POKHARA UNIVERSITY

Level: Bachelor                                  Semester: Spring                                   Year: 2023

Programme: BBA/BI/TT/BCIS/BHCM/BHM                                              Full Marks: 100

Course: Computer Architecture and Microprocessor                                      Pass Marks: 45

Time: 3 hrs. 

Candidates are required to answer in their own words as far as practicable The figures in the margin indicate full marks.

                                                                 Section "A"

                                                Very Short Answer Questions

Attempt all the questions. [10×2] 

1. Explain the basic block diagram of a computer system and the role of a microprocessor in brief.

 2. How many T-states are there in the instruction STA C00021?

3. Mention the events occurring in each T-state of the Memory Read Cycle. 

4. What do you mean by 16-bit microprocessor? Which is the first 16 bit MP? 

5. What is a DMA controller? How does it work?

6. What do you mean by Interrupt Service Routine (ISR).

7. Differentiate RISC and CISC architecture. 8.Write any four characteristics of TRAP.

9. What is the Stored program concept?

10. WAP to exchange the content of flag register and accumulator. 

                                                                   Section "B"

                                              Descriptive Answer Questions

Attempt any six questions.[6×10]

11. Compare Von-Neumann and Harvard architecture with suitable diagrams.

12. What do you mean by addressing mode? Explain several types of addressing modes available in 8085, with an example of each. 

13. Draw and explain the timing diagram of instruction ADD M.

14.What is a NULL modem? Describe the operation principle of RS-232 cable connection for DTE and DCE with suitable diagrams.

15. Describe the use of PPI. What are its different modes of operation? Discuss each mode with the proper bit format of Control Register. 

16. Describe the process of how 8259A interrupt controller handles the interrupt with a suitable diagram.

17. Discuss various level architecture of parallelism in detail. Explain accumulator-based architecture in detail.

                                                                     Section "C"

                                                         Case Analysis [2×10]

18. a) Write a program to check whether a given number is positive or negative. Explain each step in detail.

b) An 8085 assembly language program is given below. Assume that the carry flag is initially unset. What will be the content of the accumulator after the execution of the whole program? Explain each instruction and show intermediate values of the accumulator.

MVI A, 07H

RLC

MOV B, A

RLC

RLC

ADD B

RRC

HLT