vi mach 8255

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Tim boi : [email protected] Bo co thc tp tt nghip

Phn I Tm hiu mt s linh kin8255

1. Cu trc ca 8255Vi mch 8255 l vi mch c ln LSI, thng c gi l mch phi ghp vo/ra

song song lp trnh c. Do kh nng mm do trong cc ng dng thc t n l

mch phi ghp c dng rt ph bin cho cc h vi x l 8, 16, 32 bit, Vi mch 40chn ny c cc chn nh sau:

U1

8255

3433323130292827

53698356

432140393837

181920212223

2425

1415161713121110

D0D1D2D3D4D5D6D7

RDWRA0A1RESET

CS

PA0PA1PA2PA3PA4PA5PA6PA7

PB0PB1PB2PB3PB4

PB5PB6PB7

PC0PC1PC2PC3PC4PC5PC6PC7

C 24 ng dn li vo/ra xp thnh 3 cng song song ( portA, portB, portC).Mt na cng C ( PC4 PC7) thuc nhm A, cn na kia thuc nhm B.

Chn Reset phi c ni vi tn hiu Reset chung ca ton h thng (khi Reset

cc cng c nh ngha l cng vo khng gy ra s c cho cc mch iukhin).

Tn hiu CS c ni ci mch to xung chn thit b t mch 8255 vo mta ch c s no . Cc tn hiu a ch A0, A1 s chn ra 4 thanh ghi bn trong8255: mt thanh ghi ghi t iu khin (CWR control word register) cho hotng ca 8255 v 3 thanh ghi khc ng vi cc cng l PA, PB, PC ghi c dliu theo bng:

A1 A0 CS RD WR Lnh (ca VXL)Hng chuyn s liu vi

VXL

0 0 0 0 1 c PortA PortAD0 D70 1 0 0 1 c PortB PortBD0 D71 0 0 0 1 c PortC PortC D0 D71 1 0 0 1 Khng c gi tr0 0 0 1 0 Ghi PortA D0 D7 PortA0 1 0 1 0 Ghi PortB D0 D7 PortB1 0 0 1 0 Ghi PortC D0 D7 PortC1 1 0 1 0 Ghi thanh ghi

iu khinD0 D7 Thanh ghi

iu khin

x X 1 x X Vi mch trngthi tr khngcao

Khng c trao i s liu

Tm hiu mt s linh kin3
mailto:[email protected]:[email protected]

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Tnh linh hot ca vi mch ny th hin kh nng lp trnh. Ta c th t ccmode hot ng thng qua thanh ghi iu khin. Cc chn D0 D7 to nn knh dliu 2 hng c rng 8 bit. Tt c d liu khi truy nhp ghi hoc c c dn quaknh d liu ny.

Trng thi logic ghi/c c nhn bit qua cc tn hiu iu khin CS ,RD , WR .Trao i thng tin vi 8255 ch c th c tin hnh khi CS = 0. Khi RD = 0 d liuca cng c chn c a ra knh d liu v c th c s dng bi cc vi mchkhc. Khi WR = 0, th moi vic xy ra ngc li. Cc bit a ch A0 v A1 cng vicc tn hiu ghi c bo cho bit s truy nhp ln cng no.

S khi m t chc nng ca 8255:

D0D7

RD

WR

A1

A0

Reset

2. Cc ch lm vic ca 8255C 2 loi t iu khin cho 8255:

T iu khin nh ngha cu hnh cho cc cng PA, PB, PC. T iu khin lp/xo tng bit u ra ca PC.

Tu theo lnh ghi vo thanh ghi iu khin khi khi ng vi mch m ta ccc PortA,B,C hot ng :

Cc ch 0, 1, 2 khc nhau.


PortA

(8)

PortCna

cao (4)

PortCnathp(4)

PortB

(8)

iu

khinnhmA

iukhinnhm

B

ms liu

Logicikhincghi

A0PA7

C7PC4

C3PC0

8

4

4

8

B0PB7

CS

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Chiu trao i s liu khc nhau.2.1. T iu khin nh ngha cu hnh cho cc cngDng thc t iu khin nh ngha cu hnh cho 8255:

D7 D6 D5 D4 D3 D2 D1 D0

C =1 MA1 MA0 A CA MB B CB

Nhm AChn ch 00: mode 001: mode 11x: mode 2

2.2. T iu khin lp xo bit ra PCiDng thc ca t iu khin d lp xo PCi:

D7 D6 D5 D4 D3 D2 D1 D0

0 0 0 0 S/R

1 1 1 1 0 0 0 0

1 1 0 0 1 1 0 0

1 0 1 0 1 0 1 0

Cc ch lm vic ca 8255 c th c nh ngha bng t iu khin

CWR. 8255 c 3 ch lm vic: Mode 0: Vo/ra c s. Trong ch ny mi cng PA, PB, PCH

v PCL u c th c nh ngha l cc cng vo hoc ra. Mode 1: Vo/ra c xung cho php. Trong ch ny mi cng

PA,PB c th c nh ngha thnh cng vo hoc ra vi cc tnhiu mc ni ( handshaking ) do cc bit tng ng ca cng PCtrong cng nhm m nhn.

Mode 2: Vo/ra 2 chiu. Trong ch ny ch ring cng PA cth c nh ngha thnh cng vo ra 2 chiu vi cc tn hiu mc


PA:1: vo0: ra

PCH:

1: vo0: ra

Nhm BPC

L(thp):

1: vo0: ra

PB:1: vo

0: ra

Chn ch :1: vo0: ra

1: Lp PCi

0: Xo PC

PC7PC6 PC5PC4 PC3 PC2PC1 PC0

3 bit a ch

ca 8 bit PC

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ni do cc bit ca cng PC m nhim. Lc ny cng PB c thlm vic trong ch 0 hoc 1.

Trong ch 0, ngi ta c th dng cc bit ca PC lp xo iu khinhoc i thoi vi cc thit b ngoi vi, ch ny cn gi l ch lp xotng bit ca PC:

Ghp ni 8255 vi h vi x l 8255 lm vic mode 0

Trong ch 0, 8255 cho mt kh nng xut v nhp d liu n gin qua 3cng A,B,C. PA, PB, PC c s dng c lp vi nhau, 3 ng dy u c dng trao i s liu hoc thng tin v iu khin v trng thi mt cch bnh ng vinhau v tu la chn:


Mode 1

A0 PA7

A0 PA7

A0 PA7

RDWR, D0 D7 A0,A1,

B C A

B0 PB7PC0 PC3 PC4 PC7

A0 PA7

Mode 0

B APC0 PC1 PC2 PC3 PC4 PC5 PC6 PC7

B0 PB7

B0 PB7INTR

B

IBF STB INTR STB IBF I/O I/O

BOBF BACK I/OI/O

AACK AOBF

Mode 2B A

B0 PB7

PC0 PC1 PC2 PC3 PC4 PC5 PC6 PC7

INTRA

STBA

AACKAOBF

IBFA

Ca vo

Ca ra

I/O ( mode 0)i thoi (mode 1)

Ca B mode 0 hoc 1 i thoi ca A

i thoi ca Ai thoi ca B

8255

PA0 PA7

PC0 PC3

PC4

PC7

PB0 PB7

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8255 lm vic mode 1L ch vo/ra c cht, tc l c s i thoi gia ngoi vi v h vi x l thng

qua cc bit PortC. C 2 nhm:Nhm A: gm PortA dng trao i s liu v na PortC cao( PC4 PC7 )

i thoi gia vi x l v ngoi vi.Nhm B: gm PortB dng trao i s liu v na PortC thp( PC0 PC3 )

i thoi gia vi x l v ngoi vi.Hng v ch 1 ca PortA, PortB do t lnh iu khin quyt nh, cc tn hiu

i thoi PCi ph thuc hng cng vo hay ra. Xut d liu ra trong mode 1

Cng PA, PB c tn hiu i thoi tng t nhau. Tn hiu OPFBOBFA, bo rngb m ra y cho ngoi vi bit CPU ghi d liu vo cng chun b a ra.Tn hiu ny thng ni vi tn hiu STR ca thit b nhn.

Tn hiu ACKBACKA, l tn hiu ca ngoi vi cho bit n nhn c d liu tcc cng PA, PB.

Tn hiu INTRA, ITRB l tn hiu yu cu ngt t PA, PB.INTEA, INTEB l tn hiu ca mt mch lt bn trong 8255 cho php hoc

cm yu cu ngt INTRA hoc INTRB ca PA hoc PB.INTEA c lp/xo thng qua bit PC6INTEB c lp/xo thng qua bit PC2Khi lm vic ch xut thng tin mode 1, thanh ghi trng thi ca 8255 cung

cp cc thng tin phn nh trng thi hin hnh ca mnhS ghp ni ca 8255 mode 1

OBFA (Output Bufer A full) Cng A c d liu ri


PC6

PC3

PC1

PC2

PC0

PC7

PA0 PA7

PB0 PB7

PC4,5

INTEA

INTEB

OBFA

ACKA

OBFB

INRA

ACKB

INRB

I/O

RA

PC5

PC3

PC2

PC1

PC0

PC4

PA0 PA7

PB0 PB7

PC6,7

INTEA

INTEB

STBA

INTE

INRB

VO

IBFA

STBB

IBFB

I/O

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OBFB (Output Bufer B full) Cng B c d liu riINTEA ( Interrupt Enable For PortA) cho php PA chy ch ngt.INTEB ( Interrupt Enable For PortB) cho php PB chy ch ngt.INTRA ( Interrupt PortA ) PA ngtINTRB ( Interrupt PortB ) PB ngt

Ni dung thanh ghi trng thi ca 8255 mode 1 cho hng ra:D7 D6 D5 D4 D3 D2 D1 D0

OBFA INTEA IO IO INTRA INTEB OBFB INTRB

Nhn d liu vo trong mode 1Khi nhn d liuvo trong mode 1 cc cng PA, PB c tn hiu i thoi tng t

nhau:STB ( cho php cht d liu). Khi d liu sn sng trn knh PA, PB ngoi vi

phi dung STB bo cho 8255 bit cht d liu vo cng PA hoc PB.Sau khi 8255 cht c d liu do thit b ngoi vi a n, n a ra tn hiu IBF

(In Buffer full) bo cho ngoi vi bit.Ni dung thanh ghi trng thi ca 8255 mode 1 cho hng vo:D7 D6 D5 D4 D3 D2 D1 D0

IO IO OBFA INTEA INTRA INTEB OBFB INTRB

8255 lm vic mode 2Ch ny ch dng cho cng PA vi vo/ra 2 chiu cc bit PC3 PC7 dng

lm tn hiu i thoi.Mch logic ca 8255 mode 2 v cc tn hiu i thoi:


PC3

PC7

PC6

PC5

PC4

PA0 PA7

PB0 PB7

PC0,2

ACKA

OBFA

INRA

I/O

Vo

INTE 1

INTE 2

IBFA

STBA

PC3

PC7

PC6

PC5

PC4

PA0 PA7

PB0 PB7

PC1PC2

PC0

ACKA

OBFA

INRA

Ra

INTE 1

INTE 2

IBFA

STBA

INTRB

ACKA

OBFB

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Cng PB c th lm vic mode 1 hoc mode 0 tu theo bit iu khin trongthanh ghi CWR.

INTRA: yu cu ngtcho d liu 2 chiu vo/ra.INTE 1, INTE 2: l l 2 tn hiu ca 2 mch lt bn trong 8255 cho php hoc

cm yu cu ngt ca PA, cc bit ny c lp xo bi PC6 v PC4.

Khi dng 8255 trong ch bus 2 chiu trao i d liu theo cch thm d,phi kim tra xem bit IBFA c bng 0 (m vo rng) hay khng trc khidng lnhIN nhn d liu t cng PA.

Khi lm vic ch truyn thng tin 2 chiu ca mode 2, thanh ghi trng thica 8255 cung cp cc thng tin phn nh trng thi hin hnh ca mnh.

Ni dung thanh ghi trng thi:D7 D6 D5 D4 D3 D2 D1 D0

OBFA INTE1 IBFA INTE2 INTRA x x x


Nhm A Nhm B

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8254( 8253 )Mch nh thi gian lp trnh c 8254/8253 l mt mch ph rt quan trng

trong cc h vi x l ca Intel. N c th p ng c cc yu cu ng dng khcnhau trong h vi x l: m thi gian, m s kin, chia tn s, to ra dy xung

c im ca 8254/8253: Hot ng tn s cc i l 8MHz. Nh da trn cng ngh CMOS nn t c tc cao v tiu th nng lng

thp. Hot ng ch hon ton tnh. C 3 b m li ( Down- counter ) c lp 16 bit. Ngun cung cp t 3V 6V. C th m nh phn hoc thp phn. MSM82C53-2RS c 24 chn. MSM82C53-2JS c 28 chn. MSM82C53-2GS-VK c 32 chn.S khi chc nng:

Chn chn v (CS) ca vi mch 8254/8253 phi c ni vi u ra ca mt bgii m nh a ch c bn cho mch. Cng vi a ch c bn, cc chn a chA1 v A0 s cung cp cc a ch c th ca cc thanh ghi bn trong 8254/8253 khighi ( lp trnh ) hoc c thng tin ca mch. l thanh ghi cho 3 b m v mtthanh ghi cho t iu khin. Ni dung ban u ca mi b m u c th lp trnht CPU thay i c. Ngoi ra cn c th iu khin hot ng ca cc b mbng tn hiu t bn ngoi qua cc chn ca ( GATE ) cho php bt u m( GATE = 1) hay kt thc qu trnh m ( GATE = 0). Gi tr ca b m c tht bng byte hoc word.

Truyn d liu gia bus d liu( data bus ) v thanh ghi bn trong c m t bibng sau:


Counter#0

Counter#1

Counter#2

Control

wordregisrer

Read/

Write logicData bus

buffer

CLK0 GATE0 OUT0 CLK1 GATE1 OUT1 OUT2GATE2CLK2

Vcc GND

D7 D0

8

RDWR A0 A1CS

8

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CS RD WR A1 A0 Chc nng

0 1 0 0 0 Counter#0 ghi d liu t data bus0 1 0 0 1 Counter#1 ghi d liu t data bus0 1 0 1 0 Counter#2 ghi d liu t data bus0 1 0 1 1 Ghi thanh ghi t iu khin

0 0 1 0 0 Data bus c d liu t counter#00 0 1 0 1 Data bus c d liu t counter#10 0 1 1 0 Data bus c d liu t counter#20 0 1 1 11 X x X x0 1 1 X x

Data bus trng thi cao tr

1. Khi u cho 8254/8253Cng nh cc vi mch lp trnh c khc ph tr cho CPU, sau khi bt in mch

8254/8253 phi c khi u c th hot ng theo ng yu cu. Mt iu cn

ch l trng thi ca 8254/8253 sau khi bt in l khng xc nh. khi u cho 8254/8253 ta phi ghi t iu khin vo thanh ghi t iu khin

ca n. Dng thc t iu khin ca 8254/8253 nh sau:

D7 D6 D5 D4 D3 D2 D1 D0SC1 SC0 RW1 RW0 M2 M1 M0 BCD

Chn b m ( select counter ) qua CS1 v CS0:

Ghi/c :RW1 RW0

0 0 Lnh cht b m

0 1 c/ghi byte c trng s nh nht(LBS)1 0 c/ghi byte c trng s ln nht(MBS)1 1 c/ghi byte LBS, tip theo l MBS

t ch :M2 M1 M00 0 0 Mode 0- to yu cu ngt khi m ht0 0 1 Mode 1- a hi i lp trnh c0 1 0 Mode 2- b chia tn s cho N0 1 1 Mode 3- to xung vung

1 0 0 Mode 4- to xung cho php mm1 0 1 Mode 5- to xung cho php cng


Selectcounter

Ghi/cChn ch

SC1 SC0 Chn ra0 0 Counter#0 c chn0 1 Counter#1 c chn1 0 Counter#2 c chn1 1 Lnh c ngc

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t ch m qua bit BCD: bit BCD = 0 m nh phn 16bit, bit BCD = 1 mthp phn 4 decades.

Thanh ghi t iu khin dng cha t iu khin cho c 3 b m. Vi cc bitSC0, SC1 ta c th chn ra b m lm vic theo cch thc do t iu khin quyt

nh. Trng hp c bit khi SC1 v SC0 = 1 ta c th dng lnh c ngc c -c ni dung hoc trng thi ca b m trong thi im hin ti.Cc b m ca 8254/8253 u lm vic ch m li. Nh vy s m ln

nht m ta c th a vo b m bt u m l 10000H hoc 10000, v sau khili 1 ta c ni dung mi ca b m l FFFFH hoc 9999 tu theo bit BCD = 0 hayBCD =1.

Cc bit M2,M1,M0 s xc nh cc ch lm vic ca b m, trong ccu vo GATE c nhng tc ng khc nhau n cc u ra OUT.

Cc bit RW1,RW0 cho php chn cch thc ghi/c vi cc b m. Ta c thghi/c tch ring tng byte ca b m. Nu mun ghi/c lin tip 2 byte ca bm th ta phi tun theo th t byte thp trc v tip theo l byte cao.

2. Cc ch lm vic ca 8254/8253Mode 0 To yu cu ngt khi m xong ( terminal count) ch ny t iu khin CW= 10H, ch c/ghi LSB v ch m theo h 16

cho b m s 0. Sau khi ghi t iu khin vo thanh ghi t iu khin th OUT= 0.Tip theo ta hgi LSB = 4l phn thp ca s m cho b m. Gi tr ny s cchuyn vo b m chu k ng h sau. Lc ny GATE = 1 nn b m bt um ngc. Khi b m t ti 0 th OUT =1. iu c ngha nu ta np vo LSB =N th sau N+1 xung ng h ta c OUT = 1. sau khi t 0000H th b m tip tcm li t FFFFH nu nh n khng c np gi tr m mi. Xung OUT c th cdng nh l xung yu cu ngt i vi CPU bo l t s m ( terminalcount ).

Khi b m ang lm vic m GATE = 0 th ni dung ca b m c gi khngi cho n khi GATE = 1, lc ny b m li tip tc m li.

Khi b m ang lm vic m c xung iu khin np ni dung s mi, ni dungmi ch c a n b m ti xung ng h tip theo. Sau b m li tip tcm li vi s m mi.Mode 1- a hi i vi thi gian lp trnh c

ch ny ta c CW = 12H, ch c/ghi LSB v ch m theo h 16 cho bm 0. Sau khi ghi t iu khin vo thanh ghi t iu khin th OUT = 1. Tip theota ghi LSB = 3 l phn thp ca s m cho b m. Gi tr ny s c chuyn vo

b m. Lc ny GATE = 0 nn b m cha lm vic. Khi c xung kch GATE = 1th b m bt u lm vic chu k ng h sau. T y OUT=0 v bt u qutrnh m ngc. Khi b m t ti 0 th OUT = 1. iu c ngha l nu ta npvo LSB = N v GATE = 1 th OUT = 0 trong N xung ng h. B m sau khi t0000H th s m li t FFFFH nu nh n khng c np gi tr m mi v mi khic xung GATE = 1 n li to ra xung OUT = 0 trong N xung ng h.

Khi b m ang lm vic v cha t c s m m c xung GATE = 1 th sm c c np li cho b m chu k ng h sau. T lc ny b m li tip tcm li. OUT = 0 cho n khi m ht.

Khi b m ang hot ng m ta c xung iu khin np s m mi th ni

dung mi ch c a n b m ti xung ng h tip theo sau khi c xung GATE= 1.


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Mode 2-To xung c tn s fin/N ch ny ta c CW = 14H, tc l ch c/ghi LSB v ch m theo h 16

cho b m s 0. Sau khi ghi t iu khin vo thanh ghi t iu khin th OUT = 1.tip theo ta ghi LSB = 3 l phn thp ca s m cho b m. Gi tr ny c chuynvo b m ti chu k sau ca xung ng h. Lc ny GATE= 1 nn b m bt u

lm vic. T y bt u qu trnh m ngc. Khi b m t n 1 th OUT = 0trong thi gian 1 xung ng hv qu trnh m ngc li c bt u vi OUT = 1v vi s m c. iu c ngha l khi ta np LSB=N vo b m th c sau Nxung ng h, ta c u ra OUT = 0 trong thi gian 1 xung ng h.

Khi b m ang lm vic v cha t c s m m c xung GATE = 0 th gitr hin thi ca b m c c gi nguyn trong sut thi gian GATE = 0. KhiGATE = 1 th b m li tip tc m li.

Khi b m ang hot ng v cha t s m m c xung iu khin np sm mi th b m vn tip tc vi s m c, ch ti khi b m m n 1 ths m mi mi c p dng.

Mode 3- To dy xung vung ch ny ta c CW = 16H, ch c/ghi LSB v ch m theo h 16 cho bm s 0. Sau khi ghi t iu khin vo thanh ghi t iu khin th OUT = 0. Tiptheo ta ghi LSB = 4 l phn thp ca s m cho b m. Gi tr ny s c chuynvo b m ti xung ng h sau. Lc ny GATE = 1 nn b m bt u ngay qutrnh m ngc. Khi b m t ti (4/2)=2 th OUT = 0 trongtrong thi gian (4/2)=2 xung ng h cn li v qu trnh m li c bt u vi OUT = 1 v vi sm c. iu c ngha l sau khi ta np LSB = N (s chn) vo b m th c sauN xung ng hta c OUT = 1 trong N/2 xung ng h v OUT = 0 trong N/2 xungng h. Nu N l s l th c sau N xung ng h ta c OUT = 1 trong (N+1)/2xung ng h v OUT = 0 trong (N-1)/2 xung ng h cn li.

Khi b m ang hot ng m c xung GATE = 0 th b m khng thay ini dung chng no cn c GATE = 0, khi GATE = 1 n tip tc m li t gi trhin thi.Mode 4- To xung cho php bng ch ng trnh

ch ny ta c CW = 18H, ch/c ghi LSB v ch m theo h 16 cho bm s 0. Sau khi ghi t iu khin vo thanh ghi t iu khin thi OUT = 1. Tiptheo ta ghi LSB = 3 l phn thp ca s m cho b m. Gi tr ny s c chuynvo b m ti xung ng h sau. Lc ny GATE = 1 nn b m bt u ngay qutrnh m ngc. Khi b m t ti 0 th OUT = 0 trong thi gian 1 xung ng h vqua trnh m li tip tc t FFFFH vi OUT = 1. Tc l nu ta np s m N th

sau N+1 xung ng h th ta s c c xung cho php tch cc thp ko di 1 xungng h.

Sau khi b m c np s m n vn cha lm vic chng no cha c xungGATE = 1.

Khi b m ang m v cha t s m m ta c xung iu khin np s mmi th s m mi s c np v bt u m li ti xung ng h tip ngay sau .Mode 5- To xung cho php bng xung iu khin GATE

ch ny ta c CW = 1AH, ch c/ghi LSB v ch m theo h 16 chob m s 0. Sau khi ghi t iu khin vo thanh ghi t iu khin th OUT = 1. Tiptheo ta ghi LSB = 3 l phn thp ca s m cho b m. Lc ny GATE = 0 nn b

m cha lm vic. Khi c xung kch GATE = 1 th chu k ng h sau b m btu qu trnh m ngc. Khi b m t ti 0 th OUT = 0trong thi gian mt xung


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ng h v qu trnh m li tip tc t FFFFH vi OUT = 1 nu khng c xungGATE =1 mi. Tc l nu ta np s m l N v xung GATE=1 th sau N+1 xungng h ta s c xung cho php tch cc thp ko di 1 xung ng h.

Khi b m ang m li v cha t s m c xung GATE = 1 b m c npli s m c v n bt u m li ti xung ng h tip ngay sau .

Khi c lnh np s mi b m vn tip tc m li vi s m c cho ti khinhn c xung GATE =1 th s m mi mi c p dng xung ng h sau.


WR

Clk

GATE

OUT

CW=10 LSB= 4

WR

Clk

CW=10 LSB=3

GATE

OUT

WR

Clk

CW=10 LSB=3 LSB=2

GATE

OUT

Biu thi gian ca 8254/8253 mode 0

N N N 4 3 2 1 0 F F

N N 3 2 2 2 1 0 F

N N 3 2 1 2 1 0 F

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GATE

GATE

GATE

WR

Clk

CW=12 LSB=3

OUT

WR

Clk

CW=12 LSB=3

OUT

WR

Clk

CW=12 LSB=2 LSB=4

OUT


N N N N 3 2 1 0 F 3 2

N N N N 3 2 1 3 2 1 0

N N N N 2 1 0 F E 4 3

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WR

Clk

CW=14 LSB=3

GATE

OUT

WR

Clk

CW=14 LSB=3

GATE

OUT

WR

Clk

CW=14 LSB=4 LSB=5


N N N N 3 2 1 3 2 1 3

N N N N 3 2 2 3 2 1 3

GATE

OUT

N N N N 4 3 2 1 5 4 3

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WR

Clk

CW=16 LSB=4

GATE

OUT

WR

Clk

CW=16 LSB=5

GATE

OUT

WR

Clk

CW=16 LSB=4

GATE

OUT


N N N N 4 2 4 2 4 2 4 2

N N N N 4 2 0 4 2 4 2 0 4

N N N N 4 2 4 2 2 2 4 2 4

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WR

Clk

CW=18 LSB=3

GATE

OUT

WR

Clk

CW=18 LSB=3

GATE

OUT

WR

Clk

CW=18 LSB=3 LSB=2

GATE

OUT


N N N N 3 2 1 0 F E D C

N N N N 3 3 3 2 1 0 F E

N N N N 3 2 1 2 1 0 F E

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WR

Clk

CW=1A LSB=3

GATE

OUT

WR

Clk

CW=1A LSB=3

GATE

OUT

WR

Clk

CW=1A LSB=3 LSB=5

GATE

OUT


N N N N 3 2 1 0 F 3 2 1

N N N N N 3 2 3 2 1 0 F

N N N N N 3 2 1 0 F E 5 4

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7400 l IC gm 4 phn t NAND 2 u vo:S chn:

11 9 813 12 10

Vcc

14

7

GND

654321

IC7400

7402 l IC gm 4 phn t NOR 2 u vo:S chn:

1 2 3 4 5 6 7

GND

Vcc

14 101213 8911

IC7402

7404 l IC gm 6 phn t NO :

S chn:

1 2 3 4 5 6 7

GND

Vcc

14 13 12 11 10 9 8

IC7404

7432 l IC gm 4 phn t OR 2 u vo:S chn:

1 2 3 4 5 6 7

GND

Vcc

14 13 12 11 10 9 8

IC7432


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74LS138 l mch gii m:S chn:

8GND

Vcc16

Y015

Y114

Y312

Y69

Y510

Y411

7Y7

6G1

5G2B

4G2A

3C

2B

1A

Y213

74LS138

Bng chc nng ca 74LS138:Cc u vo

Chn Cho phpCc u ra

C B A BG2 AG2 G1 0Y 1Y 2Y 3Y 4Y 5Y 6Y 7YX x x 1 x x 1 1 1 1 1 1 1 1X x x x 1 x 1 1 1 1 1 1 1 1X x x x x 0 1 1 1 1 1 1 1 10 0 0 0 0 1 0 1 1 1 1 1 1 10 0 1 0 0 1 1 0 1 1 1 1 1 10 1 0 0 0 1 1 1 0 1 1 1 1 10 1 1 0 0 1 1 1 1 0 1 1 1 11 0 0 0 0 1 1 1 1 1 0 1 1 11 0 1 0 0 1 1 1 1 1 1 0 1 1

1 1 0 0 0 1 1 1 1 1 1 1 0 11 1 1 0 0 1 1 1 1 1 1 1 1 0

74273 l IC gm 8 D FF ng b theo sn xung, mch ra 3 trng thi:S chn:

Clock5Q5D6D6Q7D8D8QVcc

GND4Q4D3Q3D2Q2D1D1Qclear

7Q

74273

Bng chc nng:

Clear Clock D Output(Q)L x x L

H H HH L LH L x Q0


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S chn ca 373:

7Q

1Q 1D2D2Q 3D3Q4D4Q GND

Vcc8Q8D7D 6Q6D5D5Q

OutputControl

G

373

Bng chc nng ca 373:

Output Control G D Output(Q)L H H HL H L L

L L x Q0H x x T

H: Mc High, L: Mc Low, T: Ba trng thi, Q0: D liu c lu nhADC0808, ADC0809. L b chuyn i tng t s 8 bits, 8 knh u vo, u ra

3 trng thi.c im:

phn gii 8 bits. Ngun cung cp n 5V. 8 knh u vo.

Cng sut tiu th: 15mW. u ra 3 trng thi. in p u vo tng t 0V 5V.

Cc u ra nh s t 2-8 2-1.Cc u chn a ch: A, B, C.S chn:

IN228

IN127

IN026

A25

B24

C23

ALE22 2021 191817 15

REF(-)16

1IN3

2IN4

3IN5

4IN65IN76

START7

EDC8 9OutputEnable

10Clock11Vcc12

REF(+)13GND14

ADC0808

ADC0809

2-1 2-2

2-3 2-4 2-5

2-8 2-7


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Chn knh vou chn a ch

C B AIN0 L L LIN1 L L H

IN2 L H LIN3 L H HIN4 H L LIN5 H L HIN6 H H LIN7 H H H

DAC0808. L b bin i s tng t 8 bits.c im:

Kh chnh xc: sai s 0.19%.

Cng vo khng o, giao tip c vi TTL v CMOS. Gii in p cung cp 4.5V 18V. Cng sut 33mW ( 5V).

Cc gi tr danh nh: in p ngun:

Vcc +18VVEE - 18V

in p u vo s: 10V +18V. in p ra: -11V +18V Dng chun: 5mA. Cng sut tiu tn theo v: 1000mW

S chn:

1

2

3

4

5

6

15

14

12

11

10

9

I0

A4A5

A6

VREF(+)

VREF(-)

7

8

13

16COMPENSATION

Vcc

A8

A7

A3

A2

A1

VEE

NC

GND

DAC0808


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245 Thng dng lm b khuych i mS chn:

c im: Giao din bus 2 chiu. u ra 3 trng thi.

S chc nng:

Bng chc nng:

Inputs Inputs/outputs

OE DIR An BnL L A = B Inputs

L H Inputs B = AH x Z ZZ - trng thi cao tr.

24

vi mach 8255

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