DSD-1 (Introduction).pdf

The present lectures have been prepared for an undergraduate course in Digital System Design (DSD) of Sharif University of Technology.

1. Digital System Design
Course
Amin Foshati (/ˈfɒsˈhati/)
Sharif University of Technology
Department of Computer Engineering
Introduction
SpringSemester
2023

2. The present lectures have been prepared for an undergraduate course
in Digital System Design (DSD).
SpringSemester
2023
Introduction
Digital System Design
Evaluation
Why is this course
essential?

3. CourseEvaluation
•Thegradingisbasedon:
•Assignments(4points)
•Programmingexercises
•Midterm(8points)
•Open-bookexam
•Programming
•Multiplechoiceexam
•Final (8 points)
•Based on the university announcement
•Bonus assignments & classwork (5 points)
3

4. Timetable & TAs
•CourseTimetable:
•https://docs.google.com/spreadsheets/d/1eC6ObIJd4DHG-
zO8wMWr3w8muHid7XiRVYFAsrKoQJo/edit?usp=sharing
•Myemail:
•a.foshati@{gmail .com/sharif.edu}
•TeacherAssistants(TAs):
•Ms.Rezazad
•[email protected]
•Ms.Farahani
•Mr.Ghasab
•BScstudents
4

5. Why is this course essential?
•Weshouldevaluatethiscourseonsomeaspects:
•Prerequisitetoresearch
•Educationalfunds
•Prerequisitetojobvacancies
•Highersalary
•Emergingtechnologies
•Artificialintelligencetechnology
•Cryptocurrency
•Autonomous vehicles
5

6. What is a digital system?

7. Digital Signal vs. Analog Signal
•Physicalquantities
•Temperature
•Speed
•Distance
•Analog signal
•Continuous
•Digital signal
•Discrete
•Sampling
•Mappingcontinuoustodiscrete
•Convertinganalogtodigital
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
7

8. Digital System
•DigitalSystem
•Adigitalsystemisacombinationofdevicesdesignedto
manipulateadigitalsignals.
•Becauseofreal-worldhastheanalogquantity,thedigitalsystems
needsomemix-signalsystemstocommunicatewiththerealworld.
•AnalogtoDigitalConvertor(ADC)
•DigitaltoAnalogConvertor(DAC)
Source: openlabpro.com
8

9. Digital System Example
Source: Ronald Tocci
9

10. Shift from analog to digital
•Analog System
•Digital System
10

11. DigitalSystems
•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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12. How to Design a Digital
System?

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:Afilethatcontainstheinformationofyourhardware.Likethe
"exe"fileintheWindowsoperatingsystemthatincludesinformationon
yourapplication.
•Simulation
•Running a hardware code on a computer
14

15. Programmer Logic Device (PLD)
•Adeviceusedintheconstructionofreconfigurabledigital
circuits
•APLDhasanundefinedfunctionatthetimeofconstruction
•UnlikedigitallogicICthatdefinedfunctionality
•7400(two-inputNANDgates)
•7408(two-inputANDgates)
•…
•Youcanprogramforspecificfunctionality
•Twotypes:
•Reconfigurable
•Theycanonlybeconfiguredonce.
15

16. Field-Programmable Gate Array (FPGA)
PLD Example:
Basys3 Artix-7 FPGA Board
16

17. Computer Aided Design (CAD)
FAB
Programmer
PLDs
Writing a code by CAD tools
2 1
Application-Specific Integrated Chips (ASIC) 17

18. Which way is a better choice?
ASICs or PLDs?

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
19

20. PLD
•Cost
•Buy a PLD and programmer
•ZedBoardZynq-7000
•500 dollars
•Time
•After Synthesis
•You can program the bitstream file immediately.
•Reconfigurable after production?
•Yes
20

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
21

22. Computer Aided Design (CAD)
FAB
Programmer
PLDs
Writing a code by CAD tools
2 1
ASIC
Hardware
Description
Language (HDL)
22

23. Why are CAD tools and HDLs
essential?

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
24

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
25

26. Circuit Design Solution
•Paper and Pencil
•Suitable for:
•SSI
•MSI
•Algorithmic State Machine (ASM)
•Suitable for:
•LSI
•CAD Tools and HDL
•Suitable for:
•VLSI
26

27. Why C, Java, Python, and etc.
are not suitable?

28. Requirements of HDLs
•Concurrency
•Hardware operate parallelly
•Time
•The results should be available before the next clock
•DesignHierarchy
•Divide a system into smaller parts
•StructuralSpecification
•Defined a system by elements and interconnections
•Pragmatics
•can be physically implemented
28

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
30

31. Example of Design Hierarchy









…

…

…

…

31

32. Structural vs. Behavioral
Half Adder
Structural
S = A ^ B;
C = A & B;
Half Adder
Behavioral
32

33. CourseOverview
Thiscourseaimstolearnhowtodesigna
digitalsystemwithComputer-Aided
Design(CAD)toolsandHardware
DescriptionLanguage(HDL).
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