1. CSCI2510 Computer Organization
Introduction
Terrence Sui-tung Mak

2. Overview What is a Computer? What is a Computer used for?
Basic components
CPU
Memory
Performance measure
Architectures
Networks-on-chip

3. Why do we study computer organization?
To maximize the efficiency of computer
To design NEW computers
Why maximize efficiency?
Programs and data are getting bigger and bigger
Save costs
How to maximize efficiency?
Understand the constraints and capabilities of hardware
Write good software

4. What is a Computer?
Apple Macintosh “Personal Computer” (ca. 1990)

5. What is a Computer?
Thinking Machines “Connection Machine”

6. What is a Computer?

7. Evolution of Computing
The First Generation
First transistor, UNIAC, ENIVAC
The Second Generation
First integrated circuit,
The Third Generation
Microprocessor, Intel, Apple, IBM …
The Forth Generation
Embedded systems

8. What are Computers used for?
Word processing
Image processing
Art
Music/ Pictures/ Movies Creation and Distribution
Entertainment
Games, Virtual Reality, Movie Special Effects
Artificial Intelligence
Face Detection, Robotics, Computer Games
Simulation
Aeroplane Design, Nuclear Reactor Controller Training, Traffic Modelling, Flight Simulation
Communications
Chat, , Instant Message, Video Conferencing

9. What are Computers used for?
Computer-Aided Design
Air-Traffic Control
Weather Prediction
Weapons
Design Drugs
Oil Exploration
Human Genome Project
Financial Markets
Nuclear Reactor Control
Exploring Space
Art: Music, Pictures, Movies, creation and distribution
Internet Browsing
Games
Databases
Word Processing
Spreadsheets
Desktop/ Web Publishing
Accounts/ Stock Control/ Banking
Payroll
Education
Machines/ Appliances/ Electronic Devices

10. Computers & Central Processing Units
Apple
Power Macintosh
7100/66
CPU
Motorola
PowerPC 601/66

11. Plus… Marketing Gimmicks
CPUs
Plus… Marketing Gimmicks
Intel Core2 Duo/ Centrino/ Pentium M
Motorola DragonBall
Sun UltraSparc T2 (OpenSparc T2)
etc.
Company names
Brand names
Processor family/ series
Specific product names
Intel Pentium
Motorola/ IBM PowerPC
AMD K7
ARM StrongArm
Compaq (DIGITAL) Alpha
Zilog Z80
Motorola 68000
MOS Tech 6502 (Apple II)
MIPS
Interesting details about CPUs:

12. Math Quiz! Try to answer the following questions
4 x = ? A: 19 B: 48 C: 33 D: 29
3 – 3 x = ? A: B: C: D: 12
6 + 5 x 8 – 1 x (-3) = ? A: 10 B: 43 C: 91 D: 49

13. Course Aims
In this course, we shall focus on the Organisation and Operation of the CPU. This involves computer architecture and assembly language programming
I/O
Processor/ CPU
Output
Memory
Input
and
Arithmetic
logic
Control
Registers
Why these five components?
Human model 1: A clerk solving an accounting problem
I/O are the data in the form of paper
Memory is the paper containing the problem being solved
CPU is the human’s brain. ALU is a calculator.
History: von Neumann’s machine Memory/CPU separated
instructions

14. Computer Organization
Binary numbers – Radixes (2,16), conversions and arithmetic
Data representation – Integers, integer arithmetic, real, text
Main memory organization – Byte-ordering, alignment, interleaving
CPU organization and operation – Instructions, registers, fetch-execute cycle
CPU and programming – Registers, addressing modes, high-level programs
Input/Output control – Devce types, polling, interrupts, device driven

15. Analogy: A Student Taking a Math Quiz
Input: Math question (4 x 7 + 5)
Output: Multiple-choice answers
Memory: Arithmetic rules (x before +) Multiplication table Keeping numbers 4, 7 and 5
Register: Temporary sum (4 x 7 = 28)
ALU: Computation ( = 33)
Control: Execute rules Decide when to read input, when to compute and stop

16. Input/ Output Unit Overview
Input units
Keyboard, mouse, microphone, CDROM, etc.
Output units
Graphical display, printer, etc.
The collective term input/ output (I/O) units
Input units, output units, disk drives, etc.

17. Memory Unit Overview Memory is used to store programs and data
[Low-level] Unit of access is an n-bit word
Unique location is its address
Retrieval is in units of words
Commonly 32-bit today, moving to 64-bits
Typically 16-bit – 64-bit machines nowadays
Primary storage: random-access memory (RAM)
Secondary storage: hard disk, CDROM, etc.

18. Processor Overview Registers
Small but fast storage of intermediate values in a computation
Arithmetic logic unit (ALU): performs computations
e.g. arithmetic operations: add, subtract, multiply, divide, etc.
e.g. logical operations: and, or, not, xor, etc.
c.f. calculator
Operands taken from registers
Control
Orchestrates the transfer of data and sequencing of operations between memory, registers, ALU, I/O devices

19. Connecting the Components with Dedicated/ Multiple Buses
Disk
Keyboard
CPU
I/O Controller 1
I/O
Controller 2
I/O bus
I/O bus
DMA bus (Direct Memory Access)
Memory bus
Buses are connecting paths between components in a computer, and even between computers.
Main Memory

20. Connecting the Components with Shared-Bus Structure
Example:
keyboard
Example:
printer
I/O Controller
I/O Controller
Memory
Processor 1
Processor 2
Connecting the components.
Control: synchronization, error monitoring (to be done by programs, i.e. instructions)
Data: Information
Address: device identification (units of transfer)
Information carried along a bus: address, data , control
All devices have same address structure
All devices can be controlled by common machine instructions
Only two devices can do data communication simultaneously

21. Bus
Allows computer to be customized for different applications e.g. different peripherals
Design criteria – speed, cost, etc.
Word length can be different depending on application
E.g. USB is serial (1-bit), PCI bus is 32-bit

22. Let's Take a Break

23. Computer Memory

24. Memory Hardware: Chips and Modules

25. Digital (Binary) Memory
Primary storage, main storage, main memory
Fast Access (when compared to I/O)
Units
bit (1 binary digit, a value of 0 or 1)
Byte (1 byte = 8 bits)
Word
Manipulation of data by CPU is in words.
A single access results in one word of data being transferred.
Word length is specified in number of bits/ bytes:
for example, 8-bit, 16-bit, 32-bit, 64-bit, 4-byte, etc.
Why one byte is 8 bits?
Representation of information by bit pattern: information theory

26. Main Memory (MM) Organization
word 0
word 1
word 2 :
word i m -1 1 2 i
address
m bits
n bits
In a main memory with m-bit addresses, 0 to 2m-1 words are available.
Each word stores n bits
m, n are independent
m specifies the number of units; n specifies the unit size
What is the total number of bits?
M. N are the parameters.
Note: Given m bits, not all memory must be physical.
Example: Desktop PC.
32 bits address implies 4 G words. Not too many PC’s memory have this size!

27. Memory: Contents of a Word (I)
Here is an example of a 32-bit word.
b31
b30 b1 b0
32 bits (word length)
Examples:
A word can store information. For example,
1. Four English characters, each encoded in a common 8-bit code
ASCII: American Standard Code for Information Interchange or
EBCDIC: Extended Binary Coded Decimal Interchange Code
char 3: 8-bit
char 2: 8-bit
char 1: 8-bit
char 0: 8-bit

28. Memory: Contents of a Word (II)
2. Two Chinese characters
3. A 32-bit Signed integer
b31=0 means positive integer, b31=1 means negative integer
magnitude = b30230 + … + b0 20
4. A 32-bit machine instruction
16 bits
16 bits
Big5/GB code
Bring Examples
b31
b30 b1 b0
sign bit
8 bits
12 bits
operation code
address field
address field

29. Central Processing Unit (CPU)
Intel Pentium
IBM Power PC
Digital signal processor IC
ARM 9

30. Some Intel CPUs
4004
8008
8080
8088/ 8086 [x86]
80186
80286 [286]
80386 [386]
80486 [486]
Pentium [586]
Pentium MMX
Pentium PRO [686]
Pentium II
Pentium III
Pentium 4
Core2 Duo

31. CPU on a Chip  Microprocessor

32. CPU What does a CPU do? It executes programs. What is a program?
Program = Instruction + Data
Where are the instructions and data?
In Memory – when they are not being processed
In CPU – when they are being processed

33. Let's Take a Break

34. Performance Measurement
Computer architects use performance estimates to evaluate the effectiveness of new features
Practice is to use benchmarks available to all manufacturers
e.g. SPEC benchmark (
Benchmark figures are for comparing real computers

35. SPEC Benchmark
SPEC CPU2006 uses a historical Sun system, the "Ultra Enterprise 2" which was introduced in 1997, as the reference machine (SPEC FAQ Q.23)
The reference machine uses a 296 MHz UltraSPARC II processor
Each benchmark runs a set of program to measure the execution times. These times are then used in the SPEC calculations
Value indicates a machine how much faster than the reference machine
e.g. SPEC rating of 10 means it is 10 faster than the reference machine

36. How a program is executed
Program and data reside on secondary storage such as CDROM or hard disk are transferred to the memory
Data (stored in memory) is fetched under program control (also in memory) into ALU and processed
Processed information sent back to I/O unit
All activities directed by control unit

37. CPU and MEMORY Control unit
Memory bus: Control bus, Data bus and Address bus
ADDRESS
MAR
Memory controller
Control unit
R/W
MFC
MDR
INSTRUCTION / DATA

38. The following is the Memory Read Operation:
CPU and MEMORY
The following is the Memory Read Operation:
ADDRESS (MAR) T1 C O M N
Control Signal (READ) T1 E T M
CPU R O
(Read) O
DATA (MDR) T2 R L Y L
(RAM) E
Control Signal (MFC) T2 R
Data can be assumed to have arrived when the control unit receives the MFC (Memory Function Completed) signal!

39. The following is the Memory Write Operation:
CPU and MEMORY
The following is the Memory Write Operation:
ADDRESS (MAR) T1 C O M N
Control signal (WRITE) T1 E T M
CPU R O
(Write) O
MFC (CONTROL) R T2 L Y L
(RAM) E
Data T1 R

40. Summary
Overview of the functional components and the bus structures of a modern microcomputer system
Basic structure and operation of a CPU
Overview of the Main Memory organization
Interaction of the CPU and the Main Memory