Kingdom of Saudi Arabia
Majmaah University
College of Engineering
EE 207 Lab
Second Mid Term Exam
Academic Year: - 1434-1435 / 2013-2014
Subject: Logic Design Lab.
Date: 03 Dec, 2013 (12:00 – 02:00)
Term: Subject Code: Time: -
Mid Term-2
EE 207 Lab
2:00 Hours
Name: _________________________________ ID: _____________________________
Question # 1:
1- The Decoder converts binary information from n inputs lines to a maximum of ____
unique output lines.
2- Decoders include one or more ___________inputs to control the circuit operation.
3- In general a Decoder may operate with ____________or _______________outputs.
4- An Encoder is a digital circuit that performs the __________ operation of a Decoder.
5- An Encoder has ________ inputs lines and _________ output lines.
6- For multiplexers, the selection of a particular input line is controlled by a set of
________________.
7- A Multiplexer is also called a________________.
8- The conversion from one code to another is common in _________________.
9- A conversion circuit is necessary between two systems if each system uses
__________________for the same information.
10- Gray Code is one of the codes used in _______________Systems.
Question # 2:
1- For decoders, the 2 inputs are decoded into______ outputs.
a- 3
b- 2
c- 4
2- The Encoder has the limitation that ______input/inputs can be active at any given time.
a- One
b- Two
c- Three
3- A ____________is a combinational circuit that selects binary information from one of
many input lines and directs it to a single output line.
a- Complementer
b- Decoder
c- Multiplexer
d- Adder
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4- For proper operation, the strobe input 'S' of IC 74LS151 ( 8-to-1 line multiplexer ) must
connected to ____________.
a- Vcc
b- Ground
5- A conversion circuit is necessary between two systems if each system uses
__________codes for the same information.
a- Different
b- Same
c- Binary
Question # 3:
i.
ii.
Construct 8 To 3 Lines Encoder using IC 74LS148
Complete the Truth Table given below.
Truth Table for 8 To 3 Lines Encoder
EI
A0
A1
A2
A3
A4
A5
A6
A7
1
X
X
X
X
X
X
X
X
0
1
1
1
1
1
1
1
1
0
X
X
X
X
X
X
X
0
0
X
X
X
X
X
X
0
1
0
X
X
X
X
X
0
1
1
0
X
X
X
X
0
1
1
1
0
X
X
X
0
1
1
1
1
0
X
X
0
1
1
1
1
1
0
X
0
1
1
1
1
1
1
0
0
1
1
1
1
1
1
1
B2
B1
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B0
Question # 4:
Implement the BCD to 7-Segment Display circuit as shown in Figure.
Decimal
Instructor Signature
0
1
2
3
4
5
6
7
8
9
BCD
A
0
0
0
0
0
0
0
0
1
1
B
0
0
0
0
1
1
1
1
0
0
C
0
0
1
1
0
0
1
1
0
0
D
0
1
0
1
0
1
0
1
0
1
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