NATIONAL OPEN UNIVERSITY OF NIGERIA

UNIVERSITY VILLAGE, PLOT 91, CASDASTRAL ZONE, NNAMDI AZIKIWE EXPRESS WAY, JABI, ABUJA.
FACULTY OF SCIENCES
SEPTEMBER 2020 EXAMINATION

CIT 344 - INTRODUCTION TO COMPUTER DESIGN

Credit: 3 units

TIME ALLOWED: 2½ Hours

INSTRUCTION: Answer Question 1 and any other FOUR (4) Questions

Question 1

(a) Relate the following in terms of base number and weight: 382.91, 275, 278.35, 123 and 489 (5 marks)

(b) Identify the three steps of designing combinational circuit (3 marks)

(c) Describe briefly the attributes of combinational circuit (5 marks)

(d) Based on your understanding of this course, summarize memory organization process (6 marks)

(e) List the two classes of digital logic circuit (3 marks)

Question 2

(a) Show in tabular form the binary equivalence of decimal 1 to 12 (6 marks)

(b) Convert 100112 to its decimal equivalent (6 marks)

Question 3

(a) Identify the ways a combinational logic circuit can be analysed (3 marks)

(b) With the aid of an illustrative diagram, explain the operation of a Half-adder (6 marks)

(c) Describe briefly the operation of a half-adder using function table (3 marks)

Question 4

(a) Evaluate how an ALU will achieve an addition operation on the following numbers 2,3,4 and 5 (6 marks)

(b) Compare synchronous sequential circuit with asynchronous sequential circuit (3 marks)

(c) With the aid of a diagram, explain the operation of a sequential circuit (3 marks)

Question 5

(a) Summarize briefly any two of the following operations: (3 marks each. Total = 6 marks)

(i) Read and Write signal,

(ii) Address signals and

(iii) Data signals

(b) Differentiate between memory read operation and memory write operation using suitable (6 marks)

Question 6

(a) Differentiate between Binary addition and Binary subtraction (5 marks)

(b) Explain the process of repeated division by 2 and using the method, convert 392 to Binary. (7 marks)