Languages
Pages
Legal
Ngiboco: NguynTrungChnh Tiliu: TUT02.03
Ngy: 2/9/2006 Trang: 1/17
Tutorial02.03
Gin: onHip,DonMinhng,[email protected]
Nidung: Bi2:CHNGTRNHDELAY
MICROSOFTWORD
Tmtt:Tutorialpostlnpicvietnam,topicPIC16F877ATDTIKHthuclungCBNV
VIIUKHINVPICvinidung: Vintslcvmcchvtcdngcachngtrnhdelay.- Phntchsourcecodemtschngtrnhdelay.- Tptrungphntch,khaithcchngtrnhdelaycaNigelnhmtdngchngtrnhdelay
cchunha.TutorialnysdngkhnhiucckinthctrongtutorialcaNigel.
1. Vintslcvchngtrnhdelay.1.1. Chukxungclockvchuklnh
Trongphnny tasbnnmtvikin thccsphcvchovicvitchngtrnhdelay.CthltmhiuvchukxungclockvchuklnhtrongviiukhinPIC.
Tabitviiukhinhotngccnphicungcpmtngunxungclocktbnngoi.iviviiukhinPIC,ngunxungclockcthlmtmchdaongRCngin,mtthchanh,...Ttnhin,yucucangunxungclockphilcngnnhcngtt.
Thng thng,ngunxungsdngchoviiukhinnichungvPICniring lthchanhviccuimgithnhkhngcao,khnnhvrtthuntintrongvictnh ton, thitkmchngdngvchng trnhchoviiukhin.Trongbiny, tacngsdngthchanhlmngunxungchoviiukhin.
Mithchanhcmttnsdaongcnh,tagitnslf0,thngthngf0ccctns4MHz,10MHz,20MHz,...Tytheomiloiviiukhinmyucuivif0cthkhcnhau.iviviiukhinPIC16F877A,tnsdaongf0 phinhhnhocbng20MHz,ycng l tnshotng tiamasccviiukhinPICthucdngmidrangeckhnngpngc.Chukdaongcathchanhtagilt0vctnhtheocngthc:
t0=1/f0 (1)Rtcbn!Khngcgcnchthchthmchocngthcny.
Ngiboco: NguynTrungChnh Tiliu: TUT02.03
Ngy: 2/9/2006 Trang: 2/17
Tacngbitrngchailikintrcdngtchcmtviiukhin,lkin
trcVonNeumanvkintrcHavard.ViiukhinPICctchctheolikintrcHavard.Takhngisuvocc likintrcny,mchcnbitrngvilikintrcHavard,mi lnhsc thc thixong trongmtkhong thigian lmtchuk lnh.Khongthigiannyluncnhvphthucvochukcaxungclock.
Tacmtnhnghamang tnh ...ikhinhsau:chuk lnhcaviiukhinPIClkhongthigianmviiukhinPICthcthixongmtlnh.Tagithigiancamtchuklnhlti.
thcthixongmtlnh,viiukhinPICcnn4chukxungclock.Nhvythigianthcthixongmtlnhsctnh:
ti=4t0 (2)
Thaycngthc(1)vocngthc(2)tacccngthctnhthigiancamtlnh(mtchuklnh)nhsau:
ti=4/f0 (3)
Vd:nutasdngthchanhloi4MHzththigianthcthimtlnhcaviiukhinl:
ti=4/(4106)=1sthuntinchovictnhtonvthitkchngtrnhdelay,tassdngloithch
anh4MHzchomchngdng,vnhccbnthy,thigianthcthimtlnhcaviiukhinlcdl1s.Quchn!1.2. Mcchvtcdngcachngtrnhdelay
Nhtathymc1.1,thigianthcthilnhcamtviiukhinlrtnhanhsovitccmnhnsvthintngcaconngi.iunygynhiukhkhnchovicgiaotipgiaconngivimtviiukhincngnhkhkhntrongviccmnhnbnggicquanktquccthaotccamtviiukhin.
Vdu,tadngviiukhiniukhinmtLEDchpttlintc.Vithaotcnyviiukhinchcnhaichuklnhlhonttmtchukchptt,vthigiancamichuksl2s(khisdngthchanh4MHz),vtrongmtgiy,LEDschptt500000ln.Trongkhimtngichcthnhnbitc24hnhnhtrongmtgiy.iunycnghal,mtngingoihnhtinh,viconmtctcx lhnhnhnhanhhn,khichngkinhintngtrnsnirng:Eh,ngitrit,tithyccigangchptt.Cnngitrit,vitcxlhnhnhcamtl24hnhtrong1giy,khichngkinhintngtrnsnirng:Khng,ngingoihnhtinh,tithynsnglintcch!.
Ngiboco: NguynTrungChnh Tiliu: TUT02.03
Ngy: 2/9/2006 Trang: 3/17
Nhvy, lmsaomtngicmnhncLEDangchptt,cchduynht l
phigimslnchptttrong1giynhhn24,ccthaotcviiukhinhinthchoconngithychintngtrnlnltsl:
- BtLEDsngln- ChmtchtchotikhimtnhnchnhnhLEDsng.- TtLED- ChmtchtchotikhimtnhnchnhnhLEDtt.- Lpliccthaotctrn.Nhtabit,doviiukhinkhngccilnhgilchmtcht,chonnkhi
nimchngtrnhdelaymicphtsinhthchinqutrnhch.
Cthnichngtrnhdelayngmtvaitrquantrngtrongccthaotchinth.Bncnh,chngtrnhdelaycncvaitrquantrngtrongvicgiaotipviccthitbkhc,khimtcxlcaviiukhinvccthitbkhngngnht.Ngoira,tacn sdng chng trnhdelay trongnhiu tnhhung thc t cn ra lnh chovi iukhinphich.
2. Xydngchngtrnhdelay2.1. Cclnhsdngchochngtrnhdelay
Ngoicclnhccpntrongbi1,tacnsdngthmcclnhsauchochngtrnhdelay:
LnhDECFSZ
Cphp: DECFSZ thanh_ghi,noi_den
Lnh1
Lnh2
Tcdng:Gimgitrchatrongthamsthanh_ghivsosnhvi0.
- Nugitrsaukhigimkhc0,lnh1cthcthi.
- Nugitrsaukhigimbng0,lnh1khngcthcthivcthaybnglnhNOP(khnglmgc).
Thamsnoi_dendngxcnhnilugitrthanhghithanh_ghisaukhigim.Khikhngsdng thamsnoi_den, trnhbindchsmcnh lktqucchatrongthanhghiW.
- Nuthamsnoi_denbng1,ktqucchatrongthanhghithanh_ghi.
- Nuthamsnoi_denbng0,ktqucchatrongthanhghiW.
Ngiboco: NguynTrungChnh Tiliu: TUT02.03
Ngy: 2/9/2006 Trang: 4/17
LnhRETURN
Cphp: RETURN
Tcdng: trvchngtrnhchnhtchngtrnhcon.
LnhRETLW
Cphp: RETLW tham_so (0tham_so255) Tcdng: trvchngtrnhchnhtchngtrnhconvigitrtham_so
cchatrongthanhghiW. 2.2. Thuttonchochngtrnhdelay
Tabitphn1,chngtrnhdelaylchngtrnhdngralnhchoviiukhin...chmtcht(tmthinhnghamtcch...ikhinhvy).iunycngngnghavivicralnhchoviiukhinlmmtcngvicvnghanotrongmtkhongthigiandotaquytnh.
TrongtplnhcaviiukhinPIC,taclnhNOP.Lnhnyctcdungralnhchoviiukhin ...khng lmgc,v thigian thc thi lnhnycng l1chuklnh.Nhuvy,taccnthitphixydngthuttonchochngtrnhdelay,vchcn...NOPlintclxong?Hontonkhngnginnhvy,vkhitasgpphiccvnsau:
- Thnht,cithuttoncv...khngbnhthng.
- Thhai,vit chng trnhnhvy th rtmi tay (mun ra lnh chovi iukhinch1ms,bnphivitivit lici lnhNOP ...1000 lnnusdngloithchanh4MHz).
- Thba,dunglngbnhchngtrnhbphphmmtcch...qung.
Rrngltakhngthvitchngtrnhdelaytheocch.Vvickhcphcttcccnhcimnutrncnglcctiuchtrachomtchngtrnhdelay,l:ngngonvthuntinchovicsdng.
Mtphngphpthngsdngvitccchngtrnhdelaylchoviiukhin...nhy tinhy luimyci label.Tuynhin kimsotc thigiandelaydochngtrnhtora,tacntnhtonccgitrtrongchngtrnhmtcchphhp.
Sauytasdisuvoccthuttondngvitchngtrnhdelayny.
2.2.1 Thutton1
TrongthuttonnytasdnglnhDECFSZxydngchngtrnhdelay.
onchngtrnh1:xtmtoncodenhsau
Ngiboco: NguynTrungChnh Tiliu: TUT02.03
Ngy: 2/9/2006 Trang: 5/17
MOVLW d20 ;agitr20vothanhghiW
MOVWF delayreg ;delayreg
Ngiboco: NguynTrungChnh Tiliu: TUT02.03
Ngy: 2/9/2006 Trang: 6/17
Mun to thigiandelay luhn, taphi tng s lng ccvng lp ln. on
chngtrnhsauminhhacchtngslngvnglpchochngtrnhdelay:
onchngtrnh2:
MOVLW d255 MOVWF delayreg1 ;agitr255vothanhghidelayreg1
loop DECFSZ delayreg1,1 ;gimgitrthanhghidelayreg1vsosnhvi0 ;gitrsaukhigimluvothanhghidelayreg1
GOTO loop1 ;nuchabng0nhytilabelloop1 GOTO next ;nubng0chngtrnhdelayhonttloop1
MOVLW d255 MOVWF delayreg2 ;avothanhghidelayreg2gitr255loop2 DECFSZ delayreg2,1 ;gimgitrthanhghidelayreg2vsosnhvi0 ;gitrsaukhigimluvothanhghidelayreg2
GOTO loop2 ;nuchabng0thnhynlabelloop2 GOTO loop ;nubng0thnhynlabelloopnext ; cclnhtiptheosauchngtrnhdelay
Taxtonchngtrnht labelloop1 trc.onchngtrnhnytngtnhonchng trnh1,chonncch tnh thigiandelay trongonchng trnhnykhngcgthayi.GitrNtrongcngthc4stngngvigitrN2avothanhghidelayreg2(255).TagiT2lthigiandelaydoonchngtrnhnytorathT2sctnhnhsau:
T2=3(N2+1)ti (5) Khigitrtrongthanhghidelayreg2gimv0thcclnhtlabelloopc
thcthi.thiimnygitrtrongthanhghidelayreg1sgimimtnvvtiptcthcthivnglploop1.NhvysaumtkhongthigianT2,gitritrongthanhghidelayreg1sgimimtnv,vnutagiN1lgitravothanhghidelayreg1thslngimgitrtrongthanhghidelayreg1sl(N1+1).NhvythigiandelayTdoonchngtrnh2toral:
T=(N1+1)T2=3(N1+1)(N2+1)ti (6)
Datheoccgitravotrongonchngtrnh2tacthtnhcthigiandelaydoonchngtrnhtrntoranhsau:
T=3(255+1)(255+1)ti=196608ti
Ngiboco: NguynTrungChnh Tiliu: TUT02.03
Ngy: 2/9/2006 Trang: 7/17
Nusdng loi thchanh4MHz th thigiandelaydoonchng trnh trn
toral196608s.
Nhvy,tyvothigiandelaycnthitvtyvoloithchanhsdngtrongmchmtacthaccgitrN1vN2voccthanhghidelayreg1vdelayreg2mtcchthchhpdavocngthc(6).
Vd: tnh ton ccgi tr avo thanhghidelayreg1vdelayreg2 thigiandelaydoonchngtrnh2toral90ms.Gistaangsdngloithchanh4MHz.
Tagiibitonnhsau:doloithchanhtasdngctns4MHznnti=1s.Dotac
(N1+1)(N2+1)=T/3ti=90103/(31106)=30103
Nuchngitravothanhghidelayreg2 lN2=199thgitrN1avothanhghidelayreg1sl:
N1=30103/(199+1)1=149
Mtimcnch lbncnhvicthamncngthc (6),ccgitrN1vN2phithamniukin:
0
Ngiboco: NguynTrungChnh Tiliu: TUT02.03
Ngy: 2/9/2006 Trang: 8/17
MOVWF countb ;agitr1vothanhghicountb
delay_0
DECFSZ counta,1 ;gimgitrtrongthanghicountavsosnhvi0
GOTO $+2 ;nuchabng0,nhytilnhGOTOdelay_0
DECFSZ countb,1 ;nubng0,gimgitrtrongthanhghicountb
GOTO delay_0 ;countbsaukhigimcgitrbng0nnlnhny
;khngcthcthi
DECFSZ count1,1 ;gimgitrtrongthanhghicount1
GOTO d1 ;nhyvlabeld1
;cclnhtiptheocachngtrnhchnhsauon
;chngtrnhdelay
TrctintalunlnhGOTO$+2.LnhnyctcdngnhytilnhthhaiktdnglnhGOTO$+2,tclnhynlnhGOTOdelay_0.Hontontng t tac thdng lnhccu trctng tnhynbtcdng lnhnotrongchngtrnhthngquavicthaythhngssaudu$.
Taxtoncodebtu t labeldelay_0 trc.LnhDECFSZ counta,1mtmtchuk lnh thc thi.Nugi trcha trong thanhghicountachabng0 thlnhGOTO$+2cthcthi.Lnhnymthaichuklnh.Tiptheo,lnhGOTOdelay_0cthcthi.Lnhnycngmthaichuklnh.Sau,gitrtrongthanhghicounta tip tccgim.ny tanhn thyrng,gimmtgi tr trongthanhghicounta,tamtht5chuklnh(1chuklnhcholnhDECFSZcounta,1,2chuklnhcholnhGOTO$+2v2chuklnhcholnhGOTOdelay_0),vdogitravothanhghicountal199nnthigiancnthitthanhghicountagimhtgitrv0l:
Ta=5(199+1)ti
Dotaangsdnglaithchanh4MHznnTasmanggitr1000shay1ms.
Khigitrtrongthanhghicountabng0,lnhGOTO$+2skhngcthcthimthayvollnhNOP,tiptheolnhDECFSZcountb,1scthcthi.Tathygitravothanhghicountbl1nnsaukhigimcountbsbng0nnlnhGOTOdelay_0scthaybnglnhNOPvtiptheo,lnhDECFSZcount1,1scthcthi.Sauchngtrnhquaytrvlabeld1thchinvicnpliccgitrchothanhghicounta,countbvtiptcthcthioncoedetlabeldelay_0.
Nhvyvicagitr1vothanhghicountbthcchtch lthchinqutrnhchuyntipmikhithanhghicountagimv0.Voncodetlabeldelay_0thcchtltorathigiandelaygnng1msdotabquamtschuklnh
Ngiboco: NguynTrungChnh Tiliu: TUT02.03
Ngy: 2/9/2006 Trang: 9/17
trongbcchuyntip(lumtlnnaltaangsdngloithchanh4MHz),saugitrtrongthanhghicount1cgim1nv.Vnglpctiptcchonkhigi tr trong thanhghi count1 cgimv0.Khi lnhGOTO d1khngc thc thinavqu trnh to thigiandelaykt thc,cc lnh tip theo trongchngtrnhchnhstiptccthcthi.
nytacthnhnthyrngcmi1msthgitrtrongthanhghicount1sgimi1nv.Do,muntorabtcmtthigiandelaynolbisca1ms,tachvicagitrtngngvothanhghicount1.Trongvdonchngtrnh3,dotaavothanhghicount1gitr90nnthigiandelaysl90ms.Hontontngtchovictorathigiandelay10ms,50ms,100ms,150ms,200ms,tacngddngnhnthylthigiandelaytiadoonchngtrnhtrntoral255ms.Viccthaotcthngthngdnhchoviiukhin,cthniylthigiandelaylntacthsdng.
Thutton2tuydihnvsdngnhiuthanhghihnsovithutton1nhngncnhiuuimhnthutton1dotnhlinhngvdsdngcan.Tacthsdngonchng trnhdelaynynhmtchng trnhdelaymuchovicxydngccngdngchoviiukhinPIC.
Trong trnghpsdng lai thchanhc tnscaohn, tac thkthphaithutton1v2torathigiandelaymongmun.
3. ngdngTrongccphn trn, tac thhnhdungcmcch, tcdngvmtsgii
thutchovicxydngmtchngtrnhdelay.Bygillcsdngcckinthcchoccngdngcth.
ngdng1:Ta s pht trin ng dng u tin cho chng trnh delay tmch nguyn l v
chngtrnhcxydngtrongbi1.Trongbi1,tathchinvitxutccgitr raPORTBvkim chngbng ccLEDgnvoPORTB.Bygi ta svitchngtrnhchottcccLEDgnvoPORTBchpttsaumikhongthigian100ms.
Giithutchochngtrnhchccngkhngcgphingbn,ccbcthchinlnltsl:
- BtttcccLEDPORTB
- Delay100ms
- TtttcccLEDPORTB
- Delay100ms
- Lpliccthaotctrn
Ngiboco: NguynTrungChnh Tiliu: TUT02.03
Ngy: 2/9/2006 Trang: 10/17
Chngtrnhscvitnhsau:Chngtrnh2.1:;=============================================================================
;WWW.PICVIETNAM.COM
;Laptrinh: NGUYENTRUNGCHINH
;Ngaybatdau: 23thang01nam2006
;Ngayhoanthanh: 23thang01nam2006
;Kiemtrachuongtrinh:DoanHiep,DoanMinhDang,
;Ngaykiemtra:
;SudungvidieukhienMicrochip: PIC16F877A
title chuongtrinh21.asm
processor 16f877a
include
__CONFIG _CP_OFF&_WDT_OFF&_BODEN_OFF&_PWRTE_ON&
_XT_OSC&_WRT_OFF&_LVP_OFF&_CPD_OFF
;Capnhatvabosung:
;Motachuongtrinh: ChuongtrinhdungdedieukhientatcacacLEDganvao
; PORTBchoptatlientucsaumoikhoangthoigian100ms.
; Khongsudungchuongtrinhcon
;Motaphancung: 8LEDduocganvaoPORTBthongquacacdientro,cac
; thanhphandikembaogomthachanh,machresetvanguon
;=============================================================================
;
;Khoitaocacbien
;
count1 EQU 0x20 ;cacbiendungchodoanchuongtrinhdelay
counta EQU 0x21
countb EQU 0x22
Ngiboco: NguynTrungChnh Tiliu: TUT02.03
Ngy: 2/9/2006 Trang: 11/17
;=============================================================================
;CHUONGTRINHCHINH
;=============================================================================
ORG 0x000
GOTO start
start
;
;KhoitaoPORTB
;
BCF STATUS,RP1
BSF STATUS,RP0 ;chonBANK1
CLRF TRISB ;PORTB
Ngiboco: NguynTrungChnh Tiliu: TUT02.03
Ngy: 2/9/2006 Trang: 12/17
delay_01
DECFSZ counta,1
GOTO $+2
DECFSZ countb,1
GOTO delay_01
DECFSZ count1,1
GOTO d1_1 ;hetdoanchuongtrinhdelay
CLRF PORTB ;tatcacLEDoPORTB
MOVLW d100 ;doanchuongtrinhdelay100ms
MOVWF count1
d1_2
MOVLW d199
MOVWF counta
MOVLW d1
MOVWF countb
delay_02
DECFSZ counta,1
GOTO $+2
DECFSZ countb,1
GOTO delay_02
DECFSZ count1,1
GOTO d1_2 ;hetdoanchuongtrinhdelay1ms
GOTO loop ;trovevonglapchinhcuachuongtrinh
END
Ngiboco: NguynTrungChnh Tiliu: TUT02.03
Ngy: 2/9/2006 Trang: 13/17
Vi chng trnh trn, ta c th quan st cc hin tng do vi iu khin to ra PORTBthngquaccLED.Dothigiandelay l100mschonntrong1giytrngthicaLEDsthayi10ln.iunychophptaquanstcbngmtthng.bygi,cc bn hy th gim thi gian delay xung nh dn (gim gi tr a vo thanh ghicount1),xemhintnggsxyra.Khithigiandelaygimnmtgitrno,tasccmgicrngccLEDkhngcnchpttna,mssngmtcchlintc.
Taddngnhnthymtnhcimtrongchngtrnhtrnlphivitivitlichng trnhdelay nhai ln,vmt lnna,vn vdung lngbnh chngtrnhctra.Mtgiiphpkhcphcnhcimtrn,lchngtrnhcon.
Mtchngtrnhconcthtmhiulmtoncodenoclpilplinhiulntrongchngtrnhchnh,vthayviphivitivitlioncodenhiuln,tatchconcodethnhmtchngtrnhconvgioncodetchngtrnhchnhthngqua lnhCALL.Mtchngtrnhconsbtubng1 labelvktthcbnglnhRETURNhoclnhRETLW.
C thnichng trnhcongip tacnhiuphngnhn trongvic tchcmtchngtrnhvitchoviiukhin.
Bygi, tas tchc lichng trnh2.1 thnhmtchng trnhmibngcchsdngchng trnhconcho oncode to thigiandelay100ms.Chng trnhmi scvitnhsau:
Chngtrnh2.2:
;=============================================================================
;WWW.PICVIETNAM.COM
;Laptrinh: NGUYENTRUNGCHINH
;Ngaybatdau: 23thang01nam2006
;Ngayhoanthanh: 23thang01nam2006
;Kiemtrachuongtrinh:DoanHiep,DoanMinhDang,
;Ngaykiemtra:
;SudungvidieukhienMicrochip: PIC16F877A
title chuongtrinh22.asm
processor 16f877a
include
Ngiboco: NguynTrungChnh Tiliu: TUT02.03
Ngy: 2/9/2006 Trang: 14/17
__CONFIG _CP_OFF&_WDT_OFF&_BODEN_OFF&_PWRTE_ON&
_XT_OSC&_WRT_OFF&_LVP_OFF&_CPD_OFF
;Capnhatvabosung:
;Motachuongtrinh: ChuongtrinhdungdedieukhientatcacacLEDganvao
; PORTBchoptatlientucsaumoikhoangthoigian100ms.
; Cosudungchuongtrinhcon
;Motaphancung: 8LEDduocganvaoPORTBthongquacacdientro,cac
; thanhphandikembaogomthachanh,machresetvanguon
;=============================================================================
;
;Khoitaocacbien
;
count1 EQU 0x20 ;cacbiendungchodoanchuongtrinhdelay
counta EQU 0x21
countb EQU 0x22
;=============================================================================
;CHUONGTRINHCHINH
;=============================================================================
ORG 0x000
GOTO start
start
;
;KhoitaoPORTB
;
BCF STATUS,RP1
BSF STATUS,RP0 ;chonBANK1
CLRF TRISB ;PORTB
Ngiboco: NguynTrungChnh Tiliu: TUT02.03
Ngy: 2/9/2006 Trang: 15/17
;
;Vonglapchinh
;
loop
MOVLW 0XFF
MOVWF PORTB ;battatcacacLEDoPORTB
CALL delay_100ms;goichuongtrinhcontaothoigiandelay100ms
CLRF PORTB ;tatcacLEDoPORTB
CALL delay_100ms;goichuongtrinhcontaothoigiandelay100ms
GOTO loop ;trovevonglapchinhcuachuongtrinh
;=============================================================================
;CHUONGTRINHCON
;=============================================================================
delay_100ms ;labelbatdauchuongtrinhcon
MOVLW d100 ;doancodechochuongtrinhcondelay100ms
MOVWF count1
d1
MOVLW d199
MOVWF counta
MOVLW d1
MOVWF countb
delay_0
DECFSZ counta,1
GOTO $+2
DECFSZ countb,1
GOTO delay_0
DECFSZ count1,1
GOTO d1
RETURN ;ketthucchuongtrinhcon,trovechuongtrinhchinh
END
Ngiboco: NguynTrungChnh Tiliu: TUT02.03
Ngy: 2/9/2006 Trang: 16/17
Tanhn thy rngvi cch t chc chng trnh sdng chng tnh con, chng
trnhchnhcngtrnnngngn,dhiuvrrnghnrtnhiu.
Tip theo, tas tin thmmtbcnabngcch t lmkhmnhviyucuminhsau:
ngdng2:Yucucangdngnycng tng tnhngdng1, tuynhin ta s thayi
nhiuthigiandelaykhcnhau,cthnhsau:
- BtttcccLED
- delay100ms
- TtttcccLED
- Delay200ms
Rrngltrongonchngtrnhchnh,giithutkhngcnhiukhcbit.ThayvsaukhittLED,tagichngtrnhcondelay_100msthbygisgichngtrnhcondelay_200ms(ttnhinltaphivitchngtrnhconnythmiccigi).Vnylvitnhthnochongnnht.
pngcyucucabiny, tachcn thayimtvichi titnh trongchngtrnhcondelay.Cthnhsau:
delay_100ms ;labelbatdauchuongtrinhcondelay_100ms
MOVLW d100
GOTO delay
Delay_200ms ;labelbatdauchuongtrinhcondelay_200ms
MOVLW d200
GOTO delay
delay
MOVWF count1
d1
MOVLW d199
MOVWF counta
MOVLW d1
MOVWF countb
delay_0
DECFSZ counta,1
Ngiboco: NguynTrungChnh Tiliu: TUT02.03
Ngy: 2/9/2006 Trang: 17/17
GOTO $+2
DECFSZ countb,1
GOTO delay_0
DECFSZ count1,1
GOTO d1
RETURN ;ketthucchuongtrinhcon,trovechuongtrinhchinh
Nhtabitphn2,vithutton2,munthayithigiandelaychochngtrnhdelay,tachvicthayigitravothanhghicount1.ytacnglmthaotctngt.oncodetlabeldelaycginguynkhngthayi.Khigichngtrnh con delay_100ms, gi tr 100s c a vo thanh ghiW, sau nhy ti labeldelayagitrvothanhghicount1tiptcthchinvictothigiandelay.Ccthaotcctinhnhtngtnhkhigichngtrnhcondelay_200msvlcgitrcavothanhghiWsl200.
Hontontngttacthtoramtlotnhngchngtrnhdelay1ms,2ms,5,ms,sdngmtcchddngtytheoyucuvchngtrnhdelaycangdngcth.
nyxemnhtaphttrinmtcchkhhonthinvccgiiphpchochngtnhdelay thngquavicxydngchngtrnhcondelayvhiuccchtonhiuthigiandelaykhcnhautrongcngmtchngtrnhmkhngcnphivitivitlinhiuchngtrnhdelay.
Bygillcrtramtviktluntrckhiktthcbi2vchunbchobi3.
4. KtlunChng trnhdelay ngmt vai tr kh quan trng trong vicpht trin cc ng
dngchoviiukhin.Chngtrnhdelaycsdngnhiutrongccthaotchinthvtrongccngdngcnralnhchoviiukhinphich.
Ccthuttondngxydngchngtrnhdelayphithamncctiuchngngnvthuntinchovicsdng,ngthigiptakimsotcthigiandelaydoonchngtrnhtora.
Thigiandelaydochngtrnhdelaytorasphthucvogiithutsdngchochngtrnhdelayvloithchanhsdngchoviiukhin.
Chng trnh congip ta c cnhiuphngn t chcmt chng trnh ngdngmtcchlinhhot,gngngvdhiuhn.
Htbi2!