Giải Ngân hàng thi Kiến trúc máy tính

8/13/2019 Gii Ngn hng thi Kin trc my tnh

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GII NGN HNG CU HI

KIN TRC MY TNH

Contents

Cu hi 1.1: Kin trc my tnh l g? Kin trc my tnh c cu thnh t nhng thnh phnno ? ............................................................................................................................................... 2Cu hi 1.2: Nu s khi chc nng ca h thng my tnh. ................................................... 2Cu hi 1.3: Thanh ghi ca vi x l l g? Nu chc nng v c im ca thanh ghi tch lu A. 2Cu hi 1.4: Nu chc nng v c im ca b m chng trnh PC ....................................... 3Cu hi 1.5: Thanh ghi c (hay thanh ghi trng thi) ca vi x l c chc nng g? .................... 3Cu hi 1.6: Ch a ch ca vi x l l g? M t ch a ch tc th. Cho v d.............. 3Cu hi 1.7: Ch a ch ca vi x l l g? M t ch a ch trc tip. Cho v d........... 3Cu hi 1.8: Ch a ch ca vi x l l g? M t ch a ch gin tip qua thanh ghi. Chov d minh ho............................................................................................................................... 4Cu hi 1.9: Ch a ch ca vi x l l g? M t ch a ch gin tip qua nh. Cho vd minh ho.................................................................................................................................... 4Cu hi 1.10: Ch a ch ca vi x l l g? M t ch a ch ch s. Cho v d minhho.................................................................................................................................................. 4Cu hi 1.11: Ch a ch ca vi x l l g? M t ch a ch tng i. Cho v d minhho.................................................................................................................................................. 4Cu hi 1.12: Nu phng thc trao i d liu gia CPU, cache v b nh chnh. .................... 5Cu hi 1.13: Nu c im chnh ca a CD v a DVD. ........................................................ 5Cu hi 1.14: Nu nguyn l hot ng ca chut quang. ............................................................ 5Cu hi 2.1: Nu s khi chc nng v chc nng chnh ca cc thnh phn trong mt hthng my tnh? ............................................................................................................................. 6Cu hi 2.2: Nu s v cc c im ca kin trc my tnh von-Neumann. .......................... 6Cu hi2.3: Nu s v cc c im ca kin trc my tnh Harvard. .................................... 7Cu hi 2.4: Nu s khi tng qut v chu trnh x l lnh ca CPU. ..................................... 8Cu hi 2.5: Nu s khi v chc nng ca cc khi iu khin (CU) v khi tnh ton s hcv logic (ALU). .............................................................................................................................. 8Cu hi 2.6: Lnh my tnh l g? ............................................................................................ 9Cu hi 2.7: Nu cc dng a ch ca lnh. Cho v d minh ho vi mi dng a ch. ............ 10Cu hi 2.8: C ch x l xen k dng lnh (ng lnh pipeline) l g ? ................................... 11Cu hi 2.9: Nu cu trc phn cp ca h thng b nh my tnh. ........................................... 11Cu hi 2.10: Phn bit b nh RAM tnh v RAM ng........................................................... 12Cu hi 2.11: B nh cache l g? .............................................................................................. 13Cu hi 2.12: So snh cc chun ghp ni a cng IDE, SATA v SCSI. ............................. 14Cu hi 2.13: Trnh by nguyn l c thng tin trn a CD..................................................... 15Cu hi 2.14: Nu nguyn l hot ng ca my in laser. .......................................................... 15Cu hi 2.15: Nu nguyn l to hnh nh ca mn hnh LCD. .................................................. 16Cu hi 3.1: Nu s v c im ca hai dng kin trc cache : ............................................ 17Cu hi 3.2: So snh 3 phng php nh x cache: .................................................................... 18Cu hi 3.3: Nu cc phng php c ghi v cc chnh sch thay th dng cache. .................. 19Cu hi 3.4: RAID l g? ............................................................................................................. 20ADD R2, (R1) .............................................................................................................................. 23


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Cu hi loi 1 im

Cu hi 1.1: Kin trc my tnh l g? Kin trc my tnh c cu thnh t nhng thnhphn no?TL :Kin trc my tnh (Computer architecture) l mt khoa hc v la chn v kt ni cc thnhphn phn cng ca my tnh nhm t c cc yu cu:

- Hiu nng/tc (performance): nhanh.

- Chc nng (functionality): nhiu tnh nng.- Gi thnh (cost): r.

Kin trc my tnh l mt trong hai khi nim c bn ca cng ngh my tnh.

KTMT bao gm 3 thnh phn c bn l:

- Kin trc tp lnh (Instruction set architectureISA).

- Vi kin trc (micro-architecture).

- Thit k h thng (System Design).

Cu hi 1.2: Nu s khi chc nng ca h thng my tnh.

TL :

S khi chc nng h thng my tnh nhhnh bn:

Trong :

- B x l trung tm (CPU)- B nh trong (Internal Memory): bao

gm: ROM v RAM.- Cc thit b vo ra (Peripheral devices).- Bus h thng (system bus).

Cu hi 1.3: Thanh ghi ca vi x l l g?Nu chc nng v c im ca thanh ghitch lu A.

TL :Thanh ghi (registers) l cc nh bn trong CPU c c im l kch thc nh, tc rt cao(bng tc CPU) v c chc nng lu tr tm thi lnh v d liu cho CPU x l. S lng thanh ghi tu thuc vo i CPU, cc CPU c (80x86) c 16-32 thanh ghi; cc CPU hini (Pentium 4 v Core Duo) c hng trm thanh ghi;Kch thc thanh ghi ph thuc vo thit k CPU. Cc kch thc thng dng ca thanh ghi l 8,16, 32, 64, 128 v 256 bit.

Thanh tch lu A l mt trong cc thanh ghi quan trng nht ca hu ht cc CPU. Thanh ghi tch lu A c chc nng:

- dng cha ton hng u vo- dng cha kt qu u ra- s dng trao i d liu vi cc thit b vo ra.

Kch thc ca A bng kch thc t x l ca CPU: 8, 16, 32 v 64 bit.


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Cu hi 1.4: Nu chc nng v c im ca b m chng trnh PC

TL :

- B m chng trnh PC (Program Counter) hoc con tr lnh (IP Instruction Pointer)lun cha a ch ca nh cha lnh c thc hin tip theo.

- PC cha a ch ca nh cha lnh u tin ca chng trnh khi n c kch hot vc np vo b nh.

- Khi CPU thc hin xong lnh, ach ca nh cha lnh tip theo c np vo PC.

- Kch thc PC ph thuc vo thit k CPU. Cc kch thc thng dng l 8, 16, 32 v 64bit.

5r4Cu hi 1.5: Thanh ghi c (hay thanh ghi trng thi) ca vi x l c chc nng g?Nu ngha ca cc c nh (C), c khng (Z), c du (S).TL :Thanh ghi trng thi (SR - Status Register) hoc thanh ghi c (FR Flag Register) l thanh ghi cbit ca CPU. Mi bt ca FR lu trng thi ca kt qu ca php tnh ALU thc hin.Hai loi bt c: C trng thi (CF, OF, AF, ZF, PF, SF) v c iu khin (IF, TF, DF).Cc bt c thng c s dng nh l cc iu kin trong cc lnh r nhnh to logic chngtrnh. Kch thc ca thanh ghi FR ph thuc thit k CPU. ngha ca mt s c:ZF: C Zero, ZF=1 nu ktqu=0 v ZF=0 nu kt qu0.SF: C du, SF=1 nu kt qu m v SF=0 nu kt qu dng. CF: C nh, CF=1 nu c nh/mn, CF=0 trong trng hp khc.

Cu hi 1.6: Ch a ch ca vi x l l g?M t ch a ch tcth. Cho v d.

TL :Ch a ch (Addressing modes) l phng thc CPU t chc cc ton hng ca lnh, n chophp CPU kim tra dng v tm cc ton hng ca lnh.Ch a ch tc th: trong ch a ch tc th, gi tr hng ca ton hng ngun (sourceoperand) nm ngay sau m lnh, ton hng ch c th l 1 thanh ghi hoc 1 a ch nh. V d: LOAD R1, #1000; R1 1000; Np gi tr 1000 vo thanh ghi R1.

LOAD B, #500; M[B] 500; Np gi tr 500 vo nh B.

Cu hi 1.7: Ch a ch ca vi x l l g? M t ch a ch trc tip. Cho v d.

TL :Ch a ch (Addressing modes) l phng thc CPU t chc cc ton hng ca lnh, n chophp CPU kim tra dng v tm cc ton hng ca lnh.S dng mt hng biu din a ch mt nh lm mtton hng, ton hng cn li c th l 1 thanh ghi hoc 1 a ch nh;V d:LOAD R1, 1000; R1 M[1000]Np ni dung nh c a ch 1000 vo thanh ghi R1.


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Cu hi 1.8: Ch a ch ca vi x l l g? M t ch a ch gin tip qua thanhghi.Cho v d minhho.

TL :Ch a ch (Addressing modes) l phng thc CPU t chc cc ton hng ca lnh, n chophp CPU kim tra dng v tm cc ton hng ca lnh.

Trong ch a ch gin tipqua thanh ghi, mt thanh ghi c s dng lu a ch ton hng,ton hng cn li c th l mt hng, mt thanh ghi hoc mt nh.V d: LOAD Rj, (Ri); Rj M[Ri];Np ni dung nh c a ch lu trong thanh ghi Ri vo thanh ghi Rj.

Cu hi 1.9: Ch a ch ca vi x l l g? M t ch a ch gin tip qua nh. Cho vd minh ho.


Trong ch a ch gin tip qua nh, mt nh c s dng lu a ch ton hng, ton

hng cn li c th l mt hng, mt thanh ghi hoc mt nh.V d: LOAD Ri, (1000); Ri M(M(1000))Np ni dung nh c a ch lu trong nh 1000 vo thanh ghi Ri.

Cu hi 1.10: Ch a ch ca vi x l l g? M t ch a chch s. Cho v d minhho.


Trong ch a ch ch s, a ch ca 1 ton hng c to thnh bi php cng gia 1 hng vthanh ghi ch s (index register), ton hng cn li c th l mt hng, mt thanh ghi hoc mt nh.V d: LOAD Ri, X(Rind); Ri M[X+Rind]; X l hng v Rindl thanh ghi ch s.

Cu hi 1.11: Ch a ch ca vi x l lg? M t ch a ch tng i. Cho v d minhho.


Ch a ch tng i: trong ch a ch ny, a ch ca 1 ton hng c to thnh biphp cng gia 1 hng v b m chng trnh PC (Program Counter), ton hng cn li c th lmt hng, mt thanh ghi hoc mt nh.V d: LOAD Ri, X(PC); Ri M[X+PC]; X l hng v PC l b m chng trnh.


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Cu hi 1.12: Nu phng thc trao i d liu gia CPU, cache v b nh chnh.TL :S trao i d liu gia CPU, cache v b nh chnh nh hnh bn.

CPU trao i d liu vi cache theo cc nv c s nh byte, t, t kp. Cache trao id liu vi b nh chnh theo cc khi vikch thc 16, 32, 64 bytes. S d CPU traoi d liu vi cache theo cc n v c sm khng theo khi do d liu c lu trong cc thanh ghi ca CPU - vn c dung lng rt hnch. V vy, CPU ch trao i cc phn t d liu cn thit theo yu cu ca cc lnh. Ngc li,cache trao i d liu vi b nh chnh theo cc khi, mi khi gm nhiu byte k nhau vi mcch bao ph cc mu d liu ln cn theo khng gian v thi gian. Ngoi ra, trao i d liu theo khi (hay m) vi b nh chnh gip cache tn dng tt hn bng thng ng truyn v nh vyc th tng tc truyn d liu.

Cu hi 1.13: Nu c im chnh ca a CD v a DVD.TL: c im chnh ca a CD:

- Dung lng ti a ca a CD l 700MB hoc 80 pht nu lu m thanh - a s dng tia laser hng ngoi vi bc sng 780 nm c thng tin.

- Tc truyn thng tin ca a CD c tnh theo tc c s (150KB/s) nhn vi h snhn. V d, a c tc c 4x th tc ti a c th c l 4 x 150KB/s = 600 KB/s;nu a c tc c 50x th tc ti a c th c l 50 x 150KB/s = 7500 KB/s.

c im chnh ca a DVD:- Dung lng ti a ca a DVD l 4,7GB vi a mt mt v 8,5GB vi a 2 mt.- a DVD s dng tia laser hng ngo i c bc sng 650nm, ngn hn nhiu so vi bc

sng tia laser dng trong a CD nn c mt ghi cao hn nhiu so vi CD. - Tc truyn thng tin ca a DVD c tnh theo tc c s (1350KB/s) nhn vi h

s nhn. V d, a c tc c 4x th tc ti a c th c l 4 x 1350KB/s = 5400KB/s; nu a c tc c 16x th tc ti a c th c l 16 x 1350KB/s = 21600KB/s.

Cu hi 1.14: Nu nguyn l hot ng cachut quang.TL :Nguyn tc hot ng ca chut quang cth tm tt nhsau:Mt i-t pht nh sng qua ng knh chiuxung mt phng di chut; nh sng phn x tmt phng di chut quay ngc tr li pha dichut.Mt camera t pha di chut lin tc chpnh ca b mt di chut nh nh sng phn x.Tc chp l khong 1500 nh/giy.IC iu khin chut s phn tch v so snh ccnh k nhau v qua pht hin ra chuyn ngchut.Tn hiu biu din chuyn ng chut do ICiu khin chut sinh ra c chuyn cho mytnh x l.


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Cu hi loi 2 im

Cu hi 2.1: Nu s khi chc nng v chc nng chnh ca cc thnh phn trong mt hthng my tnh?

TL :S khi chc nng h thng my tnh nhhnh bn:

B x l trung tm (Central ProcessingUnit - CPU) c chc nng: c lnh t bnh, gii m v thc hin lnh.CPU bao gm:

- B iu khin (Control Unit - CU)- B tnh ton s hc v logic

(Arithmetic and Logic Unit - ALU)

- Cc thanh ghi (Registers)

B nh trong (Internal Memory) c chc nng: lu tr lnh (instruction) v d liu (data) choCPU x l.

B nh trong bao gm:- ROM (Read Only Memory): Lu tr lnh v d liu ca h thng, thng tin trong ROM

vn tn ti khi mt ngun nui.- RAM (Random Access Memory): Lu tr lnh v d liu ca h thng v ngi dng;

thng tin trong RAM s mt khi mt ngun nui.Cc thit b vo ra(Peripheral devices):Thit b vo (Input devices): nhp d liu v iu khin. Bao gm: Bn phm (Keyboard), Chut(Mice), a (Disk drives), My qut (Scanner)...Thit b ra (Output devices): kt xut d liu. Bao gm: Mn hnh (Monitor/screen), My in(Printer), My v (Plotter), a (Disk drives)...Bus h thng (system bus):

Bus h thng l mt tp cc ng dy kt ni CPU vi cc thnh phn khc ca my tnh. Bus h thng thng gm:- Bus a ch (Address bus) Bus A- Bus d liu (Data bus) Bus D- Bus iu khin (Control bus) - Bus C

Cu hi 2.2: Nu s v cc c im ca kin trc my tnh von-Neumann.Kin trc my tnh von-Neumann hin i khc kin trc my tnh von-Neumann c in nhngim chnh no?TL :Kin trc von-Neumann da trn 3 khi nim c s:

-

Lnh v d liu c lu tr trong b nh c ghi chia s;- B nh c nh a ch theo vng, khng ph thuc vo ni dung n lu tr; - Cc lnh ca mt chng trnh c thc hin tun t.

Cc lnh c thc hin theo 3 giai on (stages) chnh:- CPU c (fetch) lnh t b nh;- CPU gii m v thc hin lnh; nu lnh yu cu d liu, CPU c d liu t b nh;- CPU ghi kt qu thc hin lnh vo b nh (nu c).


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Cn b sung so snh gia hai kin trc ny:

Cu hi 2.3: Nu s v cc c im ca kin trc my tnh Harvard.Kin trc my tnh Harvard c nhng u im g so vi kin trc my tnh von-Neumann. Ccmy tnh hin i ngy nay s dng kin trc no?

TL : B nh c chia thnh 2 phn:- B nh lu m chng trnh- B nh lu d liuCPU s dng 2 h thng bus giao tip vi bnh:- Bus A, D v C giao tip vi b nh chng

trnh

- Bus A, D v C giao tip vi b nh d liu.So snh Kin trc Havard v Kin trc von-Neumann:

- Kin trc Harvard nhanh hn kin trc von-Neumann do bng thng ca bus ln hn.- H tr nhiu thao tc c/ghi b nh ti mt thi im gim xung t truy nhp b nh, c

bit khi CPU s dng k thut ng ng (pipeline).Tuy nhin h thng my tnh hin nay ph bin s dng kin trc von-Neumann hin i v kintrc ny t phc tp hn, r hnso vih thng dngkin trc Harvard, ngoi ra cc my tnh phn cp b nh nn tc c ci thin ng k. Hn na, kin trc von-Neumann ra i trcnn cc nh sn xut my tnh pht trin cng ngh sn xut trn nn tng ny, s thay i l rttn km.


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Cu hi 2.4: Nu s khi tng qut v chu trnh x l lnh ca CPU.

TL :CU : B iu khinALU : B s hc v logicInternal Bus : Bus trong CPU

A : Thanh ghi tch lu (Accumulator Register)PC : B m chng trnh.

IR : Thanh ghi lnhMAR : Thanh ghi a ch b nh.MBR : Thanh ghi m d liu.Y, Z : Thanh ghi tm thi.FR : Thanh ghi c.

Chu trnh x l lnh ca CPU1. Khi mt chng trnh c thc hin, h iuhnh (OS - Operating System) np m chng trnh vo b nh trong. 2. a ch ca nh cha lnh u tin ca chng trnh c np vo b m chng trnh PC. 3. a ch nh cha lnh t PC c chuyn n bus A thng qua thanh ghi MAR.

4. Bus A chuyn a ch nh n n v qun l b nh (MMU - Memory Management Unit).5. MMU chn ra nh v thc hin lnh c ni dung nh.6. Lnh (trong nh) c chuyn ra bus D v tip theo c chuyn tip n thanh ghi MBR; 7. MBR chuyn lnh n thanh ghi lnh IR; IR chuyn lnh vo b iu khin CU. 8. CU gii m lnh v sinh cc tn hiu iu khin cn thit, yu cu cc b phn chc nng nhALU thc hin lnh.9. Gi tr a ch trong b m PC c tng ln 1 n v v n tr n a ch ca nh cha lnhtip theo.10.Cc bc t 3-9 c lp li vi tt c cc lnh ca chng trnh.

Cu hi 2.5:Nu s khi v chc nng ca cc khi iu khin (CU) v khi tnh ton s

hc v logic (ALU).TL :S khi n viu khin CUn v iu khin CU (Control Unit) iu khinton b cc hot ng ca CPU theo xung nhpng hCU nhn 3 tn hiu u vo:

Lnh t IR Gi tr cc c trng thi Xung ng h

CU sinh 2 nhm tn hiu u ra: Nhm tn hiu iu khin cc b phn

bn trong CPU;

Nhm tn hiu iu khin cc b phn bn ngoi CPUCU s dng nhp ng h ng b cc n v chc nng trong CPU v gia CPU vi cc bphn bn ngoi.


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n v s hc & logic ALUALU (Arithmetic and Logic Unit) bao gm mt lot ccn v chcnng con thc hin cc php ton s hcv logic:

- B cng (ADD), b tr (SUB), b nhn (MUL), bchia (DIV),....

- Cc b dch (SHIFT) v quay (ROTATE)-

B ph nh (NOT), b v (AND), b hoc (OR) vb hoc loi tr (XOR)5tALU c:

- 2 cng vo IN: nhn ton hng t cc thanh ghi. - 1 cng ra OUT: kt ni vi bus trong chuyn kt

qu n thanh ghi.

Cu hi 2.6:Lnh my tnh l g? Chu k lnh l g? Nu cc pha in hnh trong chu k thc hin lnh. Nu dng lnh tng qut vcc thnh phn ca n.

TL :

Lnh my tnh (Computer Instruction) l mt t nh phn (binary word) c gn mt nhim vc th. Cc lnh ca chng trnh c lu trong b nh v chng ln lt c CPU c, gii mv thc hin.

Chu k thc hin lnh (Instruction execution cycle): l khong thi gian m CPU thc hin xongmt lnh:- Mt chu k thc hin lnh c th gm mt s giai on thc hin lnh.- Mt giai on thc hin lnh c th gm mt s chu k my.- Mt chu k my c th gm mt s chu k ng h. Vic thc hin lnh c th c chia thnh cc pha (phase) hay giai on (stage). Mi lnh c th

c thc hin theo 4 giai on:- c lnh (Instruction fetch - IF): lnh c c t b nh v CPU;- Gii m (Instruction decode - ID): CPU gii m lnh;- Thc hin (Instruction executionEX): CPU thc hin lnh;- Lu kt qu (Write back - WB): kt qu thc hin lnh (nu c) c lu vo b nh.Dng tng qut ca lnh gm 2 thnh phn chnh:

- M lnh (Opcode - operation code): milnh c m lnh ring

- a ch ca cc ton hng (Addresses ofOperands): mi lnh c th gm mthoc nhiu ton hng.

C th c cc dng a ch ton hng sau: 3 a ch; 2 a ch; 1 a ch; 1,5 a ch; 0 a ch.


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Cu hi 2.7:Nu cc dng a ch ca lnh. Cho v d minh ho vi mi dng a ch.

TL :Ton hng 3 a ch:Dng: opcode addr1, addr2, addr3Mi a ch addr1, addr2, addr3 tham chiu n mt nh hoc mt thanh ghi. V d:

ADD R1, R2, R3; R1 R2 + R3

R2 cng vi R3, kt qu gn vo R1.(Ril thanh ghi ca CPU) ADD A, B, C; M[A] M[B] + M[C]

A, B, C l a ch cc nh.Ton hng 2 a ch:Dng: opcode addr1, addr2Mi a ch addr1, addr2 tham chiu n mt nh hoc mt thanh ghi.V d:

ADD R1, R2; R1 R1 + R2R1 cng vi R2, kt qu gn vo R1. (Ri l thanh ghi ca CPU)

ADD A, B; M[A] M[B] + M[B]A, B l a ch cc nh.

Ton hng 1 a ch:Dng: opcode addr1a ch addr1 tham chiu n mt nh hoc mt thanh ghi. dng 1 a ch, thanh ghi tch lu A(Accumulator) c s dng nh a ch addr2 trong dng 2a ch.V d:

ADD R1; Racc Racc + R1R1 cng vi Racc, kt qu gn vo Racc.R1 l thanh ghi ca CPU.

ADD A; Racc Racc + M[A]A l a ch mt nh.

Ton hng 1,5 a ch:

Dng: opcode addr1, addr2Mt a ch tham chiu n mt nh v a ch cn li tham chiu n mt thanh ghi. Dng 1,5a ch l dng hn hp gia nh v thanh ghi.V d:

ADD A, R1; M[A] M[A] + R1Ni dung nh A cng vi R1, kt qu lu vo nh AR1 l thanh ghi ca CPU v A l a ch mt nh.

Ton hng 0 a ch:c s dng trong cc lnh thao tc vi ngn xp: PUSH v POP.


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Cu hi 2.8:C ch x l xen k dng lnh (ng lnh pipeli ne) lg ?Nu cc c im ca c ch ng lnh.TL :C ch ng lnh (pipeline) hay cngi l c ch thc hin xen k cc lnhca chng trnh l mt phng php

thc hin lnh tin tin, cho php ngthi thc hin nhiu lnh, gim thigian trung bnh thc hin mi lnh vnh vy tng c hiu nng x llnh ca CPU.

Vic thc hin lnh c chia thnhmt s giai on v mi giai onc thc thi bi mt n v chcnng khc nhau ca CPU. Nh vy CPU c th tn dng ti a nng lc x l ca cc n v chcnng ca mnh, gim thi gian ch cho tng n v chc nng.C nhiu lnh ng thi c thchin gi nhau trong CPU v hu ht cc n v chc nng ca CPU lin tc tham gia vo qu trnh

x l lnh. S lng lnh c x l ng thi ng bng s giai on thc hin lnh.

c im ca c ch ng lnh:

- L dng x l song song mc lnh (instruction level parallelism (ILP)). - Mt pipeline l y (fully pipelined) khi n lun tip nhn mt lnh mi ti mi chu k ng

h.-Ngc li, mt pipeline l khng y khi c mt s chu k tr trong tin trnh thc hin.- S lng cc giai on (stages) trong pipeline ph thuc vo thit k vi x l:

2,3, 5 giai on (pipeline n gin) 14 giai on (PII, PIII) 20-31 giai on (P4)

12-15 giai on (Core)

Cu hi 2.9:Nu cu trc phn cp ca h thng b nh mytnh.Ti sao cu trc phn cp ca h thng b nh c th gip tng hiu nng v gim gi thnh snxut my tnh?

TL :Cu trc phn cp h thng b nhc th hin nh hnh bn.Trong cu trc phn cp h thng nh,dung lng cc thnh phn tng theo

chiu t cc thanh ghi ca CPU n bnh ngoi. Ngc li, tc truy nhphay bng thng v gi thnh mt n vnh tng theo chiu t b nh ngoi ncc thanh ghi ca CPU. Nh vy, ccthanh ghi ca CPU c dung lng nhnht nhng c tc truy cp nhanh nht v cng c gi thnh cao nht. B nh ngoi c dunglng ln nht, nhng tc truy cp thp nht. B li, b nh ngoi c gi thnh r nn c thc s dung vi dung lng ln.


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CPU registers (cc thanh ghi ca CPU): Dung lng rt nh, khong t vi chc

bytes n vi KB Tc truy nhp rt cao (cc thanh ghi

hot ng vi tc ca CPU); thi gian truy nhp khong

0,25ns Gi thnh t S dng lu ton hng u vo v kt

qu ca cc lnh.

Cache (b nh cache): Dung lng tng i nh (khong

64KB n 32MB) Tc truy nhp cao; thi gian truy

nhp khong 1-5ns Gi thnh t

Cn c gi l b nh thng minh(smart memory) S dng lu lnh v d liu cho CPU

x l.

Main memory (b nh chnh): Gm ROM v RAM, c kch thc kh ln; vi h thng 32 bt, dung lng khong

256MB-4GB

Tc truy nhp chm; thi gian truy nhp khong 50-70ns Gi thnh tng i r S dng lu lnh v d liu ca h thng v ca ngi dng.

Secondary memory (b nh th cp b nh ngoi): C dung lng rt ln, khong t 20GB-1000GB Tc truy nhp rt chm; thi gian truy nhp khong 5ms Gi thnh r S dng lu d liu lu di di dng cc tp (files).

Vai tr ca vic phn cp h thng b nh: Tng hiu nng h thng

Dung ho c CPU c tc cao v phn b nh chnh v b nh ngoi c tc thp; Thi gian trung bnh CPU truy nhp d liu t h thng nh tim cn thi gian truy nhp

cache.Gim gi thnh sn xut

Cc thnh phn t tin (thanh ghi v cache) c s dng vi dung lng nh; Cc thnh phn r tin hn (b nh chnh v b nh ngoi) c s dng vi dung lngln;

Tng gi thnh ca h thng nh theo m hnh phn cp s r hn so vi h thng nh khngphn cp c cng tc .

Cu hi 2.10:Phn bit b nh RAM tnh v RAM ng.

Ti sao b nh RAM ng cn qu trnh lm ti v RAM ngthng r hn RAM tnh?

TL :SRAM (Static Ram) l loi RAM s dng mt mch lt trigo lng

n lu mt bit thng tin. Thng tin trong SRAM lun n nh vkhng phi lm ti nh k. Tc truy nhp SRAM cngnhanh hn nhiu so vi DRAM.

Mi mch lt lu 1 bit thng s dng 6, 8 hoc 10transitors (gi l mch 6T, 8T hoc 10T);SRAM thng c tc truy nhp nhanh do cc bit ca SRAM c cu trc i xng, Cc mchnh SRAM chp nhn tt c cc chn a ch ti mt thi im (khng dn knh).


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DRAM (Dynamic Ram): Mi bit DRAM da trn mt t in v mttransitor:Hai mc tch in ca t biu din 2 mc logic 0 v 1: Khng tch in: mc 0 Tch y in: mc 1.

Thng tin lu trong cc bit DRAM khng n nh v phi c lmti nh k. DRAM chm hn nhng r hn SRAM.

RAM ng cn qu trnh lm tiv t thng t phng in, intch trong t c xu hng b tn hao theo thi gian nn:

Cn np li thng tin trong t thng xuyn trnh mt thngtin.

Vic np li thng tin cho t l qu trnh lm ti (refresh), phi theo nh k.DRAM thng r hn SRAM do:

Mi bt SRAM dng nhiu transitor hn so vi 1 bit DRAM Do cu trc bn trong ca SRAM bit phc tp hn nn mt cy linh kin trong SRAM

thng thp.

Cu hi 2.11:B nh cache l g?Nu vai tr ca cache. Gii thch hai nguyn l hot ng ca cache.

TL :Cache hay cn gi l b nh m l mt thnh phn trong h thng nh phn cp ca my tnh,cache ng vai trong trung gian, trung chuyn d liu t b nh chnh v CPU v ngc li. Vai tr ca cacheTng hiu nng h thng

Dung ho c CPU c tc cao v b nh chnh c tc thp; Thi gian trung bnh CPU truy nhp d liu t h thng nh tim cn thi gian truy nhp

cache.Gim gi thnh sn xut

Nu hai h thng nh c cng gi thnh, h thng nh c cache c tc truy nhp nhanhhn;

Nu hai h thng nh c cng tc , h thng nh c cache c gi thnh r hn.Cc nguyn l hot ng cacacheCache c coi l b nh thng minh:

Cache c kh nng on trc yu cu v d liu v lnh ca CPU; D liu v lnh cn thit c chuyn trc t b nh chnh v cache CPU ch truy

nhp cache gim thi gian truy nhp h thng nh.Cache hotng da trn 2 nguyn l c bn:

Nguyn l ln cn v khng gian (Spatial locality) Nguyn l ln cn v thi gian (Temporal locality)

Nguyn l ln cn v khng gian:Nu mt nh ang c truy nhp th xc xut cc nh lin k vi n c truy nhp

trong tng lai gn l rt cao;p dng:

Ln cn v khng gian c p dng cho nhm lnh/d liu c tnh tun t cao trongkhng gian chng trnh;


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Gii thch: Do cc lnh trong mt chng trnh thng tun t cache c c khi lnh t b nh

chnh ph c cc nh ln cn ca nh ang c truy nhp. Nguyn l ln cn v thi gian:

Nu mt nh ang c truy nhp th xc xut n c truy nhp li trong tng lai gnl rt cao;p dng:

Ln cn v thi gian c p dng cho d liu v nhm lnh trong vng lp; Gii thch: Cc phn t d liu thng c cp nht, sa i thng xuyn;

Cache c c khi lnh t b nh chnh ph c c khi lnh ca vng lp.

Cu hi 2.12: So snh cc chun ghp ni a cng IDE, SATA v SCSI.

TL :

IDE SATA SCSI

Ging nhau u l cc giao din ghp ni a cng vi my tnh

Khc nhau

ATA/IDE s dng cpdt 40 hoc 80 si ghp ni cng vi bngmch chnh;

SATA s dng cng tplnh mc thp nh ATAnhng SATA s dngng truyn tin ni tiptc cao qua 2 i dy;

SCSI l mt tp ccchun v kt ni vt l vtruyn d liu giamy tnh v thit b ngoivi;

Mi cp thng h trghp ni vi 2 a

Tt c cc thit b SCSIu kt ni n bus SCSItheo cng mt kiu

u im

Truy n d liu nhanh vhiu quCm nngS dng t dy hn ATA truyn d liu.

SCSI cung cp tc

truyn d liu v tnh nnh rt cao;Cm nng

Nhc im

Tc truyn d liucn chm Cc cng SCSI thng

rt t


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Cu hi 2.13: Trnh by nguyn l c thng tin trn a CD.

TL :Nguyn l c CD-ROM Tia laser t it pht laser i qua

b tch tia n gng quay;

Gng quay c iu khin bitn hiu c, li tia laser n v trcn c trn mt a;

Tia phn x t mt a phn nhmc li lm trn mt a quay trli gng quay;

Gng quay chuyn tia phn xv b tch tia v sau n bcm bin quang in;

B cm bin quang in chuyn i tia laser phn x thnh tn hiu in u ra. Cng catia laser c biu din thnh mc tn hiu ra.

Cu hi 2.14: Nu nguyn l hot ng ca my in laser.

TL :

My in laser hot ng da trnnguyn tc chp nh in tbng tia laser. C th:

Trng cm quang c npmt lp in tch nh 1 in

cc;

Tia laser t ngun snglaser i qua mt gng quayv b iu ch tia c iukhin bi tn hiu cn in nmt trng;

nh sng laser lm thay imt in tch trn mttrng; Mt in tch trn mt trng thay i theo tn hiu cn in;

Khi trng cm quang quay n hp mcth in tch trn trng ht cc ht mc c tch intri du. Cc ht mc dnh trn trng biu din m bn ca vn bn/thng tin cn in;

Giy t khay c ko ln cng c in cc np in tch tri du vi in tch ca mc nnht cc ht mc khitrng cm quang.

Giy tip tc i qua trng sy nng lm cc ht mc chy ra v b p cht vo giy.


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Cu hi 2.15: Nu nguyn l to hnh nh ca mn hnh LCD.

TL :

Cc tinh th lng khng th t pht sng, chng c kh nng iu khin lng nh sng i quatheo nhit v dng in.

C 2 loi LCD da trn phng php iu khin:

LCD ma trn th ng (Passive matrix):

S dng li hoc ma trn nh ngha tng im nh (pixel) bi hng v ct ca n. Mt imnh (giao gia 1 hng v 1 ct) c kch hot khi in p c t vo ct v dng tng ngc ni t.

LCD ma trn ch ng (Active matrix):S dng mt TFT (Thin Film Transistor) iu khin mt phn t LCD. Cc TFT hot ngtng t nh cc b chuyn mch.

Nguyn l TFT LCD:

- TFT LCD l thit b c iu khin bng cc tn hiu in.- Lp tinh th lng nm gia 2 lp trong sut cha cc in cc ITO (Indium Tin Oxide).-

Cc phn t tinh th lng c sp t theo cc hng khc nhau theo s thay i in pt vo cc in cc ITO;- Hngca cc phn t tinh th lng trc tip nh hng n cng nh sng i qua v

n gin tip iu khin mc sng/ti (cn gi l mc xm) ca nh hin th;- Mu ca hnh nh c to bi mt lp lc mu;- Mc xm ca cc im nh c thit lp theo mc in p ca tn hiu video a vo.


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Cu hi loi 3 im

Cu hi 3.1: Nu s v c imca hai dng kin trc cache:Look Aside v Look Through. Trong hai dng kin trc trn, dng no c s dng nhiu hntrong thc t hin nay? Ti sao?

TL:

CacheLook asideSRAM: RAM lu d liu cacheTag RAM: RAM lu a ch b nhCache v b nh chnh cng kt ni vi bush thng;Cache v b nh chnh thy chu k bus caCPU ti cng mt thi im;u im:

Thit k n gin Miss nhanh

Nhc im: Hit chm

CacheLook throughSRAM: RAM lu d liu cacheTag RAM: RAM lu a ch b nhCache nm gia CPU v b nh chnh;Cache thy chu k bus ca CPU trc, sau n chuyn chu k bus cho b nh chnh;u im:

Hit nhanhNhc im:

Thit k phc tp

t tin Miss chm

B sung gii thch:

........

.... .....

.........

.......


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Cu hi 3.2: So snh 3 phng php nh x cache:nh x trc tip, nh x kt hp y v nh x tp kt hp? Phng php nh x no trong ccphng php trn c s dng nhiu nht trong thc t? Ti sao?

TL :

Tiu ch nh x trc tip nh x kt hp y nh x tp kt hp

Ging Cng l phng php nh x cache-mem

Cache c chia thnh cc dng

Khc nhau

B nh m trang 1 trang m trang

nh x

nh x dng ca trang n

dng ca ng (nh x cnh)

Mt dng trong b nhc th c nh x vo

mt dng bt k trongcache;

nh x trang n ng(nh x mm do):Mt trang ca b nhc th nh x n mt

ng bt k ca cachenh x dng ca trangn dng ca ng(nh x c nh).

u im

Thit k n gin

Nhanh do nh x l c nh:khi bit ch nh c th tmc v tr ca n trong cachert nhanh chng.

Gim c xung t donh x l khng c nhH s Hit cao hn nh xtrc tip.

Nhanh do nh x trctip c s dng chonh x dng (chim s

ln nh x);Gim xung t do nhx t cc trang b nhn cc ng cache lmm do.H s Hit cao hn.


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Nhc i m Do nh x c nh nn d gyxung tH s hit khng cao.

Chm do c n phi tm ach nh trong cachePhc tp do cn c n bso snh a ch b nhtrong cache.Thng c s dngvi cache c dung lng

nh.

Phc tp trong thi t kv iu khin v cachec chia thnh mt sng.

Cu hi 3.3: Nu cc phng php c ghi v cc chnh sch thay th dng cache.Ti sao thay th dng cache s dng phng php LRU c kh nng cho h s on trng (hit) caonht?

TL :c thng tin:

+Trng hp hit (mu tin cn c c trong cache) Mu tin c c t cache vo CPU; B nh chnh khng tham gia.

+Trng hp miss (mu tin cn c khng c trong cache) Mu tin trc ht c c t b nh chnh vo cache; Sau n c chuyn t cache vo CPU.

y l trng hp miss penalty: thi gian truy nhp mu tin bng tng thi gian truy nhp cachev b nh chnh.Ghi thng tin:+Trng hp hit (mu tin cnghi c trong cache) Ghi thng (write through): mu tin c ghi ng thi ra cache v b nh chnh;

Ghi tr (write back): mu tin trc ht c ghi ra cache v dng cha mu tin c ghi ra bnh chnh khi dng b thay th.+Trng hp miss (mu tin cn ghi khng c trong cache) Ghi c c li (write allocate / fetch on write): mu tin trc ht c ghi ra b nh chnh v

sau dng cha mu tin c c vo cache; Ghi khng c li (write non-allocate): mu tin ch c ghi ra b nh chnh (dng cha mu

tin khng c c vo cache).Chnh sch thay th (replacement policies) xc nh cc dng cache no c chn thay th bicc dng khc t b nh.Cc chnh sch thay th:

Ngu nhin (Random) Vo trc ra trc (FIFO)

Thay th cc dng t c s dng gn y nht (LRU). Thay th cc dng t c s dng gn y nht (LRULeast Recently Used): Cc dng cache t c s dng gn y nht c la chn thay th. u: C h s miss thp nht so vi thay th ngu nhin v thay th FIFO Do thay th LRU c xem xt n cc dng ang c s dng


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Cu hi 3.4: RAID lg?Ti sao RAID c th nng cao c tnh tin cy v tc truy nhp h thng lu tr? Cu hnhRAID no ph hp hn vi my ch c s d liu trong ba loi RAID 0, RAID 1 v RAID 10?TL :RAID (Redundant Array of Independent Disks) l mt cng ngh to cc thit b lu tr tin tintrn c s a cng, nhm t c cc mc ch:Tc cao (High performance / speed)

Tnh tin cy cao (High reliability)Dung lng ln (Large volume)RAID:Mt mng ca cc a cng;Cc a cng theo chun SATA v SCSI mi h tr to RAID.

Hai k thut chnh c s dng trong RAID:To lt a (Disk Stripping):Ghi: D liu c chia thnh cc khi, mi khi c ghi ng thi vo mt a c lp;c: Cc khi d liu c c ng thi cc a c lp, v c ghp li to d liu honchnh.

Tc truy nhp c ci thin.Soi gng a (Disk Mirroring):Ghi: D liu c chia thnh cc khi, mi khi c ghi ng thi vo nhiu a c lp;Ti mi thi im ta lun c nhiu hn 1 bn sao vt l ca d liu.Tnh tin cy c ci thin.RAID 10

u im:An ton cao: do ti mi thi im RAID lun cha nhiu bn copy ca d liu cc a vt lkhc nhau.

Nhanh: tc truy nhp t l vi s a ca RAID.....


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Cu hi 3.5: Nu cc c im chnh ca kin trc bus PCI v PCI-Express.Ti sao bus PCI-Express c kh nng h tr nhiu cp thit b truyn d liu ng thi vi tc cao?

TL :Bus PCI ExpressKin trcPCI Express c cu trc t cc lin kt ni tip im n im;Mt cp lin kt ni tip (theo 2 chiu ngc nhau) to thnh mt lung (lane);

Cc lung c nh tuyn qua mt b chuyn mch (crossbar switch) trn bng mch chnh; Cc khe cm PCI Express vt l c th cha t 1 n 32 ln. PCI Express s dng giao thc truyn ni tip v trnh c vn timing skew (lch thi

gian)mt trong cc yu t lm gim tc : Cc loi bus song song (ISA,PCI, AGP) i hi tt c cc bit ca mt n v d liu phi

n ch ti mt thi im; Do vn timing skew, cc bt ca mt n v d liu c th khng n ch ng thi gy

kh khn cho vic khi phc n v d liu; Phng thc truyn ni tip khng gp phi vn timing skew do giao thc ny khng

i hi tt c cc bit ca mt n v d liu phi n ch ti mt thi im.

Cu hi 3.6: C ch ng lnh (pipeline) ca CPU thng gp phi nhng vn g?Nu mt hng gii quyt xung t d liu trong pipeline khi thc hin on chng trnh sau:ADD R4, R4, #300 ; R4 R4+300ADD R1, R2, R3 ; R1 R2+R3CMP R1, #100 ; so snh R1 vi 100SUB R5, #2000 ; R5 R5 - 2000bit rng mi lnh c chia thnh 5 giai on trong pipeline: c lnh(IF), gii m & c tonhng (ID), truy nhp b nh (MEM), thc hin (EX) v lu kt qu (WB). TL :


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Cu hi 3.7: C ch ng lnh (pipeline) ca CPU thng gp phi nhng vn g?Nu mt hng gii quyt xung t d liu trong pipeline khi thc hin on chng trnh sau:ADD R4, R4, #300 ; R4 R4+300ADD R1, R1, R3 ; R1 R1+R3SUB R1, R1, #100 ; R1 R1 - 100SUB R5, #2000 ; R5 R5 - 2000bit rng mi lnh c chia thnh 5 giai on trong pipeline: c lnh (IF), gii m & c ton

hng (ID), truy nhp b nh (MEM), thc hin (EX) v lu kt qu (WB). TL :

Cu hi 3.8: Cho on chng trnh sau (R1, R2 l cc thanh ghi):

Lnh ngha Ch GT R2LOAD R2, #400

LOAD R1, #1200

STORE (R1), R2

SUBSTRACT R2, #15

ADD 1200, #10

ADD R2, (R1)


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Cu hi 3.9: Cho on chng trnh sau (R1, R2 l cc thanh ghi):

Lnh ngha Ch GT R2LOAD R2, #500

LOAD R1, #2000

STORE (R1), R2

ADD 2000, #30

SUBSTRACT R2, #15

ADD R2, (R1)

Cu hi 3.10:Cho mt dy s nguyn gm 10 phn t lu trong b nh bt u t a ch 1000.Vit chng trnh s dng tp lnh ca CPU tnh:

a. Tng ca cc s dng lu kt qu vo nh c a ch 2000.

b. Tng ca tt c cc s trong dy lu ktqu vo nh c a ch 2010.

TL :

....

..........

Giải Ngân hàng thi Kiến trúc máy tính

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