The University of Zambia
In Association with
Zambia University College of Technology (ZUCT)
Bachelor of Electrical, Electronics and Telecommunications Engineering
DIGITAL ELECTRONICS AND LOGIC DESIGN - EEE 3030
ASSIGNMENT I
DATE
:
DUE DATE :
13/04/2023
28/04/2023
Instruction
1.
Attempt all the questions.
2.
Submit your assignment in groups of three (3).
3.
Assignments that will be submitted after the due date will not be marked.
QUESTION ONE
MARKS
(a)
The main stairway in a block of flats has three switches for controlling the lights.
Switch A is located at the top of the stairs, switch B is located halfway up the stairs and
switch C is positioned at the bottom of the stairs. Design a logic circuit to control the
lights on the stairway.
[3]
(b)
Design a multiplexer using NAND gates only from the truth table shown below;
Table 1.1
𝐴
𝐵
𝐶
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
(c)
𝐹
0
1
1
0
0
0
0
1
[5]
Implement the unsimplified and simplified combinational logic circuits from following
expression;
̅
𝐹 = 𝐴𝐵𝐶𝐷 + 𝐴𝐵̅ 𝐶̅𝐷 + 𝐴̅𝐷
[6]
QUESTION TWO
MARKS
Refer to the truth table below of a certain digital arithmetic converter. Study the table
and answer the following questions:
(i)
(ii)
(iii)
(iv)
State the type of the converter and give reasons as to why it is so.
[2]
Derive the output expressions using sum-of-minterms.
[2]
Minimize the derived expressions in (ii) using K-map method.
[10]
Implement the logic circuit of the minimized expressions in (iii) using logic gates.
[6]
Table 1.1 Truth table (TT)
DECIMAL
(b)
INPUTS CODES
OUTPUT CODES
NUMBERS
A
B
C
D
𝑓0
𝑓1
𝑓2
𝑓3
0
0
0
0
0
0
0
1
1
1
0
0
0
1
0
1
0
0
2
0
0
1
0
0
1
0
1
3
0
0
1
1
0
1
1
0
4
0
1
0
0
0
1
1
1
5
0
1
0
1
1
0
0
0
6
0
1
1
0
1
0
0
1
7
0
1
1
1
1
0
1
0
8
1
0
0
0
1
0
1
1
9
1
0
0
1
1
1
0
0
Use Quine–McCluskey tabular method to minimize the following Boolean function;
̅ + 𝐴̅𝐵𝐶̅ 𝐷
𝑓(𝐴𝐵𝐶𝐷) = 𝐴̅𝐵𝐶 + 𝐴̅𝐵̅ 𝐷 + 𝐴𝐶̅ 𝐷 + 𝐵𝐶̅ 𝐷
END
[20]