NATIONAL OPEN UNIVERSITY OF NIGERIA

UNIVERSITY VILLAGE, PLOT 91, CASDASTRAL ZONE, NNAMDI AZIKIWE EXPRESS WAY, JABI, ABUJA.
FACULTY OF SCIENCES
MARCH/APRIL 2015 EXAMINATION

COURSE CODE:                                                                              CIT411

COURSE TITLE:                                                                             Microcomputers and Microprocessors

TIME ALLOWED:                                                                          2 Hours

INSTRUCTIONS:                                                                            Answer any four (4) questions out of six (6)

Q1.a     Briefly explain the Von Neumann computer architecture

  b.    Outline and discuss the four addressing modes available to an 8085 microprocessor.

Q2.a     Explain the term BUS in relation to microcontroller.

 b.    Outline and discuss the various subcategories of a computer architecture.

Q3.a     What are Condition Flags?

  b.   Enumerate and explain at least five components of the 8085 microprocessor.

Q4.a                 (i)        Define the following terms: Opcode and Operand

(ii)       Clearly stating the differences between them.

  b.   Write out clearly the following logical operation.

(i)        SET B 2FH

(ii)       CLR C

(iii)      CPL 20H

(iv)      MOVE C, 87h

(v)       ALL C, 90h

(vi)      ORL C, 91h

Q5.a     Briefly explain the term Die.

      b.   Outline and explain at least four technological innovations of microprocessors.

Q6.a     Explain the term Interrupt, listing at least four types of interrupt.

b.    Outline at least five actions taken by the microcontroller when an interrupt is triggered, enumerating at least five registers that the operation is protecting.