lecture unit1 mca

7/26/2019 Lecture Unit1 Mca

1/99

Unit 1

Introduction to Microcontrollers

Prepared By,

ANILKUMAR PATIL M.Tech, (Ph.D).,

Asst Prof- E&TC

[email protected]


2/99

Introduction A decade back the process and control operations were totally

implemented by the Microprocessors only. But now a days the situation

is totally changed and it is occupied by the new devices called

Microcontroller. The development is so drastic that we cant find any

electronic gadget without the use of a microcontroller. This

microcontroller changed the embedded system design so simple and

advanced that the embedded market has become one of the most sought

after for not only entrepreneurs but for design engineers also.

!hat is a Microcontroller"

A single chip computer or A CP with all the peripherals like !AM"

!#M" $%# Ports" Timers " A&Cs etc... on the same chip. 'or e()

Motorolas *+,," $ntels +-," /ilogs /+ and P$C ,*0 etc1

DYPIEMR AKURDI-4406/09/16


3/99

MI#$%P$%#&''%$' MI#$%#%T$%**&$'

Microprocessor+ #PU -uilt into a sinle *'I chip is called a microprocessor. It is a eneral/purpose de0ice

and additional eternal circuitr2 are added to make it a microcomputer. The microprocessorcontains arithmetic and loic unit (*U), Instruction decoder and control unit, Instruction

reister, Proram counter (P#), clock circuit (internal or eternal), reset circuit (internal or

eternal) and reisters. 3ut the microprocessor has no on chip I4% Ports, Timers , Memor2 etc.

5or eample, Intel 8687 is an 8/-it microprocessor and Intel 86848688 a 1/-it microprocessor.

The -lock diaram o the Microprocessor is sho:n in 5i.1



4/99

MI#$%#%T$%**&$+

microcontroller is a hihl2 interated sinle chip, :hich consists o on chip #PU (#entralProcessin Unit), $M ($andom ccess Memor2), &P$%M4P$%M4$%M (&rasa-leProramma-le $ead %nl2 Memor2), I4% (input4output) ; serial and parallel, timers, interrupt

controller.

5or eample, Intel 8671 is 8/-it microcontroller and Intel 869 is 1/-it microcontroller. The-lock diaram o Microcontroller is sho:n in 5i.


5/99

Dierence -et:een MPU and M#U



6/99



7/99

on eumann rchitecture) $t has single memory storage to hold both program instructionsand data i.e. common program and data space. The CP can either read an instruction or data

from the memory one at a time 2or write data to memory3 because instructions and data areaccessed using same bus system. The 4on 5eumann Architecture is named after the mathematicianand computer scientist 6ohn 4on 5eumann. The basic organi7ation of memory in this architecture is

shown in figure ,.8. The advantage of 4on 5eumann architecture is simple design of microcontroller chip because only

one memory is to be implemented which in turn reduces re9uired hardware.

The disadvantage is slower e(ecution of a program. $t is also referred as Princeton architecture asit was developed at Princeton niversity. Motorola *+:C,, microcontroller is based on

4on5eumann architecture.



8/99

>ar0ard rchitecture+$t has physically separate memory storage to hold programinstructions and data i.e. separate program and data space. ;ince it has separatebuses to access program and data memory" it is possible to access program memoryand data memory simultaneously. The organi7ation of memory and buses in thisarchitecture is shown in figure ,.+.

The advantage of a :arvard architecture microcontroller is that it is faster for a givencircuit comple(ity because it offers greater amount of parallelism. The disadvantage isthat it re9uires more hardware" because two sets of buses and memory blocks arere9uired. MC; , 2+-, family3 and P$C microcontrollers are based on :arvardarchitecture



9/99

>ar:ard and on eumann architecture



10/99

$I'# and #I'# comparison



11/99

CISC RISC

Greater no. of Instructons !esser no. of nstructons

Genera""# no nstructon $$e"nn% feature Instructon P$e"nn% an& ncrease&e'ecuton s$ee&

(on )rt*o%ona" Instructon +et ,A""nstructons are not a""oe& to o$erate onan# re%ster an& use an# a&&ressn% o&e.It s nstructon s$ecfc

)rt*o%ona" Instructon +et ,A""os eac*nstructon to o$erate on an# re%ster an&use an# a&&ressn% o&e

)$eratons are $erfore& on re%sters oreor# &e$en&n% on t*e nstructon

)$eratons are $erfore& on re%sterson"# t*e on"# eor# o$eratons are "oa&an& store

!te& no. of %enera" $ur$ose re%sters !ar%e nuer of re%sters are a2a"a"e

Instructons are "3e acros n "an%ua%e. Pro%raer nee&s to rte ore co&e to

e'ecute a tas3 snce t*e nstructons ares$"er ones

5ara"e "en%t* Instructons +n%"e 'e& "en%t* Instructons

More s"con usa%e !ess +"con usa%e an& $n count

7ar2ar& or 5on-(euann Arc*tecture 8t* 7ar2ar& Arc*tecture

06/09/16 DYPIEMR AKURDI-44


12/99

Disad0antaes o microprocessor

The o0erall s2stem cost is hih

lare si?ed P#3 is re=uired or

assem-lin all the components %0erall product desin re=uires more time

Ph2sical si?e o the product is -i

discrete components are used, thes2stem is not relia-le



13/99

d0antaes o Microcontroller

-ased '2stem s the peripherals are interated into a sinle chip, the o0erall

s2stem cost is 0er2 less

The product is o small si?e compared to micro processor -ased

s2stem The s2stem desin no: re=uires 0er2 little eorts

s the peripherals are interated :ith a microprocessor the

s2stem is more relia-le

Thouh microcontroller ma2 ha0e on chip $%M,$M and I4%

ports, addition $%M, $M I4% ports ma2 -e interaced

eternall2 i re=uired

%n chip $%M pro0ide a sot:are securit2



14/99

pplications o Microcontrollers 3iomedical instrumentations

*#D Displa2 cum recorder

3lood cell recorder cum nal2?er

Patient monitor s2stem

#ommunication '2stems

umeric Paer

cellular phones ca-le T terminals

5A

0ideo ames etc..

Peripheral controllers

ke2-oard controller D$M controller

printer controller

*'&$ controller

* controller etc..



15/99



16/99

'ur0e2 o 8 -it MicrocontrollersPI# 1#7A4AA+

1.Microchip technolo2 makes the PI# 1#7A4AAamil2 o 8/-it microcontroller chip

?, can run at lo:er

speed to sa0e ener2

C.The2 ha0e rom 71< to < 3 o $%M

B.


17/99

Comparison of the 8051 FamilyMembers

$%M t2pe

86C1 no $%M 86 mask $%M

8E &P$%M

89 5lash &&P$%M

89

8971 897#11

It uses either U erasa-le orelectronicall2 erasa-le memor2 or

permanent storae

Upto E8 -2tes o $M Upto C M>? clock re=uenc2


20/99

8671 5amilies and eatures



21/99

MotorolaGs 8>#11 5eatures



22/99

!hat is &m-edded '2stemHHH"



23/99



24/99

#haracteristics o &m-edded s2stem

'inle 5unctioned+ n &m-edded '2stem can eecute a speciic unctionrepeatedl2 i.e., dedicated unction. s an eample, ir conditioner :ill -e coolin

the room. #oolin is its dedicated unctionalit2 and it cannot -e used or an2other purposes.

Tihtl2 #onstraint + !hate0er s2stem is -ein desined, the2 ha0e constraints.

&m-edded '2stems are also tihtl2 constraint in man2 aspects. 5e: aspects are

-ein anal2?ed here. 1. Manuacturin #ost


25/99

#omple lorithms + The processor inside the em-edded s2stem shouldperorm operations that are comple in nature. n eample is diital camera. It

is used to take color photoraphs, motion pictures, -lack and :hite pictures, etc.

User Interace + >ere too :ith an eample the concept can -e eplained.

%I mo-ile phones are 0er2 -i hit in market riht, !h2" !hat is thereason" Is that -ecause other mo-ile did not perorm :ell" o, is the ans:er.

okia had ecellent and simple user interace. #alls can -e made and recei0ed

0er2 easil2. T2pin 'M' is also easierH 'o it has -een read -2 the people 0er2

:ell.

'o desinin s2stem :ith easier and comorta-le interace is most important.

lso it should ha0e options re=uired or the operation o the de0ice. &ample isTM machineK it has ot comorta-le interaces and options. eep it in mind

and desin the s2stem.

Multi $ate+ &m-edded '2stems need to control and dri0e certain operations atone rate and certain other operations at dierent rate. &ample can -e Diital

#amera. It is used to take pictures :hich are still. lso it is capa-le o shootin

0ideo. 'o it has to -e capa-le o dri0in the irst operation rom a speed dierent

than the second one.



26/99

*imitations o 8 -it Microcontrollers

Data -us :idth limits speed o eecution

ddressa-le memor2 is limited or i0en application

er2 small $M 5lash memor2

Does not ha0e hih perormance interrupt s2stem

Does not ha0e DM cache memor2 or aster

eecution

Does not ha0e memor2 protection unit MPU

Does not ha0e protected modes o operation #an not implement $T%' :hich current need o

em-edded s2stem



27/99

Three criteria in Choosing aMicrocontroller

meetin the computin needs o the task eicientl2 andcost eecti0el2 speed, the amount o $%M and $M, the num-er o I4% ports

and timers, si?e, packain, po:er consumption

eas2 to uprade cost per unit

oise o en0ironment

a0aila-ilit2 o sot:are de0elopment tools

assem-lers, de-uers, # compilers, emulator, simulator,technical support

:ide a0aila-ilit2 and relia-le sources o themicrocontrollers



28/99

5eatures Taken into consideration selectin

an Microcontrollers



29/99



30/99

$oll % Microcontroller In

&m-edded '2stem



31/99

5acts and iures o &m-edded

'2stem

L%0er B -illion em-edded processors :ere

sold last 2ear and the lo-al market is

:orth 6 -illion :ith annual ro:thrates o 1BN.

L5orecasts predict more than 1 -illion

em-edded de0ices -2


32/99

ro:th $ate

Lutomoti0e (CN),

LIndustrial utomation (


33/99

$ole o &m-edded '2stem

L5or eample, in the case o a modern car,-2


34/99

>ard:are 'ot:are Tools ssem-ler e MP'M ree

#ompilers #18,>i Tech,I$,'D## ##',micro# Do not use Mikro#initiall2

ID& MP*3 or PI# ree

'imulators -uilt in :ith ID& or Proteus, PI# 'imulator

as separate -ut not ree Prorammer, -oot loader no special prorammer in

PI#185B776,U'3 prorammin is desira-le

De0elopment -oard is 0er2 useul or learnin testin

the prorams independentl2 on ne: controller should-e lo: cost



35/99

'ot:are and hard:are tools or de0elopment o

microcontroller

Levels of Programming Languages

1) Machine Language Consists of individual instructions that will be

executed by the CPU one at a time

2) ssembly Language !Low Level Language) "esigned for a s#eci$c family of #rocessors !di%erent

#rocessor grou#s&family has di%erent ssemblyLanguage)

Consists of symbolic instructions directly related tomachine language instructions one'for'one and areassembled into machine language(

) *igh Level Languages e(g( + C, C-- and .basic

"esigned to eliminate the technicalities of a#articular com#uter(

/tatements com#iled in a high level language ty#icallygenerate many low'level instructions(


36/99

d0antaes o ssem-l2 *anuae

1( /hows how #rograminterfaceswiththe #rocessor, o#erating system, and0/(

2( /hows how datais re#resentedand

storedin memory and on externaldevices(

( Clari$es how #rocessoraccessesandexecutesinstructions and howinstructions access and #rocess data(

3( Clari$es how a #rogramaccessesexternal devices(


37/99

>ierarch2 o *anuaes


38/99

#ompiler and ssem-ler


39/99

Tools used or ssem-l2 *anuae

de0elopment

&ditor

ssem-ler

*inker

*oader

De-uer

&mulator


40/99


41/99

&ditor

It helps the user to create a ile thatcontains assem-l2 lanuae statements

The editor stores the '#II codes or theletters and num-ers in the successi0e $Mlocations

The ile is called as the source ile and an

'M etension is i0en to it &ample o editor ; :ordpad,

notepad,:ordstar etc


42/99

ssem-ler

ssem-ler is a proram :hich translates themnemonics into correspondin -inar2 codes.

%peration o ssem-ler

1) It reads the source ile o proram


43/99

*inkers

*inker is a proram :hich is used or Ooininman2 o-Oect iles into one lare o-Oect ile

'earches proram li-raries to ind li-rar2

routines used -2 the proram*i-rar2+ collection o pre/:ritten unctions and

su-routines made a0aila-le to perorm commonl2re=uired acti0ities

Determines the memor2 locations that code rom

each module :ill occup2 and relocatesinstructions -2 adOustin a-solute reerences

$esol0es reerences amon iles

*a$ter 1: Pro%ran% ;oo"s 1:-4<


44/99

*inkin

*a$ter 1: Pro%ran% ;oo"s 1:-44

)=ect

f"e or o=ect

o&u"e

)=ect f"e

"rar#

E'ecuta"e

f"e!n3er


45/99

*ocator

The locator is a proram :hich is used

or assinin the speciic address o the

locations :here the sements o theo-Oect code are to -e loaded into the

memor2


46/99

De-uer

sot:are tool that is used to detect the

source o proram -2 perormin step/

-2/step eecution o application codeand 0ie:in the content o code

0aria-les.

It is a proram :hich permits the user toload o-Oect code into s2stem memor2,

eecute the proram and de-u it.


47/99

&mulator

&mulator is used to test and de-u the

hard:are and sot:are o an eternal

s2stem.

D " ""


48/99

D%ta" stora%e osc""osco$e A digital storage oscilloscope s an osc""osco$e *c* stores an& ana"#ses t*e

s%na" &%ta""# rat*er t*an usn% ana"o%ue tec*n>ues. It s no t*e ost coon

t#$e of osc""osco$e n use ecause of t*e a&2ance& tr%%er stora%e &s$"a# an&

easureent features *c* t t#$ca""# $ro2&es.

;*e n$ut ana"o%ue s%na" s sa$"e& an& t*en con2erte& nto a &%ta" recor& of t*e

a$"tu&e of t*e s%na" at eac* sa$"e te. ;*e sa$"n% fre>uenc# s*ou"& e not

"ess t*an t*e (#>ust rate to a2o& a"asn%. ;*ese &%ta" 2a"ues are t*en turne&

ac3 nto an ana"o%ue s%na" for &s$"a# on a cat*o&e ra# tue ,R; or

transfore& as nee&e& for t*e 2arous $oss"e t#$es of out$ut?">u& cr#sta"

&s$"a# c*art recor&er $"otter or netor3 nterface. )sc""osco$es are t*e &e2ces

for testn% s%na" 2o"ta%es n fe"&s suc* as e"ectronc easureent crcut

&eu%%n% &es%nn% testn% n anufacturn% %enera" testn% an& researc*es.

You can use t*e a&2anta%es of t*e to ca$ture t*e co$"e' s%na"s an& atc* t*e

on t*e screen of t*e &%ta" osc""osco$es. 7oe2er &%ta" stora%e osc""osco$es

,D+) can stora%e t*e a2efor so t eas# for us to ca$ture f"eetn% s%na"s.


* i l


49/99

*oic nal2?er

A logic analyzer s an e"ectronc nstruent t*at ca$tures an& &s$"a#s u"t$"e s%na"s fro a

&%ta" s#ste or &%ta" crcut. A "o%c ana"#@er a# con2ert t*e ca$ture& &ata nto tn%

&a%ras $rotoco" &eco&es state ac*ne traces asse"# "an%ua%e or a# corre"ate asse"#

t* source-"e2e" softare. !o%c Ana"#@ers *a2e a&2ance& tr%%ern% ca$a"tes an& areusefu" *en a user nee&s to see t*e tn% re"atons*$s eteen an# s%na"s n a &%ta"

s#ste.

!o%c ana"#@ers can unco2er *ar&are &efects t*at are not foun& n su"aton. ;*ese $ro"es

are t#$ca""# too &ffcu"t to o&e" n su"aton or too te consun% to su"ate an& often

cross u"t$"e c"oc3 &oans

!o%c ana"#ser t#$es

Modular loic anal2?ers + ;*s t#$e of "o%c ana"#ser s $roa"# *at a# e t*ou%*t of as

t*e ost t#$ca" for of test nstruent a"t*ou%* t s t*e *%*est cost o$ton $ro2&n% t*e

*%*est "e2e" of functona"t#. It co$rses a c*asss an& t*e 2arous o&u"es - nc"u&n% c*anne"

o&u"es. ;*e nuer of o&u"es en% "ar%er for t*e *%*er c*anne" counts.

Porta-le loic anal2?ers + In a nuer of nstances t*ere a# e a nee& for a sa""er ana"#ser

$oss"# for restrcte& u&%ets or for fe"& ser2ce. ;*ese test nstruents ncor$orate a""

e"eents of t*e ana"#ser nto a sn%"e o' for ease of trans$ortaton.

P# -ased loic anal2?ers+ ;*ere s a %ron% nuer of P ase& "o%c ana"#sers. ;*ese

consst of an ana"#ser unt t*at s connecte& to a P. U+ s an o2ous o$ton for t*s ut

Et*ernet s a"so &e"# use& ecause of ts *%* s$ee&. ;*s for of P ase& nstruent uses

t*e $rocessn% $oer of t*e P cone& t* ts &s$"a# to re&uce t*e cost of t*e o2era""

s#ste.


! " 3 *


50/99

!o%c ana"#ser 3e# c*aracterstcs ;*ere are se2era" 3e# c*aracterstcs of a "o%c ana"#ser t*at se$arate t fro u"t-

c*anne" osc""osco$es an& ot*er test nstruentsB

Pro0ide a time displa2 o loic states+ !o%c ana"#sers $ossess a *or@onta" te a's

an& a 2ertca" a's to n&cate a "o%c *%* or "o states. In t*s a# a $cture of t*e&%ta" "nes can e eas"# &s$"a#e&.

Multiple channels+ !o%c ana"#@ers are &es%ne& to ontor a "ar%e nuer of &%ta"

"nes. As "o%c ana"#@ers are o$t@e& for ontorn% a "ar%e nuer of &%ta" crcuts

t#$ca""# t*e# a# *a2e an#*ere eteen aout


51/99



52/99

D'% *oic nal2?er

To see clock re=

To see control sinals like 'D,'#, *& etc

To see data address line on *

Trierin or time or state domain nal2sis

P# -ased * is cheaper than 'tand alone

To see port output hih lo: or *&D, $ela2 etc

To see P!M output on D'%

To see s=uare :a0e or other :a0eorms



53/99



54/99



55/99



56/99

UIT ) and a lo: -2te (DP*). Its

unction is to hold a 1 -it address. Itma2 -e manipulated as a 1 -it data

reister or t:o independent 8 -it

reister. It ser0es as a -ase reister inindirect Oumps, lookup ta-le instructions

and eternal data transer.



77/99

P$%$M 'TTU' !%$D (P'!)

C3 AC ! RS% RS! O. P

DYPIEMR AKURDI-44

RS! RS% &A5 S#6#CIO5

0 0 007 0:7 A(K0

0 1 07 07 A(K 1

1 0 107 1:7 A(KC

1 1 17 17 A(K .!hen 8671 po:ered up,

the 'P reister contains0alue 6E.

:7


79/99

Memor2 %rani?ation The 8671 memor2 orani?ation is rather comple.

The 8671 has separate address spaces or Proram Memor2, Data Memor2, andeternal $M.

This is reereed to as a>ar0ard architecture.

The earl2 Mark I (19BB) computer de0eloped at>ar0ard:as o this t2pe oarchitecture.

on eumannat Princeton pointed out that it :as not necessar2 to put

instructions and data in separate memories. Most machines ha0e -eenPrinceton architecture.

$ecentl2 >ar0ard architecture has -een emplo2ed to help alle0iate thememor2 -ottleneck.

3oth proram memor2 and eternal data memor2 are 8 -its :ide and use 1 -itso address. The internal data memor2 is accessed usin an 8/-it address.

'ince the same address can reer to dierent locations the speciic location isdetermined -2 the t2pe o instruction.


Proram or #ode Memor2


80/99

Proram or #ode Memor2

Ma2 consist o internal or eternal proram memor2. The amount o

internal proram memor2 0aries dependin on the de0ice. B -2tes t2pical in older de0ices.

The 'ilicon *a-s #86715C16 contains 1 o lash memor2 orprorams.

The 'ilicon *a-s #867156) F #M(6,H,5555>K E,H,6)

This notation can -e used to speci2 particular -its and -2tes o codememor2.

5or eample #M(1) reers to the -2te o code memor2 at address 1.#M(1KE) reers to the most siniicant -it in that address.



81/99

M

M)5 AHA DP;R AM,ADP;R

M)5 AHA P AM,AP

PCJ P,1F..0

'PRJ DP;R,1F..0


&ternal Memor2


82/99

'upports up to B -2tes eternal memor2.AM(6666,H,5555)

F AM(6666,H,5555K E,H,6)ccessed -2 usin the M%A instruction.

%n the oriinal usin eternal memor2 reducesnum-er o a0aila-le I4% ports.

%n some ne: de0ices this is not the case. 5or eample in #867156


83/99

2

The oriinal 8671 had 1


84/99

Data eor#

M

DMM)5 A6C7

M)5 R1L6C7

M)5 AHR1

M)5 A0AC7

M)5 R1L0AC7

M)5 AHR1



85/99

Data Meor# ,DM06/09/16 DYPIEMR AKURDI-44


86/99



87/99

DYPIEMR AKURDI-44

Intel 8671+ Timers4#ounters

06/09/16

Ti


88/99

Timer timer is a counter that is

increased :ith e0er2 time an

instruction is eecuted e.. 8671

:ith 1? increases a counter

e0er2 1.666 Qs

eneral 8671 has C timer+

< 1/-it timer

1 1/-it timer :ith

etra/unctionalit2(introduced :ith the

867


89/99

DYPIEMR AKURDI-44

- Inter2a" ;n%

- Pero&c e2ent tn%

- ;e ase for easureents

- E2ent ountn%-au& Rate Generaton

+!*% imers

- C ters ,;er 0 an& ;er 1

- 16-t ters ,6FF


90/99

ate + !hen set, timer onl2 runs :hile IT(6,1) is hih.

#4T +#ounter4Timer select -it.

M1 + Mode -it 1.

M6 + Mode -it 6.


T#% $eister+


91/99

T51+ Timer 1 o0erlo: la. T$1+ Timer 1 run control -it.

T56+ Timer 6 o0erla. T$6+ Timer 6 run control -it.

I&1+ &ternal interrupt 1 ede la. IT1+ &ternal interrupt 1 t2pe la.

I&6+ &ternal interrupt 6 ede la. IT6+ &ternal interrupt 6 t2pe la.

T5+ %0erlo: la

'et -2 hard:are on Timer4#ounter o0erlo:

#leared -2 hard:are :hen processor 0ectors to interrupt routine

T$+ $un control -it

'et4#leared -2 sot:are to turn Timer4#ounter on4o

I&+ Interrupt &de la

'et -2 hard:are :hen eternal interrupt ede detected #leared :hen interrupt processed

IT+ Interrupt T2pe control -it

'et4#leared -2 sot:are to speci2

allin ede4lo: le0el triered eternal interrupts



92/99

;o ounter/;er

Internalcloc8

#$ternal cloc8

a""n% e&%e-tr%%er



93/99

DYPIEMR AKURDI-44

imer Modes

- 0B 1< t ter

- 1B 16-t ter

- CB -t auto re"oa&-


94/99

DYPIEMR AKURDI-44

Mode %9 %:-2it

- A"" 16 ts of t*e ter ,;70/;!0 ;71;!1 are use&.

- Ma'u count s 6FF


95/99

DYPIEMR AKURDI-44

Mode (9 +-2it A"to Reload

- )n"# t*e "oer #te ,;!' s use& for countn%.

- U$$er #te ,;7' *o"&s t*e 2a"ue to re"oa& nto ;!' after

an o2erf"o.

- ;' ust e anua""# c"eare&.- Ma'u count s CF6

- Ma'u nter2a" s CF6 Mcrosecon&s or .CF6

""secon&s

06/09/16


96/99

DYPIEMR AKURDI-44

Mode )- Split imer

- +$"ts ;er 0 nto to -t ters

- ;!0 sets ;0

- ;70 sets ;1- ;er 1 s a2a"a"e for ot*er < o&es ut t*e ;1

s not a2a"a"e.

06/09/16


97/99



98/99

DYPIEMR AKURDI-44

imer 'elay and imer Reload .al"e

Timer &elay < &elay 4alue = Timer Clock Cycle &uration

&elay 4alue < how many counts before register2s3 roll over

Timer Clock Cycle &uration < *%oscillator fre9uency

&elay 4alue < Ma(imum !egister Count > Timer !eload 4alue

Ma(imum !egister Count < *?

06/09/16


99/99

http+44:::.slideshare.net4aOooani4introd

uction/to/microcontrollers/

lecture unit1 mca

Documents