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:                                                                              CIT 344                                                                               

COURSE TITLE:                                                                             Introduction to Computer Design

DURATION:                                                                                     3 Hours

INSTRUCTIONS:                                                                            Answer any Five (5) Questions

1a.       Find the sum of two 2-digit BCD numbers, 42 and 31. Your result should be in BCD.     8 marks

1b.       List 3 common forms of edge-triggered flip-flops employed in digital logic circuits        6 marks

                                                                                                                                            [Total = 14 marks]

2a.       Explain with the aid of a diagram how a full adder can be built from half adders         10 marks

2b.       Describe the term ‘Microprocessor’ in computer design                                                                4 marks

                                                                                                                                            [Total = 14 marks]

3a.       Write a simple program for declaring a CPU “fetch-execute” cycle.                                 10 marks

3b.       Distinguish between the two (2) main types of sequential circuits                                   4 marks

                                                                                                                                            [Total = 14 marks]

4.         Study the block diagram provided as it will serve as your reference in answering the

questions that follow:

4a.       Which operation is depicted in the diagram?                                                                        2 marks

4b.       Give a detailed explanation of how this process is implemented.                                     12 marks

                                                                                                                                            [Total = 14 marks]

5a.       Give a brief explanation of how sequential circuits are implemented, sing a well-labelled block diagram to illustrate this.                                                                                               8 marks

5b.       Write down the hexadecimal equivalent of the following:

1. 11010110101110010110
2. 101110010110                                                                                                             6 marks

        [Total = 14 marks]

6a.       Give the binary equivalent of the following decimal numbers

1. 4
2. 3
3. 7
4. 5

    8 marks

6b.       List 2 key operations performed on memories, within the perspective of computer design. 6 marks

 [Total = 14 marks]

7a.       Write down the decimal equivalent of the following:

1. 101110010110
2. 11010110101110010110                                                                                           8 marks

7b.       Based on your knowledge in computer design, describe any 2 types edge-triggered

flip-flops                                                                                                                                     6 marks

        [Total = 14 marks]