1. Digital System Design
Course
Amin Foshati (/ˈfɒsˈhati/)
Sharif University of Technology
Department of Computer Engineering
Introduction
Spring Semester
2023
2. The present lectures have been prepared for an undergraduate course
in Digital System Design (DSD).
Spring Semester
2023
Introduction
Digital System Design
Evaluation
Why is this course
essential?
3. Course Evaluation
•The grading is based on:
• Assignments (4 points)
• Programming exercises
• Midterm (8 points)
• Open-book exam
• Programming
• Multiple choice exam
• Final (8 points)
• Based on the university announcement
• Bonus assignments & classwork (5 points)
3
4. Timetable & TAs
• Course Timetable:
• https://docs.google.com/spreadsheets/d/1eC6ObIJd4DHG-
zO8wMWr3w8muHid7XiRVYFAsrKoQJo/edit?usp=sharing
• My email:
• a.foshati@{gmail.com/sharif.edu}
• Teacher Assistants (TAs):
• Ms. Rezazad
• rezazad.shiva@gmail.com
• Ms. Farahani
• Mr. Ghasab
• BSc students
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5. Why is this course essential?
•We should evaluate this course on some aspects:
• Prerequisite to research
• Educational funds
• Prerequisite to job vacancies
• Higher salary
• Emerging technologies
• Artificial intelligence technology
• Crypto currency
• Autonomous vehicles
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7. Digital Signal vs. Analog Signal
• Physical quantities
• Temperature
• Speed
• Distance
• Analog signal
• Continuous
• Digital signal
• Discrete
• Sampling
• Mapping continuous to discrete
• Converting analog to digital
Time
Temprature
10
20
25
4 8 12 16 20 24
Time
Temprature
10
20
25
4 8 12 16 20
Analog Signal
Sampling
Time
Temprature
10
20
25
4 8 12 16 20 24
Analog Signal Digital Signal
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8. Digital System
• Digital System
• A digital system is a combination of devices designed to
manipulate a digital signals.
• Because of real-world has the analog quantity, the digital systems
need some mix-signal systems to communicate with the real world.
• Analog to Digital Convertor (ADC)
• Digital to Analog Convertor (DAC)
Source: openlabpro.com
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11. Digital Systems
• Advantages:
• Adjustable precision
• High noise immunity
• Ease of diagnosis and repair
• Design Automation
• More digital circuit can fabricated on IC chips
• Disadvantages
• The real world is analog
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13. Design a Digital System
Synthesis:
Code Bitstream
FAB
Programmer
Programmer Logic Devices (PLDs)
Writing a code by CAD tools
2 1
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14. Computer Aided Design (CAD)
• CAD:
• The use of computer software to aid in design process
• Electronic CAD (ECAD) / Electronic Design Automation (EDA)
• Synthesis
• Convert code to bitstream
• Bitstream: A file that contains the information of your hardware. Like the
"exe" file in the Windows operating system that includes information on
your application.
• Simulation
• Running a hardware code on a computer
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15. Programmer Logic Device (PLD)
• A device used in the construction of reconfigurable digital
circuits
• A PLD has an undefined function at the time of construction
• Unlike digital logic IC that defined functionality
• 7400 (two-input NAND gates)
• 7408 (two-input AND gates)
• …
• You can program for specific functionality
• Two types:
• Reconfigurable
• They can only be configured once.
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19. ASIC
•Cost
• First chip
• Several hundred thousand dollars
• Other chips
• Very cheap
•Time
• We should be patient to produce a chip!
•Reconfigurable after production?
• No
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20. PLD
• Cost
• Buy a PLD and programmer
• ZedBoard Zynq-7000
• 500 dollars
• Time
• After Synthesis
• You can program the bitstream file immediately.
• Reconfigurable after production?
• Yes
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21. Which solution is chosen?
• Mass production
• ASIC
• Reconfigurable Computing (RC)
• Run some part of product and store result then run another part.
• PLD
• Custom hardware
• PLD
• ASIC
• Prototyping
• Creating a sample product for validation and verification
• PLD
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22. Computer Aided Design (CAD)
FAB
Programmer
PLDs
Writing a code by CAD tools
2 1
ASIC
Hardware
Description
Language (HDL)
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24. Contemporary Digital System
•More complex designs
•System on Chip (SoC)
•Shorter Time-To-Market (TTM)
•the period of time between the idea of a product
and its release to the market
•Cheaper products
•Reduce cost of designing
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25. Integrated Circuits (ICs)
• SSI (Small Scale Integration): 1 to 30 gates
• a small number of gates
• MSI (Medium Scale Integration): 30 to 300 gates
• decoder, register, counter
• LSI (Large Scale Integration): 300 to 300,000 gates
• small memories
• VLSI (Very Large Scale Integration): > 1,000,000 transistors
• microprocessors, memories
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28. Requirements of HDLs
• Concurrency
• Hardware operate parallelly
• Time
• The results should be available before the next clock
• Design Hierarchy
• Divide a system into smaller parts
• Structural Specification
• Defined a system by elements and interconnections
• Pragmatics
• can be physically implemented
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29. Requirements of HDLs (Cont.)
•Concurrency
• Hardware operate parallelly
• C language run serially by default
•Timing
• HDL can emulate seconds, milliseconds, etc.
• Order is essential in the C language
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Combinational Part Combinational Part
Registers Registers Registers
Combinational Part Combinational Part
Registers Registers Registers
30. Requirements of HDLs (Cont.)
•Design Hierarchy
• Divide a system into smaller parts
• Focus on a manageable portion of the system
•Structural Specification
• Defined a system by elements and interconnections
• A system has many subsystems
• Every subsystem has several inputs and outputs
System
Subsystem 1
…
Subsystem 2
…
…
Subsystem n
…
System
Subsystem 1
3 inputs
2 outputs
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33. Course Overview
This course aims to learn how to design a
digital system with Computer-Aided
Design (CAD) tools and Hardware
Description Language (HDL).
33
