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I HC BCH KHOA H NI

KHOA IN B MN IU KHIN T NG

THIT K H THNG X L NH S TRN NN FPGA

Nhm sinh vin thc hin: Ng Hi Bc Trung Hiu

Lp iu khin t ng 1 K48Gio vin hng dn: Ts. Lu Hng Vit

H NI - 2008

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Li cm n

Trc ht, chng em xin gi li cm n su sc n thy gio TS. Lu Hng Vit, ngi gip rt nhiu v nh hng nghin cu, thit b th nghim phc v cho nghin cu.

Chng em xin chn thnh cm n cc thy c gio ging dy chng em, c bit l cc thy c gio trong B mn iu khin t ng Khoa in, TS. Phm Ngc Nam Ph Trng b mn in t - Tin hc Khoa in t Vin Thng Trng i hc Bch Khoa H Ni to iu kin gip chng em hon thnh n tt nghip ny.

Xin chn thnh cm n Dave Vanden Bout, k s ca cng ty XESS Corporation tr li tn tnh nhng thc mc ca chng em v KIT XSA-3S1000 v XST-3.0.

V cui cng, chng em xin dnh tt c lng bit n v knh trng su sc nht ti b m chng em, nhng ngi sinh thnh, nui dng chng em nn ngi, lo lng, ch bo t nhng vic nh nht, to mi iu kin cho chng em c sng v hc tp mt cch tt nht vn ti nhng c m v hoi bo ca mnh.

Mc d rt n lc v c gng hon thnh lun vn tt nghip ny, song chc chn khng th trnh khi sai st. V vy, chng em rt mong c s ch bo ca thy c gio ti tt nghip ny hon thin hn.

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Mc lc

Li cm n.................................................................................................................................................. 2

Mc lc ....................................................................................................................................................... 3

Danh mc cc hnh v trong n tt nghip...................................................................................... 6

M u........................................................................................................................................................ 8

Phn 1 : C s l thuyt x l nh s ................................................................................................... 10

1.1. Khi qut v h thng Th gic my tnh v Cm bin th gic........................................ 10

1.3. Cc thnh phn ca h thng x l nh: ............................................................................. 16

1.3.1. Thnh phn thu thp nh, Camera v vn nh dng nh.................................. 16

1.3.2. Thnh phn x l nh .................................................................................................... 17

1.3.2.1. Cc khi nim c bn ca x l nh s ................................................................ 17

1.3.2.2. Cc thut ton x l nh s ................................................................................... 18

1.4. Mt s gii php phn cng cho h thng th gic my ................................................... 28

FPGA ................................................................................................................................................ 28

DSP Processor ................................................................................................................................. 28

Mainboard, laptop ......................................................................................................................... 29

Phn 2 : Khi qut v FPGA v mch pht trin XST 3S1000 ca XESS...................................... 31

2.1. Gii thiu chung v FPGA v ngn ng VHDL .............................................................. 31

2.1.1. Khi nim v ng dng FPGA .................................................................................... 31

2.1.2. Kin trc FPGA............................................................................................................... 32

2.1.2.1. Kin trc chung FPGA .......................................................................................... 32

Configurable Logic Blocks (CLBs)...................................................................................... 33

Configurable I/O Blocks ....................................................................................................... 34

Programmable Interconnect................................................................................................. 34

Mch ng h (Clock Circuitry )......................................................................................... 35

2.1.2.2. So snh gia cu trc nh v cu trc ln ......................................................... 36

2.1.2.3. So snh gia SDRAM Programming v Anti-fuse programming ................ 36

2.1.2.4. Cu trc FPGA ca Spartan 3............................................................................... 37

2.1.3. Trnh t thit k mt chip ............................................................................................ 38

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Ghi cc c im k thut ..................................................................................................... 39

Chn cng ngh...................................................................................................................... 40

Chn mt hng tip cn thit k ...................................................................................... 40

Chn cng c tng hp ......................................................................................................... 40

Thit k chip ........................................................................................................................... 41

M phng ci nhn tng quan v thit k ...................................................................... 41

Tng hp.................................................................................................................................. 41

Place and Route ...................................................................................................................... 41

M phng li tng quan cui cng.................................................................................. 42

Kim tra.................................................................................................................................... 42

2.1.4. Ngn ng m t phn cng VHDL............................................................................. 42

Trnh t thit k mt chp da trn VHDL........................................................................... 43

2.2. Gii thiu mch pht trin XST 3S 1000 ca hng XESS................................................ 44

2.2.1. XSA-3S1000...................................................................................................................... 45

2.2.2. XST-3.0 (XStend Board)................................................................................................. 46

2.3. Gii thiu hng Xilinx v cc cng c lp trnh: .............................................................. 49

Hng Xilinx ..................................................................................................................................... 49

ISE 9.2 ............................................................................................................................................... 49

LogicCore 9.2 ................................................................................................................................... 49

EDK 9.2............................................................................................................................................. 50

System Generator 9.2..................................................................................................................... 50

Phn 3 : Xy dng h thng x l nh ng trn nn FPGA .......................................................... 51

3.1. S cu trc h thng x l nh ng ............................................................................. 51

3.2. Xy dng h thng thu thp, lu tr, x l v hin th nh .......................................... 53

3.2.1. Thnh phn thu thp nh Framegrabber................................................................... 53

3.2.2. Lu d liu t Framegrabber vo SDRAM .............................................................. 55

3.2.3. Cc c ch ghi c SDRAM: SDRAM Controller, Dual Port SDRAM................ 55

SDRAM Controller .................................................................................................................... 55

Pipeline Read Operation ...................................................................................................... 56

Pipeline Write Operation ..................................................................................................... 56

Dualport Module for the SDRAM Controller ...................................................................... 58

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3.2.4. Image Processing core ................................................................................................... 60

3.2.5. Hin th nh ln VGA: VGA Generator .................................................................... 67

VGA Color Signals .................................................................................................................... 67

VGA Signal Timing................................................................................................................... 68

Nguyn tc hot ng ca VGA Generator .......................................................................... 69

3.2.6. Picoblaze v h thng iu khin trung tm ............................................................ 71

3.2.6.1. Khi qut PicoBlaze ............................................................................................... 71

KCPSM3 Module ................................................................................................................... 73

Kt ni vi b nh ROM chng trnh.............................................................................. 73

3.2.6.2. S cu trc ca khi x l trung tm ............................................................ 75

Thut ton ca chng trnh ................................................................................................. 75

3.3. Thit k giao din iu khin h thng............................................................................. 76

Chc nng .................................................................................................................................... 77

3.4. M phng v kt qu............................................................................................................. 77

Phng n m phng ..................................................................................................................... 77

Kt qu.............................................................................................................................................. 78

Kt lun .................................................................................................................................................... 79

Ti liu tham kho ................................................................................................................................. 82

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Danh mc cc hnh v trong n tt nghip

Hnh 1.1 Mt tay my thc hin gp i tng vi s tr gip ca h thng th gic my tnh

Hnh 1.2 Cc bc c bn ca x l nh s.Hnh 1.3 Nhng kiu lin kt gia cc im nh.Hnh 1.4 Nhng kiu ng lin kt gia cc im nh.Hnh 1.5 Kt qu ca php lc Gaussian vi ca s 3x3.Hnh 1.6 Kt qu thut ton d bin.Hnh 1.7 Phn ngng theo lc xm.Hnh 1.8 Loi b nhiu v khi phc i tng bng qu trnh lm mnh-lm y.Hnh 1.9 S thut ton gn nhn i tng.Hnh 2.1 Kin trc chung ca FPGA.Hnh 2.2 Mt Logic Block in hnh.Hnh 2.3 Configurable Logic Blocks.Hnh 2.4 Programmable Interconnect.Hnh 2.5 Cu trc cc thnh phn ca Spartan 3A.Hnh 2.6 Design Flow.Hnh 2.7 Qui trnh thit k chip da trn VHDL.Hnh 2.8 KIT XSA-3S1000.Hnh 2.9 S cu trc ca XSA-3S1000.Hnh 2.10 XST-3.0 Board.Hnh 2.11 XST-3S1000.Hnh 3.1 Mt nh cn c x l.Hnh 3.2 S chung ca h thng.Hnh 3.3 Pixel stream waveform.Hnh 3.4 Framegrabber state machine.Hnh 3.5 Pipelined Read Operation timing waveforms.Hnh 3.6 Pipelined Write Operation timing waveforms.Hnh 3.7 Ghp ni vi SDRAM Controller.Hnh 3.8 Ghp ni dualport vi SDRAM Controller.Hnh 3.9 Xy dng 4 ports SDRAM interface.Hnh 3.10 S khi x l nh.Hnh 3.11 Khi ghi d liu t read_fifo vo Buffer.

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Hnh 3.12 Khi thut ton x l nh.Hnh 3.13 C ch ghi v c buffer.Hnh 3.14 Khi c d liu t buffer.Hnh 3.15 S khi thanh ghi dch Pixel registerHnh 3.16 Cu trc nhn chp.Hnh 3.17 Cu trc b x l ng cu nh nh phn.Hnh 3.18 Khi gn nhn i tng.Hnh 3.19 VGA Connection.Hnh 3.20 8 mu c bn.Hnh 3.21 CRT Display Timing Example.Hnh 3.22 640 x 480 Mode VGA Control Timing.Hnh 3.23 S khi cu trc ca VGA Generator.Hnh 3.24 S khi cu trc ca PicoBlaze.Hnh 3.25 S cu trc PicoBlaze Microcontroller.Hnh 3.26 S khi iu khin trung tm v giao tip UART.Hnh 3.27 Giao din iu khin.

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M u

Th gic my l mt lnh vc v ang rt pht trin. Khi nim th gic

my Computer vision c lin quan ti nhiu ngnh hc v hng nghin

cu khc nhau. T nhng nm 1970 khi m nng lc tnh ton ca my tnh

ngy cng tr nn mnh m hn, cc my tnh lc ny c th x l c

nhng tp d liu ln nh cc hnh nh, cc on phim th khi nim v k

thut v th gic my ngy cng c nhc n v nghin cu nhiu hn cho

ti ngy nay.

Th gic my bao gm l thuyt v cc k thut lin quan nhm mc ch

to ra mt h thng nhn to c th tip nhn thng tin t cc hnh nh thu

c hoc cc tp d liu a chiu.

Ngy nay, ng dng ca th gic my tr nn rt rng ln v a dng,

len li vo mi lnh vc t qun s, khoa hc, v tr, cho n y hc, sn xut,

v t ng ha ta nh.

Mc ch ca n ny l nghin cu cc khi nim c bn ca Th gic

my tnh v x l nh s. ng thi trn c s , chng em xy dng mt

h thng cm bin th gic trn nn phn cng vi mch kh trnh FPGA. Cm

bin ny thc hin cc chc nng c s ca mt cm bin th gic : l tip

nhn thng tin t hnh nh thu c x l v phc v cho cc qu trnh

phn tch cao hn.

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Trong phn 1 ca n, chng em cp n nhng cc khi nim ca h

thng th gic my tnh, nhng ng dng v cc thnh phn ca n. ng

thi chng em trnh by c s kin thc x l nh s s c dng trong vic

xy dng h thng cm bin th gic.

Trong phn 2, chng em trnh by nhng khi nim c bn v chip kh

trnh FPGA, hng Xilinx v nhng cng c lp trnh v pht trin h thng

vi FPGA. Chng em cng cp n vi mch tch hp XST 3S 1000 ca

hng XESS, c s dng trong n ny.

Phn 3, chng em trnh by phng n thc thi h thng th gic my trn

nn FPGA. Vic xy dng cc thnh phn thu thp nh, lu tr nh, x l

nh v hin th nh trn mch tch hp XST 3S 1000 c cp chi tit trong

phn ny. Trong phn ny, chng em cng trnh by phng n chy m

phng kim tra hot ng ca h thng.

V cui cng, chng em tng kt nhng kt qu t c, nhng u

im, nhc im ca gii php, hiu qu ca gii php v nhng hng

pht trin.

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Phn 1 : C s l thuyt x l nh s

1.1. Khi qut v h thng Th gic my tnh v Cm bin th gic

Theo nh ngha t [1] : H thng th gic - bao gm c th gic my (machine vision) v th gic my tnh (computer vision)- l nhng h thng tip nhn thng tin t cc cm bin th gic (vision sensor) vi mc ch cho php my mc a ra nhng quyt nh thng minh.

Th gic my tnh l mt ngnh khoa hc mi pht trin. Mc d c nhng ng dng ca x l nh s trong nhng thp nin u ca th k XX vo mt s lnh vc, nhng phi n nhng nm 1970, nhng nghin cu vlnh vc ny mi c bt u khi my tnh c th qun l cc qu trnh x l mt lng ln d liu nh cc nh s.

Lnh vc nghin cu ca th gic my rt rng, v c im chung l cc bi ton v th gic my tnh u khng c mt bi chung v cch gii duy nht. Mi gii php gii quyt vn u c mt kt qu nht nh cho nhng trng hp c th. Ta c th thy s tng quan gia Computer vision vi cc lnh vc khc nh sau:

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Qua s trn, ta c th thy th gic my tnh v th gic my c lin quan n rt nhiu ngnh nh t ng iu khin, x l nh s, quang hc, sinh hc, ton hc, my hc. v Tr tu nhn to. S kt hp ca nhng ngnh ny to cho Th gic my tnh mt kh nng ng dng ht sc rng ln trong mi lnh vc ca khoa hc, sn xut v i sng. C th lit k mt s ng dng ca th gic my tnh nh sau :

iu khin tin trnh (v d: trong cc robot cng nghip, hay cc thit b, xe t hnh).

Pht hin s kin (v d: cc thit b gim st)

T ng ha ta nh.

M hnh ho i tng (v d: qu trnh kim tra trong mi trng cng nghip, x l nh trong y hc).

Tng tc (ng vai tr lm u vo cho thit b trong qu trnh tng tc gia ngi v my).

Nhn dng

Qun s.

Trong lnh vc iu khin tin trnh, th gic my tnh ng vai tr c bit quan trng nh mt cm bin v tr cho robot cng nghip hoc xe thnh.

Trong h thng my CNC, hoc cc dy chuyn cng ngh, cc cm bin th gic thu thp d liu nh v i tng cng nghip, x l v tch i tng ra khi nh. Sau khi tch i tng, h thng th gic my tnh ton cc c trng ca i tng, nh v tr, hng, gip cnh tay my ca robot cng nghip thao tc chnh xc vic gp hoc gia cng i tng.

Vi nhng h thng th gic c tch hp cc camera c phn gii ln, c lp trnh chnh xc, c th iu khin tay my thao tc vi nhng vi mch nh i hi chnh xc gn nh tuyt i.

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Hnh 1.1: Mt tay my thc hin gp i tng vi s tr gip ca h thng th gic my tnh

Cng nh vy, vi xe t hnh i trong mi trng phc tp, nhiu vt cn, h thng th gic my gip cho xe pht hin ra nhng i tng, v tr v khong cch ca chng i vi xe. Trong trng hp ny, h thng th gic my khng ch ng vai tr nh mt cm bin th gic, m cn thc hin vic v bn i tng, cho php xe t hnh chn c ng i thch hp nht.

H thng th gic my cn c ng dng trong nhng lnh vc cng nghip vi vai tr nh mt cm bin kim sot li b mt sn phm. Camera thu thp hnh nh v b mt sn phm, s truyn d liu vo cho h thng xl tm ra li trn sn phm, v tr li v kch thc li. Vi nhng h thng th gic s dng camera hng ngoi, ta cn c th o nhit sn phm v sphn b nhit trn sn phm.

Nh vy, c th ni, trong lnh vc cng nghip, th gic my v cm bin th gic c th thay th mt lng ln cc cm bin v tr thng thng, vn cn rt nhiu trong mt dy chuyn sn xut hoc CNC, gip gim thiu chi ph v cng sc lp t cm bin, v quan trng nht l to nn mt h thng x l thng nht nhng thng tin v qu trnh v i tng cng nghip.

Trong lnh vc t ng ha ta nh, h thng th gic my cng ng mt vai tr ngy cng quan trng.

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Vi s pht trin ca cc thut ton x l d liu nh, ng dng cc thnh tu mi nht ca cng ngh x l v tr tu nhn to, cc cm bin th gic ngy nay c th thc hin nhng chc nng thng minh nh m s ngi trong phng, nhn dng i tng chuyn ng, nhn dng khun mt, cnh bo s kin, nhn dng vn tay....

Cc hng nh ALTALS v SELTEC, cho ra i nhng my m sngi, da trn chui hnh nh. Bng cch quan st s di chuyn ca dng ngi v s ngi , h thng th gic my s tnh ton tc v mt dng ngi di chuyn. Bi ton ny c ng dng nhiu trong nhng khu cng cng nh nh ga, tu in ngm kim sot lu lng ngi ra vo nhm a ra nhng quyt nh iu hnh chnh xc.[2]

H thng th gic my cn c ng dng rng ri trong vic nhn dng, chun on y hc, qun s ( xc nh v tr i phng) v v tr...

Xu th pht trin ca cc cm bin ngy nay, l chnh xc cao, km vi tnh phn tn, thng minh, kh nng loi b li (fault tolerance). Cc hthng cm bin th gic ang chng t ngy cng p ng c xu th y. Cc h thng cm bin th gic ngy nay, c th thay th c mt lng ln cm bin v tr trong nhng bi ton c th, ng thi, kh nng x l thng tin khng cn n s iu khin ca b iu khin trung tm, cho php chng c th tch hp rng ri vo nhng h thng iu khin phn tn. Thm vo , cc cm bin th gic c tnh linh hot rt cao, c th ng dng trong nhiu bi ton vi nhng yu cu o c v gim st khc nhau. V cui cng, do c im hot ng ca mnh, cc cm bin th gic c th hot ng tt trong nhng mi trng khc nghit, nh nhit cao, phng x, bi, in trng, m ln...

Vi nhng l do , h thng th gic my v cm bin th gic ang ngy cng c ng dng nhiu trong nhng h thng phc tp v hin i, hot ng lin tc v i hi yu cu v chnh xc v x l thng tin cao.

1.2. Khi qut qu trnh x l nh s trong h thng th gic my tnh

H thng th gic my tnh bao gm nhiu lnh vc, trong x l nh sng mt vai tr quyt nh.

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H thng x l nh s bao gm mt phm vi rng cc kin thc v phn cng, phn mm v c s l thuyt.

Cc bc c bn ca x l nh s c m t trong s di y:

X l v nhn dng

Biu din

Tin x l

Thu nhn nh

Phn vng, phn ngng

C s kin thc

Hnh 1.2 : Cc bc c bn ca x l nh s

Thu thp nh(image acquision) : nh s c thu thp bng mt cm bin nh c kh nng bin thng tin v cng sng v mc xm ca nh thc thnh tn hiu in p di dng analog. Tn hiu ny sau c sha tr thnh tn hiu s.

Hin nay c mt s cm bin nh thc hin c vic thu nhn tn hiu vcng sng ca nh v s ha tn hiu. Trong trng hp cm bin khng c chc nng s ha th cn phi c mt b bin i nh tng t thnh nh s (video decoder). Tn hiu nh sau khi c s ha cn c m ha theo nhng chun video (video format) nht nh trc khi c a vo qu trnh lu tr v x l. Cc chun video thng gp nh IUT-R-BT 656, 601...

Tin x l nh : Sau khi nh s c thu thp di dng tn hiu s, cn phi tri qua giai on tin x l. Chc nng ch yu ca tin x l l ci thin nh, nng cao cc tnh cht ca nh gip cho cc qu trnh x l v sau

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c thun tin hn. Cc cng on c bn ca tin x l l : nng cao tng phn, lc nhiu...

Phn vng nh: Bc tip theo ca qu trnh x l l phn vng nh. nh sau khi c ci thin, s tr nn thun tin hn cho vic phn ngng v phn vng. Nhim v chnh ca phn ngng v phn vng nh l tch nh u vo thnh cc i tng, vt th ring bit. Kt qu ca qu trnh phn vng nh, ta s c mt tp hp cc im nh c lin kt vi nhau thnh cc i tng, c nh s phn bit, thun tin cho cc qu trnh x l cao hn.

u ra ca qu trnh phn vng nh l cc pixel cha c lc, bao gm lin kt ca 1 vng hoc tt c cc im nh trong vng . S liu ny cn c bin i thnh dng thch hp cho my tnh x l.

Phn tch nh: y l giai on x l bc cao trong h thng x l nh s. nh sau khi c phn vng thnh cc i tng ring bit, c nh sphn bit, s c phn tch phc v nhng mc ch khc nhau nh:

Xc nh cc c trng hnh hc ca i tng: da trn c s i tng c xc nh v phn bit, ta c th thc hin xc nh cc c trng hnh hc ca mi i tng y, nh : v tr, kch thc, hng, ... v s i tng hay mt i tng trong nh. y l cc c trng c dng nhiu trong h thng th gic my (machine vision)

Nhn dng : cc i tng c th l cc vt th c hnh dng nht nh, hoc cc k t s, ch ci, du vn tay...nh sau khi c phn vng c thc nhn dng theo nhng phng php nht nh nh phng php neural, tm ra mu hnh dng m i tng thuc v.

hng dn hot ng ca tng module x l, cn c mt h c s kin thc kim tra hot ng v tng tc gia cc module. H ny c nhim v kim sot hot ng ca tng module v sp xp trnh t hot ng ca chng trong tng thi im, gii quyt bi ton xung t.

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1.3. Cc thnh phn ca h thng x l nh:

1.3.1. Thnh phn thu thp nh, Camera v vn nh dng nh.

Gii thiu chung v camera : Trong h thng x l nh s, camera l mt thit b rt quan trng c chc nng quan st v thu nhn nh u vo ca h thng. N thng c coi l hp en trong c cc qu trnh bin i chuyn mt nh thnh dng lu tr trong my tnh. Cc bc x l ny bao gm s pht sng, thu knh, sensor, cc phn t quang in v b sho, mi thnh phn ny phi hp nhm a ra nh s cui cng. im c bit quan trng trong nhn dng nh l c tnh thi gian ca camera, v vy qu trnh x l nh c vai tr nh b ly mu trong h thng nhn dng nh.

Cm bin nhn chung gm 2 thnh phn chnh. Thnh phn th nht to ra tn hiu in u ra t l vi mc nng lng m n nhn c. Thnh phn th 2 l b s ha(digitalize) , l phn t bin i tn hiu tng tthnh tn hiu s. Ty thuc vo thnh phn s ha thc cht l b chuyn i ADC, chng ta c cc tn hiu vi s bit khc nhau: 4 bit, 8bit, 10 bit, 12 bit..., tng ng ta s c cc nh c 16, 256....mc xm khc nhau.

Trc y, ngi ta s dng cc camera da trn thit b phng tia in t, linh kin bn dn, tuy nhin nhng thit b ny thng cng knh, thiu bn vng, n nh thp. T nhng nm 1980, bt u xut hin cc sensor nh trong cc camera nh sensor CMOS, CCD. Cc sensor ny cha mt s lng phn t quang ri rc, hay cc im nh (pixel), mi phn tcha thng tin lin quan n sng chiu vo n.

phn gii ca cc sensor ph thuc vo s im nh trn n. S im nh ca cc sensor l a dng, t thp (32x32 im nh), n trung bnh (256x256 im nh) cho n cao (640x480 ) hoc cao hn na l 1280x1024 im nh.

Trong ti ny, chng em s dng loi camera AVC 301D ca hng AVTech, y l mt loi camera quan st cho nh xm, s dng sensor c phn gii tng i ln (510x482 im nh), cho ra tn hiu nh dng tng t v cn phi c s ha trc khi i vo qu trnh x l. Tn hiu nh

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tng t c s ha thnh nh s bi b video decoder TVP5150 theo chun ITU-R-BT 601.

Mi frame nh thu v c biu din di dng I(x,y) trong x,y l ta ca pixel trn frame v I l mc xm tng ng ca pixel .

Nh vy 1 frame nh thu c s c biu din di dng mt ma trn 2 chiu n x m vi n l s pixel trn 1 hng, m l s hng trong 1 frame. Trong n ny, nh thu c t camera c kch thc 510x482, tuy nhin sau qu trnh s ha theo chun ITU 601 ta c nh s 8bit vi kch thc chun l 720x525.

1.3.2. Thnh phn x l nh

1.3.2.1. Cc khi nim c bn ca x l nh s

Pixel v cc ln cn : Nh bit, mi frame nh c m t di dng ma trn 2 chiu, trong mi phn t ca ma trn tng ng vi mc xm ca 1 im nh (pixel). Mi im nh ny c cc ln cn xung quanh. Nu hin th mi pixel di dng mt vung, mi im c chung bin vi 4 im ln cn, v c chung gc vi 4 im ln cn khc.

Hai im ln cn gi l "lin kt 4" nu chng c chung bin vi nhau, v "lin kt 8" nu chung gc v chung bin vi nhau.

Hnh 1.3 : Nhng kiu lin kt gia cc im nh

ng lin kt: ng lin kt l ng ni t pixel 1, 1[ ]i j n pixel

,[ ]n ni j , qua mt chui cc pixel 1, 1[ ]i j , 2, 2[ ]i j ,... ,[ ]k ki j ..., trong mi pixel

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lin kt vi pixel trc n. Ta c ng lin kt 4 hoc lin kt 8 nu cc pixel lin kt 4 hoc 8 vi nhau

a) Lin kt 4 b) Lin kt 8

Hnh 1.4 : Nhng kiu ng lin kt gia cc im nh.

C th d dng nhn thy, nu c mt ng lin kt gia 2 im ,[ ]a ai j ,

,[ ]b bi j , v gia 2 im ,[ ]a ai j , ,[ ]c ci j th cng s c ng lin kt gia 2

im [ ]b bi j v [ ]c ci j . Lin kt c tnh tng i.

i tng v nn : nh sau khi c nh phn ha ( cc im nh ch c gi tr 0 hoc 1) s phn bit c i tng v nn. Trong ti ny, ta ginh i tng l tp hp cc im nh c lin kt vi nhau v c mc xm l 0 (en), ta k hiu l S, v nn l nhng im c mc xm 1 (trng) .

Bin: bin ca mt i tng S l tp cc im trn S v c lin kt 4 vi ~S (phn b ca S) hay nn ca nh.

Min trong ca S : l cc im thuc S nhng khng nm trn bin ca n.

1.3.2.2. Cc thut ton x l nh s

Ton t ca s (windowing operator): Trong vic thc thi cc thut ton x l nh s c bn, ngi ta thng s dng mt ton t c bit gi l ton t ca s. Ton t ca s l mt tp hp c hnh dng nht nh, gm cc pixel c lin kt vi mt pixel trung tm, l pixel ang c x l. Cc php

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ton trn cc pixel ny s c nh hng n cc pixel trung tm cng l cc pixel ang c x l trong mt thut ton x l nh.

Ton t ca s c nhiu hnh dng, ty thuc vo thut ton thc hin. Tuy nhin thng dng nht l cc ton t c dng hnh vung vi cc cnh l mt s l, v d :3x3, 5x5, 7x7...

Trong n ny, chng em s dng thng xuyn ton t ca s c dng 3x3, v y l kch thc hp l thc hin hiu qu tt c cc thut ton xl c bn v nng cao, ng thi li d thc hin v rt ngn ti a qu trnh x l. Nu s dng ca s 5x5 v 7x7, thi gian x l s tng ln rt nhiu.

Tng tng phn : nh sau khi thu c t camera, c th do stng phn nh sng km, dn n chi qu cao, kh phn bit. ci thin nh, h tr cc qu trnh x l cao hn, ta s dng cc phng php hiu chnh: hiu chnh min-max, hiu chnh histogram, hiu chnh Gamma, ...

y ta s dng phng php hiu chnh min-max v n dn u mc xm ca nh trong di cho php (khng nh hng n mc xm chung). Cng thc nng cp nh theo hiu chnh min-max:

min

max min

.256oldnewI I

II I

Trong : maxI , minI - l cc mc xm cao nht v thp nht.

newI , oldI - l mc xm sau khi hiu chnh v trc khi hiu chnh.

Sau khi hiu chnh mc xm, ta s dn mc xm ca nh ra cc gi tr cch bit nhau hn, to thut tin cho vic x l v nhn dng sau ny.

Cc thut ton nhn chp

Nhn chp (convolution) : nhn chp khng phi l mt thut ton x l nh, m l php ton thng dng trong cc thut ton x l nh s dng ton

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t ca s. Nhn chp c s dng trong cc bi ton d bin (edge detection) v lc tuyn tnh (linear filter).

Nhn chp tnh ton ra gi tr mi ca pixel trung tm ca ton t ca s, bng cch thc hin php tnh vi cc pixel ln cn v chnh pixel trung tm.

Vic thc thi php nhn chp nh sau: cho mt ca s vi pixel trung tm chy trn ton b frame nh, vi mi ca s 3x3 thu c, ta thc hin php ton :

11

1 1

( , ) ( , ). ( , )ji

n i m j

I i j c n m I n m

(1.1).

Kt qu tnh c cho ra gi tr mi ca pixel trung tm.

Trong (1.1), c(n,m) l cc phn t ca mt ma trn gi l mt n (mask). Mi thut ton x l khc nhau s dng mt mt n khc nhau tnh gi trca cc im nh.

Lc tuyn tnh, d bin: y l 2 thut ton c s s dng php nhn chp.

Lc tuyn tnh(linear filter) c tc dng ci thin nh, loi b nhiu h trcho cc qu trnh x l cao hn.

Mi b lc khc nhau s dng mt mt n khc nhau, cho hiu qu khc nhau ty vo mc ch s dng v tnh trng ca nh sau khi thu thp. V di vi nh c nhiu phn b u, ngu nhin c lp vi mi pixel, ta c ths dng mt n dnh cho lc trung bnh, mt n ny s lm gim nh hng ca nhiu i vi pixel trung tm bng cch ly trung bnh cng cc pixel ln cn trong ca s.

11 12 13

21 22 23

31 32 33

1 1 11

1 1 19

1 1 1

c c c

c c c c

c c c

Nu nh c nhiu Gaussian, ta s dng mt n

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11 12 13

21 22 23

31 32 33

1 2 11

2 4 216

1 1 1

c c c

c c c c

c c c

a) Trc khi lc b)Sau khi lc

Hnh 1.5 : Kt qu ca php lc Gaussian vi ca s 3x3

D bin : Bin ca mt i tng c xc nh ni mc xm ca cc pixel c s thay i t ngt. C nhiu cch xc nh bin, nh d bin theo gradient, d bin bng cch ly o hm bc 2 ca mc xm theo ta pixel. Hu ht cc thut ton d bin s dng nhn chp, d khng phi ltt c . Thut ton d bin m chng em s dng trong n ny l thut ton Laplacien.

Thut ton Laplacien d bin ch quan tm n s thay i t ngt ca mc xm ( ly o hm bc 2 ) m khng quan tm n hng ca bin. Thut ton ny c thc thi bng cch s dng mt n:

11 12 13

21 22 23

31 32 33

1 1 1

1 8 1

1 1 1

c c c

c c c c

c c c

cho lin kt 8

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11 12 13

21 22 23

31 32 33

0 1 0

1 4 1

0 1 0

c c c

c c c c

c c c

cho lin kt 4

a) nh gc b) Kt qu d bin

Hnh 1.6 : Kt qu thut ton d bin

Phn ngng, phn vng v nh phn ha nh s: nh sau qu trnh tin x l, nng cp, ti nhng qu trnh x l cao hn cn c nh phn ha, phn vng thnh cc i tng ring bit.

Tm ngng : y l qu trnh tm ra ngng ca mt nh thc hin vic phn vng. Ngng ng vai tr quyt nh qu trnh nh phn ha nh s c hiu qu hay khng. Nu chn ngng khng tt, s b qua mt s i tng, hoc cho i tng vi kch thc, v tr khng ng, hoc t hn l lm cc i tng khng phn bit c vi nhau.

C nhiu thut ton tm ngng, cho kt qu khc nhau : Trong in hnh l tm ngng trung bnh v tm ngng theo histogram.

Tm ngng trung bnh, ngng c tnh theo cng thc:

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1 1

1( , )

.

n m

tbi j

ng tb

I I i jn m

I I

n x m - kch thc nh

tbI , ngI , - mc xm trung bnh, gi tr ngng v s gia hiu chnh.

Tm ngng theo histogram: l phng php tm ngng da theo lc xm.

Hnh 1.7 : Phn ngng theo lc xm

Ngng tm c theo cng thc: ngI =( max1I + max2I )/2. Trong max1I

v max2I l 2 mc xm tng ng cc i trn histogram.

Phn vng v nh phn ha nh s: sau khi tm ngng, ta c th nhphn ha nh s v tch cc i tng. Trong nh xm ban u, ta coi i tng l nhng vng nh c mc xm thp, nn l vng nh c mc xm cao. Ta c th tch i tng ra bng thut ton phn ngng:

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Ta s c i tng c mu en( mc xm 1) v nn c mu trng (mc xm 0).

X l ng cu nh nh phn

nh nh phn thu c sau khi phn ngng, phn vng nh thnh cc i tng, vn c th cha hon chnh thc hin cc qu trnh phn tch tip theo. l do trn nh vn c th tn ti cc nhiu l cc chm en cha b loi b sau cc thut ton nng cp nh v lc, hoc do ngng c chn cha thc s tt tch hon ton cc i tng. gii quyt vn ny, ta s dng cc thut ton x l ng cu nh nh phn (morphological algorithms) .

C 2 phng php x l tiu biu : Thut ton lm y( dilation) v lm mnh (erosion).

2 phng php ny u s dng mt ca s- phn t cu trc(structure element) qut qua nh. Da trn vic phn tch ca s ny ta tnh ra gi trca pixel trung tm.

Lm y (dilation) ( , )I i j = 0 ch khi tt c cc pixel trong phn tcu trc c gi tr bng 0 (ca s nm hon ton bn ngoi i tng)

Lm mnh (erosion) ( , )I i j = 1 ch khi tt c cc pixel trong phn tcu trc c gi tr bng 1 ( ca s nm hon ton trong i tng )

Kt qu ca qu trnh lm mnh l nh s loi b bt c nhng nhiu nh, ng thi lm nh bt i tng, tch cc i tng gn nhau ra. khi phc i tng tr li nh c, ta dng thut ton lm y. Sau qu trnh ny cc nhiu b loi b s khng xut hin tr li. C th loi b hn cc nhiu tng i ln bng cch thc hin nhiu ln thut ton lm mnh v lm y. Tuy nhin sau hnh dng i tng khng c khi phc hon ton nh trc.

vaioUnderline

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Hnh 1.8 : Loi b nhiu v khi phc i tng bng qu trnh lm mnh-lm y.

Bi ton nh nhn i tng: vi phng php x l ng cu nh nhphn, ta c 1 nh nh phn vi cc i tng c tch ra r rt, v loi b c cc nhiu. thc hin vic xc nh cc c trng hnh hc ca i tng, phc v cho h thng nh v v nhn dng, cn phi phn bit cc i tng (cc vng nh en) vi nhau bng cch gn cho chng cc nhn khc nhau.

Thut ton gn nhn i tng cng s dng mt ca s 3x3 chy khp frame. Pixel trung tm s c kim tra gn nhn, v cc pixel ln cn c dng xc nh nhn mi cho pixel trung tm. Thut ton thc hin nh sau:

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Hnh 1.9 : S thut ton gn nhn i tng

Thut ton gn nhn i tng c thc hin nh sau: ban u ta khi to bin m i tng n_object=0. Ca s c t v tr xut pht (gc tri

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pha trn ca frame). Kim tra xem pixel trung tm c bng 0. Nu khc 0 th dch ca s. Nu bng 0, kim tra nhn ca pixel trung tm(pixel_index). Nu khc 0 th quay tr li. Nu bng 0 th kim tra nhn cc pixel ln cn (pixel_nei_index) v gn pixel_cen_index=min(pixel_nei_index). Nu pixel_cen_index khc 0 th dch ca s. Nu bng 0 th pixel l thuc i tng cha nh nhn. Ta tng bin m i tng n_object thm 1, ng thi gn pixel_cen_index = n_object. Sau quay tr li dch ca s.

Vi thut ton ny, ta s thc hin nh nhn i tng gm cc pixel c lin kt 8 vi nhau. Nhn i tng c lu vo mt phn ca thng tin vpixel cha trong RAM.

Cc c trng hnh hc ca i tng

Sau khi nh c phn vng v nh nhn thnh cng, ta thc hin vic xc nh cc c trng ca i tng.

Cc c trng hnh hc ca i tng cn c xc nh bao gm :

-Din tch: bng s pixel ca i tng :

1 1

( , )n m

i j

A I i j

trong ( , )I i j =1 hoc 0;

-Chu vi i tng: bng s pixel nm trn bin i tng.

-V tr (ta ) ca i tng, cng l ta trng tm vt th,c tnh theo cng thc :

1 1

1 1

1. ( , );

1. ( , );

n m

i j

n n

i j

x i I i jA

y j I i jA

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1.4. Mt s gii php phn cng cho h thng th gic my

C th thy, cc thut ton x l nh s trong h thng th gic my u

tng i phc tp, vi khi lng tnh ton rt ln (hng trm ngn pixel).

Do , tha mn yu cu v tc v hiu sut x l, i hi nhng nn

phn cng mnh vi kh nng x l v tnh thi gian thc cao.

Di y l mt s gii php phn cng thng c s dng cho mt h

thng x l nh s.

FPGA

y l gii php v phn cng m hay c s dng hin nay. Tn dng

c tnh ca FPGA l linh hot v tc x l nhanh (cng ho cc gii

thut), c bit vi kh nng x l song song, FPGA rt ph hp vi cc bi

ton x l nh i hi mt khi lng tnh ton phc tp.

DSP Processor

DSP Processor c gii thiu u tin vo nhng nm 1978, 1979 bi

Intel, Bell Labs. Cc b x l DSP c nhng c tnh ni bt nh sau:

Thch hp cho cc qu trnh cn x l theo thi gian thc

Hiu nng c ti u vi d liu dng lung

Chng trnh v d liu c b ch ring bit (kin trc Harvard)

Tch hp cc ch th lnh c bit SIMD (Single Instruction, Multiple

Data)

Khng h tr a nhim

Tng tc trc tip vi b nh ca thit b

Tch hp sn ADC v DAC

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DSP Processor ngy nay c tch hp nhiu thnh phn khc nhau,

lm tng kh nng linh hot v tc x l. c bit cc DSP Processor rt

thch hp cho nhng nhu cu cn tnh ton nhanh, x l s thc. c bit mt

s cn c sn nhng ch th lnh gip cho vic tnh ton ma trn, tch chp

hay thm ch cc php bin i DCT trong qu tnh nn nh. Vi nhng u

im DSP Processor c dng trong nhiu thit b x l nh chuyn

nghip.

Mainboard, laptop

y l mt trong nhng phng php n gin nht. C th tn dng cc

mainboard my tnh hay thm ch cc my tnh xch tay vi chc nng l mt

n v x l nh, v a ra quyt nh. Vi vic kt ni mt camera hay

webcam ta hon ton ch ng trong qu trnh nhn/x l nh. Cc giao tip

ngoi vi ph bin nh UART, Parallel, USB hay Keyboard.

Vic s dng mainboard, laptop s c nhng u/ nhc im sau:

u im

C tc x l cao

D dng lp trnh, kim li

H iu hnh quen thuc (windows/linux)

Cc cng c lp trnh/bin dch ph bin (MSVC, gcc)

Nhc im

Kch thc, khi lng ln

D h hng do va p hay cc tc nhn khc

Gi thnh rt t (>600$)

C qu nhiu thnh phn khng s dng n

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Ch c th giao tip vi ngoi vi thng qua cc chun ph bin nh

UART, USB

Ngoi cc gii php trn, cn nhiu nhng gii php phn cng khc cho

mt h thng x l nh s nh : Main cng nghip, Single Board

Computer(SBC) s dng Single on Chip (SoC)....

Trong n ny, chng em s dng gii php l vi mch kh trnh FPGA

xy dng ton b h thng x l nh v iu khin trung tm. Mc ch

ca ti l xy dng mt h thng x l nh trn nn FPGA, trong thc

hin c mt s thut ton c bn nh lc, phn ngng, phn vng, x l

ng cu nh nh phn, nh nhn i tng v cui cng l tnh ton cc

c trng ca i tng. (v tr, din tch...)

H thng c xy dng vi mc ch th nghim nhng thut ton x

l nh s c nghin cu, s dng cng ngh FPGA, ng thi to nn

tng cho h thng th gic my tnh vi nhng thut ton x l cao hn.

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Phn 2 : Khi qut v FPGA v mch pht trin XST 3S1000 ca XESS

2.1. Gii thiu chung v FPGA v ngn ng VHDL

2.1.1. Khi nim v ng dng FPGA

Khi nim

FPGA (Field Programable Gate Arrays) l mt thit b bn dn bao gm cc khi logic lp trnh c gi l "Logic Block", v cc kt ni kh trnh. Cc khi logic c th c lp trnh thc hin cc chc nng ca cc khi logic c bn nh AND, XOR, hoc cc chc nng kt hp phc tp hn nh decoder hoc cc php tnh ton hc. Trong hu ht cc kin trc FPGA, cc khi logic cng bao gm c cc phn t nh. c th l cc Flip-Flop hoc nhng b nh hon chnh hn.

Cc kt ni kh trnh cho php cc khi logic c th ni vi nhau theo thit k ca ngi xy dng h thng, ging nh mt bng mch kh trnh.

Mt kin trc khc tng t nhng n gin hn FPGA, l CPLD ( Complex Programable Logic Device ). Thc cht y l tin thn ca FPGA. Nm 1984, Ross Freeman, mt ng sng lp ca Xilinx pht minh ra FPGA. FPGA v CPLC u bao gm mt s lng kh ln cc phn t logic kh trnh. Mt cng logic (Logic Gate) ca CPLD nm trong khon t vi nghn cho n 10 nghn cng. Trong khi FPGA thng thng cha t 10 nghn cho n vi triu cng.

Khc bit c bn gia FPGA v CPLD l kin trc ca chng. CPLD c mt kin trc b gii hn trong mt hoc mt vi dy logic kh trnh cng vi mt lng nh thanh ghi nh thi. Do n km linh hot hn, nhng li c u im l kh nng d on tr ln hn v t l logic-kt ni cao hn.

Ngc li, trong kin trc ca FPGA li c s tri hn v s lng kt ni. iu ny lm cho n tr nn linh hot hn ( v s lng thit k c thc

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thi bn trong) nhng cng ng ngha vi vic phc tp hn trong qu trnh thit k.

Mt khc bit ng ch na gia FPGA v CPLD l : hu ht cc FPGA hin nay u bao c cc phn t chc nng tch hp cao hn ( nh b cng, nhn tch hp) , v b nh tch hp.

Mt s kin trc FPGA hin nay cn c th cho php cu hnh li tng phn (partial re-configuration). C ngha l cho php mt phn ca thit kc cu hnh li trong khi nhng thit k khc vn tip tc hot ng.

Mt u im khc ca FPGA, l ngi thit k c th tch hp vo cc b x l mm (soft processor) hay vi x l tch hp (embedded processor). Cc vi x l ny c th c thit k nh cc khi logic thng thng, m m ngun do cc hng cung cp, thc thi cc lnh theo chng trnh c np ring bit, v c cc ngoi vi c thit k linh ng ( khi giao tip UART, vo/ra a chc nng GPIO, ethernet...). Cc vi x l ny cng c th c lp trnh li (re-configurable computing) ngay trong khi ang chy.

ng dng.

FPGA c ng dng in hnh trong cc lnh vc nh: x l tn hiu s, x l nh, th gic my, nhn dng ging ni, m ha, m phng (emulation)...FPGA c bit mnh trong cc lnh vc hoc ng dng m kin trc ca n yu cu mt lng rt ln x l song song, c bit l m ha v gii m. FPGA cng c s dng trong nhng ng dng cn thc thi cc thut ton nh FFT, nhn chp (convolution), thay th cho vi x l.

Hin nay cng ngh FPGA ang c sn xut v h tr phn mm bi cc hng nh :Xilinx, Altera, Actel, Atmel... Trong Xilinx v Altera l 2 hng hng u. Xilinx cung cp phn mm min ph trn nn Windows, Linux, trong khi Altera cung cp nhng cng c min ph trn nn Windows, Linux v Solaris.

2.1.2. Kin trc FPGA

2.1.2.1. Kin trc chung FPGA

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Hnh 2.1 : Kin trc chung ca FPGA

Mi nh sn xut FPGA c ring cu trc FPGA, nhng nhn chung cu trc c th hin ging nh trong hnh bn trn. Cu trc FPGA bao gm c configuration logic blocks (CLBs), configurable I/O blocks (IOB), v programmable interconnect. V tt nhin, chng c mch clock truyn tn hiu clock ti cc logic block, v thm vo c cc logic resources nh ALUs, memory v c th c c decoders. Cc phn t lp trnh c ca FPGA c 2 dng c bn l cc RAM tnh (Static RAM) v anti-fuses.

Configurable Logic Blocks (CLBs)

Configurable Logic Blocks (CLBs) bao gm cc Look-Up Tables (LUTs) rt linh ng c chc nng thc thi cc logic v cc phn t nh dng nh l cc flip-flop hoc cc cht (latch). CLB thc hin phn ln cc chc nng logic nh l lu tr d liu,..

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Hnh 2.2 : Mt Logic Block in hnh

Configurable I/O Blocks

Input/Output Blocks (IOBs) iu khin dng d liu gia cc chn vo ra I/O v cc logic bn trong ca FPGA. N bao gm c cc b m vo v ra vi 3 trng thi v iu khin ng ra dng open collector. Phn ln l c trko ln ng ra v thnh thong li c tr ko xung.IOBs h tr lung dliu 2 chiu (bidirectional data flow) v hot ng logic 3 trng thi (3 state). H tr phn ln cc chun tn hiu, bao gm mt vi chun tc cao, nh Double Data-Rate (DDR).

Hnh 2.3 : Configurable Logic Blocks

Programmable Interconnect

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Interconnect FPGA khc xa so vi CPLD, tuy nhin li ging vi ca gate array ASIC. C mt line di c dng ni cc CLBs quan trng m chng li cch xa nhau m khng gy ra qu nhiu tr. Chng c th c dng nh l cc bus trong chip. C cc line ngn c dng lin kt cc CLBs ring r nhng t gn nhau. V cng thng c vi ma trn chuyn i (switch matrices), ging nh trong CPLD, ni gia cc line di v ngn li vi nhau theo mt s cch c bit. Cc chuyn i lp trnh c (Programmable switches) bn trong chip cho php kt ni gia CLBs ti cc interconnect line v gia interconnect line vi cc line khc v vi switch matrix. Cc b m 3 trng thi c dng kt ni phn ln cc CLBs vi cc line di (long line), to nn cc bus. Cc long line c bit, gi l cc line clock ton cc (global clock lines), c thit k c bit cho tr khng thp v nh m thi gian lan truyn nhanh hn. Chng c kt ni vi cc bm clock v vi mi phn t c clock trong mi CLB. l cch m clock c th phn phi bn trong FPGA.

Hnh 2.4 : Programmable Interconnect

Mch ng h (Clock Circuitry )

Cc khi vo ra vi b m clock high drive gi l cc clock driver,nm ri rc xung quanh chip. Cc b m ny c ni vi cc chn clock vo v li

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cc tn hiu clock vo cc ng clock ton cc (global clock line) nh m t bn trn. Cc ng clock c thit k sao cho thi gian thi gian lch nhnht v thi gian lan truyn nhanh. Thit k ng b l yu cu bt buc vi FPGA, t khi lch tuyt i v tr khng c bo m. Ch khi dng cc tn hiu clock t cc b m clock th thi gian tr tng i v thi gian lchmi c m bo.

2.1.2.2. So snh gia cu trc nh v cu trc ln

FPGA c cu trc nh ging nh cc mng cng ca h ASIC vi cc CLBs ch bao gm cc phn t c bn rt nh nh cc cng NAND, cng NOR, Cc nh l lun cho rng cc phn t nh c th ni vi nhau to ln cc chc nng ln hn m khng tn nhiu cc phn t logic. Trong cc FPGA c cu trc ln, cc CLB c th bao gm 2 hoc nhiu flip-flop, cc thit k m khng cn nhiu flip-flop s khin cho nhiu flip-flop khng c dng n. Tic rng, cc cu trc nh li yu cu kh nhiu ngun kt ni (routing resource), dn n tng khng gian v thm vo mt lng ln tr m khng th b li c hiu qu hn.

2.1.2.3. So snh gia SDRAM Programming v Anti-fuse programming

C 2 cch lp trnh FPGA. Cch u tin l SDRAM Programming, bao gm mt vi bit Static RAM cho mi phn t lp trnh. Ghi mt bit vi gi tr0 s ngt switch, trong khi ghi gi tr 1 s ng switch. Cch cn li l anti-fuse bao gm cc cu trc rt nh, khng ging nh cc cu ch thng thng, bnh thng chng khng to ra mt kt ni no c. Mt dng in c cng nht nh trong khi lp trnh thit b s dn n vic hai bn ca anti-fuse kt ni vi nhau.

Thun li ca cu trc FPGA da trn SRAM l chng dng mt qu trnh sn xut chun m cc k hoch sn xut chip l gn nh ging nhau v lun lun c ti u cho kh nng hot ng. T khi m SRAM c th lp trnh li c th FPGA c th lp trnh li bt c khi no mun, thn ch ngay c khi chng ang trong h thng, n gin nh l ghi vo SRAM thng thng. Chng c nhc im l vng nh volatile nn mt vn v

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ngun c th thay i ni dung ca RAM. Cc thit b da trn SDRAM cng c thi gian tr ng truyn ln.

Thun li ca cu trc FPGA da trn anti-fuse l chng l non-volatile v cc tr khi ni dy s rt nh v th nn chng c khuynh hng nhanh hn. Nhc im l chng yu cu mt b lp trnh bn ngoi lp trnh v mi khi lp trnh xong th khng th thay i c.

2.1.2.4. Cu trc FPGA ca Spartan 3

Cu trc tng quan ca Spartan 3 gm c 5 thnh phn c chc nng khtrnh c bn sau:

Configurable Logic Blocks (CLBs) bao gm cc Look-Up Tables (LUTs) rt linh ng c chc nng thc thi cc logic v cc phn t nh dng nh l cc flip-flop hoc cc cht (latch). CLB thc hin phn ln cc chc nng logic nh l lu tr d liu,..

Input/Output Blocks (IOBs) iu khin dng d liu gia cc chn vo ra I/O v cc logic bn trong ca FPGA. IOBs h tr lung d liu 2 chiu (bidirectional data flow) v hot ng logic 3 trng thi (3 state). H tr phn ln cc chun tn hiu, bao gm mt vi chun tc cao, nh Double Data-Rate (DDR).

Block RAM cho php lu tr d liu di dng cc khi (block) dual-port 18-Kbit.

Multiplier Blocks cho php 2 s nh phn 18bit lm u vo v d dng tnh ton tch ca chng.

Digital Clock Manager (DCM) Blocks cung cp kh nng t xc nh xung clock, l gii php s hon chnh cho cc tn hiu clock phn phi, tr, nhn, chia v dch bit.

Cc phn t ny c t chc nh trong hnh sau:

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.

Hnh 2.5 : Cu trc cc thnh phn ca Spartan 3A

T hnh v ta thy, cc IOBs bao quanh cc mng CLBs, ring Spartan-3E ch c mt vng cc IOBs. Mi ct block RAM bao gm mt vi block RAM 18-Kbit, mi block RAM li gn lin vi mt multiplier dnh ring. Cc DCM c t cc v tr: 2 DCM pha trn v 2 ci pha di ca thit b, v i vi cc device ln hn th c thm cc DCM pha bn cnh.

c im chung mng Spartan-3 l kt ni lin thng gia 5 phn t c bn ny, v truyn tn hiu gia chng. Mi thnh phn chc nng ny c mt switch matrix dnh ring cho php chn la kt ni cho vic i dy trong FPGA.

2.1.3. Trnh t thit k mt chip

Trnh t thit k mt h thng trn nn FPGA bao gm cc bc sau:

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Hnh 2.6. Design Flow

Ghi cc c im k thut

Tm quan trng ca cc c im k thut (specification) khng th phng i qu. N ch tuyt i cn c bit khi l mt hng dn chn cng ngh ph hp v to nhng yu cu ca bn cho cc nh sn xut chip. V cc c im k thut cho php mi k s hiu v thit k h thng chung v cng vic ca h trong h thng l g. V n cng cho php cc k s thit k giao din ng cho mt lot cc phn ca chip. Cc c im k thut cng gip tit kim thi gian v s hiu lm. S khng lm g c nu khng c cc bng ghi cc c im k thut.

Chi tit k thut nn bao gm cc thng tin sau y:

S khi bn ngoi ch ra chip c t vo trong h thng nh th no.

S khi bn trong ch r mi chc nng ca cc thnh phn.

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Miu t cc chn vo ra bao gm kh nng li u ra, mc ngng u vo.

Thi gian c lng bao gm thi gian thit lp v gi cc chn vo, thi gian lan truyn ra cc cng ra v thi gian chu k clock.

m xp x s gate Dng ng gi Tiu th ngun Gi c Cc th tc kim tra

Mt iu rt quan trng na l l cc ti liu trc tuyn. Rt nhiu phn s c d on tt nht trong , nhng s thay i trong qu trnh chip c thit k.

Chn cng ngh

Mi khi mt chi tit miu t k thut c xut bn, n c th c dng chn nh sn xut chip tt nht vi cng ngh v cu trc gi c l tt nht p ng c yu cu ca bn.

Chn mt hng tip cn thit k

Ti thi im ny bn phi quyt nh cch thc hin thit k m bn mong mun. i vi cc chip nh th cch tip cn bng s nguyn l (schematic) thng c chn, c bit l khi cc k s thit k quen thuc vi cc cng c ny. Th nhng i vi cc thit k ln hn, ngun ng miu t phn cng (hardware description language) HDL nh Verilog v VHDL c dng bi kh nng mm do, d c, d chuyn giao. Khi dng ngn ng cp cao, phn mm tng hp (synthesis software) s c yu cu tng hp (synthesize) thit k. C ngha rng phn mm ny s to ra cc cng cp thp t miu t cp cao hn.

Chn cng c tng hp

Ti im ny, bn phi quyt nh chn phn mm tng hp no s c dng nu bn c k hoch thit k FPGA vi HDL. iu rt quan trng k

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t khi mi cng c tng hp c khuyn dng v s y thc ca cch thit k phn cng nn n c th hot ng tng hp ng hn.

Thit k chip

C mt s cch thit k chip

Top-down design (Thit k t trn xung di) Macros Synchronous design Protect against metastability Avoid floating nodes Avoid bus contention

M phng ci nhn tng quan v thit k

M phng l mt qu trnh lin tc khi m thit k xong. Tng phn nhca thit k nn c m phng trc khi kt hp chng thnh cc phn ln hn. iu ny rt l cn thit v s m phng theo th t s kim tra chc nng hot ng ng ca tng phn.

Mi khi thit k v m phng hon thnh, dn n mt ci nhn tng quan khc v thit k v th thit k c th c kim tra li. Tht l quan trng nhn cc kt qu khc cho php nhn qua cc m phng v chc chn rng khng c iu g b qun v khng s tn hao no gp phi. l mt trong nhng khi qut quan trng nht bi v khi m phng ng v thnh cng th bn s bit c chip ca bn s hot ng ng trong h thng.

Tng hp

Nu thit k dng HDL, bc tip theo l tng hp chip, bao gm vic dng phn mm tng hp chuyn i tht ti u t thit k mc RTL (register transfer level) sang thit k mc gate m c th gn vo cc khi logic trong FPGA.

Place and Route

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Bc tip theo l sp t chip, kt qu trong vic thit k vt l cho chip thc. iu ny bao gm cc cng c ca nh sn xut ti u lp trnh cho chip thc hin thit k. Sau , thit k c lp trnh vo cho chip.

M phng li tng quan cui cng

Sau khi sp t xong, th chip phi c m phng li vi cc con s vthi gian to ra bi cc layout thc t. Nu mi th u tt n thi im ny, th mt kt qu m phng mi s ng vi cc kt qu d on.

Kim tra

i vi cc thit b lp trnh c, n gin l lp trnh thit b v ngay lp tc c mu th. Sau bn c trch nhim t mu th ny vo trong hthng v xem xem h thng c lm vic ng khng. Nu bn lm ln lt cc bc bn trn th a phn l h thng s hot ng ng ch vi mt vi li rt nh. Cc li ny thng c lm vic xung quanh vi vic thay i h thng v thay i phn mm h thng. Cc li ny cn c kim tra v trch dn li c th c sa cha trong phin bn tip theo ca chip. Kim tra h thng nhng l cn thit ti thi im ny a ra kt qu rng mi phn ca h thng u hot ng ng khi kt hp vi nhau.

Khi cc chp c a vo sn xut, rt cn thit c mt vi kim tra c mt vi kim tra burn-in trong h thng test thng xuyn h thng qua thi gian di. Nu mt chip c thit k ng, th n ch b hng khi li in hc hoc li c hc s thng xuyn xy ra vi loi kim tra khc nghit ny.

2.1.4. Ngn ng m t phn cng VHDL

VHDL l mt ngn ng m t phn cng (hardware description language), m t hnh vi ca mch in hoc h thng, t mch in vt l hoc h thng c th c thc thi.

VHDL l vit tt ca VHSIC Hardware Description Language. Bn thn VHSIC l vit tt ca Very High Speed Integrated Circuits (mch tch hp tc cao), ln u tin c sng lp bi United State Department of Defensetrong nhng nm 80, sau to ra VHDL. Phin bn u tin l VHDL 87,

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ln nng cp sau c tn l VHDL 93. VHDL l ngn ng m t phn cng nguyn gc u tin c chun ha bi Institue of Electrical and Electronics Engineers (IEEE), ti chun IEEE 1076. Trong IEEE 1164, c mt chun c thm vo l gii thiu h thng logic a gi tr (multi-valued logic system).

ng c thc y c bn khi dng VHDL (hay dng Verilog) l VHDL l mt ngn ng c lp chun ca cc nh cng ngh, cc nh phn phi do chng c kh nng portable v k tha cao (reusable). Hai ng dng trc tip chnh ca VHDL l trong mng cc thit b logic lp trnh c ( Programmable Logic Devices) (bao gm CPLDs Complex Programmable Logic Devices v FPGAs Field Programmable Gate Arrays). Mi khi m ngun VHDL c vit, chng c th c dng thc thi mch in trong cc thit b lp trnh c (t Altera, Xilinx, Almel, ..) hoc c th gi n cc xng ch to cc chp ASIC. Hin ny, rt nhiu cc chip thng mi phc tp (v d nh cc microcontrollers ) c thit k da trn cch tip cn ny.

Mt iu ch v VHDL l tri ngc vi cc chng trnh my tnh thng thng c thc hin tun t th cc cu lnh c thc hin song song (concurrent). V l do , nn VHDL thng c coi l mt m ngun hn l mt chng trnh. Trong VHDL ch c cc cu lnh t trong PROCESS, FUNCTION, hay PROCEDURE c thc thi tun t.

Trnh t thit k mt chp da trn VHDL

Mt trong nhng tin ch ln ca VHDL l cho php tng hp mch in hoc h thng trong thit b kh lp trnh (programmable devide) (PLD hoc FPGA) hoc trong mt h ASIC. Cc bc thc hin mt project c tng kt nh trong hnh di:

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Hnh 2.7: Qui trnh thit k chip da trn VHDL

Chng ta bt u thit k bng cch vit m VHDL, c ghi trong cc file vi ui m rng .vhd v tn ging nh tn ca ENTITY (thc th). Bc u tin trong qu trnh synthesis l bin dch. Bin dch l mt qu trnh chuyn i gia ngn ng VHDL bc cao ti Register Transfer Level (RTL)sang netlist mc gate level. Bc th 2 l ti u thc hin trn gate level netlist ti u v tc hoc cho din tch. Cui cng l mt phn mm place and route s to ra mt physical layout cho cc chp PLD/FPGA hoc to ra cc mt n cho mt h ASIC.

2.2. Gii thiu mch pht trin XST 3S 1000 ca hng XESS

Trang ch ca XESS Corp. : http://www.xess.com

X Engineering Software Systems Corporation (XESS) l cng ty ti pha Bc Carolina (M) c thnh lp t nm 1990. XESS Corp. a ra nhng cng c pht trin logic lp trnh c vi gi phi chng v cc hng dn cho ngi dng c vit bi cc k s, cc nh nghin cu, nh thit k v ngay c ca sinh vin.

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XESS gii thiu 2 board chuyn dng cho x l nh v audio:

2.2.1. XSA-3S1000

Hnh 2.8 : KIT XSA-3S1000

KIT FPGA ny bao gm c 32 Mbyte DRAM ng b v 2 Mbyte Flash xy dng h thng vi iu khin RISC hon thin da trn phn mm (soft-core).

C th c ti 4 bitstream c lu tr trong Flash v ta c th dng switch la chn bitstream no c cu hnh cho FPGA khi p t ngun in vo KIT. Hoc chng ta c th download trc tip vo FPGA nh cng song song (parallel port) dng cng c XSTOOLS ( trong b cng c ca XESS). Giao din CPLD trn XSA-3S1000 cng h tr download dng XILINX iMPACT v circuit test/debug vi ChipScope dng cp download song song ca Xilinx.

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B sung thm vo cc chip FPGA, SDRAM v Flash, c thm cng VGA c th hin th ha vi 512 mu. Thm vo , cn c thm prototyping header a cho ta 65 chn I/O xy dng cc giao din vi cc ngoi vi khc.

Hnh 2.9. S cu trc ca XSA-3S1000

2.2.2. XST-3.0 (XStend Board)

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Hnh 2.10 : XST-3.0 Board

Xstend Board l mch h tr cho XSA Board c th truy nhp qua giao din prototype. Bo mch ny m rng kh nng ca XSA Board trn mt smt:

Cc pushbuttons, DIP switches, LEDs, v protopying area rt c ch cho cc th nghim phng Lab.

Mch stereo v dual-chanel analog I/O dng cho x l m thanh kt hp vi cc thnh phn DSP c synthesize vi phn mm CORE generation ca Xilinx.

Video decoder (b gii m video) cho php s ha cc video dng NTSC/PAL/SECAM trong cc ng dng x l nh.

Giao din Ethernet 10/100 lm cho XSA Board c kh nng truy nhp TCP/IP v cc dng mng khc.

Giao din USB 1.1 lm cho XSA Board nh mt ngoi vi USB dng low-speed hoc full-speed vi PC.

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Giao din RS-232 rt hu ch khi XSA Board cn phi gi thng tin qua lin kt giao tip ni tip vi tc thp.

Giao din IDE cung cp cho XSA Board kh nng truy cp vo a cng (hard disk) lu v phc hi d liu.

Cc module vi chc nng khc c th thm vo trong XST Board nhcc doughterboard connector.

Nh vy, kt hp gia XSA-3S1000 v XST-3.0 cho ta mt Board ng dng x l video rt hiu qu.

Hnh 2.11 : XST-3S1000

H tr k thut: XESS c mt group xsboard-user l mt mailing list, gii p mi thc mc v thit k phn cng v h thng phn mm khi dng bo mch logic kh trnh ca XESS Corp. Ngoi ra, cc phn mm v module pht trin kh y .

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2.3. Gii thiu hng Xilinx v cc cng c lp trnh:

Hng Xilinx

Xilinx l nh pht trin hng u hin nay trong lnh vc chip kh trnh. c thnh lp bi Ross Freeman, Bernie Vonderschmitt, v Jim Barnett, v c tr s ti thung lng Silicon. Tr s chnh hin nay San Jose , California. L thnh vin ca nhm 100 cng ti hng u th gii hin nay do tp ch Fortune bnh chn.

Xilinx l nh pht trin FPGA, CPLD c s dng rng ri trong nhng ng dng truyn thng, t ng ha, mt m...v cc lnh vc khc. Cc sn phm phn cng ca Xilin gm c cc dng CPLD : CoolRunner, cc hFPGA nh Spartans, Virtex...

Xilinx cn cung cp cc phn mm h tr lp trnh FPGA, CPLD nh ISE, EDK, LogicCore, System Generator. Cc cng c ny h tr rt nhiu cho qu trnh lp trnh FPGA, gip gim thi gian v cng sc thit k. Cc phin bn phn mm trn c nng cp thng xuyn. (Hin gi c phin bn 10.1 cho cc ng dng).

ISE 9.2

L cng c xy dng v lp trnh FPGA. ISE 9.2 thc s l mt mi trng tng hp v thc thi ton din cho cc chip kh trnh ca Xilinx. Vi ISE9.2, ngi thit k c th lp trnh, g ri, m phng, dch v np chng trnh mt cch nhanh chng v d dng. Ngi thit k cng c th thit k hthng ca mnh theo nhiu cch khc nhau : vi m vhd, vi s RTL, hoc vi s trng thi (state machine)

LogicCore 9.2

LogicCore 9.2 l th vin ca ISE 9.2, trong cha cc m ngun cho cc khi logic c th c s dng cho vic xy dng nhng h thng khc nhau. Vi Logic Core, ngi thit k c th gim i rt nhiu cng sc thit k, bqua vic xy dng nhng thnh phn c sn v tp trung vo vic xy dng h thng, ng thi cng ti u ha cc thit k ca mnh.

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EDK 9.2

L cng c xy dng h thng c cc vi x l nhng trong FPGA nh MicroBlaze (cho tt c cc h FPGA ) v Power PC ( ch cho h Virtex).

EDK 9.2 khng ch gip to ra cc vi x l nhng m cn h tr thit kcc ngoi vi, giao din cho chng, vi mt th vin ngoi vi s, cho php vi x l thc thi bt c mt nhim v no m cc vi x l thng thng c th thc hin c : nh giao tip UART, Ethernet, cc b nh RAM, ROM, cc I/O,....Cc thit k vi x l nhng cng c ti u ha. Ngoi ra EDK cng c cng c m phng rt mnh.

System Generator 9.2

System Generator (sysgen)l cng c pht trin h thng cho FPGA, cho php thit k h thng dng cc khi, v h tr m phng, debug, to code np vo FPGA hoc kt hp vo nhng ng dng ln hn.

Sysgen c xy dng nh mt Block Set ca Simulink trong Matlab. Do , sysgen tha hng tt c cc u im ca Simulink trong vic xy dng h thng v m phng. Sysgen cn s dng th vin ca Logic Core xy dng cc block ca mnh. Trong th vin ca Sysgen c tt c cc khi thc hin cc chc nng t c bn nh cng, tr, nhn, cc khi logic,...cho n nhng thit k phc tp hn nh cc DSPs, b lc s, nhn chp, UART..., cc b nh tch hp: Single Port, DualPort Ram, FIFOs, cc thanh ghi...

Sysgen cn cho php ngi thit k to ra cc khi thc hin nhng nhim v ring bng khi Black Box, ti y ngi thit k s to ra cc entity v ci m ca n vo Black Box to ra cc thit k ring ca mnh.

Nhng thit k ca Sysgen c th c dch ra nhiu kiu d liu, c ththnh file bit np ngay vo phn cng, hoc thnh cc thit k ghp vo mt h thng ln hn.Vi vic kt hp vi Mathwork xy dng Sysgen, Xilinx lm cho vic thit k h thng trn nn FPGA ca mnh trnn thun tin v n gin hn rt nhiu i vi ngi lm k thut. Trong n ny, chng em s dng Sysgen xy dng ton b phn thut ton x l nh s cho thit k ca mnh.

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Phn 3 : Xy dng h thng x l nh ng trn nn FPGA

Yu cu h thng :

Trong phn ny, chng em trnh by chi tit vic thc thi h thng cm bin th gic trn nn FPGA. D liu nh thu c l ca mt tp hp cc i tng tch ri nhau trn nn trng. Nhim v ca h thng l thu thp nh v x l bng cc thut ton x l nu, nhm loi b nhiu, tch cc i tng ra khi nn, gn nhn cho i tng, ng thi xc nh cc c trng c bn ca i tng cho qu trnh x l cao hn hoc cho vic iu khin tay my thao tc vi i tng.

ng thi, h thng cng c nhim v giao tip vi b x l trung tm ( my tnh PC ) truyn thng tin c x l ( s i tng, kch thc, vtr, ...ca i tng ) v nhn tn hiu iu khin, trong khi iu khin giao tip VGA hin th hnh nh.

Hnh 3.1 : Mt nh cn c x l.

3.1. S cu trc h thng x l nh ng

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Hnh 3.2 : S chung ca h thng

Trn y l s cu trc ca h thng x l nh s. H thng gm c 3 phn chnh sau:

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Khi thu thp d liu t Camera v ghi vo SDRAM: d liu t video decoder c x l khi Framegrabber ch ly d liu luminance v ghi vo FIFO, sau c ghi vo SDRAM. Chip Video decoder c kch hot nh tn hiu iu khin qua chun I2C trn PC qua cng Parallel Port (LPT).

Khi x l nh: c d liu t SDRAM vo FIFO, x l v sau li ghi vo FIFO v ghi vo SDRAM qua dual port, SDRAM Controller. Chn thut ton v kch hot tng module x l tng thut ton c kch hot t bn ngoi qua cc nt bm (button) v cc kha chuyn (switch).

Khi hin th nh ln VGA: hin th cc pixel ca nh trong SDRAM ln mn hnh my tnh CRT.

3.2. Xy dng h thng thu thp, lu tr, x l v hin th nh

3.2.1. Thnh phn thu thp nh Framegrabber

Nhim v: nhim v c bn ca khi Framegrabber l ng b vi chip Video Decoder c cc pixel v ghi vo FIFO.

Phn tch cch thc thi

Framegrabber dng mt Finite State Machine gii m v cht thnh phn luminance (ch ly cc thnh phn xm grayscale) t pixel stream ca ITU-R BT.656 4:2:2 ( nh dng xut ra mc nh ca video decoder).

Pixel stream c nh dng nh sau:

Hnh 3.3: Pixel stream waveform

u tin l cc byte nh du bt u mt frame (FF-00-00), tip theo l byte ng b (embedded sync byte) ES. Theo sau l 1440 byte gm: 720 gi trluminance (Y), 360 gi tr blue chromiance (Cb) v 360 gi tr red chrominace (Cr) theo nhm c mt Cb v Cr th c 2 gi tr Y: 1b n r nC Y C Y .

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S cu trc ca State machine nh hnh v di y:

Hnh 3.4 : Framegrabber state machine

T hnh v ta thy 3 trng thi u: wait_for_embedded_sync, wait_embedded_sync_1, wait_embedded_sync_2 dng kim tra 3 byte nh du u tin (FF-00-00).

Ti trng thi check_embedded_sync kim tra cc tn hiu ng b gm c field id, field change v ghi byte ng b vo FIFO phc v cho vic ghi d liu vo FIFO v hin th VGA. Nu c tn hiu image_processing_start khi ng khi ny th tip tc chuyn sang cc trng thi tip theo nhn d liu v ghi vo FIFO, cn khng th quay li trng thi ban u kim tra cc byte nh du ca frame mi.

Sau khi ng b xong th lin tc thc hin cc trng thi grab_chromar v grab_luminance2. D liu lumincance c ly trng thi grab_luminance2. Qu trnh nhn d liu kt thc (tn hiu done) xy ra khi trong cc trng thi ny nhn c byte c gi tr 0xFF.

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D liu ghi vo FIFO bao gm 16 bit c 2 bit u tin l cc bit ng b: field_id v field_change, theo sau l cc bit 0 v byte luminance:

Pixel_in

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Trong n ny, chng em dng read, write vi ch pipeline.

Hnh 3.5 : Pipelined Read Operation timing waveforms

Pipeline Read Operation

Trn y l dng sng cho hot ng c kiu pipeline. Hot ng c ch pipeline c thc hin bng cch gi cho tn hiu rd ln cao trong ghi lin tc cung cp a ch cn c mi khi m tn hiu earlyOpBegun hoc opBegun ln cao bo hiu hot ng c trc bt u. V d trn m t 3 hot ng c truy nhp cc vng nh SDRAM ti bank v hng ca SDRAM ang c active. Nu vic c thc hin bank hoc hng khc ca SDRAM th SDRAM Controller s hon thnh qu trnh c hin ti v active bank v row mi trc khi tn hiu earlyOpBegun v opBegun ln cao.

Pipeline Write Operation

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Hnh 3.6 : Pipelined Write Operation timing waveforms

Hot ng ghi ch pipeline c thc hin bng cch gi cho tn hiu wr ln cao trong khi th lin tc cung cp a ch mi mi khi tn hiu earlyOpBegun hay opBegun ln cao bo hiu rng qu trnh ghi trc bt u. V d trn y thc hin 3 hot ng ghi vo b nh trong bank v row hin ti ca SDRAM. Nu ghi vo a ch bank hoc row khc th SDRAM Controller s hon thnh vic ghi hin ti v sau kch hot bank v row mi trc khi tn hiu earlyOpBegun v opBegun ln cao.

Nh m vic ghi, c SDRAM tr nn d dng hn, theo cu trc sau:

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Hnh 3.7 : Ghp ni vi SDRAM Controller

Dualport Module for the SDRAM Controller

Chc nng: Dualport module nh vo pha cc cng bn host-side ca biu khin XESS SDRAM Controller v chia thnh hai phn host-side ring bit, mi phn c th hot ng nh cc cng ca host-side ban u do ng dng c th gm nhiu thnh phn truy nhp SDRAM nhng ch dng 1 b iu khin SDRAM Controller. Bt k ng dng no thc hin vic ghi c b nh SDRAM u c lp vi hot ng cc post khc. Bng thng tng cng ca SDRAM c th c phn phi gia 2 port cho khp vi data rate ca cc ng dng dng dual port. Dualport module c th xy dng kiu tng xy dng giao din SDRAM vi 3 hay nhiu cng c lp.

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Hnh 3.8 : Ghp ni dualport vi SDRAM Controller

Hnh 3.9 : Xy dng 4 ports SDRAM interface

Phn phi bng thng SDRAM cho cc port ca mt dualport c thc hin qua tham s PORT_TIME_SLOTS, l mt vector 16 bit vi mi bit tng ng vi mt time slot trong khi mt hot ng c hoc ghi ca SDRAM c

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th xy ra. Thit lp bit bng 0 cu hnh time slot cho port0, v thit lp bng 1 dnh time slot cho port 1. Sau y l mt s cch thit lp:

PORT_TIME_SLOTS => 1111000011110000 p dng 8 time slot cho mi port, vi mi port c 4 ln truy cp lin nhau vo SDRAM trc khi dual port chuyn iu khin cho port kia. V th, mi port c phn phi mt na bng thng ca dual port.

Tham s PORT_TIME_SLOTS ch c tc ng ti hot ng ca dualport module khi cc ng dng trn c 2 port cng c gng truy nhp vo SDRAM. ng dng mt port s truy nhp trc tip vo SDRAM nu khng c hot ng ghi v c ang tin hnh port kia. V th PORT_TIME_SLOTS = 1111111111111111 s cho php port 0 truy nhp SDRAM ch khi port 1 khng truy cp, nhng khng ngn hon ton port 0 trong vic truy cp SDRAM.

PORT_TIME_SLOTS = 1111111100000000 cu hnh mt na bng thng cho mi port tuy nhin c th block truy cp ca mt port ln ti 8 time slottrong khi port kia c u tin hn. gim tr ch cn gn PORT_TIME_SLOTS = 0101010101010101 tuy nhin s lng ph thi gian bi v SDRAM Controller phi xa pipeline trc mi qu trnh chuyn port. V th, nhm cc bit lin nhau cng mt gi tr l gii php tt nht.

3.2.4. Image Processing core

Image Processing core l thnh phn quan trng nht ca h thng x l nh, trong thc thi tt c cc thut ton t c bn( lc, d bin, phn ngng...) n nng cao ( gn nhn i tng, xc nh cc c trng ). Hot ng ca thnh phn ny c iu khin bi b x l trung tm.

Nh thy trn, mi pixel c thu thp, x l v lu vo SDRAM c dng mt word 16bit cha thng tin nh sau :

'field_id' | 'field_change' | "000000" | "luminance"

Trong , field_id v field_change l nhng bit thng tin v frame v pixel, khng c thay i trong qu trnh x l. Luminance l s 8 bit biu

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th mc xm ca pixel, s c x l trong cc thut ton v sau. Cn li 6 bit cao sau field_change cha c s dng n, s c dng gn nhn i tng.

Vic thit k Image Processing Core ch yu s dng cng c System Generator. Vi cng c ny, ngi thit k c th s dng cc core c sn c cung cp bi Xilinx, gim thiu cng sc v thi gian thit k, ng thi vn c th t to ra cc block ring cho mnh s dng cng c Black Box, v c bit, vic g ri v m phng h thng c th thc hin hon ton trn Matlab, vn rt quen thuc vi sinh vin iu khin t ng.

Hnh 3.10: S khi x l nh.

Khi x l nh giao tip vi SDRAM thng qua 2 FIFO l read_fifo v store_fifo.

read_fifo c nhim v c tun t d liu t SDRAM vo khi x l nh lu vo buffer v x l. Vic c bt u khi tn hiu bo read_fifo khng cn trng (read_fifo_empty='0' hay read_fifo_avail='1') v dng khi c ht mt frame. Vic c c th tm dng khi sp xy ra xung t qu trnh c v x l.

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store_fifo c nhim v ly d liu x l t khi x l nh v lu tun t tr li vo SDRAM ti v tr xc nh. Cng nh read_fifo, vic ghi ca store_fifo iu khin qu trnh x l, khi store_fifo y th tm dng vic xl.

Cu trc ca Image Processing Core gm 2 thnh phn :

fifo_to_buffer : thc thi vic giao tip vi read_fifo v lu d liu vo mt b m. Thc cht b m d liu l mt Block Ram trong FPGA, c khnng lu n 27 dng ca frame. Vic lu d liu c iu khin sao cho trnh xung t vi thnh phn x l.

Hnh 3.11 : Khi ghi d liu t read_fifo vo Buffer

processing_algorithms : la chn, thc thi tt c cc thut ton x l nh, t lc, d bin, cc thut ton x l ng cu,... cho n phn ngng, phn vng v gn nhn i tng. ng thi thnh phn ny cn thc hin giao tip gia Image Processing Core trong vic giao tip vi store_fifo a dliu x l ra ngoi.

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Hnh 3.12 : Khi thut ton x l nh

Khi x l ny c d liu t b m theo cng mt phng php trong tt c cc thut ton x l. iu ny c th gy ko di thi gian x l i vi mt s t thut ton, nhng li gip tit kim rt nhiu ti nguyn v cng sc thit k cng nh gim thiu kh nng gy li hoc nhm ln trong qu trnh thit k.

Vic ghi v c d liu b m buffer nh sau:

Ban u ta c tun t d liu vo buffer cho n khi y 10 dng, ta liquay ngc tr li v tr ban u v tip tc c. ng thi, ca s ghi ra x l c dch tun t cho n ht 10 dng , ri cng quay ngc tr li dng u tin. Vic ghi v c c iu khin sao cho khng xy ra s xung t : ch ghi vo nhng dng x l v ch c khi ghi s dng cn thit x l.

Vic c v ghi nh trn cho php s dng mt cch hiu qu s block ram hu hn ca FPGA, trnh hon ton kh nng xung t c/ghi, ng thi loi gip cho vic c v ghi tr nn tng i c lp vi nhau, gim thiu sai st trong qu trnh x l.

Vic c v ghi cng c iu khin bi tn hiu bo t read_fifo v store_fifo: dng ghi khi read_fifo trng (read_fifo_avail= 0) v dng x l khi store_fifo y (store_fifo_full = 1).

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Cc khi x l c bn

Khi c d liu : cc ca s c c ra t b m, a vo mt thanh ghi dch 9 word. Vic c c thc hin tun t t trn xung theo tng ct t tri sang, d liu c ra c dch dn vo thanh ghi dch.

Hnh 3.13 : Khi c d liu t buffer

Khi chuyn sang ca s k tip, do 2 ca s k nhau c chung 6 word nn tit kim thi gian, ta s khng c li t u 6 word c m s dng li chng vi s tr gip ca thanh ghi dch. Do ta s ch vic c tip 3 pixel ct tip theo. Tn hiu full_win bo hiu mt ca s va c c xong, cn a vo qu trnh x l.

Thanh ghi dch Pixel register : Thanh ghi ny c nhim v ghi dn cc pixel c t buffer do khi c d liu iu khin. Cc pixel c dch dn trong qu trnh x l, do , c mi 3 chu k x l, trong thanh ghi li lu mt ca s mi.

Hnh 3.14: S khi thanh ghi dch Pixel register

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C th thy, vi thanh ghi dch ny, ta c th tn dng ti a kh nng xl song song ca FPGA cho cc thut ton x l nh s.

Khi x l : Khi x l bao gm nhiu thut ton x l khc nhau. Tuy nhin, cu trc ca cc thut ton l tng i ging nhau v ta c th tn dng mt c ch c duy nht dng chung cho tt c cc thut ton.

Cu trc b lc tuyn tnh, d bin : B lc tuyn tnh v d bin theo phng php Laplacien cng s dng php nhn chp vi 2 mt n khc nhau. Do ta c th ghp chung li thnh mt khi. Php nhn chp c thc thc hin rt nhanh chng s dng cu trc song song. Di y l cu trc b nhn chp trong cc b x l ny :

Hnh 3.15 : Cu trc nhn chp

B x l ng cu nh nh phn : Khi ny ch yu tnh ra gi tr max,min ca cc pixel trong ca s, do s dng cc block so snh. Cu trc nh sau:

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Hnh 3.16 : Cu trc b x l ng cu nh nh phn.

Khi tnh ngng v phn ngng : Ngng c tnh theo phng php trung bnh. Tng mc xm ca cc pixel s c cng dn vo mt thanh ghi v thc hin php chia bng cch dch bit. Kt hp nhiu khi dch bit vi nhau cho php ta thc hin php chia vi sai s ca ngng nh hn 3 v thut ton ch cn thc hin trong 1 chu k xung.

Khi m i tng: Khi m i tng cng tn dng kh nng x l song song ca FPGA thc hin m i tng. Vi khi ny, vic gn nhn cho mi pixel da trn nhn ca cc pixel ln cn ch cn thc hin trong 1 chu k ng h.

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Hnh 3.17 : Khi gn nhn i tng

u vo khi gn nhn i tng l 9 pixel ca ca s hin ti, vi pixel 5 l trung tm, cn c xem xt gn nhn. Vic gn nhn cho pixel trung tm thc hin nh thut ton trnh by phn 1.

3.2.5. Hin th nh ln VGA: VGA Generator

VGA Color Signals

C 3 tn hiu color l: red, green v blue gi tn hiu mu sc (color information) n mn hnh VGA. Mi mt tn hiu iu khin mt sng bn in t (electron gun) phng cc ht electron v ln mt mu c bn ti mt im trn mn hnh. Di ca tn hiu nm t t 0 V (tng ng vi mu ti hon ton) v 0.7V (sng hon ton) iu khin cng ca mi thnh phn mu v 3 thnh phn mu kt hp vi nhau to ln mu ca im nh (dot) hay phn t nh (pixel) trn mn hnh.

Hnh 3.19 : VGA Connection

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Mi tn hiu mu analog c th l mt trong 8 mc bng 3 tn hiu digital bng cch dng b chuyn i digital to analog 3 bit (DAC 3 bit). Do , 8 mc trn mi tn hiu analog kt hp vi nhau to nn phn t nh (pixel) vi 8 x 8 x 8 = 512 mu khc nhau. Tuy nhin trong n ny, chng em chdng camera en trng nn hin th trn mn hnh ch c 8 mu khc nhau hay 8 mc thi.

Hnh 3.20 : 8 mu c bn

VGA Signal Timing

Mi mt nh (hay frame) trn mn hnh hin th l kt hp ca h dng, mi dng c w pixel. Kch thc ca mi frame c biu din w x h di cc dng tiu biu gm 640 x 480m 800 x 600, 1024 x 768 v 1280 x 1024.

Hnh 3.21 : CRT Display Timing Example

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v mt frame, c nhng mch in c trch nhim di chuyn dng electron t tri sang phi v t trn xung di dc theo mn hnh gi l deflection circuit. Nhng mch ny yu cu phi c 2 tn hiu ng b khi ng v dng dng electron ti ng thi im cho mt dng cc im nh c v dc theo mn hnh v mi dng c in theo c ch ttrn xung di to ln mt nh.

Sau y l v d VGA Display Timing vi ch 640 x 480:

Hnh 3.22 : 640 x 480 Mode VGA Control Timing

Nguyn tc hot ng ca VGA Generator

S cu trc ca b hin th hnh nh ln VGA nh trn hnh v di. H thng bn ngoi ghi gi tr pixel vo trong b m pixel (pixel buffer) (trong trng hp ny l FIFO 256 x 16). Cc pixel c ly t b m ri ghi vo trong thanh ghi pixel (pixel register). Mi pixel cso th l 1, 2, 4, 8 hoc 16 bit v th nn ni dung ca thanh ghi pixel ny c dch sau mi xung clock thay th pixel hin ti theo th t cc bt c trng s thp n cao. Cc bit ny c gi n colormap circuit chuyn cc pixel ny sang cc gi trred, green v blue ri gi n b DAC video bn ngoi.

Hai mch to xung ng b (pulse generation circuit) c dng to cc xung ng b ng v nm ngang (horizontal v vertical). B hirizontal

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sync generator c u ra l tn hiu gate mt chu k trng khp vi sn ln ca xung ng b ngang ( horizontal sync pulse), tn hiu gate ny ni vi tn hiu clock-enable ca b vertical sync generator v th nn clock-enable ch cp nht b m thi gian sau mi dng pixel (line of pixels). Tn hiu gate ca vertical sync generator c dng nh tn hiu bo kt thc mt frame cho cc khi d liu pixel bn ngoi, ng thi n cng reset v xa ton b ni dung ca pixel buffer nn b VGA generator lun khi ng ttrng thi xa sch hon ton vi mi frame.

B to tn hiu ng b cng to ra cc tn hiu horizontal v vertical blanking. Khi dng php ton OR logic ta c tn hiu blanking ton cc. Cc tn hiu blanking c kt hp vi cc bit c trng s thp hn b m horizontal pixel counter xc nh khi no c pixel t b m. V d, nu mi pixel c rng 16 bit, th mt t 16 bit s cn c c sau mi chu k clock. V th nn hot ng c c khi to bt c khi no tn hiu video khng trng v 2 bit thp ca b m pixel u bng 0.

Hnh 3.23 : S khi cu trc ca VGA Generator

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Tn hiu full signal c gi ra ngun d liu pixel bn ngoi bo cho bit khi no th dng vic in d liu vo b m. Vi b m FIFO 256, tn hiu full ln cao khi 5 bit cao ca tn hiu FIFO level bng 11111. Khin cho b trng 7 bit trong FIFO in cc pixel khi cc ngun d liu bn ngoi cht gi d liu vo trong pipe. y gi l c ch b m an ton.

3.2.6. Picoblaze v h thng iu khin trung tm

3.2.6.1. Khi qut PicoBlaze

Vi iu khin PicoBlaze l vi iu khin nhng 8 bit c cu trc RISC c ti u pht trin cho cc h FPGA nh Spartan 3, Virtex II v Virtex II Pro ca Xilinx. Vi vi iu khin ny chng ta c th lm mt b iu khin da trn nn vi iu khin rt hiu qu, hay x l d liu n gin.

Vi iu khin PicoBlaze c ti u v mt hiu sut v chi ph pht trin thp. N chim khong 96 FPGA slices, hay ch 12.5% ca XC3S50 FPGA v chim mt phn rt nh mc 0.3% ca XC3S5000 FPGA. Bnh thng mi block RAM ca FPGA c th lu tr ti 1024 cu lnh chng trnh (program instructions) v cc lnh ny c t ng load trong khi cu hnh FPGA, khi vi iu khin PicoBlaze c th hot ng t 44000 ti 100000 cu lnh trn giy (MIPS million instructions per second) ty thuc vo h FPGA c dng l loi g v tc ca h .

Nhn ca vi iu khin PicoBlaze c nhng hon ton trong FPGA v khng cn mt ngun thm no. n gin l cc ngoi vi ca PicoBlaze c tht do la chn cho ph hp vi cc mc ch c bit, chc nng v yu cu v gi c ca sn phm cui cng. PicoBlaze c nhng vo di dng mt m ngun VHDL v th n c th nhng vo cc i FPGA sau ny v do project ca chng ta s c tnh k tha cao. c nhng trong FPGA, vi iu khin PicoBlaze s gim kch thc mch, gi thit k v thc hin.

PicoBlaze FPC c h tr bi mt s cc cng c pht trin ph hp bao gm assembler v mi trng pht trin ha tch hp (IDE integrated development environment), graphical instruction set simulator v m ngun

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VHDL v khi m phng. V rt n gin l vi iu khin PicoBlaze c htr trong mi trng pht trin Xilinx System Generator hay ISE.

Hnh 3.24 : S khi cu trc ca PicoBlaze

Vi iu khin PicoBlaze c cc c im sau:

16 thanh ghi d liu chc nng chung c rng 8 bit. Lu tr c 1K lnh trong chng trnh c th lp trnh c trong

chip v t ng np khi cu hnh FPGA hay khi khi ng FPGA. Khi tnh ton logic (Arithmetic Logic Unit ALU) vi cc c CARRY

v ZERO. Mt bng RAM 64 byte. 256 u vo v 256 u ra d dng c th m rng thm. Automatic 31 location CALL/RETURN stack. Predictable performance, lun lun dng 2 xung nhp h thng cho mt

cu lnh, c th t ti 200 MHz hoc 100 MIPS trong Virtex II Pro FPGA. p ng ngt nhanh; worst-case 5 clock cycles. c ti u cho cu truc Spartan 3, Virtex II, v Virtex II Pro FPGA

ca Xilinx ch chim 96 slices v 0.5 ti 1 block RAM. H tr m phng tp lnh assembler.

Vi iu khin PicoBlaze c cung cp di file ngun VHDL gi l KCPSM3.vhd, c ti u v vic thc thi hiu qu v chc chn trong cc h Spartan-3, Virtex-II hay Vertex-II Pro. Cc m ngun ph hp vi c qu trnh tng hp v m phng v c pht trin v kim tra dng cng c

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Xilinx Synthesizs Tool (XST) cho tng hp logic v ModelSim cho m phng. Cc nh thit k cng thnh cng khi dng cc cng c tng hp logic v m phng khc. Cc m ngun VHDL khng nn b chnh sa trong bt k hon cnh no.

KCPSM3 Module

Module KCPSM3 bao gm ALU, register file, scratchpad RAM, Ch duy nht chc nng khng nm trong KCPSM3 l b nh chng trnh. Khai bo component v gn chn nh sau:

Kt ni vi b nh ROM chng trnh

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B nh ROM chng trnh ca PicoBlaze c dng trong thit k VHDL. T file assembler to ra file VHDL, nh ngha block RAM v khi to ni dung cho RAM. File VHDL ny c th c dng cho c tng hp logic v m phng vi iu khin.

Sau y l khai bo component v gn cc thc th ca b nh chng trnh trong FPGA:

Do , s cu trc ca vi iu khin PicoBlaze nh sau:

Hnh 3.25: S cu trc PicoBlaze Microcontroller

vit m lnh cho chng trnh (vi tn m rng l .psm) th chng ta c th dng bt c trnh son tho no lp trnh da theo 31 lnh c cung cp. V dng file thc thi KCPSM3.exe v cc form c nh ngha sn

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ca ROM di dng file .vhd, .coe, .v dch ra cc file .vhd, .v v cho vo chng trnh FPGA.

phi hp hot ng ca tt c cc thnh phn trn, m bo h thng hot ng chnh xc, ta phi c mt h thng iu khin trung tm. Trong n ny, chng em s dng mt vi x l nhng c tn l PicoBlaze iu khin hot ng ca cc khi x l trong FPGA, ng thi giao tip vi my tnh thng qua cng RS232 v khi iu khin giao tip RS232 : UART Controller.

3.2.6.2. S cu trc ca khi x l trung tm

S cu trc ca khi x l dng PicoBlaze:

Hnh 3.26 : S khi iu khin trung tm v giao tip UART

Ngoi vi iu khin PicoBlaze, c s dng thm 2 component l UART Receive v UART Transmit. Hai component c cung cp min ph bi Xilinx, bao gm b m v cc tn hiu trng thi giao tip vi cng RS232.

Vi iu khin PicoBlaze c nhim v nhn lnh iu khin t chng trnh trn PC v ra cc lnh iu khin capture nh t camera v cc tn hiu la chn thut ton v kch hot khi x l frame nh lu trong SDRAM, ng thi nhn tn hiu done v bo v giao din bit thut ton x l xong.

Thut ton ca chng trnh

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Chng trnh chnh lun lun nhn cc k t t giao din ngi dng v kim tra xem gi lnh vi c php g. V d: lnh bt u bng ch ci C dng capture nh, bt u bng ch ci M chn thut ton x l nh M1 lc nhiu, M2 phn vng, v ra cc tn hiu iu khin tng ng vo cc chn Algorithm Selection ca khi x l nh.

Khi x l ngt s c kch hot khi c tn hiu done t b x l nh v khi xa tn hiu kch hot khi x l nh v gi messenger ln PC.

3.3. Thit k giao din iu khin h thng

Giao din ca chng trnh c xy dng trn nn GUI (Graphic User Interface) ca Matlab R2007a.

Giao din ca chng trnh iu khin nh hnh v di. Giao din ny c th thay i ti thi im bo v.

Hnh 3.27 : Giao din iu khin

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Chc nng

Chn thng s ca cng RS232 thit lp giao tip RS232 vi mch phn cng bn di. Mc nh chn cng COM1, tc 115200. C th la chn kt ni hoc ngt kt ni vi RS232, c hp thoi hin th trng thi ca giao tip RS232.

Kch hot chip Video Decoder trn mch phn cng qua nt I2C giao tip I2C vi chip qua cng LPT. Mc nh chn cng LPT1, c th pht trin thm la chn cc cng LPT khc na.

Cho php download trc tip file cu hnh cho FPGA hoc Flash qua cng LPT, nh cc nt bm phn LPT FPGA Programming.

Cho php la chn thut ton thc hin v c led hin th s th t thut ton tng ng. Do cha c tn c th ca tng thut ton c th nn mi cht tn l thut ton 1, thut ton 2, Mi khi kt thc thut ton u c bc in thng bo thc hin thnh cng.

Cho php kch hot capture nh t camera v t hin ln mn hnh VGA. ang pht trin thc hin la chn gia capture mt nh v chp lin tc khong 30 hnh/s.

3.4. M phng v kt qu

Phng n m phng

Yu cu ca bi ton m phng: thc hin tt cc thut ton x l nh m s vt trn mt frame, v nh v tng vt.

Phng n m phng y c thc hin nh sau: dng camera chiu vo mt tm bng mt mu (en) c cc vt c kch thc khc nhau. Khi , dng chng trnh giao tip trn PC iu khin camera capture mt nh r nt, sau tin hnh thc hin tng thut ton theo trnh t nht nh v xc nh s vt. Tng kt qu chy mi thut ton u hin th trc tip trn mn hnh VGA.

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Trnh t thc hin nh sau:

Thut ton 1 : Lc nh bng php lc Gausse, ng thi tnh ngng trung bnh

Thut ton 2 : Phn ngng nh theo thut ton phn ngng, sdng ngng va tnh.

Thut ton 3 : Lm mnh.

Thut ton 4 : Lm y, khi phc nh.

Thut ton 5 : Thc hin gn nhn i tng, hin th s i tng trong frame.

Thut ton 6 : Tnh ton cc c tnh ca ln lt tng i tng, ng thi hin i tng ln., hin th cc c tnh ca i tng cn xc nh ra giao din. Hon thnh lt m phng.

Kt qu

Kt qu m phng cho thy vic thc thi cc thut ton v thit k hthng thc hin ng nh mong mun. Vic phn vng v nh nhn nh thnh cng. Tuy nhin, nu nh c nhng nhiu tng i ln ( dy khong hn 3 pixel ) th cn nhiu qu trnh lm mnh lin tip mi xa bhon ton c nhiu.

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Kt lunTrong cc gii php phn cng cho vic xy dng h thng th gic my

tnh, c th thy FPGA l mt trong nhng gii php ph hp nht. Vi FPGA, chng ta c th thit k h thng theo tng khi hot ng song song, cho php tng tc x l ln nhiu ln so vi x l tun t. iu ny l rt quan trng i vi nhng h thng i hi tc x l nhanh, chng hn nh nhng cnh tay robot gp vt ang chuyn ng nhanh.

Trong n ny, chng em thc thi thnh cng mt h thng th gic my vi nhim v l tch cc i tng trong mt nh, gn nhn v xc nh cc c trng hnh hc ca i tng. Vi kh nng x l nh vy, chng em nhn thy hon ton c th m rng ti ra gii quyt cc bi ton x l nng cao nh :

Nhn dng : da trn cc c trng hnh hc ca i tng, ta cn c th nhn dng i tng, phc v cho bi ton nhn dng vt hoc chci v s v sau. Vic nhn dng c th bng mng neural xy dng trc tip trn FPGA, bng cch to ra cc neural nh cc n v x l kt ni vi nhau.

Xc nh i tng chuyn ng: i tng c x l y mi ch l i tng tnh, trong khi camera truyn nh lin tc v i tng. Nu kt hp cc qu trnh x l trong nhng thi im khc nhau, ta c th gii quyt bi ton xc nh i tng chuyn ng v c tc chuyn ng ca n. Vic gii quyt bi ton ny c ngha thc tin rt ln i vi cc c cu bm i tng chuyn ng.

Xc nh khong cch vt trong khng gian : Mch XST 3S 1000 c 2 cng video. Thm vo , project ca chng ta cha chim ht mt na ti nguyn ca h thng, trong khi nu thm mt project na, ta vn c th tn dng nhng ti nguyn c. Do chng ta hon ton c th thc thi mt hthng vi 2 camera cng hot ng. iu ny cho php ta c th quan st cc i tng trong khng gian 3D, thm ch xc nh hnh dng, kch thc v th tch ca chng. Ta cng c th xc nh khong cch gia cc i tng trong khng gian nu kt hp kt qu x l c vi cc php tnh quang hc chnh xc. Xa hn na, ta hon ton c th xy dng mt h thng th

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gic my gip cho vic di chuyn ca xe t hnh v cc thao tc ca h thng CNC i vi vt th 3 chiu.

M rng kh nng giao tip ca cm bin th gic ph hp vi nhiu chun ch khng ch ring RS232: chun Ethernet, USB, CAN, RS 485... gip cho thit b d dng tch hp vo cc h thng iu khin phn tn tht s.

Ci thin cc thut ton nhm lm tng kh nng x l, cht lng nh sau tin x l.

u l nhng ng dng rt c gi tr thc tin trong nhiu lnh vc, c bit l T ng iu khin, v c kh nng thc thi nu i su nghin cu.

Qua qu trnh thc hin n ny, chng em cm thy hc c rt nhiu iu.

l k nng t nghin cu trong nhng lnh vc cn ht sc mi m i vi sinh vin iu khin t ng : l X l nh s, Th gic my tnh v cng ngh FPGA, trn nn tng nhng kin thc c s hc c nh trng.

l k nng lm vic theo nhm : bng cch phn cng tng i hp l, chng em chia tch cng vic ra mt cch kh cn bng, m bo mi ngi pht huy ht s trng ca mnh, thc hin n mt cch tt nht trong kh nng c th. y l mt trong nhng k nng quan trng nht cho cng vic ca mt k s v sau

l k nng trnh by nhng tng , hiu bit v kin thc ca mnh vo mt n, nhm truyn ti mt cch y nht c th nhng g mnh hiu v lnh vc m mnh ang nghin cu.

Cui cng, cng phi ni rng d c gng rt nhiu, nhng chng em vn khng trnh khi nhng sai st, trong vic xy dng h thng, trong vic trnh by lun vn. Nhng chng em vn lun thc c rng, nhng sai st y cng l mt c hi cho chng em rn luyn k nng ca mnh : knng sa cha nhng sai st v khim khuyt, thc hin nhng ti, d

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n v sau mt cch hon chnh hn. tt c l nh s theo di, hng dn , phn bin tn tnh v nghim tc ca cc thy, c trong hi ng bo v.

Chng em xin chn thnh cm n cc thy c v s tn ty y!

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Ti liu tham kho

[1]. Volnei A. Pedroni, Circuit Design with VHDL, MIT Press Cambridge, Massachusetts London, England, 2004.

[2]. Texas Instruments, TVP5150PBS Ultralow-Power NTSC/PAL Video Decoder, Texas Instruments Incorporated, May 2006.

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