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Question 1.

A. State at least 2 advantages and 2 disadvantages of a microcontroller system over a hard

wired relay based or digital logic based system. (see slide no. 13)

B. State at least 4 dierences between a microcontroller and microrocessor. (see slide nos

3!" 3#" 4$)

%. State at least one alication when a microrocessor is best s&itable and another

alication when a microcontroller is best s&itable. (see slide no 42)

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Question 2.

Sketch the internal RAM map of a typlical 8051 microcontroller showing the following

 A!!ress range

Register "anks #it$#yte a!!ressa"le

%eneral purpose area an! a!!resses

&see sli!e no '()

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Question *.

+raw a typical "lock !iagram of a computer system showing the following components ,-/ RAM/ RM/ $s/ A!!ress #us/ +ata #us an! ,ontrol #us. &see sli!e no 2*)

+escri"e each components "riefly. &see sli!e nos 21/ 2()

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Question (.

+raw a typical "lock !iagram of a microcontroller system showing the following components ,-/ memory &RAM an! -RM)/ $ ports/ programma"le units &counter$timer/ serial an!

parallel $ ports/ A$+ an! +$A). & see sli!e no. (3)

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Question 5.

sing the 8051 instruction list/ gi4e eample for the following mo!es of a!!ressing an! eplaininstruction outcome if eecute!

a6 mme!iate M7 A/ **9

"6 +irectM7 A/ **9

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c6 n!irect using registers R0 : R1M7 R0/ **9

M7 A/ ;R0

!6 n!irect using Acc. A/

M7 A/ *29

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M7 R0/ ;A

Question <

=rite a short program to sol4e the following pro"lem nput 2 num"ers an! y then output theresult of 5y > (.

=rite !own all the steps in the program "elow.

?ine pco!e peran! ,omments

1 R% 09 S@ @9 -R%RAM ,@R @ 009

2 M7 -0/ 0BB9 S@ -0 AS -@

* M7 A/ -0 ,-C 7A? B -0 @ A,, A

( M7 #/ 0(9 MM+A@ M7 0(9 @ #

5 M? A/ # M?@-?C A @ #

< M7 R0/ A ,-C A @ R0

' M7 -1/ 0BB9 S@ -1 AS -@

8 M7 A/ -1 ,-C 7A? B -1 @ A,, A

3 M7 #/ 059 MM+A@ M7 0(9 @ #

10 M? A/ # M?@-?C A @ #

11 S#, A/ R0 S#@RA,@ =$ ,ARRC A,, A @ R0

12 M7 -2/ A M7 A @ -2

1* + + B -R%RAM

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Question '

=rite a short program to sol4e the following pro"lem nput 2 num"ers an! y then output theresult of 5y > *y.

=rite !own all the steps in the program "elow.

?ine pco!e peran! ,omments

1 or 

2

*

(

5

<

'

8

3

10

11

12

1*

1(

15

1<

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Question 8

+raw a flowchart to sol4e the following pro"lems.

 A large reception room uses a centraliDe! air con!itioning system. An , sensor is use! tomeasure the room temperature. An in!ucti4e !oor limit sensor counts the num"er of people that enter the room. @he system uses on$off control to switch on the fan that "lows col! air to the room.

 @here are * mo!es !epen!ing on how many people are in the house.

f there are more than 10 people in the room an! the measure! temperature is greater than*0E, / it will turn on the fan.

f there are more than 5 people an! less than 10 people in the room an! the measure!temperature is greater than 25E,/ it will turn on the fan.

f the num"er of people is less than 5 an! the temperature is greater than 22E,/ it will turn onthe fan.

Question 1*.

mplement the algorithm "elow using the 8051 assem"ly co!e.

1. nput pressure2. ,ompare pressure is pressure greater than 50 psi F

*. f pressure is greater than 50 psi turn off compressor (. f yes/ repeat step 1G if no procee! to step 55. @urn compressor on.

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Question 3.

Rea! the following program an! use the 8051 instruction list to i!entify the result & 4alue ) of e4ery instruction. =rite result "esi!e each instructions.

.C O M M E N T S

MOV A,#FFH ; ____________________________________ 

MOV R0,#77H ; ____________________________________ 

ANL A,R0 ; ____________________________________ 

MOV 15H,A ; ____________________________________ 

CPL A ; ____________________________________  

ORL 15H,#88H ; ____________________________________ 

ANL A,15H ; ____________________________________ 

ORL A,R0 ; ____________________________________ 

CLR A ; ____________________________________  

ADD A,#0Ch ; ____________________________________ 

MOV B,#03H ; ____________________________________ 

MUL AB ; _______________________________________ 

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Question 10. Wih !""!"$%" & h" 8051 'i%!&%&$!&(("!, )$*+"! h" &((&+i$ -

a) 9ow many ports are a4aila"le F( ports

HHHHHH...........

") =hich port has pull6up resistors F-16p*

HHHHHH...........

c) =hich port you prefer to use as input an! why F

HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH

HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH

!) =hat hea!ecimal 4alue you output to a port to set as input/ an! why Fffh

HHHHHH...........

e) =here !oes the ,- store the Ireturn a!!ressI/ when A,A?? instruction is eecute!F

HHHHHH...........

f) =hy !o we nee! to write + at the en! of your programF@o tell the compiler where the program will en!

HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH

g) =hy !o we use R% 00009 at the "eginning of the programFStart the program counter at 0000h

HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH.

h) =hat is the a!!ress of the stack when 8051 is resetF0'h

HHHHHH...........

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i) =hat is the name of the register that contains the stack a!!ressFStack pointer 

HHHHHH...........

 J) =hat !oes -, is use! for.@he program counter points to the a!!ress of net instruction to "e eecute!

HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH

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