NATIONAL OPEN UNIVERSITY OF NIGERIA

UNIVERSITY VILLAGE, PLOT 91, CASDASTRAL ZONE, NNAMDI AZIKIWE EXPRESS WAY, JABI, ABUJA.
FACULTY OF SCIENCES
OCTOBER/NOVEMBER 2016 EXAMINATION

COURSE CODE:                                                                              CIT411

COURSE TITLE:                                                                             Microcomputers and Microprocessors

TIME ALLOWED:                                                                          2 Hours

INSTRUCTIONS:                                                                            Answer Question One (1) and any other Three (3) Questions

Q1.a     Distinguish between a microcomputer and a microprocessor.

  b.   Write a brief note on each of the following:

(i)        VLSI technology                    (ii)       RISC processor                      (iii)      ALU

  c.    Distinguish between Von Neumann and Harvard architectures.                                (25 marks)

Q2.a     For a microprocessor briefly describe the following:

(i)        Word-size                  (ii)       Processing speed                  (iii)      Instruction set

(iv)      Memory

      b.   Distinguish between independent I/O and, memory-mapped I/O. (15 marks)

Q3.a     Distinguish between machine language and assembly language.

      b.   Write a brief note on each of the following:

(i)        Assembler directive              (ii)       Subroutine                 (iii)      Instruction    (15 marks)

Q4.a     Briefly describe what Direct Memory Access (DMA) is.

      b.   Distinguish between Instruction Set Architecture and Micro architecture.                   (15 marks)

Q5.a     Write brief notes on the following:

(i)        Accumulator              (ii)       Program counter                  (iii)      Stack pointer

      b.   Write down the full interpretation of the following instructions:

(i)        MOVE R2, #80h

(ii)       POP 90h

(iii)      ADD A, #25h

(iv)      INC R7                                                                                                                           (15 marks)

      c.    Briefly describe what an interrupt is, and explain what happens when it is triggered.

     d.    Write brief notes on the following:

(i)        Opcode

(ii)       Operand

(iii)      Address Bus

(iv)      Data Bus                                                                                                         (15 marks)