1.
PORT A: 8-bit input and output port. Both bus hold high and bus
hold low circuitry are present on PA0-PA7I/O this
port.PB0-PB7I/OPORT B: 8-bit input and output port. Bus hold high
circuitry is present on this port.29 http://www.ebook.edu.vn 30 16.
PC0-PC7I/OPORT C: 8-bit input and output port. Bus hold circuitry
is present on this port. Ccngtnhiuvokhngccht
Cthcuhnh16kiuhotngvorakhcnhau
82C55Acungcp3chhotngchnhvcthlptrnhlachnMode1(Voracbttay):Chhotngnycungcpkhnngtruyndliuti
Mode0:Hotngvoracbnhocitmtcngcthcngvicctnhiubttay.TrongchnycngA,B
Mode1:Hotngvoranmbt(strobed)csdngtruyndliuvcngChotngnhcngiukhincchng
Mode2:HotngBus2chiubbttay.Chhotngnycungcpccchcnngchnhsau:
Viclachnchhotngcthchinthngquathanhghitiukhinv Hai nhm cng (Nhm A v
Nhm B). Mi nhm bao gm 1 cng 8bit v mt cmtnhtrongHnh227.
cngdliuiukhin4bit. Cngdliu8bitcthhotngnhhoclcngvohoclcngravchai
chiudliuuccht.
The4bitportisusedforcontrolandstatusofthe8bitport.Mode 2 (Bus vo ra
hai chiu c bt tay): Ch hot ng ny cung cp kh
nngtruynthngviccngoivihocccbusdliu8bitchovictruynnhndliu.Cctnhiubttayccungcpduytrdngtnhiubustngtnhch1.Cc
c ch to ngt cng c th c thc hin ch ny. Mt s cc chc
nngchnhhtrtrongchnybaogm: ChsdngnhmA
Mtcngbus2chiu8bit(cngA)vmtcngiukhin5bit(CngC)
Chaichiudliuvovrauccht. Cngiukhin5bit(CngC)csdngchomcchiukhinvtrng
thichocngAtraoidliu2chiu8bit. Bnhthi/BmC8254
Hnh227:Thanhghitiukhinchnchhotngcho82C55Aylbmtccaocungcp3bnhthi16bitclpvcthccuhnhhotngnhiuchhotng.Mibmcccknhdliuviukhin
KhiuvoRESETciukhinmccaothttccccngscthitlphotring bit. H tr 2 kiu m
ho m nh phn (0 65535) hoc BCD (binary coded ng ch cng vo vi 24 ng
tn hiu vo duy tr mc logic 1. Sau khi tn
decimal)(09999).C4thanhghitchhpOnchiplugitrmvcuhnhhot
hiuiukhinRESETmctchccbloibth82C55Acthduytrchhot ng(tiukhin).
ngmkhngcnthmbtkvickhitonona.iunysgiploibc
ccintrtreocaohoctreothptrongccthitkchomchCMOS.KhikchhotTnshotngcabmcthlmvicvixungnhptns10MHzvhtr6
ch thit lp th thanh ghi t iu khin s cha gi tr 9Bh. Trong qa trnh
thcchhotngvcthcuhnhringl.
hinchngtrnhvncththayilachnchhotngkhcnhau,iuny cho php 82C55 hot ng
mt cch a dng p ng cho nhiu bi ton ng dng
khcnhau.Trongqatrnhthanhghitiukhinangcvitthttccccng
cthitlphotngchcngrasckhitobngzero.
Mode0(Voracbn):Cuhnhchhotngnycungcpcchotngvora
nginchoc3cngA,BvC.Dliuctraoitrctipvkhngcnphic
cchbttay.Chhotngnyhtrccchcnngcthnhsau: Haicng8bitv2cng4bit
Btkcngnocngcthlcngvohoccngra Ccngdliutnhiuraccht 31
http://www.ebook.edu.vn32 17. Giaodinnitip USART
Hnh228:Scutrcchcnng8254 Hnh230:CutrcnginhocaUSART 2.1.7Giao
dinGiaodinsongsong8bit/16bit
Cccngsongsonglmtdnggiaodinvoranginvphbinnhtktni
thngtinvingoivi.Cnhiuloicutrcgiaodinvtlinttdngcngvo
ranginccCollectorTTLhtrongccngdngcngmyinnccloicutrc
giaodincngtccaonhccchunbusIEEE488haySCSI.Huhtccchipiu khin nhng c
mt vi cng vo ra song song kh trnh (c th cu hnh). Cc giao
dinphhpvicccngvoranginnhcckhochuyn.Chngcngph
hptrongccbitonphcvgiaodinktniiukhinvgimsttheoccgiao
dinnhkiurlebndn. Hnh231:Modehotngtruynthngngb
Hnh229:Cutrcnguynlinhnhcamtcngvo/ralogic
Hnh232:Modehotngtruynthngdb33 http://www.ebook.edu.vn34 18.
I2C(InterIC) cmtVKgivaitrlCh(Master)vccVKcnlicthhoclChhocl Giao thc
u tin truyn thng ni tip c pht trin bi Philips Semiconductor v
T.SPIc4tccthlptrnh,ccvphanhpnghkhtrnhvktthcngt
cgilbusI2C.VngungcncthitkliukhinlinthngIC(Inter
truynthng.Nhpnghkhngnmtrongdngdliuvphiccungcpnh
IC)nnncttnlI2C.TtcccchpctchhpvtngthchviI2Cucmttnhiutchclp.CbathanhghiSPSR,SPCRvSPDRchophpthchincc
thmmtgiaodintchhptrnChiptruynthngtrctipviccthitbtng
chcnngiukhin,trngthivlutr.Cbnchncbncnthitthcthi
thchI2Ckhc.Victruyndliunitiptheohaihng8bitcthcthitheo3ch
chungiaodintruynthngny.
sau:Chun(Standard)100Kbits/secDliuraMOSI(MasterOutputSlaveInput)Nhanh(Fast)400Kbits/secDliuvoMISO(MasterInputSlaveOutput)Tccao(HighSpeed)3.4Mbits/sec
NhpxungchunSCLK(SerialClock) LachnthnhphntSS(SlaveSelect)
ngbusthchintruynthngnitipI2Cgmhainglngtruyndliu
nitipSDAvngtruynnhpxungnghnitipSCL.Vcchhotngl
ngbnnncncmtnhpxungtnhiungb.CcthitbhtrI2Cuc
mtachnhnghatrc,trongmtsbitachlthpcthcuhnh.nv
hocthitbkhitoqutrnhtruynthnglnvChvcnglnvtoxung nhpng b,iu khin cho
phpktthc qutrnhtruyn. NunvChmun
Hnh233:KtninguynltruynthngSPIgiamtMastervmtT
truynthngvinvkhcnsgikmthngtinachcanvmnmun
truyntrongdliutruyn.nvTucgnvnhachthngquan
Hnh233chranguynlktnigiamtnvChvmtnvTtrongtruyn
vChcththitlptruynthngvtraoidliu.Busdliucthitkcho
thngSPI.TrongtnhiuSCLKsctorabinvChvltnhiuvoca
phpthchinnhiunvChvTtrncngBus.
nvT.MOSIlngtruyndliuratnvChtinvTvMISOl
ngtruyndliuvonvChntnvT.nvTclachnkhi
QutrnhtruynthngI2CcbtubngtnhiustarttorabinvCh.Sau nvChkchhottnhiu
SS . nvChstruynidliu7bitchaachcanvTmnmuntruyn
thng,theothtlccbitctrngslnnhtMSBsctruyntrc.Bitthtm
tiptheoschathngtinxcnhnvTsthchinvaitrnhn(0)haygi
(1)dliu.TiptheoslmtbitACKxcnhnbinvnhnnhnc1byte
trchaykhng.nvtruyn(gi)struyni1bytedliubtubiMSB.
Tiimcuicabytetruyn,nvnhnstoramtbitxcnhnACKmi.Khun
mu9bitny(gm8bitdliuv1bitxcnhn)sclplinucntruyntip
bytena.KhinvChtraoixongdliucnnsquanstbitxcnhnACK cui cng ri sau s
to ra mt tn hiu dng STOP kt thc qu trnh truyn thng. I2C l mt giao
din truyn thng c bit thch hp cho cc ng dng truyn thng
giaccnvtrncngmtbomchvikhongcchngnvtcthp.Vdnh
truynthnggiaCPUvicckhichcnngtrncngmtbomchnhEEPROM,
Hnh234:SktnitruynthngSPIcamtnvChvinhiunvT
cmbin,nghtothigianthc...HuhtccthitbhtrI2Chotngtc
400Kbps,mtschophphotngtccaoviMbps.I2Ckhnginthc
NuhthngcnhiunvtnvChstophiracctnhiutchbitchn
thiktninhiunvvnhtrcchxcnhach.nvT.CchcthchinnhsktninguynlmtnhtrongHnh
234.nvChstoratnhiuchnnvTnhccchntnhiulogicachc
SPInng.Cctnhiunyphiciukhinvmbonnhvthigiantrnh
SPIlmtgiaodincngnitipngbbadychophpktnitruynthngnhiutrnghptnhiubthayitrongqutrnhangtruyndliu.Mtiudnhn
VKcphttrinbiMotorola.Trongcuhnhmngktnitruynthngnyphi35
http://www.ebook.edu.vn 36 19.
rarngSPIkhnghtrcchxcnhntrongqutrnhthchintruynthng.iu
hpthmccngoivi.Ccngoivithnglcckhichcnngngoivithngdng
nyphthucvogiaothcnhnghahocphithchinbsungthmmtsccnhbnhthigian,bm,bchuyniA/D,giaodinsongsong,nitipMc
mrngphbnngoi.tchhpngoivi cngkhcnhaututhucvomcchngdngscthtm
cChipphhp.Thctviccngdngyucutchhpcaothssdng Kh nng truyn thng ng thi
hai chiu vi tc ln n khong vi Mbit/s v
giiphptchhptrnchip,nukhngthhuhtccChipucungcpgiiphp
nguynlkhnginnnSPIhontonphhpthchintruynthnggiacc
mrngngoivipngchomtslngngdngrngvmmdo.
thitbyucutruynthngtcchm,cbithiuqutrongccngdngmt
nvChvmtnvT.TuynhintrongccngdngvinhiunvTvic
thcthilikhphctpvthiucchxcnhach,vsphctpstnglnkhi snvTtng.Khi gii m a
chCPU v iu khin LogicB nh Ngoi vi 2.2Mt s nn phn cng nhng thng dng
(P/DSP/PLA) TrongphnnygiithiungngncutrcnguynlcaccchipxlnhngngBus a
ch dngtrongccnnphncngnhnghinnay. Bus D liu
SphttrinnhanhchngccchngloiChipkhtrnhvimttchhpcaov angcmttcngngk
nsthayi trongvicthitkccnnphncngBus iu khin
thitbxlviukhinstrongthpkgny.Michngloiucnhngc
imvphmviitngngdngvlunkhngngngphttrinpngmt
Hnh235:KintrcnguynlcaVKvicutrcHavard
cchttnhtchoccyucucngngh.ChnganghngtitptrungchomtthVdvkintrccahVKAVR
trng cng ngh tim nng rng ln l cc thit b x l v iu khin nhng.
Trongbivitnytcgigiithiungngnvccchngloichipxl,iukhin
nhnginhnhangtntivphttrinvmtscimvhngphmving dngcachng. C thkrahng
lot ccChpkhtrnh c ths dng choccbitonthitkh nhng nh cc h vi x l/vi
iu khin nhng (Microprocessor/ Microcontroller), Chip DSP (Digital
Signal Processing), cc Chip kh trnh trng (FPD Field Programmable
Device).Chngtadbchongngpnubtucngvicthitkbngvictmkim
mtChipxliukhinphhpchongdng.Vvycnphicmthiubitv
sphnbitvcimvngdngcachngkhilachnvthitk.Ccthngtin lin quan nh nh sn
xut cung cp Chip, cc kin thc v cng c pht trin km
theoMtschngloiChipinhnhscgiithiu.2.2.1Chip Vi x l / Vi iu khin nhng
y l mt chng loi rt in hnh v ang c s dng rt ph bin hin ny.
ChngcraivsdngtheosphttrincaccChipxlngdngchomy
tnh.Vitngngdnglccthitbnhngnncutrccngcthayitheo
pngccngdng.Hinnaychngtacththycchvixliukhinca rt nhiu cc nh ch to
cung cp nh, Intel, Atmel, Motorola, Infineon. V cu trc,
chngcngtngtnhccChpxlphttrinchoPCnhngmcngin
hnnhiuvcngnngvtinguyn.PhbinvnlccChipcrngbusdliu
l8bit,16bit,32bit.Vbnchtcutrc,Chipviiukhinlchipvixlctch
Hnh236:KintrccahVKAVR37http://www.ebook.edu.vn38 20.
snguyn16bithocccsthctrongmtmingitrcnh.Tuynhinccgitr
vhstrunggiancthclutrvichnhxcl32bittrongthanhghitch lu 40bit nhm gim
thiu li tnh ton do php lm trn trong qu trnh tnh ton.
ThngthngccloiDSPduphytnhcgithnhrhnccloiDSPduphy
ngvyucuslngchnOnchipthnvcnsdnglngsiliconthn.
uimnibtcaccDSPduphynglcthxlvbiudinstrongdi
phmvigitrrngvng.Dovnvchuynivhnchvphmvibiu
dinskhngphiquantmnhiviloiDSPduphytnh.MtloiDSP32bit du phy tnh in
hnh l TMS320C67x c th x l v biu din s gm 24bit
mantissav8bitexponent.Phnmantissabiudinphnsltrongphmvi1.0+1.0
vphnexponentbiudinvtrcaduphynhphnvcthdchchuynsangtri
hocphitutheogitrsmnbiudin.iunytringcviccthitktrn nn DSP du phy tnh,
ngi pht trin chng trnh phi t qui c, tnh ton v
phnchiannhthangbiudinsvphilunlutmtikhnngtrnscth
xyratrongqutrnhxltnhton.Chnhiunygyrakhkhnkhngnh i vi ngi lp trnh.
Ni chung pht trin chng trnh cho DSP du phy ng
thngnginhnnhnggithnhlicaohnnhiuvnnglngtiuththng thngcnglnhn. V d
chnh xc ca DSP du phy ng 32 bit l 223 vi 24 bit biu din phn
mantissa.Vngngl1.181038x3.41038. Nhngnhthitkhthngphiquyt
nhvngvchnhxccnthitchocc ngdng.Ccvixlduphyngthngcsdngchoccngdngyucu
vchnhxccaovdibiudinslnphhpvihthngccutrcbnhln
HnnaccDSPduphyngchophpphttrinphnmmhiuquvngin
Hnh237:SkhichcnngkintrcPIC16F873A
hnbngcctrnhbindchngnngbccaonhCdocthgimcgithnh v thi gian pht trin.
Tuy nhin gi thnh li cao nn cc DSP du phy ng ph 2.2.2 Chip
DSPhpviccngdngkhcbitvthnglvislngt. [Ref.SenKuo]
DSPvncbittinhmtloiviiukhincbitvikhnngxlnhanh
phcvccbitonyucukhilngvtcxltnhtonln.Viuimni
btvrngbngthngcabusvthanhghitchlu,chophpALUxlsongsong
vitccvxllnhnhanhhnccloiviiukhinthngthng.ChipDSP
chophpthchinnhiulnhtrongmtnhpnhvokintrcbnhHavard.
ThngthngkhiphisdngDSPtclpngccbitontnhtonlnvtc
caovvynhdngbiudintonhcslmtyutquantrngphnloiv
cquantm.Hinnaychyuchngvncphnloitheohaikiulduphy
ngvduphytnh.ycngchnhlmtyutquantrngphiquantmivi ngi thit k la chn c
mt DSP ph hp vi ng dng ca mnh. Cc loi
DSPduphytnhthnglloi16bithoc24bitcnccloiduphytnhthng
l32bit.MtvdinhnhvmtDSP16bitduphytnhlTMS320C55x,lucc39http://www.ebook.edu.vn40
21. Hnh239:CutrcPROMvPLA Lch s pht trin ca cc chng loi Chip kh trnh
mng PLA (Programmable LogicArray)cbtngunt nguynl b nh chng trnhPROM
(ProgrammableReadOnlyMemory).Trongccuvoachngvaitrnhccngvocamchlogicvccngdliurangvaitrnhccngracamchlogic.VPROMkhng
thc s ph hp cho mc ch thit k cc mch logic nn PLA ra i
vouthpk70.Nrtphhpthchinmchlogiccdngtngcctch(vcuthnhbiccphntlogicANDvOR).Nhngnhcimlchiphsnxutcaovtchotngthp.khcphcnhcimnyPAL(ProgrammableArrayLogic)cphttrin.NccuthnhtccphntANDkhtrnhvphntORgncnhvcchacphntflipflopurannckhnngthcthiccmchlogictunt.Hnh240mtcutrcchungcaPAL.
Hnh238:GinkhichcnngcaDSPTMS320C28xx2.2.3 PAL
NgynaykhininccchngloiChipkhtrnhmngtathngbittimtstn gi nh PAL, CPLD,
FPGAMt cht lc s v s ra i v pht trin sau y s
gipchngtahnhdungccimvngungcraicachng. Hnh240:CutrcchungcaPAL
TkhicraivphttrinPALtrthnhcschosraicahnglotccchngloiChipkhtrnhmngvicutrcphctphnnhSPLD(SimpleProgrammable
Logic Device), CPLD (Complex Programmable Logic Device), v sau ny l
FPGA(Field Programmable Gate Array). SPLD cng l tn gi cho nhm cc
chng loi Chip41 http://www.ebook.edu.vn 42 22.
kiutngtnhPAL,PLA.VmtcutrcthSPLDchophptchhplogicvimt
caohnsoviPALthngthng,nhngkchthccanstnglnrtnhanh
nutiptcmrngvtngmttchhpsuvo.pngnhucumrng
mttchhpCPLDcphttrin.NlstchhpcanhiukhiSPLDv cung cp thm kh nng kt ni
kh trnh gia cc khi SPLD n l vi nhau. Vi
nguynlcutrcnyCPLDckhnngtchhpvimtcaotngngvi50 khiSPLDthngthng. Nu ch
dng n y chng ta c th thy mt c im chung ca cc chng loi
chipkiuPLAhayCPLDuchophpthchinccmchlogictrncsthplogic
caccuvovrabngccphntANDvOR.Vinguynlnyrrngsgp Hnh242:CutrcCLBvLAB
khkhnkhithcthiccngdngihiccphptnhtonlogicphctpvitc
cao.pngiunyFPGA(FieldProgrammableGateArrays)rai.Nlscu
NgynaycthphnloiramtskiuchngloiFPGAdavocutocachng:
thnhcacckhilogickhtrnhcngviccknhktnilinthngkhtrnhgia
cckhivinhau.MthnhnhtiubiuvcutrcnguynlcaFPGAcmCutotSRAM:
tnhtrongHnh241:CutrcnguynlcaFPGA.ViloinyccmtktnikhtrnhcthchinbngccphntSRAM,chnhv
vychophpthchinlptrnhlplinhiuln.uimnibtcaloinylcc
tngthitkmicthcthcthivthnghimnhanhchng.HnnaSRAM
cnganglmthngphttrinrtmnhhinnaytrongnncngnghipsnxut
bnhvcnguthcthitheocngnghCMOSrtphhpvicngnghchto FPGA.
TuynhinmtcimcthxemnhlnhcimcaFPGAcutotccphn
tSRAMlchngphicuhnhlimikhingunhthngccungcp.Cngvic
nythngcthchinbimtbnhngoichuyndnghocbimtbviiu
khinkmtheomch.ChnhvvycnglmgithnhcaFPGAtngthm.
Hnh241:CutrcnguynlcaFPGA Cutotcuch(antifused) FPGA ang tr thnh mt s
la chn thay th rt cnh tranh ca cc chip x l
KhnggingnhloiFPGAcutotSRAM,FPGAvicutkiucuchclp
nhngASICs.NhtrccuimvchcnnglachngingnhASICsnhng trnh offline bng mt
thit b lp trnh chuyn dng. tng ch to loi FPGA ny cho php chnh sa v
thit k li sau khi s dng v gi thnh pht trin thp hn.
xutphttnhucuvmtthitbkhtrnhckhnnglucuhnhsaukhics
FPGAchophpkhnngthitklinhhotvthchnghiddngchocctinchthit
dng.Tclnkhngphilmcngviccuhnhmikhingunhthngccung
btiu,trongkhivnduytrckhnggiankchthcphncngvnnglngcp.KhiFPGAantifusedclptrnhthnkhngthbthayihayclp
tiuthcahthng.iunykhngddngnhnckhithitkdatrnnncctrnhlina.Chnh
nhiunynnnkhngcn btkmtbnhngoino ChipDSP.
lutrcuhnhvcthtitkim,gimgithnhcathitb.
FPGAthcsphhpchoccngdngihilngtnhtonlnnhtrongxlMtuimnibtcaFPGAantifusedlkiucutrclinktkhbnvngvicc
tnhiu.FPGActhclptrnhhotngngthivimtsccngdliuloi nhiu bc x. c im ny
kh quan trng khi thit b phi lm vic trong mi
songsong.Chnglccngdliuhotngcathpnhiuccchcnngttrngtimnngnhqunshochngkhngvtr.Vvyntrnhctrng
nginnphctpnhbcng,bnhn,bm,blutr,bsosnh,btnh hp ri ro c th xy ra nu s
dng cng ngh SRAM l hin tng lt trng thi
tngquan,(flipped).Tuynhinhintngnycngcthckhcphcbngcchdphng
chp3nhnglilmtngthmchiphchto. 43http://www.ebook.edu.vn44 23.
MtuimnibtcaloiFPGAantifusedlkhnngbovcngngh.Tcld liucu hnhlptrnh cho
FPGA c th cbo vbivicc bthpphphoc Ngi ta cng thng phn loi FPGA da vo
phn t kin trc ca chng v bao
khngchophpc.Trongqatrnhxlhocphttrin,ngilptrnhssdnggm3loichnh:mn,thvtrungbnh.Bnchtvicphnloinyldavokiu
mt tp d liu cu hnh lp trnh v kim tra qu trnh np cu hnh cho FPGA.
khilogickhtrnhcuthnhnnFPGA.ViloiFPGAmnthkintrccckhilogic
Cngvicnychthchinmtlnvskhngththayicna.Khithchin
khtrnhthnglcccnglogicngin(kiuAND,OR,vccphntlugi
xongncthcthitlpthmmtthuctnhlchngctrctiptFPGAdnhTrigerD).Kiukintrcnyphhpvthngsdnghiuquvikintrc
liulinquanncuhnh.NgoirachngtacngcthbitthmrngFPGAantiASIC.GnyxuthphttrincaFPGAangtptrungvoloikintrcth.Tc
fusedthngsdngtnnglnghnloiFPGASRAM,kchthccngnhhn,v
lcckhilogickhtrnhlcckhickhnngxllogiclnvinhiuthplin
tccngnhanhhnmtchtnhkhongcchktnicnggiaccphntngnktvphctpvinhiuuvovralinkt.Tutheomccakhilogickh
hn. trnhmngitaphnrathnhccloitrungbnh.
TuynhinnhcimlnnhtcaFPGAantifusedlchcthclptrnhvcuChailoicutrccbncuthnhnncckhilogickhtrnhtrongkintrcFPGA
hnh mt ln. V vy n ch thc s ph hp khi thc thi hon chnh sn phm cuith
hoc trung bnh l MUX (Multiplexer) v LUT (Lookup Table). Trong loi
cu trc cngvkhngphhpvimcchthitkphttrin.MUX th cc phn t logic c cu
thnh theo cu trc t hp cc u vo ra theo
nguynlMUXnhmttrongHnh243:KhilogicdngMUX. CutotEEPROM/FLASH
EEPROMorFLASHbasedFPGAscngcnguynlcutotngtnhloiFPGA SRAM. Cc phn t
cu hnh cancktni da trn mtchuithanhghidch
di.Chngcthccuhnhofflinebngccthitblptrnhchuyndng.Cngc mtscthlp
trnhonlinenhngthigianlptrnhcuhnhsgpkhong3ln thi gian thc thi vi nn
FPGASRAM. Khi c cu hnh c lp trnh th
chngcthcduytrvkhngbmtinhnguynllugicaEEPROMhoc FLASH. Loi
FPGAEEPROM/FLASH c cu to nh hn so vi loi FPGASRAM v vy cng c th gim
c thi gian lan truyn tn hiu kt ni lin thng gia cc phntlogic.
bovcngnghkhiFPGAccuhnhvarasdng,tacthbov
bngcchkhammm(cutotkhong50bitnvitrmbit).Muncc
thngtincuhnhtrctiptFPGA,ngitacnphicmkhavcngrtkh
hockhngthmctheonguynlthsai.Vmunvytheoctnhcngphi
mtnhngtriunmmihyvngthnhcngmrac.Hnh243:KhilogicdngMUX
iviloicutrcLUTthccuvothcchtlccthpchnragitrtrong
TuynhincngnghchtoFPGAEEPROM/FLASHihithcthiquanhiucngbngchtlcahmchcnngcnthcthi.Nguynlcaloikhilogicnyc
onxlhnsoviloiFPGASRAMvvymsphttrincachngcngchm mtnhtrongHnh244.
hn.Hnnannglngtiuthcachngcnglnhnvphinuirtnhiucc
phntintrko(pullupresistor). CutotthpFLASHSRAM
NgynayngitacngphttrinchtoccloiFPGAcutotccthpSRAM
vFLASHtndngcccuimcachaichngloiny.Thngthngcc
phntcuhnhFLASHscsdngluccnidungcuhnhsaochp
choccphntcuhnhSRAM.VccphntcuhnhSRAMhontoncthc
cuhnhlitheoyucuthitktrongkhivnduytrmtphnthitkcuhnhgc
Hnh244:LUTthchinhmthpANDvOR
lutrongccphntFLASH.45http://www.ebook.edu.vn 46 24. Hu ht cc ng dng
u c nhu cu v b nh RAM on Chip v vy mt s dng FPGA hin nay cng tch hp
thm c cc phn t nh RAM v c gi l RAM 3 C S K THUT PHN MM NHNG nhng
(embedded RAM). Cc phn t RAM c t chc thnh tng khi v tu3.1 c im phn
mm nhng thucvokintrccaFPGAnscphnblinhhot,thnglxungquanhcc
phntngoivihocphnbutrnbmtChip.MthnhnhminhhovphnHngchcnnghocth
bRAMtrongkintrcFPGAcmtnhtrongHnh245.Hnchvtinguynbnh
Yucuthigianthc3.2 Biu din s v d liu n v c bn nht trong biu din thng
tin ca h thng s c gi l bit, chnhlkhiuvitttcathutngbinarydigit.
1964,IBMthitkvchtomytnhssdngmtnhm8bitnh
achbnhvnhngharathutng8bit=1byte.
Ngynaysdngrngrithutngwordlmttdliudngbiudin
kchthcdliumcxlmtcchhiuqunhtivimiloikin
trcxlscth.Chnhvvymttcthl16bits,32bits,hoc64bits
Mimtbytecthcchiarathnhhaina4bitvcgilccnibble.
Nibblechaccbttrngslncgilnibblebccao,vnibblechaccbit
trngsnhcgilnibblebcthp. Hnh245:HnhnhcaChipcccctlcckhiRAMnhng 3.2.1
Cc h thng c s
FPGAvihtnhnDSPTrongcchthngbiudinshinnayucbiudindngtngqutltng
Thcchtlmtthpnhmtngtcvkhnngtnhton.Khinimnycng
luthatheocs,vcphnloitheogitrcs.Mtcchtngqutmthbiu
tngtnhccbngxltonhctrongkintrcmytnh.Nguynllnhmdinscsbvalmtsnguynnmtrongkhonggitrcsbcbiudin
sansvgimbttisangFPGAthcthiccchcnngtnhtonln(thngthng nhsau: n
ihithchintrongnhiunhphotngcaChipDSP)vchophpChipDSPtp A = an b n +
an 1b n 1 + + a0 = ai bi (1.1)
trungthchinccchcnngnnhptiu.ThpFPGAvDSPlmtkintrci
=0rtlinhhotvcbitcithinchiusutthchinvtngtchnrtnhiusoVdnhcsbinary(nhphn),csdecimal(thpphn),cshexadecimal,cs8
vikintrcnhiuChipDPShocASICsngthigithnhlithphn. Octal(btphn).
Vdvbiudinccgitrtrongcchcskhcnhau:
243.5110=2x102+4x101+3x100+5x101+1x102 2123=2x32+1x31+2x30=2310
101102=1x24+0x23+1x22+1x21+0x20=2210
Hailoicsbiudinthngdngnhthinnaychocchthngxlslcsnh phnvcsmisu.3.2.2 S
nguyn Trongbiudinscduphnbitsdngvsmngitasdngbittrngs
lnnhtquiclmbitduvccbitcnlicsdngbiudingitrln
cas.Vdmtt8bitcsdngbiudingitr1scdngnhphnl
Hnh246:SnguynlmchghpniVKvFPGA10000001,vgitr+1scdng00000001.Nhvyvimtt8bitcthbiudin47
http://www.ebook.edu.vn48 25.
cccstrongphmvit127n+127.MtcchtngqutmttNbitsbiuHinnayngitasdnghaiquicbiudinsnguynphnbittheothtca
dinc2(N1)1n+2(N1)1. bytetrngstrongmttcbiudin:
Litteedian:bytetrngsnhnhtngtrc thunlichophpcnghoc
Chkhithchincnghaiscdu:trvNuhaiscngduththchinphpcngphnbiudingitrvsdngbit
Bigendian:bytetrngslnnhtngtrc thunlichophpnhnhocducngduvihais.
chia.Nu hai s khc du th kt qu s nhn du ca ton t ln hn, v thc hin
Vdxtmtsnhphn4bytephptrgiatontcgitrlnhnvitontbhn.
Vd1:Cnghaiscdu010011112v001000112.
Theoquicbiudinlitteedianththtachlutrongbnhsl: 1111 carries
achcs+0=Byte0 01001111 (79) achcs+1=Byte1 0+0100011 +(35)
achcs+2=Byte2 01110010 (114) achcs+3=Byte3
Vtheoquicbiudinsbigediansl: Vd2:Cnghaiscdu010011112v011000112.
achcs+0=Byte3 Nhcuicng 1 1111 carries achcs+1=Byte2 Trn 0 1001111
(79) achcs+2=Byte1 bnh 0+ 1100011 +(99) achcs+3=Byte0 0 0110010(50)
3.2.3 S du phy tnh Vd3:Trhaiscdu010011112v011000112.
Chngtacthsdngmtkhiuduchmobiudinmtsthc.Duchm 0112 borrows
ocsdngtrongtdliudngphnbitvngncchgiaphnbiudin 0 1100011
(99)gitrnguyncadliuvmtphnlthpphn.Vdvmtt8bitbiudins 0 1001111 (79)
duphyngcchranhtrongHnh31.Vicchbiudinny,gitrthcca 0 0010100
(20)sctnhnhsau: N = a4 24 + a3 23 + a2 22 + a1 21 + a0 20 + a1 21 +
a2 22 + a3 23 Vd4:Cnghaiskhcdu100100112(19)v000011012(+13)= 0 24 +
1 23 + 0 22 + 1 21 + 1 20 + 1 21 + 0 22 + 1 23 012 borrows= 8 + 2 +
1 + 1/ 2 + 1/ 8 10010011 (19) 0 0001101+(13)= 11.625 1 0000110(6)
Thuttonthchinphptnhcdu:(1)
Khaibovxaccbinlugitrvduchunbthchinphptnh.(2)
Kimtraducatontthnhtxemcphismkhng.Nulsm
ththchinbduvbtont.Nukhngthchuynquathchinbc3.(3)
Kimtraducatontthhaixemcphismkhng.NulsmthHnh31:nhdngbiudinsduphytnh8bit
thchinbduvbtont.Nukhngthchuynsangthchinbc4.
Nhcimcaphngphpbiudinsduphytnhlvngbiudinsnguyn(4)
Thchinphpnhnhocchiavicctontvaxl.bhnchbiduphytnhcgncnh.iunydxyrahintngtrns(5)
Kimtradu.Nuzerothcoinhktthc.Nubng1(0ffh)ththchinkhithchinccphpnhnhaisln.
phptnhbhaiviktquthucvktthc. 49http://www.ebook.edu.vn50 26. 3.2.4S
du phy ng N min = 0.5 2 (2e11)(1.4)
PhngphpbiudinschnhxcvlinhhotcsdngrngrihinnaylhTheotiuchunIEEE754v854c2nhdngchnhchosduphynglsthc
thng biu dins du phyng.ycng l mt phngphp biudins
khoadi(long)vsthcngn(short)chngkhcnhauvdibiudinvlnlutr
hcbaogm2phn:phnbiudinlutrsmantissavmtphnlutrbiudinyucu.Theochunny,sthcdicnhdng8bytebaogm1bitdu,11bit
s exponent. V d trong h c s thp phn, mt s nguyn bng 5 c th c
biuexponentv53bitlugitrscngha.Mtsthcngncnhdng4bytebao dinhocl 0.5
101 , 50 101 ,hoc 0.05 102
,Trongmytnhshochthngsnigm1bitdu,8bitlythav24bitlugitrscngha.Mtsthcngncth
chung,ccsduphyngnhphnthngcbiudindng
biudinvxlcscgitrnmtrongdi1038to1038vsthcdicthbiu N = M 2E (1.2)
dinvxlcscgitrthucdi10308to10308 .biudinmtgitrtng
Trong,Mlphngitrsmantissa,ElphnlythacasN.Mthnglccngnhvybngsduphytnhthcnti256bithay32bytedliu.
gitrlmphnthpphncanthngnmtrongkhong 0.5 M 1 . 3.2.5Mt s php tnh c bn
Hnh32mtbiudinmtsduphyngcat8bitgm5bitbiudinphnsThchinphpnhn c ngha
mantissa, v 3 bit biu din phn ly tha. V cc phn mantissa v ly
thaVtrongccVKnhngthngkhnghtrccphpnhnnhiubyte.Cngvicny
ucthnhnccgitrmvvyccbitutincaccphngitructh
phicthchinbingiphttrinchngtrnhvthhindidngmtthut
csdngbiudindukhicnthit.
tondatrnccphptoncsnpdngchosnhphnlcng/trvdch.cmtshiubitrrnghnvthuttonthchinphpnhn,chngtaxtmtvdvmtphptnhnhnhaisnhphntngqutnhsau:A
= an 2n + + a1 21 + a0 20 B = bn 2n + + b1 21 + b0 20 bn ( A) 2n +
+ b1 ( A) 21 + b0 ( A) 20Hnh32:Biudinduphyng8bt
TrongmtsVXL,VKdorngtnhphnnhnncthsdng2tbiuNguynlthchinphp nhncngging
nh ta thchin phpnhn haiathc.
dinmtsduphyng.Mttsdngbiudingitrmantissa,vmtphnTrongtrnghpnhnhaisnhphnthmiphntlmtbit,bytehoct.Vd
biudingitrexponent.cthvihaisnhphn4bittathucphpnhnthchinnhsau:
Nuphnmantissacchunhathnhmtslcgitrtrongkhong 0.5 M 1
thbitutinsaubitduthnglmtvscmtduphynhphnnngaysaua3 23 + a2 22 + a1
21 + a0 20 bitdu.b3 23 + b2 22 + b1 21 + b0 20
PhnbiudinexponentEsquytnhvtrcaduphyngsdchsangtri(E>0)
haysangphi(E divisor) divisor = 1; Counter 001(1) while (i != 0){
Product 111100(60) quotient =1 , i--;
ThcthithuttonthchinphpnhnsnguynkhngdubngngnngC/C++: } long product
= 0; Trckhithchinphpchiayucucnphikimtralichiakhngcthxyra.while
(multipier != 0){
Thuttonthchinphpchiachyudatrnphpdchvphptr.Sbchiasif (multiplier
& 1){ dchsangtrivluvomtbin,phndscsosnhvischia.Nuphndproduct +=
multiplicand; bnghoclnhnschiathphndsctrimtgitrbngschiavsb }chia s c
cng thm mt v dch sang tri mt v tr bit v chnh c gi l multiplier
>> =1;thngs.Qutrnhnyclplivtiptcchonkhislndchbngngs
multiplicand
