Tribhuvan University

Institute of Science and Technology

2078

Bachelor Level / second-semester / Science

Computer Science and Information Technology( CSC167 )

Microprocessor

Full Marks: 60 + 20 + 20

Pass Marks: 24 + 8 + 8

Time: 3 Hours

Candidates are required to give their answers in their own words as far as practicable.

The figures in the margin indicate full marks.

Group A

Attempts any TWO questions

1

Explain instruction cycle, machine cycle and T-states. Draw timing diagram of IN instruction with brief description.

2

Draw block diagram of 80286 microprocessor and explain its main four functional sub-units. Differentiate between Real Address Mode and Protected Virtual address mode.

3

Explain LXI and CMP instruction. Write an assembly language program for 8-bit microprocessor to divide 8 bit data stored in memory location 8050 by 8 bit data stored in 8051 and store the quotient in 8052 and remainder in 8053.

Group B

Attempts any EIGHT questions

4

What are the different modes of parallel communication? Construct a control word for 8255 PPI for following configuration:

Port A and Port Cupper – mode 0

Port B and Port Clower  – mode 0

Port A and Port Cupper as input port

Port B and Port Clower as output port

5

Differentiate between interrupt based I/O and DMA based I/O. Explain based DMA operation in brief

6

Differentiate between PUSH and POP instruction with example illustrating the use of these instruction.

7

Write an assembly language program for 16 bit microprocessor to reverse the string “This is  Microprocessor”

8

What is the use of AD7 – AD0 in 8085 microprocessor? Explain address de-multiplexing process in 8085 microprocessor with suitable diagram.

9

What is mean by addressing mode? Explain all the addressing mode available in 8085 microprocessor.

10

Explain Register Organization in 80386 microprocessor.

11

Draw a logic diagram showing generation of memory and I/O read/write control signals in 8085 microprocessor

12

Write short notes on (Any two):

  1. Program Counter
  2. Von-Neumann Architecture
  3. Interrupt Masking