POKHARA UNIVERSITY
Level: Bachelor
Semester – Spring
Programme: BE
Course: Microprocessor System and Interfacing
Year
: 2010
Full Marks: 100
Pass Marks: 45
Time
: 3hrs.
Candidates are required to give their answers in their own words as far
as practicable.
The figures in the margin indicate full marks.
Attempt all the questions.
1.
2.
a)
Define address decoding. Design a circuit to interface an 8 KB ROM,
a 4 KB RAM and a 2 KB EPROM with a microprocessor.
8
b)
Explain the addressing modes used in 8051 microcontroller with
suitable examples.
7
a)
Describe following instruction for 8051 microcontroller.
6
MOVC, CLR bit, LJMP, DJNZ, ACALL, and CJNE
b)
Assume that P2 is an input port connected to a temperature sensor
through an ADC. Write a program to read the temperature and test it
for value 25. According to the test results do the following:
If
9
T = 25; No action
T < 25; Switch OFF the Air Conditioner
T > 25; Switch On the Air Conditioner
Show the connection diagram for sensor, 8051 and air conditioner.
OR
3.
Write a program for 8051 microcontroller to get input continuously from
a light sensor connected to P1.1, bit by bit, count the number of 1’s and
turn on a dc motor connected at port P2 for 5 seconds if the number of 1’s
is 44 else continue checking the switch input. Show the connection
diagram for sensor, motor and 8051.
9
a)
Write a program for 8255 to set bit PC3 and PC2 in BSR mode and
RESET them after 10 seconds .The address of control register is 83H.
7
b)
Write instructions to generate a pulse in every 50 microsecond from
counter 0 of 8253 PIT. Assume your own counter address and clock
period. Also draw the timing diagram.
8
1
4.
5.
6.
7.
a)
Define IVT and explain different types of interrupt in 8086? Explain
any one application of hardware interrupt.
b)
How does 8259A PIC handles 20 sources of interrupt using a single
interrupt pin of the microprocessor? Explain.
7
a)
Explain the printer port connection for parallel communication.
7
b)
What are the limitations of 8-bit ISA bus? Explain the advantages of
using PCI bus.
8
a)
Explain the terms reliability, fault tolerance, crosstalk and impedance
matching.
8
b)
What are the types of shielding mechanism available? Explain with
suitable diagrams.
Write short notes on any two:
8
7
2×5
a)
Electrostatic discharge
b)
PCB design
c)
Redundant architecture for electronic circuit
2