USB -- pIC - Tieng Viet

8/2/2019 USB -- pIC - Tieng Viet

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TM TT KT QU NGHIN CU TI KHOA HC V CNG NGH CP B

Tn ti:

THIT K V CH TO MY PHN TCH A KNH(1024 KNH)

GHP VI MY VI TNH QUA CNG USB.

M s: B2008-14-22.Ch nhim ti: Nguyn Vn SnCquan ch tr ti: Trng i hc Lt

B GIO DC V O TOTRNG I HC LT

---o0o---

BO CO TNG KT TI KHOA HC V CNG NGH CP B

(2008-2010)

THIT K V CH TO MY PHN TCHA KNH (1024 knh) GHP VI MYVI TNH QUA CNG USB

Xc nhn ca cquan ch qun Ch nhim ti

NGUYN VN SN

M s: B2008-14-22.Ch nhim ti: Ths. Nguyn Vn Sn

Lt, 08 / 2010


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DANH SCH THC HIN TI

CH NHIM TI: TH.S NGUYN VN SN Khoa Vt l, i hc Lt

CC CNG TC VIN:

TS. LU TH VINH Khoa Vt l, i hc Lt TH.S PHAN VN CHUNKhoa Vt l, i hc Lt THS TRN HU DUYKhoa Vt l, i hc Lt THS NGUYN VN KINKhoa Vt l, i hc Lt


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MC LCMu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Chng 1. GII THIU TNG QUAN V TI1.1 L do chn ti . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.2 Slc v my phn tch a knh . . . . . . . . . .. . . . . . . . . . . . . . . . 3Chng 2. TNG QUAN VI IU KHIN PIC18F2455/2550/4455/4550

2.1 Gii thiu vi iu khin PIC18F2455/2550/4455/4550 . . . . . . . . . . 52.2 Giao ng xung nhp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.3 B nh. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102.4 Khi timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112.5 Khi CAPTURE/SO SNH/PWM . . . . . . . . . . . . . . . . . . . . . . . . . . 122.6 Khi CAPTURE/SO SNH/PWM nng . . . . . . . . . . . . . . . . . . . . . . 132.7 Khi USB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132.8 Cng song song streaming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152.9 Khi truyn ni tip ng b ch MSSP . . . . . . . . . . . . . . . . . . . . . . 162.10 Thu pht bt ng ba nng nng cao EUSART . . . . . . . . . . . . . . 17

2.11 Khi bin i AD 10 bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182.12 Khi so snh in p tng t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202.13 Khi tham chiu in p so snh . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202.14 Khi pht hin in p cao/thp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202.15 Ngt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212.16 Cc chi tit c bit h PIC18F2455/2550/4455/4550 . . . . . . . . . . . . 22

Chng 3. CNG USB3.1 Cng USB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243.2 M hnh BUS USB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

3.3 Cc kiu truyn USB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273.4 Giao din vt l BUS USB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283.5 Giao thc truyn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313.6 Cc qu trnh truyn USB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333.7 im danh v gi phn mm iu khin . . . . . . . . . . . . . . . . . . . . . . . . 363.8 Mt s vi mch s dng trong kt ni USB . . . . . . . . . . . . . . . . . . . . . . 413.9 Cc mch chuyn i USB sang RS232 . . . . . . . . . . . . . . . . . . . . . . . . . 43

Chng 4. THIT K V CH TO CC KHI CHC NNG4.1Khi cao th . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 444.2Khi khuch i ph v khi pht xung iu khin ADC . . . . . . . . . 454.3Khi logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 474.4Khi ngun nui th thp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48Chng 5. CC GII THUT PHN MM5.1 Gii thut ng mv iu khin in p cao p, iu khin h s khuchi khi khuch i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495.2 Gii thut hin th ph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515.3 Gii thut lm trn ph . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 575.4 Gii thut ly tch phn v hin th min ly tch phn . . . . . . . . . . . . . 625.5 Gii thut ly din tch hnh thang . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 635.6 Gii thut chun ha nng lng cho ph . . . . . . . . . . . . . . . . . . . . . . . 645.7 Gii thut o thi gian cht phn trm . . . . . . . . . . . . . . . . . . . . . . . . . . 675.8 M ngun lu file, mfile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70


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Chng 6. O CC C TRNG CA PHN CNG6.1 phi tuyn tch phn v phi tuyn vi phn . . . . . . . . . . . . . . . . . 716.2 phn gii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 726.3 tri nh ph . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 726.4Thi gian cht trn mt xung . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 726.5 tri h s khuch i ph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 726.6 tri mc zero ca khuch i ph . . . . . . . . . . . . . . . . . . . . . . . . . . 736.7Cc c trng khi cao p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 736.8Cc c trng khi ngun nui in p thp . . . . . . . . . . . . . . . . . . . . . 736.9So snh cc c trng MCA ch to v CANBERRA series 30. . . . . . . 73Chng 7. CC KT QU THIT K PHN MM7.1 Phn mm v cc kt quo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 747.2 Hin th ph3 ch: ton gii, na gii cao, na gii thp . . . . . . . 747.3 Tnh nng tnh tch phn v din tch hnh thang gia 2 v tr

con tr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

7.4 Cng c lm trn ph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 777.5 Cng c chun ha nng lng . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 777.6 Tnh nng lu ph, mph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

KT LUN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80Ti liu tham kho . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81Ph lc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82


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TM TT

Tn ti:

THIT K V CH TO MY PHN TCH A KNH (1024KNH)GHP VI MY VI TNH QUA CNG USB.

Nhim v ca ti ny gm thit k & ch to phn cng v phn mmh phn tch a knh.

Phn cng: Thit k v ch to cc khi chc nng ca h myphn tch a knh:

- Khi khuch i ph v pht xung iu khin ADC-

Khi ngun nui cao p- Khi logic v giao tip PC qua cng USB- Khi ngun nui th thp

. Phn mm: Vit phn mm iu khin v thu thp d liu trnmy vi tnh.

Cui cng l th nghim, hiu chnh phn mm, phn cng, o vnh gi cc c trng k thut ca my phn tch a knh ch to.Cc c trng k thut cn bn ca h ch to o c l phngii n

ng l

ng nh

h

n 39 keV ti

nh Cs-137 664keV dng v

idetector nhp nhy Bicron Model 302-2x2 ca CANBERRA, tri ph nh hn 0 trn ton thang o, phi tuyn tchphn nh hn 0.05% trn ton thang o, phi tuyn vi phn nhhn 3.4% trn ton thang o. Vi cc c trng va nu, h myny c kh nng p ng nhu cu thc tp mn vt l ht nhn casinh vin Khoa Vt l, Trng i hc Lt.

0.01%/ C


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ABSTRACT

Project name: DESIGNING AND CONSTRUCTION OF A 1KMULTICHANNEL ANALYZER CONNECTED WITH PC VIA USBPORT

The commision of this project is to build a multichannel analyzerinvolving software and hardware.

Concrete task of building hardware for multichannel analyzer isdesigning and manufacturing function blocks:

- Spectroscopy amplifier- High voltage board- Logic board and USB interface- Low voltage power supply

Writing control and spectrum measurement software. The last is testing and correcting hardware and software so that it

operates stably and has good specifications. The basicspecifications of manufactured multichannel analyzer weremeasured: The energy resolution less than 39keV at peak Cs-137

664 KeV using CANBERRA Bicron model 302-2x2 scintillationdetector; The peak drift less than 0 of full scale; Theintegral nonlinearity less than 0.05% over total output range; Thedifferential nonlinearity less than 3.4% over total output range.With these specifications of manufactured multichannel analyzer,absolutely this equipment will be used for practising nuclear

physics of Physics deparment students of Dalat University.

0.01%/ C


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ti cp b: Thit k v ch to my phn tch a knh (1024 knh) ghp vi my tnh qua cng USB

Ch nhim ti:Nguyn Vn Sn 1

MU

My phn tch a knh l thit b ch lc ca phng th nghim vt l ht nhn. Lu

nay thit b ny vn phi nhp ngoi v y l thit bt tin. Nu t ch to c myphn tch a knh th s chng cung cp thit b. Ngoi vn v kinh t, t ch tomy a knh cn c cc ngha sau:

Cung cp m ngun ca thit b cho ngi s dng, cho php ngi s dngpht trin cc cng c phn tch v thu thp d liu. iu ny l khng th cc nu mua thit b ca nc ngoi.

Ch to thnh cng my phn tch a knh to tin ch to cc thit bkhc cho phng th nghim vt l ht nhn. Cc thit b ny c th thit k vch to theo yu cu ca vic nghin cu v vt l ht nhn.

Nng cao nng lc thit k v ch to thit bin t ca nhm thc hin

ti.

My phn tch a knh CANBERRA series 30 ca khoa Vt l, trng i hc Lt hng t lu khng kh nng sa c vi hai l do: h my qu phc tp do y lh my a knh hp b v mt s linh kin khng mua c. Do nhu cu cn my phntch a knh sinh vin thc tp l bc bch.

Phng n thit k my phn tch a knh ca chng ti l khi chc nng bn ngoighp vi my vi tnh qua cng USB, l cng tin tin c nhiu u im. Dng vi cngUSB nn c th ghp vi my vi tnh bn hay vi tnh xch tay m khng cn qua thit b

chuyn i cng. Phng n ra c tnh kh thi cao v r tin. Mc tiu thit k mya knh ch to c cc c trng tng ng hay gn tng ng vi my phn tch aknh CANBERRA series 30. Do y l ti u tin v thit b th nghim vt l ht nhnca nhm thc hin ti nn chng ti chng k s knh l 1024 knh.

Trong khi thc hin ti ny nhm thc hin ti chng ti c s gip v phng din kin thc, kinh nghim v k thut ca Phng in T Ht Nhn - Vin

Nghin Cu Ht Nhn Lt. Chng ti trn trng cm n tt c cc anh ch em Phngin t Ht Nhn - Vin Nghin Cu Ht Nhn Lt, c bit cm n n anh ngLnh, anh Trng Vn t v anh Phm Ngc Tun.


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CHNG 1. GII THIU TNG QUAN V TI

1.1L DO CHN TIMy phn tch a knh l thit b khng th thiu c trong th nghim mn vt l

ht nhn. Hin phng th nghim vt l ht nhn ti Khoa Vt l, Trng i hc Lt

cn thiu my phn tch a knh cho sinh vin thc tp, gi nhp ngoi thit b ny rt t,h phn tch a knh CANBERRA Series 30 hng t lu. y l l do chng ti ngk thc hin ti ny. My phn tch a knh hp b nh h CANBERRA Series 30 thkh nng cng ngh ca Vit Nam kh m thc hin v chi ph l rt cao, nn phng nhp l ca chng ti l thit k my phn tch a knh ghp vi my vi tnh, s knh l1024 knh. Phng n ghp ni vi my vi tnh c th l cng ni tip, cng song song,cng USB. Chng ti chn cng USB, y l cng tin tin, ghp ni n gin, tc cao,USB 2.0 full speed-12Mbits/s. Vi s knh 1024, phn gii tt (nh hn 40 keV dngvi detector nhp nhy) cng vi cc c trng tt khc th thit b t ch to c thpng c nhu cu thc tp mn vt l ht nhn cho sinh vin Khoa Vt l, i hc

Lt.

1.2 SLC V MY PHN TCH A KNHMy phn tch a knh (MultiChannel Analyzer-MCA) c coi l thit b ch lc

trong vic nghin cu v th nghim v vt l ht nhn. My phn tch a knh cho hnhnh ph mt cch trc quan, cng vi cc cng c trn my phn tch a knh lm cho vicnghin cu v th nghim vt l ht nhn trnn thun tin v hp dn hn. My phn tcha knh tri qua nhiu th h khc nhau, c th phn loi cc th h my phn tch aknh nh sau. Th h tin my vi tnh pht trin: my phn tch a knh dng hp b, vd nh MCA series 30, 40 ca CANBERRA. Th h my phn tch a knh ny c kchthc knh cng v gi thnh rt t. Vi trnh cng ngh cn hn ch ca Vit Nam ththit k v thi cng my a knh dng hp b l kh kh thi.

Hnh 1.1 My phn tch a knh hp b series 40 ca CANBERRA.

Th h hu my vi tnh pht trin: My vi tnh a knh khng cn sn xut dnghp b m dng cc card, cc khi ghp vi my vi tnh. Card MCA c th ghp vi myvi tnh qua slot ca my vi tnh, loi card ny yu cu linh kin phi gn nh, linh kin


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thng l loi hn b mt v c mt tch hp cao kch thc card gn nh c thcm vo slot ca my vi tnh, v tt nhin loi card MCA ny khng th cm vo my vitnh xch tay.

Hnh 1.2 Card MCA ASA-100 cm vo Slot ca my vi tnh ca CANBERRA.

Card MCA ghp vi my vi tnh qua cc cng giao tip nh cng song song, cng

ni tip, cng USB. Cc card bn ngoi my vi tnh c thun li l khng c yu cu vkch thc card. Cng song song c nhc im sng dy kt ni ln, khong cchngn. Cng ni tip khc phc c nhc im sng dy ln ca cng song song,nhng tc truyn chm. My vi tnh xch tay hin ti b hn cng song song v cngni tip. Cng USB l cng tin tin, lin kt vi my vi tnh bng 4 ng dy k c dyngun 5V, nu khng dng dy ngun ch cn li 3 dy: mass, D+, D-, tc truyn dliu cao USB 2.0 high speed: 480Mbits/s. Do u im MCA card ngoi v u im cngUSB l cc l do ti ny chn phng n thit k v ch to.


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Hnh 1.3 DSA-1000 l my phn tch a knh ghp vi my vi tnh

qua cng USB v RS232 ca CANBERRA.

Th h my phn tch a knh tin tin l da trn cng ngh DSP (Digital SignalProcessing). Tn hiu t tin khuch i c x l bng phng php s (DSP), tnhkhng n nh ca phng php tng tc loi b. tri cc thng s theo nhit v thi gian b loi b, cc thng s nh l h s khuch i, ng cbn.CANBERRA c thit b InSpector 2000 l my phn tch a knh da trn cng ngh DSP.My phn tch a knh da trn cng ngh DSP l s chn la ti nghin cu tip theoca chng ti

.

Hnh 1.4 InSpector 2000 My phn tch a knh ghp vi my vi tnhda trn cng ngh DSP.


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CHNG 2.TNG QUAN VI IU KHIN PIC18F2455/2550/4455/4550

2.1 GII THIU VI IU KHIN PIC18F2455/2550/4455/4550H vi iu khin PIC18F2455/2550/4455/4550 l h vi iu khin tin tin caMICROCHIP, c bit h ny c tch hp cng USB 2.0, ADC 10 bit v tch hp nhiucng c khc. Mnh, mm do l tnh gi ngn gn v h vi iu khin ny. Chngny gii thiu tng quan cc khi tch hp ca h vi iu khin PIC18F v cc c imca cc khi tch hp, mc ch l phc v cho vic thit kcc chng sau.

Cc c im cng USB: USB V2.0 Tc thp (1.5 Mb/s) v tc ton phn (12Mb/s) H trti 32 im cui RAM 1 kByte cho khi USB Mch thu pht USB trn chip cng vi mch n p 3.3V Cng song song streaming (SPP) cho truyn streaming USB H trc 4 ch truyn:- Truyn iu khin (Control transfer)- Truyn ngt (Interrupt transfer)- Truyn ng b (Isochronous transfer)- Truyn khi (Bulk transfer)

Cc ch qun l nng lng : c nhiu ch qun l nng lng gim nng lngtiu th ti a, c bit c ngha cho cc ng dng s dng pin.

Hot ng bnh thng (Run): CPU bt, ngoi vi bt Ngh (Idle): CPU tt, ngoi vi bt, tiu th dng tiu biu 5.8 A Ng (Sleep): CPU tt, ngoi vi tt, tiu th dng tiu biu 0.1 A Dao ng timer1: tiu th dng tiu biu 1.1 A , 32kHz, 2V. Watchdog timer: tiu th dng tiu biu 2.1 A Khi ng dao ng 2 tc

Cu trc dao ng mm do: Bn ch tinh th bao gm PLL chnh xc cao cho USB Hai ch xung clock ngoi ln n 48 MHz Khi dao ng ni

- 8 tn s chn c bi ngi s dng, t 31kHz n 8 Mhz- Tinh chnh bi ngi dng b chnh tri tn s

Dao ng th cp dng timer1 32kHz Ty chn dao ng i cho php CPU v USB hot ng 2 tn s xung nhp khc

nhau Khi theo di an ton xung nhp

- Cho php shutdown an ton khi tt xung nhp- hay vi iu khin s tip tc hot ng vi tn s xung nhp thp hn

Cc c im ngoi vi: Dng vo/ra (sink/source) cao 25mA/25mA


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Ba ngt ngoi Bn khi timer (timer0 n timer3) C ti 2 khi CCP (Capture/Compare/PWM)- Capture 16 bit cc i, phn gii 6.25 ns ( CYT /16 )- So snh 16 bit cc i, phn gii 100 ns ( CYT )

- PWM c li ra vi gii t 1 n 10 bit Khi CCP nng cao ECCP (Enhanced Capture/Compare/PWM)- Nhiu ch li ra- C th chn cc tnh- Thi gian cht lp trnh c- Tng tt v tng khi ng Khi USART nng cao- H trbus LIN Cng truyn ni tip ng b ch MSSP (Master Synchronous Serial Port) ADC 10 bit, 13 li vo, thi gian thu thp d liu lp trnh c 2 b so snh tng t vi a hp li vo

Cc c im ca vi iu khin Cu trc ti u bin dch C vi tp lnh mrng ty chn B nhchng trnh flash nng cao cho php 100.000 ln xa/ghi B nhd liu EEPROM cho php 1.000.000 ln xa/ghi Lu tr d liu trong b nhflash/EEPROM hn 40 nm Ngt nhiu mc u tin Watchdog timer mrng, chu k kh trnh t 41 ms n 131 s Bo v m lp trnh Ngun nui n 5V cho lp trnh ni tip trn mch qua 2 chn Mch gli qua 2 chn Di in p hot ng rng (2.0V n 5.5V)

Bnh 2.1 Cc tnh nng k thut ca cc vi iu khin PIC18F2455/2550/4455/4550

Trong h vi iu khin PIC18, ch gia F cho php Vdd t 4.2V n 5.5V, ch giaLF cho php mrng gii Vdd t 2.0V n 5.5V.

2.2 DAO NG XUNG NHPMch dao ng vi nhiu ty chn. H vi iu khin PIC18F2455/2550/4550 c 12 tychn mch dao ng, bao gm:

- 4 ch dao ng tinh th hoc cng hng gm

- 4 ch xung nhp ngoi- Mt b dao ng ni cung cp xung nhp 8MHz v mch dao ng RC ni cungcp xung nhp 31KHz, cng nh 6 la chn tn s xung nhp t 125kHz n4MHz, tt c ta c 8 la chn tn s xung nhp.


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- Nhn tn dng PLL (Phase Loop Lock) p dng cho c dao ng tinh th tn scao v dao ng ngoi cho di tn s xung nhp t 4MHz n 48MHz.

- Hot ng xung nhp kp khng ng b (Asynchronous dual clock operation):khi USB hot ng xung nhp tn s cao trong khi cc khi cn li trong viiu khin hot ng vi xung nhp tn s thp hn.

- Theo di an ton xung nhp (Fail-Safe clock monitor): ty chn ny cho phpngun xung nhp chnh lun lun c theo di, nu xy ra trng hp xungnhp chnh tt vi iu khin s tip tc hot ng vi tn s xung nhp thp hn.

- Khi ng hai tc (Two-Speed Start-up): Ty chn ny cho php ngun xungnhp ni hot ng khi reset lc khi ng hay vi iu khin hot ng trli tch ng (wake-up from sleep mode) cho n khi ngun xung nhp chnh sn sng.

Hnh 2.1 S khi PIC18F2455/2550 (28 chn)


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Thch anh dao ng / cng hng gm: ch HS, HSPLL, XT, XTPLL thch anhdao ng/ cng hng gm mc chn OSC1 v OSC2. mi ch C1, C2 t cnhthch anh dao ng/ cng hng gm c gi tr khc nhau (tham kho datasheetPIC18F2455/2550/4550)

Nhn tn s PLL: Trong vi iu khin PIC18F2455/2550/4550 c khi PLL (Phase Loop

Lock), iu ny cho php khi USB hot ng tn s cao trong khi xung nhp ca hthng tn s thp hn. PLL c php hot ng cc ch dao ng HSPLL,XTPLL, ECPLL v ECPIO. N c thit k sinh ra tn s xung nhp chun 96MHz ttn s li vo cnh 4MHz.

Hnh 2.2 S khi PIC18F4455/4550 (40/44 chn)

Khi dao ng ni (INTOSC): Trong vi iu khin PIC18F2455/2550/4550 c khi daong ni pht ra hai tn hiu xung nhp khc nhau. Li ra trc tip 8 MHz, li ra qua b


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chia (postscaler) cung cp xung nhp t 31 KHz n 4 MHz. Lu ngun dao ng ly tthch anh dao ng/ cng hng gm gi l dao ng ngoi. Ngun dao ng ni li ra 31KHZ cho php trong cc trng hp:

- Timer bt ngun (Power-up timer)- Theo di an ton xung nhp

- Watchdog timer- Khi ng hai tc (Two-Speed Start-up)Li ra dao ng ni c chun bi hng ch to nhng vn c th tinh chnh bi ngi sdng, vic tinh chnh ny c thc hin nhthanh ghi iu chnh dao ng (OscillatorControl Register)

Cc ch dao ng ni: S la chn ngun xung nhp cho USB xc nh bi cc ch dao ng ni ring bit.

- Ch INTHS: Xung nhp USB c cung cp bi dao ng trong ch HS.- Ch INTXT: Xung nhp USB c cung cp bi dao ng trong ch XT

- Ch INTXT: Xung nhp USB c cung cp bi dao ng trong ch XT- Ch INTCKO: Xung nhp USB c cung cp t dao ng bn ngoi thchanh dao ng/ cng hng gm.

- Ch INTIO: xung nhp cho USB c cung cp vo chn OSC1/CLK1, cnchn OSC2/CLK2 c chc nng nh chn I/O.

- Tn s dao ng cho USB l 6 MHz hoc 48 MHz ty thuc vo ch tc thp (low speed) hay ch tc ton phn (full speed)

- Tn s dao ng cho USB l 6 MHz hoc 48 MHz ty thuc vo ch tc thp (low speed) hay ch tc ton phn (full speed)


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Hnh 2.3 S khi dao ng

2.3 B NHB nhFlash nng cao (Enhanced Flash) s dng cho b nhchng trnh v b nhd

liu EEPROM. S ln xa/ghi cho b nhchng trnh l 100.000 ln v cho b nhdliu l 1.000.000 ln. D liu lu li trong b nhn 40 nm m khng cn lm ti.C ba loi b nhtrong h PIC18:

B nhchng trnh RAM d liu EEPROM d liu

Theo cu trc Harvard, b nhchng trnh v d liu dng 2 bus ring, iu ny chophp tip cn ng thi 2 vng b nh. EEPROM d liu c th coi nh thit b ngoi vi vtip cn thng qua b thanh ghi iu khin. H vi iu khin PIC18 c bm chng

trnh 21 bit nn c kh nng nh v 2 Mbyte b nhchng trnh. PIC18F2455,PIC18F4455 c 24 Kbyte b nhflash v c th cha ti 12.288 lnh tn. PIC18F2550,PIC18F4550 c 32 Kbyte b nhflash v c th cha n 16.384 lnh tn.


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Kh nng t lp trnh: H vi iu khin PIC18F2455/2550/4550 c kh nng t npchng trnh vo b nhchng trnh m khng cn phi c thit b ph bn ngoi, iuny c thc hin bng on chng trnh con Bootloadert trn phn cao b nhchng trnh vo c bo v. Kh nng t lp trnh cho php cc ng dng dng h vi

iu khin ny c kh nng nng cp firm-ware.

B nhchng trnh Flash: 24Kbytes cho PIC18FX455, 32 Kbytes cho PIC18FX550.

Hnh 2.3 Bn t chc b nhh vi iu khin PIC18F2455/2550/4550

2.4 KHI TIMERH vi iu khin PIC18 c 4 b timer: timer0, timer1, timer2 v timer3. Mi timer c tnhnng ring.Timer0:

nh ch hot ng bng phn mm: timer hoc counter, 8 bit hoc 16 bit B chia kh trnh 8 bit chuyn dng Ngun xung nhp chn c (trong hay ngoi) Kh nng chn cnh i vi xung nhp ngoi Ngt khi trn

Timer1: Chn bng phn mm timer hay counter 16 bit


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Kh nng c vit thanh ghi 8 bit (TMR1H v TMR1L) Chn ngun xung nhp trong hay ngoi Ngt khi trn Khi RESET hot ng trn csxung kch s kin CCP. Ctrng thi xung nhp (T1RUN)

Timer2: Timer 8 bit (TMR2) v thanh ghi chu k (PR2) Kh nng c vit c 2 thanh ghi Lp trnh bng phn mm cho b chia (1:1, 1:4, 1:16) Ngt khi TMR2 gp PR2 Ty chn dng nh xung nhp dch cho khi MSSP

Timer3: Chn bng phn mm hot ng nh l timer hoc counter 16 bit Kh nng c ghi thanh ghi 8 bit (TMR3H v TMR3L) Kh nng chn ngun xung nhp (trong hoc ngoi) Ngt khi trn Khi RESET hot ng trn csxung kch s kin CCP

2.5 Khi CAPTURE/SO SNH/PWM (CCP).H vi iu khin PIC18F2455/2550/4455/4550 c tt c 2 khi CCP. Mi khi cha thanhghi 16 bit.Ch Capture: Cp thanh ghi CCPRxH:CCPRxL bt gi tr 16 bit ca thanh ghi TMR1hoc TMR3 khi s kin xy ra chn CCPx tng ng. Mt s kin c nh ngha:

Mi khi c cnh ln Mi khi c cnh xung Mi khi c cnh ln th 4 Mi khi c cnh ln th 16

S kin c chn bi bit chn ch CCPxM3:CCPxM0 (CCPxCON). Khi s kinCapture c thc hin, bit cyu cu ngt (CCPxIF) c SET v ch xa bng phnmm.

Ch so snh: Thanh ghi 16 bit CCPRx c gi tr hng sc so snh vi gi tr ca

cp thanh ghi TMR1 hoc TMR3. Khi xy ra s kin bng nhau, chn CCPx c th l: Chuyn mc cao Chuyn mc thp Pht xung (cc tnh dng hoc m) Gi nguyn khng thay i trng thi (phn nh trng thi cht I/O)

Chn CCPx xc nh trn csgi tr ca bit chn ch (CCPxM3:CCPxM0) . Khi skin so snh bng nhau bit cngt CCPxIF c set (mc1).

Ch PWM (Pulse-Width Modulation: iu ch rng xung): Chn CCPx pht sinh

xung PMW phn gii 10 bit. rng xung (Duty Cycle) ca xung PWM c hnhthnh theo minh ha hnh di y.


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Hnh 2.4 Hnh thnh xung PWM li ra

rng xung PWM c xc nh bng cch vit vo thanh ghi CCPRxL v cc bitCCPxCON , CCPRxL cha 8 bit cao v CCPxCON cha 2 bit thp. gi tr 10

bit phn gii l gi tr CCPRxL : CCPxCON

rng xung PWM c tnh theo cng thc:PWM Duty Cycle (CCPRxL : CCPxCON 5 : 4 *Tosc *(TMR2 Pr esscale Value)

CCPRxL v CCPxCON c thc vit vo mi thi im nhng gi tr rngxung khng cht vo CCPRxH cho ti khi c s gp nhau (bng) gia PR2 v TMR2.Trong ch PWM CCPRxH l thanh ghi chc.

2.6 KhiCapture/so snh/PWM nng cao (ECCP).Khi ECCP ch c PIC18 vi v40/44 chn. PIC18F4455/4550, CCP1 thc hin chc nng ca CCP chun vi kh nngPWM nng cao, c ngha chc nng Capture v so snh khng thay i, ging CCP chun.

Thanh ghi iu khin cho CCP nng cao khc vi thanh ghi CCPxCON PIC18F2255/2550 l 2 bit MBS thc hin chc nng iu khin PWM. Hai bit ny chophp xung li ra thc hin cc kiu khc nhau:

00 = li ra n: P1A iu ch; P1B, P1C, P1D chc nng chn cng. 01 = li ra ton cu thun: P1D iu ch; P1A tc ng; P1B, P1C khng tc ng. 10 = li ra na cu: P1A, P1B iu ch vi iu khin di cht; P1C, P1D chc

nng chn cng. 11 = li ra ton cu nghch: P1B iu ch; P1C tc ng; P1A, P1D khng tc

ng.

2.7 KHI USB (Universal Serial Bus)H PIC18FX455/X550 tch hp cng USB h trc tc truyn ton phn (full-speed)12Mb/s v tc thp (low-speed) 1.5 Mb/s cho php giao tip nhanh gia USB my chv USB vi iu khin PIC. H trn 32 im cui. RAM 1 kbyte cho USB. H tr 4li truyn: truyn iu khin (Control transfer); truyn ngt (Interrupt transfer); truynng thi (Isochronous transfer) v truyn khi (Bulk transfer).


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Hnh 2.5 S khi USB

Hot ng ca khi USB c nh cu hnh v qun l thng qua 3 thanh ghi iu khin.Hn na c 19 thanh ghi qun l giao tip USB thc. Cc thanh ghi l:

Thanh ghi iu khin USB (UCON): Thanh ghi ny cha cc bit cn cho iu khintrong qu trnh truyn gm: cho php ngoi vi USB chnh; reset con tr bm

ping-pong; iu khin ch treo; cm truyn gi. Thanh ghi cu hnh USB (UCFG): Trc khi lin lc qua USB, khi USB kt hp

phn cng ngoi v/hoc trong phi c t cu hnh. UCFG cha cc bit linquan n vic t: tc full-speed hay low-speed; cho php dng in trko lntrong IC; cho php thu-phat trong IC; s dng bm ping-pong.

Thanh ghi trng thi truyn USB (USTAT): Bo co trng thi giao tip trong SIE. Thanh ghi a ch linh kin USB (UADDR): Cha duy nht a ch USB m ngoi

vi s gii m khi tch cc. UADDR = 00h khi reset USB bi vi iu khin. a chUSB phi c vit bi vi iu khin trong pha setup USB c h trbifirmware ca Microchip.

Thanh ghi s frame (UFRMH:UFRML): Thanh ghi s frame cha s frame 11 bit, 8bit thp cha trong UFRML, 3 bit cao cha trong UFRMH. Cp thanh ghi c cpnht vi s frame hin ti khi gi SOF c nhn. Thanh ghi s frame c dngcn bn cho li truyn ng thi (isochronous transfer).

Thanh ghi cho php im cui t 0 n 15 (UEPn): Mi ca 16 im cui hai chiuc thanh ghi iu khin c lp UEPn, n l sim cui.


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IU KHIN IM CUI USBMi ca 16 im cui hai chiu c thanh ghi iu khin c lp UEPn, n l sim cuiUSB RAMD liu USB di chuyn gia li vi iu khin v SIE (Serial Interface Engine) thng quavng nhgi l RAM USB. y l nhcng i c bit, vng nhd liu bnh thng

Bank 4 n Bank 7 (400h ti 7FFh) dung lng 1Kbyte. Bank 4 (400h n 4FFh) cdng c bit cho iu khin m im cui, trong khi Bank 5 n Bank 7 dng cho dliu USB.

Ngt USB: Khi USB c th pht ra nhiu iu kin ngt. Trn hnh 2.6 cho thy logicngt cho khi USB. C hai lp ngt trong khi USB. Mc cao gm cc ngt trng thiUSB, n t cho php v t ctrong thanh ghi cho php ngt UIE (USB Interrupt Enable)v thanh ghi trng thi ngt USB UIR (USB Interrupt Status Register) tng ng. Mcthp gm cc iu kin li USB, n t cho php v t ctrong thanh ghi trng thi ngtli USB UEIR (USB Error Interrupt Status Register) v thanh ghi cho php ngt li USBUEIE (USB Error Interrupt Enable Register).

Hnh 2.6 Cc ngt ca khi USB

2.8 CNG SONG SONG STREAMING (SPP: Streaming Parallel Port)PIC18F4455/4550 cung cp cng song song streaming l cng giao tip ra bn ngoi tc cao. Cng song song ny hot ng nh cng master cung cp tn hiu chn chip vxung nhp iu khin giao tip d liu vi cc thit b slave.Hot ng SPP lin quan n 2 thanh ghi: Thanh ghi iu khin cng song song SPPCONv thanh ghi cu hnh cng song song SPPCFG. Cc ng dy ca cng song songstreaming l: 8 dy d liu/a ch SPP; 2 dy li ra xung nhp CK1SPP v CK2SPP;cho php li ra OESPP; chn chip CSSPP


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Hnh 2.7 Cng song song streaming vi cc chn d liu v iu khin

2.9 KHI TRUYN NI TIP NG B CH MSSP ( Master Synchronous SerialPort)

Giao din ni tip ny dng trao i d liu vi cc linh kin nh EEPROM ni tip,thanh ghi dch, bin i AD Khi MSSP c 2 dng: giao din ngoi vi ni tip SPI(Serial Peripheral Interface) v giao tip gia cc linh kin tch hp I2C (Inter-IntergratedCircuit). Giao tip I2C h trphn cng cc ch sau:

Ch ch Cha ch Ch t

Khi MSSP c 3 thanh ghi kt hp l: thanh ghi trng thi (SSPSTAT) v 2 thanh ghi iukhin (SSPCON1 v SSPCON2). Dng nhng thanh ghi ny xc nh khi MSSP hot

ng dng SPI hoc I

2

C.DNG SPI: Dng ny cho php 8 bit d liu thu pht ni tip ng b mt cch ngthi. Tt c 4 ch SPI c h tr. Giao tip dng SPI c cc chn:

D liu ra ni tip SDO (Serial Data Out) D liu vo ni tip SDI (serial Data In) Xung nhp ni tip SCK (Serial Clock) V chn th 4 c dng ch t: Chn tSS (Slave Select)

Khi MSSP c 4 thanh ghi: Thanh ghi iu khin 1 MSSP (SSPCON1) Thanh ghi trng thi MSSP (SSPSTAT) Thanh ghi m thu/pht ni tip (SSPBUF) Thanh ghi dch MSSP (SSPSR)


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Hnh 2.8 S giao tip bng SDI

DNG I2C: Giao thc I2C thc hin giao tip theo kiu ch-t, 2 chn dng trong giaothc ny l: xung nhp ni tip SCL (Serial Clock) v d liu ni tip SDA (Serial Data).Thanh ghi lin quan n giao thc I2C l:

Thanh ghi iu khin 1 MSSP (SSPCON1) Thanh ghi iu khin 2 MSSP (SSPCON2) Thanh ghi trng thi MSSP (SSPSTAT) Thanh ghi m thu/pht ni tip (SSPBUF) Thanh ghi dch MSSP (SSPSR) Thanh ghi a ch MSSP (SSPADD)

2.10 THU PHT BT NG BA NNG NNG CAO EUSART (EnhancedUniversal Asynchronous Receiver Transmitter)Khi USART c thnh cu hnh thnh h thng bt ng b song cng, v d nh traoi d liu t my v mn hnh CRT. V cng c thnh cu hnh thnh bt ng b

bn song cng, v d nh trao i d liu vi ngoi vi nh mch tch hp bin i A/D,D/A, EEPROM ni tip Khi thu pht bt ng b nng cao c thm cc tnh nng nh:tng pht hin tc BAUD v ly chun tc BAUD; tng nh thc khi nhnSync Break v pht k t Break 12 bit. Cc chi tit ny lm EUSART thch hp vi hthng LIN bus (Local Interconnect Network). EUSART c thnh cu hnh theo cc ch sau:

Song cng vi:- Tng nh thc khi nhn k t- Ly chun tc BAUD- Pht k t Break 12 bit

Chng b vi cc tnh xung ng h chn c (bn song cng) T ng b vi cc tnh xung ng h chn c (bn song cng)

Cc chn ca EUSART a hp vi cng C: RC6/TX/CK v RC7/RX/DT/SDOHot ng khi EUSART lin quan n 3 thanh ghi:

Thanh ghi iu khin v trng thi pht (TXSTA) Thanh ghi iu khin v trng thi thu (RCSTA) Thanh ghi iu khin tc BAUD (BAUDCON)


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2.11 KHI BIN I AD 10 BITKhi ADC 10 bit: Khi ADC ca h vi iu khin ny c kh nng kt hp vi vic thigian thu thp d liu kh trnh cho php khng cn chchu k ly mu nn gim thi gian

bin i AD.

Khi bin i AD c 10 li vo i vi PIC18 v 28 chn v 13 li vo i vi v 40/44chn. Khi ny c 5 thanh ghi:

Thanh ghi kt qu A/D cao (ADRESH) Thanh ghi kt qu A/D thp (ADRESL) Thanh ghi iu khin A/D 0 (ADCON0) Thanh ghi iu khin A/D 1 (ADCON1) Thanh ghi iu khin A/D 2 (ADCON2)

Hnh 2.9 S mch in thu thp d liu cho bin i A/D

Hnh 2.10 S khi bin i A/D


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Thi gian thu thp d liu

ACQT Thi gian xc lp khuch i + thi gian np in t gi + h s nhit

AMP C COFFT T T

Thi gian np in t giHOLD IC SS STc / C (R R R )

HOLD REF REFV (V (V / 2048))*(1 e )

C HOLD IC SS ST (C )(R R R ) ln(1/ 2048)

Vi cc s liu tiu biuAMPT 0.2 s

C)

s

o 0

COFFT (temp 25 C)(0.02 s / o o o(50 C 25 C)(0.02 s / C) 1.2 s

Lu : di 25oC COFFT 0

C HOLD IC SS ST (C )(R R R ) ln(1/ 2048)

Vi cc s liu tiu biu

CT (25pf )(1k 2k 2.5k ) ln(0.0004883) s = 5.03 s

ACQT 0.2 s 5 s 1.2 s 6.4 s

Chn xung nhp bin i A/D: Thi gian bin i A/D mi bit c nh ngha l .

Yu cu thi gian bin i A/D l 11* cho bin i A/D 10 bit. C 7 ty chn cho :ADT

TADT AD 2 OSCT

4 OSCT 8 OSCT

16 OSCT

32 OSCT

64 OSCT

Dao ng RC ni bin i A/D hot ng ng, phi nh c th c nhng ln hn ti thiu.ADT ADT

Bng 2.2 theo tn s hot ng ca vi iu khinADT


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Thi gian bin i A/D = , trong l thi gian t xACQ AD AD1T 11*T T AD1T

2.12 KHI SO SNH TNG TKhi so snh gm 2 mch so snh c thnh cc cu hnh khc nhau. Li vo c th chn

t li vo tng ta hp vi cc chn t RA0 n RA5. Li ra digital (bnh thng hayo) c qua thanh ghi iu khin so snh.

Bng 2.3 Li ra (digital) ca mch so snh c qua thanh ghi iu khin so snh

Li ra mch so snh 1 v 2 ln lt bit 6 v 7, li ra o mch so snh 1 v 2 ln lt bit 4 v 5 ca thanh ghi iu khin so snh.C 8 cu hnh ca khi so snh c nh bi thanh ghi CMCON

2.13 KHI THAM CHIU IN P SO SNHKhi tham chiu in p so snh l mt cu chia p gm 16 in tr(trn hnh 2.11).Mc ch ca khi ny l to ra in p chun kh trnh cho cho cc mch so snh tngt. nh cu hnh cho tham chiu in p so snh bng thanh ghi iu khin tham chiuin p so snh CVRCON.

Hnh 2.11 S tham chiu in p so snh

2.14 KHI PHT HIN IN P CAO/THPH vi iu khin PIC18F2455/2550/4455/4550 c khi pht hin in p cao/thp. y lmch kh trnh cho php ngi s dng xc nh c. Nu in p ti im cn pht hin

cao hn hay thp hn in p t th cngt HLVDIF c SET v nu s dng ngtchng trnh r nhnh n a ch vector ngt v phn mm thc hin p ng ngt. Lin


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quan n khi pht hin in p cao/thp l thanh ghi iu khin pht hin in p cao/thpHLVDCON (High/Low Voltage Detect Control)

Hnh 2.12 S khi pht hin in p cao thp

2.15 NGTPIC18F2455/2550/4455/4550 c nhiu ngun tn hiu ngt v hai mc u tin ngt.Vector ngt u tin mc cao l 000008h v vector ngt u tin mc thp l 000018h. C10 thanh ghi c dng iu khin ngt l:

RCON INTCON INTCON2 INTCON3 PIR1, PIR2 PIE1, PIE2 IPR1, IPR2

Mi ngun tn hiu ngt c 3 bit iu khin hot ng. Chc nng ca 3 bit ny l: Bit c ch th mt s kin ngt xy ra Bit cho php cho php ngt, chng trnh nhy n a ch vector ngt ca tn

hiu ngt khi bit cc set Bit u tin ngt chn mc u tin ngt


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Hnh 2.13 S logic cc tn hiu ngt

Mc u tin ngt c cho php bng cch SET bit IPEN (RCON). Khi u tinc cho php, c 2 bit cho php ngt ton cc. SET bit GIEH (INTCON) cho php ttc cc ngt m SET u tin cao. SET bit GIEL (INTCON) cho php tt c cc ngtm SET u tin thp. Khi cngt, bit cho php v ccho php ngt ton cc SETchng trnh s nhy n a ch vector ngt 000008h hoc 000018h ty thuc vo mc u tin. Cc ngt ring r c th khng cho php thng qua cc bit cho php tng ng.

Ngt USBKhng ging nh cc giao din ngoi vi khc, khi USB c kh nng pht ra nhiu tn hiungt. Cc tn hiu ngt USB gm c vi tn hiu ngt lin lc thng thng, vi tn hiungt s kin trng thi v vi tn hiu ngt s kin li. Trong khi USB c trang b mchlogic ngt ring cho khi USB ( trnh by trong phn 2.7 v s logic ngt USB hnh2.6)

2.16 CC CHI TIT C BIT H PIC18F2455/2550/4455/4550H vi iu khin ny c vi chi tit c bit nhm tng tin cy ti a v gim gi thnhdo cc linh kin bn ngoi c gim ti a. Cc chi tit c bit c th k ra l:

Ngun dao ng phong ph Cc reset:

- reset ngun bt (POR)- timer ngun bt (PWRT)


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- timer khi ng dao ng (OST)- reset Brown-out (BOR)

Qun l nng lng vi nhiu ch hot ng Theo di an ton xung nhp Khi ng 2 tc Bo v m chng trnh Lp trnh ni tip trong chip Tp lnh phong ph

y l h vi iu khin 8 bit mnh, mm do v cht lng ca hng MICROCHIP niring v ca c th gii ni chung.


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CHNG 3. CNG USB

3.1 CNG USBCng USB (Universal Serial Bus) thc cht l mt bus ni tip c pht trin bi

mt nhm gm nhiu cng ty: Compaq, DEC, IBM, Intel, Microsoft,NEC vNortel.

tng khi xy dng cng USB l pht trin mt cng c th kt d dng n nhiu thit bmrng khc nhau. Bus USB c pht trin qua mt s phin bn sau:

USB 1.0: c gii thiu vo nm 1996, l phin bn u tin. Tc truyn dliu gia my tnh v thit b kt ni c tht c l 12Mbit/s.

USB 1.1: c gii thiu vo nm 1997 k tha v pht trin t USB 1.0. Bn cnhnhng tnh nng ca USB 1.0, USB 1.1 h trhai tc truyn l: 12Mbit/s chothit b (Full speed) v 1,5Mbit/s cho cc thit b c tc thp (low speed).

USB 2.0: c gii thiu vo nm 2000, vi tnh tng thch vi cc phin bn

trc v thm la chn tc cao 480Mbit/s (High-Speed). Thng 12 nm 2000cng ty ECN a ra chun u ni kiu mi (kiu u ni B).

USB 3.0 ra i t nm 2008, tc c th gp hng chc ln tc ca phin bnUSB 2.0.

(a)

b)Hnh 3.1 Biu tng ca bus usb (a), cp v cng kt ni (b)

Vi cc my tnh c sn xut gn y u trang b mt s cng giao tip USB chophp d dng kt ni n cc thit b c h trUSB nh: my in, my qut hnh, camera,cc thit bo lng,

V mt phn mm t phin bn OEM 2.1 ca Windows 95 bt u c h trmt stnh nng. Trong phin bn Windows 98 mt s thit bc cung cp trnh iu khinthit b (Device Driver) km theo Windows. Cc gi phn mn h trcho cng USB tiptc xy dng v tch hp trong cc phin bn ca Windows Me, Windows 2000 v

Windows XP lm cho cng USB trln rt thng dng.Mt sc im ca bus USB l:

D dng s dng: khng phi quan tm nhiu n cu hnh v ci t chi tit. iukhin lung d liu thng qua bm bng vic qun l giao thc t sn bn trong

Nhanh: giao din khng b tht c chai vi cc thit b truyn thng chm.

Tin cy: t xy ra do c cch tng sa cha li.

Mm do: c th kt ni nhiu loi thit b vi giao din ny.

Cung cp ngun trn bus: iu ny rt thun tin cho cc thit b xch tay vi dngtiu th nh c thc cung cp thng qua bus.
http://en.wikipedia.org/wiki/Compaqhttp://en.wikipedia.org/wiki/Digital_Equipment_Corporationhttp://en.wikipedia.org/wiki/IBMhttp://en.wikipedia.org/wiki/Intelhttp://en.wikipedia.org/wiki/Microsofthttp://en.wikipedia.org/wiki/NEChttp://en.wikipedia.org/wiki/Nortelhttp://en.wikipedia.org/wiki/Nortelhttp://en.wikipedia.org/wiki/NEChttp://en.wikipedia.org/wiki/Microsofthttp://en.wikipedia.org/wiki/Intelhttp://en.wikipedia.org/wiki/IBMhttp://en.wikipedia.org/wiki/Digital_Equipment_Corporationhttp://en.wikipedia.org/wiki/Compaq


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c h trbi h thng: khi mt thit bc u ni vo, h thng t pht hinv gi phn mm ci t cho chng. c tnh ngy gi l cm nng (Plus and Play)l mt trong nhng c tnh m cc cng trc khng nh LPT hay RS232khng c c.

Kt ni nhiu thit b: c th kt ni n 127 thit b c cu hnh v tc khcnhau trn mt h thng bus USB.

Bng 3.1 So snh giao din USB vi cc giao din thng dng trn my tnh

Dng truyn Giao dinS thitb ln

nht

Chiu di(m)

Tc ln nht(bit/sec)

Thit b s dng

Ni tip khngng b

USB 1275 m 1.5, 12,

480MBMouse, Keyboard,Disk Drive

Ni tip khngng b

RS 232 2 9 30.5 20115KModem, Mouse, cc thit

biu khin khcNi tip khngng b

RS 485 32256 1200 10MH thng thu d liu viu khin

Ni tip hngngoi

IrDA 8 1.8 115M Printers, kt ni mng

SynchronousSerial

MiCroWire 8 3 2MTruyn thng vi vi iukhin

SynchronousSerial

SPI 40 3 2.1MTruyn thng vi vi iukhin

Synchronous

Serial

IC 64 5.5 3.4MTruyn thng vi vi iu

khinSerial (FireWire)

IEEE 1394 15 4.5 400M Video, Mass Storage

ParallelIEEE 488 1024 18 8M Cc thit b khoa hc

Serial Ethernet 2 480 10M1G Networked PCSerial CurrentLoop

MIDI 2 15 31.5K Music, Show Control

Parallel Parallel port 2 3 - 9 8MPrinter, Scanners, DiskDrive

3.2 M HNH BUS USB

Cu trc cbn ca mng USB l cc tng hnh sao. Mt h thng USB bao gm:mt hay nhiu thit b ngoi vi(Peripherals), mt hay nhiu Hub v mt ch duy nht(thng l my tnh) gi l chiu khin (Host Controller). Chiu khin kt hp chtch vi Hub gc (Root Hub) mrng cc im ni n ch, t hub gc s kt ni ncc thit b hay cc Hub khc. Hub l thit bc s dng m rng cc cng, v d(hnh 3.3) mt hub gm 1 kt ni ni v my ch (upstream) v 4 cng ra k ni vi thit

b ngoi (downstream).


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Hnh 3.2 M hnh kt ni bus ca USB

Hnh 3.3 S kt ni sao mt bus USB

My ch nhn bit mt thit bc u ni vo bus bng cch hi vng cc hublin tc. Khi mt thit bc cm vo mt cng ca Hub, Hub bo ti my ch bit cthit b cm vo. Ch USB a ra lnh cho php v t li cng , thit b gn thm pli v ch USB yu cu mt bn m t t thit b. T bn m t thit b ch USB bit yucu, trng thi, loi thit b v lp h trnu c ca thit b. Ch USB gn cho thit b mta ch duy nht v gi phn mm iu khin cho thit b. i vi cc thit bc h trdriver trong h thng cc thit b c mt sc im chung c xp vo thuc mt lp.Khi mt thit b khai bo thuc mt lp no h thng gi phn mm iu khin v cho

php trao i d liu m khng cn np thm driver cho thit b. V d mt thit b khaibo vi h thng thuc lp HID (Human Interface Device) khi thit bc h thng t

ng nhn v np Device Driveriu khin cho n. Bng 3.2 m t mt s lp h trchocc thit b thng dng trong Windows.


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Hnh 3.4 Kt ni USB theo hnh sao qua cc Hub

Bng 3.2 Cc lp thit b h trtheo hiu hnh

Class (lp) Loi thit bc h trAudio Audio, thit b nghe nhc, h thng m thanhChip/smart card interface devices(CCID)

Smart Card Devices

Common class (CCS) Mt s thit b thng dngCommunications device Modems, Telephones v cc giao din mng

HIDCc thit b giao tip ngi my nh: chut,

bn phm,v.v.Hub Hub USBFrDA Thit b hng ngoiMass strorage a cng, CD-ROM, DVD-ROMMonitor Mn hnh v cc thit b hin thPhysical interface devices Joysticks v cc thit b khc

POS terminalsMy bn hng, my tnh tin v cc thit b

EFTPOSPower

Cc thit b gim st v iu khin ngun, v dnh: qun l pin.

Printer class PrintersImaging class Scanners v Cameras.

3.3 CC KIU TRUYN USB

D liu trao i vi gia thit b USB vi my tnh s dng mt trong bn kiutruyn l: truyn iu khin, truyn ngt, truyn khi v truyn theo kiu ng b.

1) Truyn iu khin (Control Transfers): thng s dng ci t phn cng v a

ra cc lnh cho iu khin thit b. Kiu truyn ny c lm vic mc u tin caovi kh nng kim sot li tng. Mi gi tin c th truyn ln n 64byte.


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2) Truyn ngt (Interrupt Transfers): s dng cho cc thit b cn cung cp mt lng dliu nh (ch truyn theo hng vo) v tun hon chng hn nh: chut, bn phm us dng kiu truyn ngt. Khng ging nh cch ngt, y khng c yu cu ngtc gi ti ch USB m my tnh s hi vng theo chu k xem c thit b no gi dliu ti khng. Thng thit b gi ti ch my tnh 8 byte d liu trong mt ln truyn.

Cc thit b s dng kiu truyn ngt nh bn phm, chut hay cng c th dng chomt thit bo lng khc.

3) Truyn theo khi (Bulk Transfers): khi c lng d liu ln cn truyn v cn kimsot li tryun, nhng li khng c yu cu thc p v thi gian truyn th d liuthng c truyn theo kiu khi. Kiu truyn ny thng p dng cho cc thit bnh my in, my qut.

4) Truyn ng b(Isochronous Transfers): khi lng d liu cn truyn ln vi tc d liu c qui nh, chng hn nh dng cho card m thanh th thng p dngtruyn ng b. Theo cch truyn ny mt gi tr tc d liu xc nh c duy tr.

Vic hiu chnh li khng c thc hin v cc li l t cng khng gy nh hngng kn cht lng cuc truyn.

Trong lnh vc o lng v iu khin bng my tnh thng s dng kiu truyniu khin v c mc u tin cao v c th kim sot c li. Ngoi ra cn c th thchin c giao thc truyn ring trong mt s trng hp ng dng c th tip tc x l.

3.4 GIAO DIN VT L BUS USB

Bus USB c hai kiu u ni thng dng: kiu A v kiu B, thit k nh vy nhmmc ch khng xy ra u ni nhm gia u cm vi thit b v u cm vi Hub. Khcvi chun RS 232, vic u ni bus USB khng chia ra cc kiu u ni khc nhau,chng hn ni thng v bt cho. Bus USB s dng mt Cable bn si dy ni vi ccthit b, trong mt cp ng truyn hai si xon c dng lm cc d liu vi sai (D+v D-) cn hai dy lm ngun nui 5V v ni t (GND) (hnh 3.5).

Hnh 3.5 Cable USB

Cable ni lun thc hin s lin kt 1:1, ngha l Cable ch ni vi Hub v thit b.Kt ni qua Cable USB s dng 4 ng dn c mu khc nhau qui nh cho cc tn hiutrn bus.

Bng 3.3 Cc dy dn trong USB

Chn Tn gi Mu dy M t1234

VCCD-D+

GND

Trng

Xanh lcen

+5VCCD liu (D-)D liu (D+)

Ni t

Cc cm pha sau my tnh thng l kiu u ni A, qua c th ni trc tipcc thit b USB vo my tnh PC. Cc thit b c tc thp chng hn nh chut cng cthu thng vo cm ny bng mt phch cm cng kiu A.


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a)

b)

Hnh 3.6 u cm USB kiu A trn my tnh v u cm kiu B trn thit b

c) d)

Hnh 3.7 nh s cc chn ni cm USB v cab ni kiu A v B

Ngoi cc u cm thng dng A v B bus USB cn c cc u cm kiu Mini vMicro s dng cho cc thit b nh di ng nh: my quay phim, my chp, in thoi ding.

Trong cc trng hp khc thit b thng c mt cm kiu B, vic u ni mytnh c thc hin bng mt Cable kiu A-B (hnh 3.8).

Hnh 3.8 Kt ni USB v Cable

Cc Cable dng ko di khong cch t my tnh n cc thit b thng l kiuA-A. Ngy nay, cc Cable ni USB u c cc nh sn xut cung cp di dng honchnh, trn : u cm, di, cht lng bc kim chng nhiu u khng th thay ic. V vy, tu theo mc ch s dng m la chn Cable cho ph hp.

Mt c tnh khc l cc thit b USB c th c tc truyn d liu khc nhau: tc thp (Low Speed) v tc ton phn (Full Speed). Nn c th xy ra trng hpcc thit b c tc cao li c kt ni vi my tnh qua mt Cable c tc truynthp. khc phc tnh trng ny tt c cc Cable ni u c ch to thch ng vitc cao. Loi Cable truyn vi tc thp c chnh dng cho cc thit b, c thc nh sn xut ch r khi cung cp.

Qua cm USB c th ly ra n p +5V vi dng in tiu th khong 100mA,trong mt s trng hp c th ly ra dng ln n 500mA. Hai ng dn D+ v D- cho

php u ni vi cc chip USB chuyn dng hay cc vi iu khin c tch hp thm giaotip USB.

Tn hiu trn hai ng D+ v D- l cc tn hiu vi sai vi mc in p bng 0/3.3V.in p ngun nui USB c th ln ti a +5.25V v khi chu dng ti ln c th gimxung + 4.2V.


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Khi ghp ni cc thit b vi bus USB thng phi phn bit r cc thit b s dngngun nui ring, chng hn nh my in vi cc thit b nhn in p ngun nui qua bus(Bus Powered). Trong nhiu trng hp c hai ch ngun nui c th cng tn ti cho php la chn theo cch thit k ca USB, dng tiu th ly t bus c tng hnch. Khi dng tiu th vt qu gii hn cho php th in p cung cp tng c ngt.

Cc thit b USB c chia ra gm 3 ch ngun:Ch Low power: dng thit bc cung cp ti a 100mA, in p 4.4V 5.25V.

Ch High power: dng cung cp trong ch ny c th ln n 500mA, in p4.7V 5.25V.

Ch Self power: ngun nui c cung cp t ngoi.

My tnh nhn bit c mt thit b Low Speed (1.5Mbps) hay Full Speed(12Mbps) c cm vo thng qua in p trn trn chn D+ hay trn chn D- nhy lnmc cao. V vy, khi thit k cc mch giao tip vi my tnh qua cng USB cn ch ni

chn D+ ln ngun nui (+5V) i vi thit b Full - Speed. Cn i vi thit b Low -Speed cn ni chn D- ni ln ngun nui. Hnh 3.9 v hnh 3.10 m t su niCable qua cng USB cho thit b Full - Speed v Low - Speed. V pha ch USB hay hubgm hai in trni dy D+ v D- xung t, nh vy bnh thng khi khng c thit bcm vo, 2 ng ny c mc in p l 0V. Khi c mt thit bc kt ni vo cng,mt trong hai ng dy c in p nhy ln mc cao. Bng cch ny Hub nhn bitmt thit b mi c cm thm vo h thng bus.

Hnh 3.9 Kt ni vi thit b USB Full - Speed

Hnh 3.10 Kt ni vi cc thit b USB Low - Speed

Mi Hub v mi dy Cable u gy ra s lm tr tn hiu nhng thi gian tr khngc vt qu gi tr cc i c qui nh. Bus USB cho php n 7 Hub u ni tip

nhau, do vy c thu ni ti a l 127 thit b vo bus USB. Trn thc t con s ny ll thuyt v tuy c thu ni n 127 thit b nhng cng nhiu thit bu ni th tc truyn cng chm do di thng ca ton b bus b phn chia n tng thit bu vo bus.


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3.5 GIAO THC TRUYN

1) Cc trng trong truyn thng USB

Th t bit c truyn qua bus USB l bit c trng s nh nht (LSB) c truynu tin cho n bit MSB. USB c 4 loi gi truyn trn bus l: gi nhn dng (Token), gi

d liu (Data), gi khi u khung (Start Of Frame) v gi bt tay (Handshake). Trongmi gi li gm c nhiu trng, truyn thng USB c cc loi trng sau:

Trng ng b (SYNC): tt c cc gi u c bt u bng trng SYNC, lchui nh phn mNRZI(Non Return to Zero Inverted) ca chui KJKJKJ. Vics dng SYNC lm khi u cho mt gi n ging nh bit Start trong RS 232. Ttc cc gi u gii hn gia SOP (Start Of - Packet) v EOP (End Of Packet).

Trng nhn dng (PID): theo sau ngay trng SYNC trong mi gi ca USB,gi c chiu di 8bit gm 4bit thp l 4bit nhn dng gi, 4bit cao l o ca 4bitthp nhm kim sot li khi truyn. Trng PID m t loi gi sc truyn sau

n. C ch USB v cc thit b USB u nhn bit c cc m trng nhn dng c qui nh. Nu m nhn c l khng nm trong cc m qui nh chUSB s khng h tr. Sau y l bng danh sch m trng nhn dng ca cc loigi trong USB.

Bng 3.4 Cc loi gi truyn trong USB

Loi PID Tn PID PID [3:0] M tOut 0001B Ch USB ghi ra.

Token In 1001B Ch USB c t thit b.SOF 0101B Khi u khung v s khung.

SETUP 1101B Ch USB ci t thit b.Data DATA0 0011B Gi d liu data0

DATA1 1011B Gi d liu data1ACK 0010B Tr li xc nhn.

NAK 1010B Thit b ngoi khng chp nhn d liuhay d liu truyn b hng.

Handshake STALL 1110B im cui tm ngng hay khng h tr.

Special PRE 1100BCh USB a ra cho php ng ra ca

bus trao i vi cc thit b c tc thp.

Trng a ch (ADDR): l a ch ring truy cp ti thit b. Thit b c th nhnd liu hay truyn d liu v my ch (ph thuc vo gi tr gi nhn dng PID)

thng qua a ch ca n. Trng a ch s dng 7 bit [A0 A6]. Trng a ch ctrong cc gi IN, SETUP, OUT. Mi a ch, chnh cho mt thit bn l khi btu c cp ngun cc thit b c a ch mc nh l zero v ch USB nhn bngm t ca thit b thng qua a ch mc nh ny.

Trng im cui (End Point): mt trng im cui s dng 4 bit cho php lachn im cui trong thit b. Trim cui zero, sim cui l ring bit chotng thit b chc nng. Mt im cui l a ch ca mt bm trong thit b,trng a chc nh ngha trong cc gi IN, SETUP v OUT. Tim cui tich USB thit lp mt knh trao i thng tin gi l ng ng. Tt c cc thit bchc nng u h trmt ng ng mc nh vi im cui l zero, ch USB strao i vi thit b mi gn vo thng qua ng ng ny.


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Trng s khung: trng s khung c di 11bit, n c gi trong gi SOF(Start Of Frame Packets). SOF c gi bi ch USB theo chu k 1ms 0.005ms.

Trng d liu: trng d liu c di t 0 n 1023byte, cc byte c gi iln lt. Trong mi byte d liu bit d liu nh nht c gi trc v cui cng l

bit bit c trong s ln nht (Msb).

2) Cc loi gi trong truyn thng USB

Gi nhn dng (Token Packets): ch cho bit loi truyn ngay sau n. C 3 loi ginhn dng:

o IN: Bo thit b bit ch USB mun c thng tin.

o OUT: bo cho thit b rng ch USB mun gi thng tin.

o SETUP: c s dng bt u trong truyn iu khin.

Dng chung cc gi nhn dng nh hnh sau:

Hnh 3.11 Gi nhn dng

Cc gi nhn dng m USB s dng l mt trong cc gi IN, OUT, Setup. Mi giu c 4 trng: PID c chiu di 1 byte ch ra loi gi, 7 bit a ch (Address), 4 bit im

cui (End point) v cui cng l 5 bit kim tra li truyn (CRC).

Gi khi u khung (Start Of Frame): gi khi u khung c pht ra t ch USBtheo chu k 1.00ms 0.005ms, gi khi u khung (SOF) bao gm cc trng:

o 8bit: PID nhn dng loi gi.

o 11bit: s khung.

o 5bit: kim tra li CRC5.

Hnh 3.12 Gi SOF

Gi dliu (DataPackets): mt gi d liu bao gm mt trng PID (8bit). Trngd liu c chiu di nm trong khong 0 1023byte v 16bit CRC. C hai loi gid liu c nhn bit qua trng PID l Data 0 v Data 1, hai loi gi ny cnh ngha h trtrong truyn d liu ng b.

Hnh 3.13 Gi d liu


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Gi bt tay (Handshake Packets): c 3 loi gi bt tay

ACK: tr li d liu nhn thnh cng.

NAK: bo thit b khng tr li d liu nhn hay nhn b li. Tt c cc gi bt tayu c truyn theo kiu ngt bo tin cho ch USB bit d liu khng c gi.

STALL: ch ra rng thit b USB l khng c kh nng truyn hoc nhn d liu hayng ng yu cu l khng h tr.

Hnh 3.14 Gi bt tay

3.6 CC QU TRNH TRUYN USB1) Truyn iu khin

Truyn iu khin c thc hin qua 3 giai on: Setup, Data v Status. i vithit b Low - Speed kch thc gi tin l 8byte, cn i vi Full - Speed kch thc gi cth l 8, 16, 32 hay 64byte.

a) Giai on 1(Setup): gm 3 gi tin:

+ Gi nhn dng: do ch USB gi ti thit b USB. Trong gi ny ch USB gi ach v im cui ca thit b.

+ Gi nhn dng: c gi ngay sau khi gi Setup kt thc v trng PID ca gilun l kiu Data0.

+ Gi bt tay: gi cui cng do thit b USB tr li: ACK nu khng c li, NAK nuc li xy ra.

Hnh 3.15 Cc gi tin trong giai on 1 ca truyn iu khin

b) Giai on 2 (Data): giai on ny cng cha 3 gi tin: nhn dng, d liu v bt tay(hnh 3.16).

Gi d liu: ch ra d liu theo chiu vo (IN) hay ra (OUT).

Gi d liu: cha d liu cn truyn.

o Trng hp d liu c chiu t thit b USB vo ch USB. Nu khng c lixy ra, d liu sc gi v ch USB. Trng hp c li xy ra ty theo lim thit b USB gi tr li bng STALL hoc NAK.


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o Trong trng hp d liu c chiu t ch USB n thit b USB th gi dliu sc gi ti thit b.

o Gi bt tay: khi nhn c d liu ch USB s tr li bng gi ACK ti thitb. Trong trng hp ra ty theo d liu m thit b USB nhn c li haykhng m n gi tr li ch USB bng mt trong cc gi: ACK, NACK,STALL.

Hnh 3.16 Cc gi tin trong giai on 2 ca truyn iu khin

c) Giai on 3 (Status Stage): tr v trng thi ton b qu trnh

Chiu vo: ty theo qu trnh trao i c li xy ra hay khng m thit b USB s trli ti ch USB mt trong cc tn hiu:ACK, STALL hayNACK(hnh 3.17a).

Chiu ra: ch gi cc gi tr li n thit b USB.

Hnh 3.17Cc gi trong giai on 3 ca truyn iu khin.

2) Truyn ngt

Khng ging vi phng thc trao i tin theo ngt m chng ta xt ti chng

2, tc l tn hiu yu cu trao i tin do thit ba ra v yu cu CPU phc v ngt chon. Truyn ngt trong USB hon ton do ch USB hi vng. Nu mt thit b USB chng yu cu n phi i n khi ch USB hi ti v p ng. Qu trnh truyn ngt din


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ra tng i n gin ch c 3 gi trong mi ln truyn (hnh 3.18). Truyn ngt thng sdng trong cc thit b truyn thng c tnh di b, cc thit b nh v n gin.

Truyn ngt qui nh kch thc cc gi ty thuc vo tc thit b:

Vi thit b Low - Speed: kch thc gi ti a 8 byte.

Vi thit b Full - Speed kch thc gi ti a l 64byte.

Vi thit b High - Speed kch thc gi ti a c th ln n 1024byte.

Hnh 3.18 Cc giai on truyn ngt

a) Interrupt IN: ch USB s hi cc im cui ngt theo chu k. Tc qut hi vng cthc t trong gi m tim cui ca mi thit b. Mi khi hi vng yu cu ch phi

gi mt IN Token. Nu IN Tokenb hng, thit b b qua gi ny v tip tc gim st buscho cc IN Token mi.

Nu c yu cu thit b gi mt gi d liu ti ch USB v chmy ch tr li. Nukhng c ngt thit b tr li ch bng NACK hay STALL.

b) Intrrupt OUT: khi ch mun gi d liu ti thit b ngt, n pht ra mt OUT Tokenv theo sau l mt gi d liu ngt (Interrupt Data). Nu OUT Token hoc gi d liu(Data Packet) b hng, thit b USB s b qua gi ny. Nu bm im cui ngt cathit b trng n s tr v gi ACK cho ch USB. Trong trng hp bm im cui lkhng trng do d liu nhn trc , th thit b USB s tr v NAK. Tuy nhin nu mt

li xy ra vi mt im cui, n s tr v STALL.3) Truyn ng b (Isochronous Transfers)

S dng khi d liu cn truyn ln v tc d liu c qui nh nh: audio,video stream. Trong cch truyn ny mt gi tr tc d liu c duy tr v khng kimtra li. Truyn ng b cng cho h tr trn c hai chiu: truyn ng b theo chiu vo(Isochronous IN) v truyn ng b theo chiu ra (Isochronous OUT). Kch thc ln nhtca gi d liu truyn trong kiu ny:

Thit b Full - Speed l 1023byte.

Thit b High - Speed l 1024byte.


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Hnh 3.19 Truyn ng b

4) Truyn khi (Bulk Transfers)S dng khi c lng d liu ln cn truyn v cn kim sot li truyn, nhng li

khng c yu cu thc p v thi gian truyn th d liu thng c truyn theo khi(Bulk transfers). Kiu truyn ny thng p dng cho cc thit b nh my in, myqut,v.v. Truyn khi ch h tr cho cc thit b Full - Speed v High - Speed. Kchthc gi d liu ln nht m thit b h tr:

Vi thit b Full - Speed: 8, 16, 32 hay 64byte. Vi thit b High - Speed: 512byte.

Truyn khi cng tng i n gin, ch gm 3 gi: gi nhn dng, gi d liu vbt tay.

Hnh 3.20 Cc gi trong truyn khi

a) Chiu vo: khi ch USB sn sng nhn d liu, n pht ra mt IN Token. Nu thit

b nhn c mt IN Token vi mt li n s b qua gi. Nu IN Token nhn c khngc li th thit b USB tr v gi d liu cn truyn. Trng hp li xy ra thit b gi vNACK hoc STALL.

b) Chiu ra: khi ch USB mun gi ti thit b chc nng mt gi d liu, n gi ti thitb USB mt gi OUT Token v tip theo sau l gi d liu cn truyn. Trng hp giOUT Token, d liu b hng hay b m thit b ang y n s gi tr li bng gi

NACK. Trng hp khng c li xy ra, khi nhn xong d liu thit b USB tr li bnggi ACK. Trong trng hp im cui b li n s tr li bng STALL.

3.7 IM DANH V GI PHN MM IU KHIN

1) im danh

Kh nng tng nhn ra v ci t phn mn iu khin cho cc thit b USB l doh thng thng xuyn kim tra thng tin thit b trn cng. Vic im danh c thc


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hin c lp bi hiu hnh, khng cn mt chng trnh ngi s dng phi thc hincng vic ny. Khi mt thit b USB c kt ni vo mng, hub nhn ra n thng quamc in p trn ng d liu. V trong mi thit b USB ng d liu c ni ngunthng qua in tr, do khi kt ni vo bus in p ng d liu trn hub c a lnmc cao bo cho hub bit mt thit b kt ni vo cng tng ng.

Khi hiu hnh nhn bit mt thit b mi c kt ni, n yu cu thit b kt nicung cp thng tin v thit b. Thit b c nhim va ra bng cung cp thng tin v mnhdi dng mt bng m t (Description). Bng m t l mt cu trc d liu c qui nhchnh xc v ni dung, cch sp xp d liu v chiu di ca n. Hiu hnh da vothng tin cung cp t bng m t thit b m gi cc phn mm iu khin tng ng.

Qu trnh im danh v ci t cc thit b USB din ra gm cc bc nh sau:

Hub thng bo cho my ch bit l c mt thit b mi c ni vo.

My ch hi li Hub xem thit bc ni vo cng no.

My ch by gi bit c thit b mi c ni vo cng no. N a ra mt lnhni sang cng v thc hin mt thao tc t ti bus.

Hub to ra mt tn hiu reset vi di 10ms v cp dng in vi cng 100mAcho thit b. By githit b sn sng hot ng v tr li qua a ch mc nh 0.

Trc khi thit b USB nhn c a ch bus ring, n vn c thc trao i quaa ch mc nh 0. My chc 8 byte u tin ca bng tm lc thit b khngnh cc gi d liu c th c chiu di bng bao nhiu.

My ch gn cho thit b mt a ch bus ring.

Qua a ch mi my chc tt c cc thng tin, cu hnh c t thit b.

My ch gn cho thit b mt trong cc cu hnh c th. By githit b sc phply ra dng in tiu th nh trong bng tm lc cu hnh ca n nh. Nhvy, tt c sn sng v c a vo s dng.

Hnh 3.21 Qu trnh nhn v ng k mt thit b USB khi cm vo


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Hnh 3.22Kt n

i ch

USB v

i cc thi

t b

ch

c n

ng thnh cc

ng

ng

Mi yu cu t my chc b vi x l trn thit b USB nhn ra v tr li. Timi im cui (Endpoint) trn thit bc b tr mt mt b nhFIFO(First In, FirstOut) lm bmvo/ra cho im cui. Khi nhn c d liu, b vi x l phn tch lnh,c d liu ci t trong ROM v ghi ln bm ra. Thng tin u tin thit b gi l bngm t thit b (Device Descriptor) c di 18 byte. My chc 8 byte u tin trong

bng ny xc nh lp thit b sau ton b bng m tc c. T cc thng tin cc, trong mt vi trng hp m lp (bDeviceClass) ch cho ta thy l thit b thuc vmt lp xc nh, qua hiu hnh c th chnh phn mm iu khin dng cho thit

b. Nh vy, chng hn i vi mt chut USB ngi dng khng cn c thm phn mm

ring. Nhcc thng tin ny thit bc a vo lm vic v c ghi vo b qun lthit b. Khi thit b thuc v mt lp, thng tin v thit b c thc vit chi tit trongbDeviceClass v bDeviceProtocol.

bDescriptorType: loi bng m t (01h: m t thit b).

bcdUSB: l s BCD ch r phin bn ca USB: Version 1.0: l 0100h. Version 1.1: l 0110h. Version 2.0: l 0200h.

Bng 3.5 S sp xp ni dung ca bng m t thit bTn trng S byte M t

bLength 1 Chiu di ca bng tm lc tnh bng bytebDescriptorType 1 Kiu Descriptor (01h = Device Descriptor)bcdUSB 2 Phin bn USBbDeviceClass 1 M lp (Class)bDeviceSubClass 1 M lp con (SubClass)bDeviceProtocol 1 M giao thcbMaxPacketSize 1 ln ca EPO-FIFOidVendor 2 ID nh cung cpidProduct 2 ID sn phmbcdDevice 2 S hiu nh sn xutiManufacturer 1 Ch s xu dng cho nh sn xut


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iProduct 1 Ch s xu dng cho sn phmiSerialNumber 1 Ch s xu dng cho s hiu sn phmbNumConfigurations 1 S lng cu hnh cui cng.

bDeviceClass: cha m lp thit b, ch cho bit n thuc lp thit b no.

bDeviceSubclass: trng ny s dng nhn bit lp con trong mt lp xc nh. Nugi tr bDevice l 0 th gi tr ny cng l 0.

bMaxPacketSize: kch thc ln nht cho b m im cui zero (Endpoint-O-FIFO).

idVendorv idProduct: s hiu nh sn xut v s hiu sn phm, c h thng sdng tm Device Driver tng ng cho thit b.

bcdDevice: s dng cung cp version ca thit b.

Ba ch s chui (iManufacturer, iProductv iSerialNumber): cung cp tn nh sn

xut, tn thit b v s serial ca sn phm.bNumConfigurations: ch ra s cu hnh thit bng vi tc hin ti.

Cc bng m t cu hnh c dng cu trc phn lp, cho php m t cc thng sthit lp v cc tnh cht khc nhau. i vi tng thit b c th:

Mi thit b c mt bng tm lc thit b duy nht.

C th c nhiu cu hnh.

Trong mi cu hnh c th cho ra nhiu giao din.

Mi giao din c th c nhiu cch thit lp la chn.

Trong mt cu hnh c th tn ti nhiu giao din, cc giao din chc nng cchia ra theo cc im cui ang c. Mi giao din c th c nhiu cch thit lp, cc cchny khc nhau lin quan n di thng b chim dng.

Hnh 3.23 Cu trc hnh cy ca bng m t thit b USB

Ngoi bng tm lc thit b cn c bng tm lc cu hnh, mt hay nhiu bngtm lc giao din, cc bng tm lc im cui. H thng cng phc tp th thng s tin

phi qun l cng nhiu, chng hn thit b c bao nhiu im cui vi lnFIFOmth no, liu thit b c h trnhiu cu hnh, nhiu giao din v bao nhiu cch thit lp


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la chn i vi mi giao din. Nh vy c th ni bng m t thit b l mt dng hnhcy (hnh 3.23).

Bng lit k cu hnh m t s lng giao din v cu hnh hin thi cng nh bngtm lc xu cui cng ang tn ti. Trong bmAttributes c thc ch dn liu thit bc cung cp in p ngun t bus v liu chc nng RemoteWakeup c h trcngnhc nh thc t bus. Hm Maxpower ch dn nhu cu v dng in ly t bus, nv tnh l 2mA. Cng dng in ny cng c thc cung cp t mt Hub trong ch t cp in.

Bng 3.6 Bng m t cu hnh

Tn trng S byte M tbLength 1 Chiu di ca Descriptor tnh theo bytebPescriptorType 1 Kiu Descriptor (02h = Descriptor cu hnh)wTotalLength 1 Chiu di ca Descriptor c ca cu hnh nybNumInterfaces 1 S lng giao dinbConfigurationValue 1 S hiu ca cu hnh nybConfiguration 1 Ch s xubmAttributes 1 Thuc tnh ca cu hnh

Maxpower 1 Dng tiu th, n v tnh x2mANhiu bng tm lc ghp ni c thc qui nh ni dung bng vic t cc

thng s la chn. Thng tin quan trng nht v tng cch thit lp l s lng im cuitrong mt bng lit k Endpoint thuc v mi im Endpoint. Nu nh thit b thuc vmt lp thit b c chnh trong Device - Descriptor th cc thng tin tng ng cthc cho y mt ln na.

Bng 3.7 S sp xp ni dung ca bng tm lc giao dinTn trng S byte M t

bLength 1 Chiu di ca kiuDescriptortnh ra bytebPescriptorType 1 1 (04h =Interface Descriptor)bInterfaceNumber 1 S giao din.bAlternateSettiny 1 t thng s theo cch la chn.bNumEndpoint 1 S lng im cui khng c EPObInterfaceClass 1 Giao din lp cui cng.bInterfaceSubClass 1 Giao din lp con cui cng.

bInterfaceProtocol 1 M giao thc cui cng.iInterface 1 Ch s xu (String-Index)

Bng 3.8 Bng tm lc im cui

Tn trng S byte M tbLength 1 Chiu di ca bng lit k tnh ra byte.bPescriptorType 1 1 kiu lit k (05h = lit k im cui).bEndpointAddress 1 a ch Endpoint (ED2, OUT).bmAttributes 1 Kiu truyn (2 = truyn khi).bMaxPacketSize 1 Dung lng b nhFIFO.

bMaxPacketSize 1 Khong hi cui cng.Khi h thng im danh tt c cc thng tin quan trng ca thit bu c kim

tra. Khi hiu hnh kim tra xem liu ti nguyn c yu cu nh: phn mm iu


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khin, dng tiu th, di thng bus c mt. Sau khi hon thnh khu im danh, ta cth s dng ngay cc yu cu iu khin (Control-Request) quaEndpoint 0. CcEndpointv cc hot ng khc cn phi c cho php hot ng bng vic gn thng s thit lpln hn 0.

2) Phn mm iu khin

Chc nng ca phn mm iu khin (driver) thit b ni chung, c th m t nhmt mt xch lin kt gia phn cng v phn mm ca mt h thng. Trong mi trng tWindow 98 khng c mt chng trnh ng dng no c th truy cp trc tip ln phncng. Cch tt nht l gi ra mt phn mm iu khin thit b, phnmm ny trao itrc tip vi phn cng hoc qua lp m nm su hn trong h thng. Phn mm iukhin c cc nh sn xut thit b cung cp km theo v c vit trong khun khut cho thit b ca mt cng ty. Phn mm lm vic trong ch li vi quyn u tin caohn. Mt phn mm iu khin c xem xt ging nh mt thit b o, ngha l mtchng trnh ngi dng s dng mt phn mm iu khin ging nh chnh mt thit b.

Tt c cc phn mm iu khin USBu da trn Win32-Driver-Model (WDM),m hnh ny c s dng trong Window NTv c tng thch trong Window 98. Ttc cc lnh gi phn mm iu khin u chy qua phm mm qun l vo/ra (I/O

Manager). Cc chng trnh ngi dng khc nhau gi gi yu cu ti phn mm qun lvo/ra, phn mm ny sau phn phi ti phn mm iu khin c th.

Vi mc ngi dng ch cn quan tn n 5 hm truy cp trong Windows:

Mmt thit b bng hm CreateFile( ).

Truy nhp ghi s dng hm WriteFile( ).

Truy nhp c s dng hmReadFile( ).

Kt thc qu trnh truy nhp s dng CloseHadre( ).

i vi cc trng hp khng theo khun mu trn, ta c th thc hin hm truycp bng hmDeviceloControl( ).

Trong gii hn gio trnh ny, khng i su vo cch to ra cc Driver cho thit biu khin v chng kh phc tp.

3.8 MT S VI MCH SDNG TRONG KT NI USB

Trn th trng hin nay cung cp mt s IC chuyn dng s dng cho vic ktni USB. Bn cnh nhiu vi iu khin (Microcontroller) ca cc hng khc nhau cng tch hp cng USB to thun li trong vic s dng. Cc IC ny u tch hp phn cng

b trtng pht hin cc gi d liu, yu cu t ch USB, v tng gi cc bng mt thit b ti ch USB.

Cc vi mch h trkt ni USB l cc Microcontroller c h trphn cng, phndo. Phn mm trao i dnh cho ngi thit k to iu khin ti a cho ngi s dng.Cc Microcontroller h tr USB vi cc tc trao i tin: 1.5Mbps (Low - Speed),12Mbps (Full - Speed) v 480Mbps (Hight - Speed). Cc thit b truyn tin tc thp vtrung bnh nh: CY7C63001, AN21XX, CY7C64xxx, PIC18f4550, 68HC705JB2,v.v...Cc thit b c tc cao nh: FTDI FT8U232, FTDI FT8U245, CY68013 FX2,NET2280,v.v... Sau y l mt s vi iu khin hay dng:

1) CY7C63001
http://www.netchip.com/products/2280.htmhttp://www.netchip.com/products/2280.htm


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B vi x l 8bit theo khin trc Harvard.

Chy h 6MHz.

128byte RAM.

H trUSB tc 1.5Mbps.

ng gi 20 chn.

2) PIC16C745, PIC16C765 (Microchip)

H trUSB 1Mbps vi 6 im cui.

5 knh ADC 8bit,v.v

3) PIC18F4550 (Microchip)

H trUSB 12Mbps vi 16 im cui. Mi im cui 2 bm 512byte.

Chy xung nhp 48MHz.4) NET2888 (Netchip)

H trUSB 1.0 v 1.1.

H tr5 m cui.

Chy vi xung nhp 48MHz.

5) 68HC705JB3 (Motorola)

H trUSB tc 1.5Mbps.

H tr2 ngt iu khin im cui. 144byte RAM.

6) PDIUSBD11 (ca Philips)

H trUSB 12Mbps.

Mt im iu khin v 6 im cui chung.

Chy vi xung nhp 12MHz.

7) CY7C68001

H trUSB tc 480Mbps v 12Mbps.

H tr5 im cui vi bm 512byte cho truyn khi v 1024byte cho truynng thi.

4Kbyte FIFO.


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3.9 CC MCH CHUYN I USB SANG RS232.

0

C3

0.1uF

USB Connector

21

34

-Data+5V

+DataGND

D1LED

C1

4.7uF

U1A

100301/SO

514

20

1516

819242728

17

25

7 18

21

26

1213142223

31129106

RXDTXDVCCIO

VCC

USBDP

USBDM

NC1RESETNC2OSCIOSCO

3V3OUT

AGND

GND1

GND2

GND3

TEST

CBUS4CBUS3CBUS2CBUS1CBUS0

RTSCTS

DTRDSRDCD

RI

R133

C4

0.1uF

RXDTXD

C2

0.1uF

Hnh 3.24 Mt mch chuyn i USB sang RS232 sdng FT232R.

Mch chuyn i t USB sang RS232 i khi cng rt cn thit khi m ta mun ktni n thit b s dng cng RS232, m my tnh khng c trang b cng RS232. Trnmch hnh 3.24 m t s mch ca mt b chuyn i t USB sang tn hiu RS232 sdng IC chuyn dng FT232R. Cng c th s dng cc vi iu khin lm nh b chuyni USB sang RS232, tuy nhin ta phi vit phn sn (Firmware) cho vi iu khin lmcc cng vic ng k, nhn d liu t cng USB v chuyn d liu ra cng ni tip. Hnh3.25 l mt mch chuyn i ghp ni vi vi iu khin PIC 16F876 s dng vi mch

PDIUSBD 11. D liu truyn gia vi iu khin vi PDIUSBD 11 l dng I2C. PDIUSBD11 thc cht l mt vi iu khin, vic ng k c thc hin tng vi cc thng s cit sn trong ROM.

Hnh 3.25 Mt mch ghp ni USB s dng PDIUSB 11


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CHNG 4. THIT K V CH TO CC KHI CHC NNG

4.1. KHI CAO TH. (s nguyn l hnh 4.1)Khi cao th c th phn thnh cc khi chc nng: dao ng (U6); to xung iu

khin cho 2 MOSFET (U5A,U4A-U4D); linh kin ngt-ml MOSFET IRF840 (Q3, Q4),to xung cao p nhbin p ferit T1; chnh lu to in p dng (D6, D7) v cc tin(C5, C6, C9); chnh lu to in p m (D8, D9) v cc tin (C7, C8, C10); khi phnhi to n nh cao p (U1C, U1D, U1A, U1B, U2B v Q1, Q2); khi bo v qu cao p(U2C, U2A, U3B, U3A); khi bo v qu dng cho Q3 v Q4 (U3D, U3A).

Khi dao ng v to xung iu khin ngt mcho MOSFET: dao ng nhU6 LM555, tn s dao ng c iu chnh nhbin trPOT5 c tn s dao ng lpli c32KHz, t s rng xung (duty factor) l ty . Xung dao ng t U6 LM555 an b chia i tn s trn U5A-CD4013B, mc ch vic chia i tn s l cho ra xung

cn xng (h s rng xung l 50%) v to xung pha ngc nhau ly ra ti Q v Q caU5A. Cc linh kin D6,C11, R32 v D7,C12, R33 c cng dng co hp rng xung, hs rng xung b hn 50% c cng dng trnh hin tng 1 MOSFET cha tt hn trongkhi MOSFET kia kch dn.

Khi to xung cao p v chnh lu: Tng bin xung nhbin p, bin xung c 1KV v khi chnh lu nhn hai c 2KVDC t s bin p phi tha mn l1:100. Chnh lu dng nhn hai in p nhdiode D6, D7 v C5, C6, san bng nhp nhnhR30, C9. Tng t, phn chnh lu m gm cc linh kin D8, D9, C7, C8 v san bng

nhp nh nhR31, C10.Khi phn hi to n nh cao p: B phn ly mu in p gm R8, R9 v

POT1, khuch i in p ly mu U1C, U1A, U1B v khuch i o du khi dng caop cc tnh m l U1D, khuch i so snh l U2B, in p chun a vo u trn ca

bin trPOT2,in p chun ny l thay i mong mun in p li ra thay i v lyt board logic. in p li ra khuch i so snh c m nhQ1 v Q2 cp in pnui cho bin p xung T1.

Khi bo v: Gm bo v qu cao p v bo v qu dng cho 2 MOSFET. Khi

bo v qu cao p gm: khuch i m U2C; khuch i so snh U3B v transistor Q5.Khi in p cao p li ra cao qu mc quy nh, li ra U3B ln mc cao lm Q5 dn, koin th nui cho bin p T1 v khng, ng thi LED D5 sng bo c s c bo v. Bov qu dng cho MOSFET gm: in trly mu dng R21; khuch i so snh U3D. Khic hin tng qu dng, li ra U3D ln cao lm Q5 dn, ko in th nui cho bin p T1v khng.

Cc c trng k thut thit k khi ngun cao p.- in p ra t 0V n 2 kV trn 256 bc.- Dng cao p cc i l 10mA ti 2000V, c ngha cng sut cc i ngun cao

p l 10VA.- i cc tnh ngun cao p bng b chuyn ckh.


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-15V

+5V

+5V

-15V

+5V

-

+

U1

OP373

4

6

7

2

-

+

U2

OP373

4

6

7

2-

+

U3

3

4

6

7

2

C1

1

3

2

13

2

Q1

32

1 Q2

32

1

SW1

18

3

+

- U4B

TL0845

67

4

11

+

- U4A

TL0843

21

4

11

+

- U4D

TL08412

1314

4

11

+

- U4C

TL08410

98

4

11

U8A

74LS123

14

15

12

3

13

4

16

CEXTREXT/CEXT

AB

CLR

Q

Q

VCC

C2

J1

MCP41010

CS

SCK

SI

Vss

VDD

B

W

A

+

-U5A

TL0843

21

4

11

+

-U5D

TL08412

1314

4

11

+

- U5C

TL08410

98

4

11

+

- U5B

TL0845

67

4

11

+

-

U9

LM311

2

37

56

41

8

1

3

2

D2

1

2

D1

1

2

R27

+

-U6

TL0813

26

71

45

1

2

+

-

U7

CA3080

3

26

7

45

1

2

BLR

BLR

To

RB7

To

RB5

To

RB6

INPUT

OUTPUT

R7 R8

R9

R10

R 11 R 12

R13

R14

C3

R15 R16

C4 R17

C5

R18

R19

R20

R21

C6

R22

C7

R23

R24 R25

C8

C9

D3 D4

R26

R28

R29

R30

P2

R31

R32

R33

R34

R35 R36

R37

C10

R38

C11

R39

R40

R41

R42

P3

R5

R6

R2R1

P1

R3

R4

R43

Hnh 4.2 S nguyn l khi khuch i v khi pht xung iu khin ADC.

Hnh 4.3 Gin xung khi pht xung iu khin ADC(a) Tn hiu li vo (+) U3A

(b) Tn hiu li ra ginh ti li ra U3C(c) Tn hiu li ra U3A(d) Tn hiu ra ti chn 6 U4, rng 15us(e) Tn hiu ra ti chn 10 U4 xa in tch trn t C19, rng 2 us


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Cc c trng thit k khi khuch i ph:

- iu chnh h s khuch i t x20-x130 / 256 bc, tng ng 26db-42db/256 bc.

- iu chnh h s khuch i bng phn mm trn my tnh.

4.3 KHI LOGICKhi logic c xy dng trn vi iu khin PIC18F4550 vi cc l do: 1. vi iu

khin ny c ADC 10 bit; 2. vi iu khin ny tch hp cng USB 2.0. Vi iu khin nym nhn cc chc nng:

- Bin i AD: Xung khuch i phc ginh a vo pin 2 (AN0) bini AD. Mc logic cao ti RD4 t khi pht xung iu khin ADC dng lm tnhiu bt u bin i AD. Bin i AD xong vi iu khin pht xung ti RB4 xa in tch trn tc ginh C19.

- iu khin h s khuch i: Vi iu khin iu khin h s khuch i ca

khuch i ph thng qua vi mch bin trs U5 MCP41010 ti board mchkhuch i.

- iu khin in p cao p: Bin trs U9 c iu khin bi vi iu khin,in p ca im gia bin tr(W) c khuch i m nhU10. in p lira khuch i m U10 (CTL-HV) c dng lm in p chun cho khuch iso snh ca board mch cao p.

- Truyn dliu : Truyn d liu t my tnh ti vi iu khin v ngc li.Hng d liu t my vi tnh n vi iu khin l cc lnh iu khin: ng mcao p; t cao p; t h s khuch i Hng d liu t vi iu khinn my vi tnh l d liu ph, in p cao p bin i ADC hin th ln

giao din iu khin trn my vi tnh.

RD4

C25100nF

VDD=5V

MEAS

CONN USB

1234

1234

RB6

RB7

+

-

U10A

LM324A

3

21

4

11

VCC=12V

X1 20MHz

RB5

VDD=5V

CTL- HV

U8 PIC18F4550

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20 21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40MCLR/Vpp/RE3

RA0/AN0

RA1/AN1

RA2/AN2/VREF-/CVREF

RA3/AN3/VREF+

RA4/TOCKI

RA5/SS

RE0/RD

RE1/WR

RE2/CS

VDD

Vss

OSC1/CLKIN

OSC2/CLKOUT

RC0/T1OSO/T1CKI

RC1/T1OSI/CCP2

RC2/CCP1

VUSB

RD0/PSP0

RD1/PSP1 RD2/PSP2

RD3/PSP3

RC4/D-/VM

RC5/D+/VP

RC6/TX/CK

RC7/RX/DT

RD4/PSP4

RD5/PSP5

RD6/PSP6

RD7/PSP7

Vss

VDD

RB0/INT

RB1

RB2

RB3

RB4

RB5

RB6

RB7

U9

+

-

U10B

LM324A

5

67

4

11

RD5C23

20pF

RB4U10

POT10

1

3

2

C24100nF

-VCC=-12V

VDD=5V

C22

20pF

-VCC=-12V

AN0

R374.7K

MCP41010

CS

SCK

SI

Vss

VDD

B

W

A

VDD=5V

VDD=5V

VCC=12V

Hnh 4.4 S nguyn l khi logic.


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Cc c trng thit k khi logic:

- Cng USB thit k hot ng mode full speed.

4.4 KHI NGUN NUI IN P THP

C30

C28

C31

0VAC

D15 1N4007

D16 1N4007

OUTPUT 5VR38

T21 5

6

4 8

C27

D17 1N4007

220V

R39

C26

U13LM7912

1

2

3VI

GND VO

AC

C32

C33

15VAC

U12LM7805

1

2

3VI

GND

VO

OUTPUT 12V

D14 1N4007

T3

1

5

4

8

U11LM7812

1

2

3VI

GND

VO

C29

OUTPUT -12V15VAC

Hnh 4.5 S nguyn l khi ngun nui in p thp

Khi ngun nui in p thp c xy dng trn bin p h p T2220VAC/15VAC, 15VAC, 40VA . Cc linh kin R38, R39, T3,C26, C27, C28 to thnh

b lc in li (line filter). Chnh lu 2 bn kin p dng: D14; D15; C29. n p12V, 5V nhIC U11 v U12. Chnh lu 2 bn kin p m: D16; D17; C30. n p -12VnhIC U13.

Cc c trng thit k khi ngun nui in p thp:- Dng cc i li ra +12V, -12V, +5V l 1A- Cng sut tiu th cc i khi ngun nui: 30VA

- in p li vo 220VAC 20%


55/146



CHNG 5. CCGII THUT PHN MM

5.1Gii thut ng mv iu khin in p cao p, iu khin h s khuch ikhi khuch i

My vi tnh iu khin cho vi iu khin ti my phn tch bng cch gi 2 byte quacng USB, byte th nht tm gi l m lnh ra lnh cho vi iu khin lm cng vic g,

byte th 2 l d liu cng vic cn iu khin. Sau y l bng tng kt quy c cc byteiu khin chuyn t my tnh n vi iu khin.

Cng vic iu khin Byte thnht (m lnh)(dng s thp phn)

Byte thhai (d liu)(dng s thp phn)

ng mcao p 01 0: tt cao p1: mcao p

iu khin in p cao p 02 0 - 255iu khin h s khuch ikhi khuch i

03 0-255

Bng 5.1 Bng tng kt quy c cc byte iu khin chuyn t my tnh n viiu khin.

ng mcao p: Khi vi iu khin nhn byte th nht s 01, byte th hai s 0, viiu khin xut ra mc cao bit RD5 lm Q5 (mch cao th) dn, ko theo Q1, Q2 ngngdn lm mt in p nui cho bin p xung T1 (mch cao th) v tt cao p. Ngc li,

byte th hai s 1, vi iu khin xut ra mc thp bit RD5 lm Q5 ngng, ko theo Q1, Q2dn, c in p nui cho bin p xung T1 , c cao p.

iu khin in p cao p: Khi vi iu khin nhn byte th nht l s 2, byte thl con s 0-255, vi iu khin ly d liu byte th hai iu khin bin trs U9-MCP41010 bng giao thc SPI (ti mch logic). MCP41010 l bin trs10 . Khi dliu byte th hai l 255, im gia W ca bin trsi vim A v c in th bng 5V,in th li ra ny c m bi U10-LM324 (ti mch logic) tng ng vi in th caop li ra cc i l 2 kV. T 0V n 2KV c chia thnh 255 bc, mi bc ng vi8V.

KW

M ngun ng/mcao p v iu chnh cao pPrivate Sub CmdHVon-off_Click() nt lnh on/off cao pIf Command2.Caption = "OFF" ThenCommand2.Caption = "ON"Command1.Enabled = TrueIf Not MyDeviceDetected Then

MyDeviceDetected = FindTheHidEnd IfIf MyDeviceDetected Then

OutputReportData(0) = 2If HScroll1.Value


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OutputReportData(1) = 250End IfOutputReportData(2) = 255OutputReportData(3) = 255OutputReportData(4) = 255

OutputReportData(5) = 255OutputReportData(6) = 255OutputReportData(7) = 255Call ReadAndWriteToDevice

End IfLabel3.Caption = Str(8 * HScroll1.Value) + "V"

ElseCommand2.Caption = "OFF"Command1.Enabled = FalseIf Not MyDeviceDetected Then


OutputReportData(0) = 2OutputReportData(1) = 0OutputReportData(2) = 255OutputReportData(3) = 255OutputReportData(4) = 255OutputReportData(5) = 255OutputReportData(6) = 255

OutputReportData(7) = 255Call ReadAndWriteToDeviceEnd IfLabel3.Caption = "0V"

End IfEnd SubPrivate Sub HScrollHV_Change() thanh cun t cao p'High VoltageIf Not MyDeviceDetected Then

MyDeviceDetected = FindTheHid

End IfIf MyDeviceDetected ThenIf Label10.Caption = "HV ON" Then

OutputReportData(0) = 2If HScroll1.Value


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OutputReportData(6) = 255OutputReportData(7) = 255Call ReadAndWriteToDevice

ElseOutputReportData(1) = 0

OutputReportData(2) = 255OutputReportData(3) = 255OutputReportData(4) = 255OutputReportData(5) = 255OutputReportData(6) = 255OutputReportData(7) = 255Call ReadAndWriteToDevice

End IfEnd IfLabel3.Caption = Str(8 * HScroll1.Value) + "V"

End Sub

iu khin h s khuch i khi khuch i: Khi vi iu khin nhn byte thnht l s 3, byte d liu th hai vi iu khin dng iu khin bin trs U5 (ti mchkhuch i). H s khuch i ca U2 (ti mch khuch i) tnh theo cng thc sau:

18 WBV

17 WA

R RA 1

R R

+= +

+

M nguniu khin h s khuch i khi khuch i

Private Sub HScrollAmp_Change() thanh cun t h s khuch i'amplifier gainIf Not MyDeviceDetected Then


OutputReportData(0) = 4OutputReportData(1) = HScroll2.ValueOutputReportData(2) = 255OutputReportData(3) = 255OutputReportData(4) = 255OutputReportData(5) = 255OutputReportData(6) = 255OutputReportData(7) = 255

Call ReadAndWriteToDeviceEnd IfLabel4.Caption = Str(0.063 * HScroll2.Value + 26) + "db"

End Sub

5.2Gii thut hin th ph: Mt im ph tng trng bi mt im (Shape1(i)), caol hm ca sm M(i) v gi tr thanh cun Vscroll1.


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Hnh 5.1 Lu thut ton o v hin th ph.

Cc on m ngun hin th ph

Private Sub Form_Load() hin th ph lc form-loadDim i As Integer

Line4.Visible = FalseFor i = 0 To 1023

Shape1(i).Height = 40Shape1(i).Width = 40Shape1(i).Left = 400 + i * 15Shape1(i).Top = 5800

NextOption1.Value = TrueOption4.Value = TrueCommand1.Caption = "START"

Command1.Enabled = FalseTimer1.Enabled = FalseLabel10.Caption = "HV OFF"Label10.ForeColor = &H0&Image1.Left = 300Image1.Top = 4750Line2.X1 = 540Line2.X2 = 540Line2.Y1 = 5800Line2.Y2 = 5200

Image2.Left = 800Image2.Top = 4750Line1.X1 = 1040


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Line1.X2 = 1040Line1.Y1 = 5800Line1.Y2 = 5200S = 0Hr = 0

Mn = 0End Sub

Private Sub VScroll1_Change() hin th ph lc ko thanh cun tng gim chiu cao ph

If FlagInt = True Or FlagTra = True ThenLine4.Visible = FalseFlagTra = FalseFor i = 0 To 1023

Line3(i).Visible = False

NextFlagInt = False

End IfFor i = 0 To 1023Shape1(i).Top = 5800 - VScroll1.Value * M(i)

NextImage2.Top = Shape1(Vtt2).Top - 1000Line1.Y1 = Shape1(Vtt2).TopLine1.Y2 = Shape1(Vtt2).Top - 600Image1.Top = Shape1(Vtt1).Top - 1000

Line2.Y1 = Shape1(Vtt1).TopLine2.Y2 = Shape1(Vtt1).Top - 600End Sub

Private Sub Option1_Click() ty chn full scale'Full ScaleIf FlagInt = True Or FlagTra = True Then

Line4.Visible = FalseFlagTra = FalseFor i = 0 To 1023

Line3(i).Visible = FalseNextFlagInt = False

End IfFor i = 0 To 1023

Shape1(i).Left = 400 + i * 15Shape1(i).Visible = True

NextEnd Sub

Private Sub Option2_Click() ty chn low half scale'Low Half ScaleIf FlagInt = True Or FlagTra = True Then


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Line3(i).Visible = FalseNext

FlagInt = FalseEnd IfFor i = 0 To 511Shape1(i).Left = 400 + i * 30Shape1(i).Visible = TrueShape1(i + 512).Visible = False

NextEnd Sub

Private Sub Option3_Click() ty chn high half scale

'High Half ScaleIf FlagInt = True Or FlagTra = True Then


Line3(i).Visible = FalseNextFlagInt = False

End IfFor i = 512 To 1023

Shape1(i).Left = -14960 + i * 30Shape1(i).Visible = TrueShape1(i - 512).Visible = False

NextEnd Sub

Private Sub Timer1_Timer() cp nht phtempL = Re

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USB -- pIC - Tieng Viet