Digital System logic Lab Report

University
of
Hartford
 ECE‐232:
Digital
System
Logic
 Design
with
Multiplexers












































Performed
by:


Peter
Bowers
 Date:





















03/24/2010
 Room:
















Dana
Hall
325
 Partner:












Dan
Suttmeier
 Instructor:













Dr.
Ying
Yu














Purpose



 The
purpose
of
the
experiment
was
to
design
and
construct
a
specific
circuit
 using
a
multiplexer.
At
the
beginning
of
the
lab
we
were
assigned
a
function
by
the
 instructor.
The
function
was
expanded
and
a
truth
table
was
created.
A
diagram
 showing
the
internal
structure
of
an
IC
type
74151
multiplexer
was
analyzed
to
 create
the
proper
circuit
that
would
execute
the
function.
A
single
output
to
an
LED
 was
used
to
verify
the
combinations
of
the
inputs
as
described
in
given
Boolean
 function
and
verify
the
multiplexer
could
be
used
for
the
application.
 

 
 


Equipment
diagram





(Figure
A)
 
 





Knight
ML2001
Ultimate
Lab
Station
 
 1
–
LED
indicators
 2
–
Power
Supply/Ground
 3
–
Level
Switches
 4
–
Breadboarding
Area
 5
–
Solid
Wires
 6
–
Integrated
Circuit


Equipment
List


1
–
Knight
ML2001
Ultimate
Lab
Station
(Figure
A)
 15
–
Solid
electrical
wires
of
various
lengths
(short,
medium,
long)
 1
–
74151
38
x
1
multiplexer
IC
(Figure
B
and
C)
 





(Figure
B)



 
 (Figure
C)





Procedure
 
 


1
–
The
lab
instructor
supplied
the
class
with
a
function:
 

 F(w,x,y,z)
=
wxy
+
x’y’z
 The
function
was
expanded
and
the
sum
of
minterms
was
found.
A
truth
table
was
 developed
using
the
sum
of
minterms.
 2
–
The
diagram
of
the
IC
type
74151
38
x
1
multiplexer
on
page
526
of
the
textbook
 ‘Digital
Design:
Fourth
Edition’
was
studied
and
was
redrawn
with
pins
arranged
 according
to
their
actual
physical
position(Figures
B
and
C).
The
circuit
of
the
 function
was
designed
(Figure
1).
 3
–
A
74151
integrated
circuit
and
wires
were
obtained
from
lab
instructor.
The
lab
 station
was
opened
and
plugged
into
power
supply.
The
circuit
was
assembled
using
 the
74151
IC,
the
lab
station,
and
wires.
The
lab
station
was
then
powered
on.
 4
–
By
flipping
the
appropriate
toggle
switches
on
the
lab
station,
each
minterm
of
 the
developed
truth
table
was
tested.
If
the
LED
light
was
lit
then
the
minterm
 resulted
in
an
output
equal
to
1.
If
the
LED
light
was
off
then
the
minterm
resulted
in
 an
output
equal
to
0.
The
minterms
were
verified.
 5
–
After
completion
of
the
experiment,
the
IC
and
wires
were
returned
to
their
bins
 and
the
lab
workstation
was
returned
to
its
cabinet.
 



 
 (Figure
1)





Data
 


Given
function:
 F(w,x,y,z)
=
wxy
+
x’y’z
=
wxy(z+z’)
+
(w+w’)x’y’z

 

 





=
wxyz
+
wxyz’
+
wx’y’z
+
w’x’y’z
 


 





=
Σ
(1,9,14,15)
 
 Truth
Table



w
 x
 y
 z
 F
 F
 0
 0
 0
 0
 0
 0
 0
 0
 1
 1


z


0
 0
 1
 0
 0
 0
 0
 1
 1
 0


0


0
 1
 0
 0
 0
 0
 1
 0
 1
 0


0


0
 1
 1
 0
 0
 0
 1
 1
 1
 0


0


1
 0
 0
 0
 0
 1
 0
 0
 1
 1


z


1
 0
 1
 0
 0
 1
 0
 1
 1
 0


0


1
 1
 0
 0
 0
 1
 1
 0
 1
 0


0


1
 1
 1
 0
 1
 1
 1
 1
 1
 1


1





Function
Table


Strobe
 Select
 Output
 S
 C
 B
 A
 Y
 1
 X
 X
 X
 0
 0
 0
 0
 0
 D0
 0
 0
 0
 1
 D1
 0
 0
 1
 0
 D2
 0
 0
 1
 1
 D3
 0
 1
 0
 0
 D4
 0
 1
 0
 1
 D5
 0
 1
 1
 0
 D6
 0
 1
 1
 1
 D7








Sample
Calculations


F(w,x,y,z)
=
wxy
+
x’y’z
=
wxy(z+z’)
+
(w+w’)x’y’z

 

 





=
wxyz
+
wxyz’
+
wx’y’z
+
w’x’y’z
 


 





=
Σ
(1,9,14,15)
 





Data
Analysis
and
Conclusion



 The
Truth
Table
in
the
data
section
was
developed
using
the
original
 supplied
function.
For
the
developed
circuit
the
output
was
expected
to
match
the
 corresponding
output
listed
in
the
function’s
truth
table.
The
output
of
the
circuit
 matched
the
expected
output
of
the
truth
table.
The
circuit
developed
was
effective
 and
the
function
was
verified.
Using
a
74151
38
x1
multiplexer
it
was
possible
to
 create
and
implement
a
circuit
for
the
Boolean
function
that
was
provided.