Transcript Slide 1

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B. Haddad
Digital Electronics CPE 461
Lecture 1
Introduction
Eng. Bashar Haddad
The University of Jordan
7/20/2015
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Outline
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Course Information
Text Book and References
Course Outline
Grading
Polices
B. Haddad
7/20/2015
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Course Information
• Instructor
B. Haddad
7/20/2015
Eng. Bashar Haddad
• Prerequisites
Knowledge in Circuit 1, Electronics 1,
Electronics 2, Digital Design
• Office Hours
Sunday Tuesday Thursday (2-3)
Monday Wednesday (2-3)
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Text Book and References
B. Haddad
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• Text Book
Digital Electronics, A Practical Approach,
William Kleitz, 8th ed., Pentice Hall, 2008 (Main
book).
• References
A. Digital Electronics, Principles, Devices and
Applications, 1st Ed. By: Anil K. Maini, John Wiley & Sons Ltd,
2007
B. Complete Digital Design, A Comprehensive Guide to
Digital Electronics and Computer System Architecture,
By: Mark Balch.
C. Digital Electronics, Demystified, By: Myke Predko
D. Hands on Electronics, A practical Introduction to Analog
and Digital Circuits, By: Daniel M. Kaplan, Christopher G.
White
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Course Outline
B. Haddad
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• Introduction
• Review of basic electronics concepts including
diodes, BJTs and FETs. Circuits.
• Logic families.
• Multivibrator And The 555 Timer.
• D/A and A/D Converters structure and basic
operation.
• Semiconductor, Magnetic and Optical Memory
• Digital Arithmetic and Arithmetic
Circuits
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Grading
B. Haddad
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• 4 Quizzes 5-Marks/Each 20 , (Not Scheduled)
• Midterm Exam
30
• Final Exam
50
• Reports and Projects (Hand Written) (Optional – No Weights)
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Policies
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• Attendance is required (Attend the Class and the
Section that you Registered)
• All submitted work must be yours.
• Cheating will not be tolerated.
• This course requires significant effort.
• There will be no make-up quizzes.
• You are responsible for any material mentioned
in class whether text book or not.
• This material involves a lot of details; therefore,
make sure to study it day by day.
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What You Shouldn’t / Should Do?
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• Don’t memorize any thing, if you have to explain
or define anything, use your own language to
express your ideas, there will be no ideal answer
to such question in the exam.
• Solve many problems, solving problems is the
only way can be used to discover if you really
understand.
• Be a Computer Engineer, think as an engineer,
what if ? how to design? ……
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Introduction to digital electronics
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• Digital signals vs. Analog signals
• Digital Signal: a signal that can only take specific
values, 0, 1, 2, 3, (Binary Signals is a specific case in
which the only two values that can be taken is 0, 1)
• Analog signal: a signal that can take any value
within or not a range.
• Analog
▫ Continuous
▫ Can take on any values in a given range
▫ Very susceptible to noise
• Digital
▫ Discrete
▫ Can only take on certain values in a given range
▫ Can be less susceptible to noise
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Introduction to digital electronics
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Introduction to digital electronics cont
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• Continuous signals vs. Discrete signals
• The continuous signal is a signal that take a
value at any point of time.
• Discrete signal is a signal that takes values at
only specific values of time
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Introduction to digital electronics cont
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• So What This??!!
Analog Continuous Signal
Digital Continuous Signal
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Introduction to digital electronics cont
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• Digital Systems vs. Analog Systems
• Analog systems process time-varying signals
that can take on any value across a continuous
range of voltages (in electrical/electronics
systems).
• Digital systems process time-varying signals that
can take on only one of two discrete values of
voltages (in electrical/electronics systems).
▫ Discrete values are called 1 and 0 (ON and OFF,
HIGH and LOW, TRUE and FALSE, etc.)
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Introduction to digital electronics cont
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• Digital Electronics represents information (0, 1)
with only two discrete values.
• Ideally
“no voltage” (e.g., 0v) represents a 0 and
“full source voltage” (e.g., 5v) represents a 1
• Reality
“low voltage” (e.g., <1v) represents a 0 and
“high voltage” (e.g., >4v) represents a 1
• We achieve these discrete values by using
switches.
• We use transistor switches, which operates at
high speed, electronically, a small in size.
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Introduction to digital electronics cont
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• Benefits of Digital over Analog
Reproducibility
Not effected by noise means quality
Ease of design
Data protection
Programmable
Speed
Economy
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Digital Revolution
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• Digital systems started back in 1940s.
• Digital systems cover all areas of life:
pictures
digital video
digital audio
telephone
traffic lights
Animation
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Where we are??
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Hi, I am The Result of
Human Efforts
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The Levels
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• Users or Application-Program Level:
At this level the user interacts with the computer by
running programs, such as word processor, text editors,
Games and simulators. Microsoft Office
• High Level Language Level:
Programmers are most familiar with this level, here the
programmers see the programming language and
nothing of the low level details of the machine.
Compilers, C++, Java …etc.
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The Levels, cont
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• Assembly Language/ Machine Code Level
 The compiler convert the high level language to low
level language. The low level language is somewhat
related to the details of the instruction provided by
the machine. NOT ONE TO ONE RELATION
Move R1, R2
Add R1, R2, R3
The Assembler convert the low level language to the
machine binary code 0, 1. ONE TO ONE RELATION
(USUALLY)
10101111100001111010111110000111
10100011101101111111000011010011
The dot. Net
Applications,
Assembly
Folder
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The Levels, cont
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• Microprogrammed Hardwired control:
The control unit that effects the register transfers
described above. It does so by means of control signals
that transfer the data from register to register, possibly
through a logic circuit that transforms it in some way.
Data Path, Control Unit, Memory,…..
• Functional Unit
The register transfers and other operations implemented
by the control unit move data in and out of functional
units. Functional units include internal CPU registers,
the ALU, and the computer’s main memory.
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The Levels, cont
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• Logic Gates, Transistors and Wires:
The lowest levels at which any layer of the computer’s
higher-level functioning is visible is at the logic gate
and transistor levels.
Logic Gates: the simplest units that can perform logical
operations, AND, OR, XOR..etc. these units affect
seriously many aspects of the overall computing system.
Transistors: is the basic units that used to build the
computer, at this level usually have to deal with electrical
specifications, such as current, voltage and power
dissipation …etc.
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The Levels, cont
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Where we should start? Digital Electronics, the art of designing and
implementing Gates, Functional units, and any other supported circuits for
digital systems, regarding many factors, performance, power dissipation,
cost, reliability, flexibility
Computer Skills
C++, Java, Compilers
Assembler, Assembly Language
Computer Org, Design
Digital Arithmetic, Digital
Electronics, Digital Design
Digital Electronics
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More about digital and analog signals
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• The real word is analog? What does that mean?
An analog signal can take any value at any point of time.
Ex. Temperature don’t take specific values, 34, 33, the
interval [33-34] has an infinite number of values:
33.0000009 33.0000008, ….etc
• Computers look at the world with a fixed resolution in
both time and magnitude.
Ex. Sound Wave, the computer can only measure the
signal at intervals. Sample, Sampling Rate.
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More about digital and analog signals
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• Two problems arise from this process: information can
be lost between the measurements and information can
be lost due to the rounding of the measurement.
• First, if the sampling rate is too slow, then some details
of the signal may be missed.
• Second, if the computer does not record with enough
accuracy (i.e., enough digits after the decimal point) an
error may be introduced between the actual
measurement and the recorded value).
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More about digital and analog signals
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• The effect can be reduced by increasing the
resolution of the measurement and increasing
the sampling rate. ???!!! Tradeoff
• This requires more processing capabilities and
more storage. If the number of sample values is
4 you need two bits, but if 8 you need three bits.
If you take 10000 samples (30000 bit)
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More about digital and analog signals
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• Types of digital signals:
Edges: represent the transition of the digital signal,
Falling edge, Rising edge.
Pulses: A binary pulse occurs when a signal changes from
one value to the other for a short period, then returns to
its original value. Positive Pulse, Negative Pulse.
Non-Periodic Pulse Trains: haven't characteristic
pattern in their changes between logic 1 and logic 0.
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More about digital and analog signals
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Periodic Pulse Trains:
The defining characteristic of this type of waveform is
that all measurements between any two subsequent,
identical parts of the waveform produce the same value.
This value is referred to as the period, T, and it has units of
seconds/cycle.
• The measurement of the period does not fully describe a periodic
pulse train, however; a second measurement, the width of the pulse,
tw, is needed.
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More about digital and analog signals
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• It is also common to represent the rate of the
pulses in a periodic pulse train with the inverse
measurement of the period. frequency of the
periodic pulse train (cycles/second) Hertz
(Hz).
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Frequency 
Period Time (Seconds )
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Last word
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• Digital electronics is the art of designing and
implementing Gates, Functional Units, and
other electronic circuit that used to support the
digital systems. Clock, A/D D/A convertors,
Timers…etc.
• This dos not mark the end of the analog world,
remember that the world in it is nature is analog.
• Recently Mixed-Systems start to play major
roles in system development