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Bo Co Thc Hnh K Thut S: Thit K Mch Logic

BO CO THC HNH K THUT STn ti:

THIT K V NG DNG MCH HIN TH NG H S

I.

Mc ch yu cu: Vn dng cc kin thc hc v in t c bn, k thut xung,k thut s,thit k mch Logic. S dng cc IC c sn ti phng TN Tin Hc Cng Nghip (PFIEV) v cc IC khc mua thm, thit k lp rp cc mch in t ng dng. II. Mch ng h s: 1. Mch ti xung 1Hz(T=1s) Mch to xung chun s dng thch anh 32.768khz v chip m & chia tn s CD4060 Thch anh 32,768khz l thch anh chuyn dng cho ng h c kch thc b xu nh rut bt bi. Hu nh u c s hin din ca "anh thch" ny th c mch ng h... sau khi chia 2^14 = 16.384 ln qua IC cd4060 chn s 3 ta c tn s u ra l 2HZ tip tc chia 2 bng mh D flip - flop cdc4013 ta c 1Hz . Ta c s sau:

MCH TO XUNG 1Hz

Tuy nhin tn s dao ng ca thch anh li ph thuc vo lt ct ra n nn d k thut c hin i n u th vn c sai s do vy trong s dng thm tr v t vi chnh to mch cng hng b tr chn thch anh

GVHD: Trn nh Khi Quc - Nguyn Hu Lp Trng

Nhm SV:07CLC2


2. Mch m v hin th gi,pht,giy. Ta s dng IC74ls90 l IC m 10 v IC74ls47 l IC gii m led 7 on vi ng ra tch cc m dng cho led 7 thanh c anot chung 2.1 Tm hiu v b m v IC74ls90. 2.1.1 nh ngha v phn loi b m 1. nh ngha: B m l mt mch dy tun hon c mt u vo m v mt u ra,mch c s trng thi trong bng chnh h s m(Kd).Di tc dng ca tn hiu vo m,mch s chuyn t trnh thi trong ny n mt trng thi trong khc theo mt th t nht nh.C sau Kd tn hiu vo m,mch tr li trng thi xut pht ban u. 2. Phn loi b m Cn c vo s khc bit ca tnh hung chuyn i trng thi cc Flip Flop trong b m,ngi ta phn thnh 2 loi ln: b m ng b v b m d b.Trong b m ng b,cc Flip Flop u chu tc ng iu khin ca mt xung ng h duy nht, l xung m u vo.Vy s chuyn i trng thi ca chng l ng b.B m d b th khc,c Flip Flop(FF) chu tc ng iu khin trc tip ca xung u vo,nhng cng c FF chu tc ng iu khin ca xung u ra ca FF khc(c vai tr nh thi ca xung ng b).S chuyn i trng thi ca FF khng cng lc,tc l d b. Cn c vo s khc bit v h s m ca b m,ngi ta phn thnh cc loi: B m nh phn,b m thp phn,b m N phn. Nu gi n l s ch s ch s v tr trong m s nh phn(cng l s FF trong b m), gi N l s trng thi tch cc(cng l s trng thi m ha c lp khi gii m)th i vi b m nh phn N=2^n i vi b m nh phn N=10. 3. B m ng b Thit k b m 10 ng b,m ln,m Gray,s dng JK Flip Flop Bng trng thi:


Nhm SV:07CLC2

Bo Co Thc Hnh K Thut S: Thit K Mch Logic Bng chuyn i trng thi: Trng thi hin ti Q3 0 0 0 0 0 1 1 1 1 1 Q2 0 0 0 0 1 1 0 0 0 0 Q1 0 0 1 1 1 1 1 1 0 0 Q0 0 1 1 0 0 0 0 1 1 0 Trng thi tip theo Q3 0 0 0 0 1 1 1 1 1 0 Q2 0 0 0 1 1 0 0 0 0 0 Q1 0 1 1 1 1 1 1 0 0 0 Q0 1 1 0 0 0 0 1 1 0 0 u vo kch thch cc FF J3K3 J2K2 J1K1 J0J0 0X 0X 0X 1X 0X 0X 1X X0 0X 0X X0 X1 0X 1X X0 0X 1X X0 X0 0X X0 X1 X0 0X X0 0X X0 0X X0 0X X1 X0 X0 0X 0X X1 X1 0X 0X 0X

Biu din cc hm trn bng Karnaugh v ti thiu ha:

00 X X

01 X X

11 X X

10 00 1 X 01 11 10

00 X X X 1

01 X X X

11 X X X

10 X

J3=Q2

K3=Q1Q0


Nhm SV:07CLC2

Bo Co Thc Hnh K Thut S: Thit K Mch Logic 00 00 X X 01 X X 11 X X 10 1 X X X X X X 01 X X X X 11 X X X X 1 X 10 X

J2=Q1Q0Q3 00 00 X X 01 1 X X 11 X X X X J1=Q0Q3 10 X X X X X X X X 01

K2=Q3 11 10

X X X X X X 1

K1=Q0Q3

00 1 X X

01 X X X X

11 X X X X

10

00 X X X

01

11 1

10 X X X X

X X 1

X X

1

X

J0=Q1Q3+Q1Q2Q3

K0=Q3Q1+Q1Q3 Nhm SV:07CLC2



T h phng trnh ti thiu ha nhn c s ca b m nh sau:

II.1.2 Tm hiu IC74ls90 IC 74ls90 l IC thuc h 74xx,IC ny c chc nng m thp phn.Con TTL ny cng kh quen thuc n l con m m nh phn chia 10 m ha ra BCD. C mi 1 xung vo th n m tin ln 1 v c m ha ra 4 chn. Khi m n 10 t n s reset v quay tr v ban u. Hai thng s quan trng thit k mch m ny l: Bng chn l m ha ra BCD v iu kin Reset (Tr v trng thi ban u) Theo datasheet ta c s chn nh sau:


Nhm SV:07CLC2


S cu to:

+ Bng chn l m ha ra BCD


Nhm SV:07CLC2

Bo Co Thc Hnh K Thut S: Thit K Mch LogicKhi sn xut ra con ny nh sn xut cung cp cho chng ta bng m ha ca con ny do m mnh khng th to ra bng m ny c. Sau y l bng m ca n c ly t datasheet

Trong bng chn l trn n c 1 ch v ch ny v cng quan trng l : u ra ca Q0 c ni vi u vo ca CP1. + Mc Reset cho 74LS90. N c 4 chn Reset dng reset h thng vi cc chn : MR1, MR2, MS1, MS2. a cc mc thch hp vo cc chn ny th n s t ng Reset. Sau y l bng mc Reset


Nhm SV:07CLC2


II.2 Tm hiu mch gii m led 7 on v IC74ls47 2.2.1 Mch chuyn m Trong cc h thng in t dng mch s,d liu(lnh,s liu) c truyn i hay x l dng t(word) nh phn gm cc bit 0 v 1.Mt t n bit c th biu din cho 2^n phn t tin khc nhau vi gi tr thp phn t: 0=>2^n -1.T nh phn n bits gi l m (Code)ca cc phn t tin tc.C rt nhiu loi m, sau y l mt s loi m thng gp: a. Cc loi m k t thng dng: M ASCII(American Standard Code for Information Interchange): m dng cho 8 bits m ha 1 k t. M EBCDI(Extended Binary Code Decimal Interchange Code ): dng 8 bits m ha 1 k t. M BAUDOT: m ny dng 5 bit biu din cho mt k t,n c dng trong bu in v mt s loi teletype. b. Cc loi m thng dng m ha cc con s m ha cc con s thng dng cc loi m: M nh phn,m d 3(XS3), m Gray,m Gray d 3,m nh phn ca s thp phn(BCD),m thp phn,m 7 vch. M c th chia lm 2 loi: loi c trng s(trng s ca cc k hiu nh phnc sp xp theo th t 2^0,2^1,2^2,2^n) v loi khng c trng s(trng s ca cc k hiu nh phn khng ph thuc v tr ca chng trong t m). -m nh phn: y l loi m c trng s,trng s ca cc k hiu nh phn c sp xp t thp n cao l 1,2,4,8,. -m BCD(Binary Code Decimal):


Nhm SV:07CLC2

Bo Co Thc Hnh K Thut S: Thit K Mch Logic m ha nh phn cho 10 ch s thp phn cn t m c di 4 bit.ty theo cch s dng 10 trn 16 t hp m nh phn 4 bit m ta c cc loi m BCD khc nhau.mt s loi m BCD thng gp: BCD-normal,2421,5121. -m Gray: L loi m khng c trng s,cc t m k cnh nhau ch khac nhau mt bin s,m Gray c dng biu din bng Karnaugh. II.2.2 B gii m hin th Chng ta s thuyt minh nguyn l cng tc v qu trnh thit k ca b gi m hin th qua v d b gii m kch cho led 7 on Thit k b gii m hin th kch cho hin th Led 7 thanh vi tn hiu u vo l m BCD 8421. Phn tch yu cu thit k:

Xem s khi hnh trn. Cc u vo D, C, B, A l m BCD 8421,trong 6 trng thi 1010->1111 khng c s dng, nh du cho X x l ti thiu ha. Tn hiu u ra a, b, c, d, e, f, g l kch sng led tng ng ca hin th led 7 thanh.Cn c mch kch sang,tn hiu u ra b gii m phi tch cc mc thp(Led sng khi tn hiu kch mc thp) K bng chn l: D C B A a b c d e f g S c hin th 0 1 2 3 4 5 6 7 8 9

0 0 0 0 0 0 0 0 1 1

0 0 0 0 1 1 1 1 0 0

0 0 1 1 0 0 1 1 0 0

0 1 0 1 0 1 0 1 0 1

0 1 0 0 1 0 0 0 0 0

0 0 0 0 0 1 0 0 0 0

0 0 1 0 0 0 0 0 0 0

0 1 0 0 1 0 1 1 0 0

0 1 0 1 1 1 1 1 0 1

0 1 1 1 0 0 1 1 0 0

1 1 0 0 0 0 1 1 0 0


Nhm SV:07CLC2


Cc t m u vo ca BCD8421 quyt nh s c hin th.nhng do cu trc khng gian cc LED a,b,..g m cc gi tr tn hiu u ra b gii m c xc nh sao cho: -mc thp 0(L): LED sng. -mc cao 1(H): LED tt. -cc LED sng hnh thnh s c hin th. Ti hiu ha: Dng phng php hnh v.chng ta chn dng cng NORAND trong s . Do u tin ta ti thiu ha hm o bng dng ORAND i vi cc gi tr 0 ca hm u ra,sau ly o th c dng NORAND i vi cc gi tr 1 ca hm u ra. Xem bng Karnaugh Xt Led thanh a. Ti thiu ha dng chun tc tuyt i vi cc trong bng Karnaugh c gi tr 0 d xc nh hm o: a = D+B+CA+CA (dng ORAND) ly o: a = a=D+B+CA+CA (dng NORAND)

00 0 1 X 0

01 1 0 X 0 (a)

11 0 0 X X

10 0 0 X X

00 0 0 X 0

01 0 1 X 0 (b)

11 0 0 X X

10 0 1 X X

00 0 0 X 0

01 0 0 X 0

11 0 0 X X

10 1 0 X X

00 0 1 X 0

01 1 0 X 0

11 0 1 X X

10 0 0 X X


Nhm SV:07CLC2


00 0 1 X 0

(c) 01 11 1 1 X 1 (e) 1 1 X X

10 0 0 X X

00 0 0 X 0

(d) 01 1 0 X 0

11 1 1 X X

10 1 0 X X

(f) 00 1 0 X 0 01 1 0 X 0 11 0 1 X X 10 0 0 X X

(g)

(b) b= C+BA+BA (c) c=C+B+A (d) d=D+CB+BA+CA+CBA (e) e= CA+BA (f) f=D+CB+CA+BA (g) g=D+CB+CB+BA S logic:

b=C+BA+BA c=C+B+A d=D+CB+BA+CA+CBA e=CA+BA f=D+CB+CA+BA g=D+CB+CB+BA


Nhm SV:07CLC2


IC gii m BCD => LED 7 thanh : 74LS47 * Hnh dng v kch thc chn ngoi thc t:


Nhm SV:07CLC2


y l IC gii m t BCD sang m LED 7 vch vi 4 chn u vo v 7 chn u ra vi chc nng ca tng chn nh sau: + Chn 1, 2, 6, 7: Chn d liu BCD vo d liu ny c ly t IC m. + Chn 9, 10, 11, 12, 13, 14, 15: Cc chn ra tc ng mc thp (0) v c ni vi LED 7. + Chn 8: Chn ni GND. + Chn 16: Chn ni Vcc = 5V. + Chn 4: Chn ny khng cn bit theo datasheet th cho n ln Vcc + Chn 5: Ng vo xo dn sng RBI c khng hay ni ln cao khi khng c dng xo s 0( s 0 trc s c ngha hay s 0 tha bn tri du chm thp phn). +Chn 3: Chn ny cng th cho n ln Vcc = 5V


Nhm SV:07CLC2

Bo Co Thc Hnh K Thut S: Thit K Mch Logic* Bng chn l cc gi tr IO ca 74LS47

Nhn trn bng chn l trn ta thy vi 4 u vo sau khi gii m n cho ra 16 gi tr ca m LED 7 vch v hin th c ln LED 7 vch. S hot ng ca mch c th hin bng chn l, trong i vi cc ng ra H l tt v L l sng, ngha l nu 74LS47 thc n led 7 on th cc on a, b, c, d, e, f, g ca n s sng hay tt tu vo ng ra tng ng ca 74LS47 l L hay H nn do ta phi dng LED anot chung!


Nhm SV:07CLC2


Kt qu hin th nh hnh trn

II.3

Led 7 thanh


Nhm SV:07CLC2


Led 7 thanh(LED7SEG) c 2 loi: Anot chung v Katot chung Trong thit k s dung loi Anot chung.nu dng loi Katot chung th cn dng loi IC gii m c u ra tch cc mc dng (+) nh IC 74ls247 Trn s chn: gm 10 chn chia ra 2 hng chn nh hnh:

Chn s 3 ni VCC Chn s 5 (poin) v chn s 8(Anode) khng c s dng trong thit k Cc chn 1(e), 2(d), 4(c), 6(b), 7(a), 9(f), 10(g) c ni vi cc chn tng ng ca IC 74ls47 3 S thit k v lp rp cc linh kin. Di y l s mch nguyn l :


Nhm SV:07CLC2



Nhm SV:07CLC2


Nguyn l hot ng: Chng ta quy c th t cc IC74ls90: Nh hnh trn theo th t di ln t 1 n 6. Da vo bng chn l 74ls90 hnh bn: Xung 1Hz chun c ly t b to xung, a vo chn 14(clock up) ca IC 47ls90 th nht ca b hin thi giy,qua b m v b gii m s c hin th. Khi 74ls90(1) m n 9.QD(Q3) t mc logic 1(H) v mc 0(L),QD(Q3) c ni vi chn 14(clock up) ca 74ls90(2) c kch m ln mt n v,tng t nh th,khi 74ls90(2) m n 6 ta reset v 0 v clock up IC74ls90(3) ln 1 xung.ta khi count n 6,ch c chn Q1 t 0(L) ln 1(H) kt hp vi chn Q2 ang mc1 cho qua cng AND,u ra ni vi 2 chn reset R01 v R02 ca74ls90(2) v chn 14 (clock up) ca 74ls90(3).mch hin th pht kt ni hon ton tng t hin th giy. b hin th gi,ta khi 74ls90(5) m n 4 v 74ls90(6) m n 2 tc l 24 gi.ta chn Q2 ca 74ls90(5) ang t mc 0 ln mc 1 kt hp chn Q1 ca 74ls90(6) t mc 0 ln mc 1 cho qua cng AND,u ra cho vo chn reset ca 74ls90(5) v 74ls90(6) Cng AND s dng trn hnh v c ly t IC 7408:


Nhm SV:07CLC2

Bo Co Thc Hnh K Thut S: Thit K Mch Logic c th iu chnh gi v pht ng vi thi gian thc,ta cn dng thm cc nt n chnh gi v pht:

S RESET(CHNH GI,PHT)

u ra ca cng AND c a vo chn clock up(14) ca IC74ls90 b hin thi gi v pht 4 .Kt qu Mch in: Mch to xung 1Hz chn:


Nhm SV:07CLC2

Bo Co Thc Hnh K Thut S: Thit K Mch LogicMch hin th led 7 thanh:

5. Cc linh kin s dng trong mch: STT 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Tn linh kin Led 7 thanh loi va Led 7 thanh loi nh IC 74ls90 IC 74ls47 IC7408 IC 4060 IC 4013 Diode cu Cu cm ngun Led Nt reset T 33pf,103,104,100uF Diode Zener Tr 220,300,1k,1.5k,2.5k,4m7 u v dy cm 3 li IC 14dip IC 16dip Board ng lm mch Dy jumper S lng 4 2 6 6 2 1 1 1 1 5 2 1 1 9 7 Ghi ch


Nhm SV:07CLC2



Nhm SV:07CLC2

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