1. Chapter 1 Introduction to Computer Organization & Architecture

2. Lecture Overview Course description Chapter 1 : Introduction
Overview of computer organization and architecture
The main components of a computer
An example system: wading through the jargon
Standards organizations
Historical development of computers
The computer level hierarchy
The Von Neumann model

3. Course description (1/3)
Course name
T103 - Computer Organization and Architecture
Course level
Level 1 course
Equivalent to 3 CH (Credit Hours)
Assessment
Continuous Assessment (CA) : 50%
1 TMA (Tutor Marked Assignment) : 20%
1 MTA (Mid-Term Assessment): 30%
Final Exam: 50%

4. Course description (2/3)
Success Requirements
Attend at least 4/6 lectures (≈70% attendance)
Get at least 15/50 on the CA (TMA + MTA)
Get at least 20/50 on the Final Exam
Get at least a total of 50/100 (TMA + MTA + Final)
Course Lectures
Number of lectures: 7 lectures
Bi-Weekly lectures: One lecture every 2 weeks
Lecture duration : 2 Hours

5. Course description (3/3)
Reference Book
The essentials of Computer Organization and Architecture, 2nd edition – Author: Linda Null and Julia Lobur
Topics to be covered
Chapters 1, 2, 3, 4, 5, 6
Topics: Introduction, Boolean algebra, …

6. Lecture Overview Course description Chapter 1 : Introduction
Overview of computer organization and architecture
The main components of a computer
An example system: wading through the jargon
Standards organizations
Historical development of computers
The computer level hierarchy
The Von Neumann model

7. Overview of computer organization and architecture (1/5)
Chapter 1: Introduction
Overview of computer organization and architecture (1/5)
Some programs/algorithms are today computationally infeasible, why?
Tomorrow, those could become feasible, why?
To understand why we need to:
see the program from the computer’s point of view
explore the “computer organization and architecture”

8. Overview of computer organization and architecture (2/5)
Chapter 1: Introduction
Overview of computer organization and architecture (2/5)
What is computer organization and architecture?
In a computer system, hardware and many software components are fundamentally related
Computer organization and architecture help us to understand how hardware and software interact with each other

9. Overview of computer organization and architecture (3/5)
Chapter 1: Introduction
Overview of computer organization and architecture (3/5)
Computer organization?
It encompasses all physical aspects of computer systems.
How components are connected together?
How components interact with/talk to each other?
It addresses issues such as
Control signals, signaling methods
Memory types, …
It helps us to answer the question: How does a computer work?

10. Overview of computer organization and architecture (4/5)
Chapter 1: Introduction
Overview of computer organization and architecture (4/5)
Computer architecture?
It focuses on the structure and behavior of the computer system
It refers to the logical aspects of system implementation as seen by the programmer.
It includes many elements such as
instruction sets and formats, data types, addressing modes, number and type of registers, …
It helps us to answer the question: How do I design a computer?

11. Overview of computer organization and architecture (5/5)
Chapter 1: Introduction
Overview of computer organization and architecture (5/5)
Computer organization VS architecture?
The distinction between computer organization and computer architecture is not clear-cut.
These are strongly interrelated and interdependent.
We can truly understand each of them only when we comprehend both of them.

12. Lecture Overview Course description Chapter 1 : Introduction
Overview of computer organization and architecture
The main components of a computer
An example system: wading through the jargon
Standards organizations
Historical development of computers
The computer level hierarchy
The Von Neumann model

13. The main components of a computer (1/3)
Chapter 1: Introduction
The main components of a computer (1/3)
From Software to Hardware
Computer scientists design algorithms
Computer scientists implement an algorithm by using high level programing language (Java, C, etc.)
Another algorithm runs this algorithm and another one runs that algorithm and so on
We finally get down to machine level
Machine level can be thought of as an algorithm implemented as an electronic device

14. The main components of a computer (2/3)
Chapter 1: Introduction
The main components of a computer (2/3)
Principle of Equivalence of Hardware and Software
Anything that can be done with software can also be done with hardware, and anything that can be done with hardware can also be done with software
We implement an application in Hardware or Software level?
Our knowledge of computer organization and architecture will help us to make the best choice

15. The main components of a computer (3/3)
Chapter 1: Introduction
The main components of a computer (3/3)
Computer Hardware main components
A processor to interpret and execute programs
A memory to store both data and programs
A mechanism for transferring data to and from the outside world (Input/Output)
Think of how a student sitting in class exhibits the three components of a computer?

16. Lecture Overview Course description Chapter 1 : Introduction
Overview of computer organization and architecture
The main components of a computer
An example system: wading through the jargon
Standards organizations
Historical development of computers
The computer level hierarchy
The Von Neumann model

17. An example system: wading through the jargon (1/7)
Chapter 1: Introduction
An example system: wading through the jargon (1/7)
The stated system is a wise buy?
Does it serve your needs?

18. An example system: wading through the jargon (2/7)
Chapter 1: Introduction
An example system: wading through the jargon (2/7)
“64MB SDRAM”, “64-bit PCI sound card”, “32KB L1cache”, …?
Without having a handle on such terminology, you would be hard-pressed to answer such questions…
The next few slides explain the content of the advertisement (ad)

19. An example system: wading through the jargon (3/7)
Chapter 1: Introduction
An example system: wading through the jargon (3/7)
A reminder (TU170):
Computers do computations in base 2 (binary system)
A binary character is called a bit (0 or 1)
A byte is a set of 8 bits

20. An example system: wading through the jargon (4/7)
Chapter 1: Introduction
An example system: wading through the jargon (4/7)
Pentium III 667 MHz?
Pentium III : The microprocessor type
667 MHz: microprocessor’s clock speed
Each microprocessor has a synchronization clock (it sends electrical pulses)
Here, the clock speed is 667 million electrical pulse per second
The number of instructions per second that a processor can execute is proportionate to its clock speed (not equal to).
133 MHz 64MB SDRAM?
SDRAM: Main memory type, “Synchronous Dynamic Random Access Memory”
133 MHz: Speed of the system bus (between the memory and the microprocessor)
64 MB : Memory Capacity (64 x 220 x 8 bits = bits)

21. An example system: wading through the jargon (5/7)
Chapter 1: Introduction
An example system: wading through the jargon (5/7)
32KB L1 cache, 256KB L2 cache?
Two cache memory to speed up the data transfer between the main memory and the processor
32KB and 256KB are the capacity of level 1 (L1) and level 2 (L2) memory respectively
30GB EIDE hard drive (7200 RPM)?
30GB: The capacity of the hard drive
7200 RPM: Speed of disk rotation is 7200 round per minute
EIDE: disk interface (connectivity with the rest of the computer’s components). EIDE stands for Enhanced Integrated Drive Electronics
48X max variable CD-ROM
CD-ROM drive
48X: the maximum reading data rate the CD drive can achieve (48 times the traditional audio CD data transfer rate)

22. An example system: wading through the jargon (6/7)
Chapter 1: Introduction
An example system: wading through the jargon (6/7)
2 USB ports, 1 serial port, 1 parallel port?
Ports that allow movement of data to and from devices external to the computer.
19" monitor, .24mm AG, 1280 x 1024 at 85Hz?
The monitor size (19”), resolution (1280 x 1024), refresh rate (85Hz) and pixel size (0.24mm).
Intel 3D AGP graphics card?
Graphic interface for 3D graphics
56K PCI voice modem? 64-bit PCI sound card?
PCI : Dedicated I/O buses, PCI stands for Peripherial Component Interconnect
PCI voice modem: for internet connection
PCI sound card : for the system’s stereo speakers

23. An example system: wading through the jargon (7/7)
Chapter 1: Introduction
An example system: wading through the jargon (7/7)
A look inside a computer

24. Lecture Overview Course description Chapter 1 : Introduction
Overview of computer organization and architecture
The main components of a computer
An example system: wading through the jargon
Standards organizations
Historical development of computers
The computer level hierarchy
The Von Neumann model

25. Standards organizations (1/2)
Chapter 1: Introduction
Standards organizations (1/2)
Standards organizations?
Number of government and industry organizations
Some standards-setting organizations are consortia made up of industry leaders
Aims
Establish common guide lines for a particular type of equipment
Why? To ensure a “worldwide”1 interoperability (compatibility)
1 The term “worldwide” is correct only when the organization and its standards are international

26. Standards organizations (2/2)
Chapter 1: Introduction
Standards organizations (2/2)
Some international standards organizations
IEEE
Institute of Electrical and Electronic Engineers
sets standards for various computer components, signaling protocols, and data representation
ITU
International Telecommunications Union
Sets standards for telecommunications systems, including telephone, telegraph, and data communication systems
ISO
International Standards Organization
coordinates worldwide standards development
Other county(ies)-wide organizations
ANSI: American National Standards Institute
CEN: Comité Européenne de Normalisation (European committee for standardization)
BSI: British Standards Institution

27. Lecture Overview Course description Chapter 1 : Introduction
Overview of computer organization and architecture
The main components of a computer
An example system: wading through the jargon
Standards organizations
Historical development of computers
The computer level hierarchy
The Von Neumann model

28. Historical development of computers (1/5)
Chapter 1: Introduction
Historical development of computers (1/5)
Generation Zero: Mechanical Calculating Machines (1642 – 1945)
Use of mechanical technology to do calculations
Suggest the use of binary number system rather than the decimal number system
First Generation: Vacuum tube computers (1945–1953)
Use of electrical/electronic technology (much faster than mechanical technology)
Invent binary machines built from vacuum tubes
Invent vaccum tubes diodes and triodes
Disadvantages: Bulky systems, Power consumption and heat dissipation.

29. Historical development of computers (2/5)
Chapter 1: Introduction
Historical development of computers (2/5)
The Second Generation: Transistorized Computers (1954–1965)
Transistors revolutionize computers
Transistors consume less power than vacuum tubes, are smaller, and work more reliably,
the circuitry in computers became smaller and more reliable.
The Third Generation: Integrated Circuit Computers (1965–1980)
Integrating multiple transistors in a single silicon/germanium chip
Explosion in computer use
Computers became faster, smaller, and cheaper, bringing huge gains in processing power

30. Historical development of computers (3/5)
Chapter 1: Introduction
Historical development of computers (3/5)
The Fourth Generation: VLSI Computers (>1980)
More integration, more transistors on a single silicon chip (see the table below)
Computers became smaller: Appearance of micro-computers
Increasing the processing power of all computers types (also supercomputers and main frame computers)
Scale Integration
Number of components per chip
SSI: Small Scale Integration
10 – 100
MSI: Medium Scale Integration
100 – 1000
LSI: Large Scale Integration
VLSI: Very Large Scale Integration
> 10000

31. Historical development of computers (4/5)
Chapter 1: Introduction
Historical development of computers (4/5)
Size comparison
Vacuum Tube
Transistor
Integrated circuit chip
Integrated circuit package

32. Historical development of computers (5/5)
Chapter 1: Introduction
Historical development of computers (5/5)
Moore’s Law (Gordon Moore – Intel Founder, 1965)
The density of transistors in an integrated circuit doubles every 18 months (1.5 year).
The law hold for almost today (2013)!
Rock’s Law (early Intel capitalist Arthur Rock)
The cost of capital equipment to build semiconductors will double every four years
If Moore’s Law is to hold, Rock’s Law must fall or computers must shift to a radically different technology
Research into new computing paradigms has been proceeding in earnest during the last half decade

33. Lecture Overview Course description Chapter 1 : Introduction
Overview of computer organization and architecture
The main components of a computer
An example system: wading through the jargon
Standards organizations
Historical development of computers
The computer level hierarchy
The Von Neumann model

34. The computer level hierarchy (1/6)
Chapter 1: Introduction
The computer level hierarchy (1/6)
The user executes programs on a PC (Paint, word files, games, etc.)
The user is outside the computer! He uses input and output devices to communicate with the computer.
Now, what happens INSIDE the computer?
To understand, we will use a “divide and conquer” approach.

35. The computer level hierarchy (2/6)
Chapter 1: Introduction
The computer level hierarchy (2/6)
Imagine the machine (computer) as a hierarchy of levels, in which each level has a specific function.
The highest level – Level 6 – is the “user’s level”
Level 6 is composed of applications
User runs programs such as word processors, graphics packages, or games.
The lower levels are unseen by the user those can be considered as “virtual machines”.
Let us discover these “virtual machines”.

36. The computer level hierarchy (3/6)
Chapter 1: Introduction
The computer level hierarchy (3/6)

37. The computer level hierarchy (4/6)
Chapter 1: Introduction
The computer level hierarchy (4/6)
Level 5: High-Level Language Level
Consists of languages such as C, C++, FORTRAN, Lisp, Pascal, and Prolog.
Programmers write programs at this level.
Compilers translates these languages to a language the machine can understand (that lower levels could understand): Assembly then machine languages.
Level 4: Assembly Language Level
More “machine dependent” language.
Assembly language is then one to one translated to machine language (one assembly language instruction is translated to exactly one machine language instruction).

38. The computer level hierarchy (5/6)
Chapter 1: Introduction
The computer level hierarchy (5/6)
Level 3: System Software Level
Deals with operating system instructions (multiprogramming, protecting memory, synchronizing processes, and various other important functions)
Instructions translated from assembly language to machine language are passed through this level unmodified
Level 2: Instruction Set Architecture (ISA), or Machine Level
Machine language recognized by the particular architecture of the computer system
Programs written in machine language can be executed directly by the electronic circuits without any interpreters, translators, or compilers.

39. The computer level hierarchy (6/6)
Chapter 1: Introduction
The computer level hierarchy (6/6)
Level 1: The Control Level
Is where a control unit do its job
Receives machine instructions from the level above
decodes and executes those instructions properly
Moves data to where and when it should be
The control unit interprets the machine instructions
Level 0: The Digital Logic Level
is where we find the physical components of the computer system: the gates and wires

40. Lecture Overview Course description Chapter 1 : Introduction
Overview of computer organization and architecture
The main components of a computer
An example system: wading through the jargon
Standards organizations
Historical development of computers
The computer level hierarchy
The Von Neumann model

41. The Von Neumann model (1/6)
Chapter 1: Introduction
The Von Neumann model (1/6)
A computer architecture model published by a famous Hungarian mathematician named John von Neumann
The idea is to store programs’ instructions inside a main memory in order to avoid rewiring the system each time it had a new problem to solve, or an old one to debug.
All stored-program computers have come to be known as von Neumann systems using the von Neumann architecture

42. The Von Neumann model (2/6)
Chapter 1: Introduction
The Von Neumann model (2/6)
The Von Neumann architecture is shown in Figure 1.4 – Slide 43
It satisfies at least the following characteristics
Consists of three hardware systems (see figure 1.4 – slide 43)
A central processing unit (CPU) with a control unit, an arithmetic logic unit (ALU), registers (small storage areas), and a program counter;
a main-memory system, which holds programs that control the computer’s operation;
and an I/O system.
Capacity to carry out sequential instruction processing
Contains a single path, between the main memory system and the control unit of the CPU

43. The Von Neumann model (3/6)
Chapter 1: Introduction
The Von Neumann model (3/6)

44. The Von Neumann model (4/6)
Chapter 1: Introduction
The Von Neumann model (4/6)
Program instructions are stored inside the main memory
The machine runs the programs sequentially (instruction per instruction – machine instruction)
Each machine instruction is fetched, decoded and executed during one cycle known as the von Neumann execution cycle (also called the fetch-decode-execute cycle)
One iteration of the cycle is as follows:
1. The control unit fetches the next program instruction from the memory, using the program counter to determine where the instruction is located.
2. The instruction is decoded into a language the ALU can understand.
3. Any data operands required to execute the instruction are fetched from memory and placed into registers within the CPU.
4. The ALU executes the instruction and places the results in registers or memory.

45. The Von Neumann model (5/6)
Chapter 1: Introduction
The Von Neumann model (5/6)
Fetch
PC indicates the iteration number
CU fill the instruction register
Instruction 1
Instruction 2
Instruction 3
Instruction 3
Data 1
Data 2
Instruction 4 … …
2. Decode
what ALU should do (add, multiply, …)?
Fill registers with needed data …
Instruction N

46. The Von Neumann model (6/6)
Chapter 1: Introduction
The Von Neumann model (6/6)
3. Execute
Execute the instruction
Place the results in registers or memory
Instruction 1
Instruction 2
Instruction 3
Instruction 3
Data 1
Data 2
Instruction 4
Result … … …
Instruction N

47. End of lecture 1 Try to solve all exercises related to lecture 1