Download The Processor

FY04: Introduction to the use of computers
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Acknowledgement

Jeremy Gow
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Last week’s lecture
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Measuring digital data
 Bits
 Bytes
 Kilobytes
 Megabytes
 ...
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SI and Binary units
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More Last week
Binary files
 Hexadecimal
 Text files
 Character sets
 Text encodings
 ASCII, Unicode
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This week
What a computer really is
 The Processor
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 Transistors
 Processor architecture
 Moore’s Law
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The story so far
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Computers deal with binary data
Data storage have grown bigger over 50
years
Data is stored in files
Files are accessed through filesystems
The same file could be on several
filesystems
Text files = binary files + encoding
Binary data may be viewed as hexadecimal
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Storage and processing
So far we have looked at storing data
 But computers also process data
 Processing changes data
 Computers are data processors
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Input and Output
I/O devices
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Input
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Output
 Keyboard
 Screen
 Mouse
 Speakers
 Scanner
 Printer
 Network card
 Network card
 Storage
 Storage
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Motherboard
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Describing Processors
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A computer might be described as a
 64-bit (Word)
 2.3 GHz (Processor Speed)
 3072 MB (Memory Capacity)
 PC (Operating System/Platform)
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The Processor
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Central Processing Unit (CPU)
 AKA The Processor
 Performs processing (computation)
 Accesses resources (I/O devices)
Modern CPU built of millions of
transistors
 Clock regulates processing (speed in
GHz)
 e.g. Intel Core Duo: 151m transistors,
2.33 GHz
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‘Computer Speed & Capacity’
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A computer’s speed is defined by:
 The type of processor
 Amount of RAM
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....on the motherboard
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Who makes the (micro)processors?
Intel
 Motorola
 Advanced Micro Devices (AMD)
 Cyrix
 IBM
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* Within the context of a PC, the terms
processors and microprocessors are
used interchangeably
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Microprocessors
Smaller than a postage stamp
 Found in wristwatches, sewing
machines, CD players, elevators and
anything electronic
 This is a computer on a chip
 Chip refers to a self integrated circuit
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Known Microprocessors
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1971: Intel 4004, 4044
 First microprocessor
 4-bit
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1981 – 1984: Intel 8088, 8085
 First 8-bit processor
Into the 90’s: Intel 286 (Intel 80286),
386, 386
 1990’s-2000’s: Intel Pentium , Pentium
Pro, Pentium II & III, Celeron, Itanium
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The Processor
The nucleus or the brain of any
computer
 The CPU(Processor) has two
fundamental sections:
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 Control Unit
 Arithmetic and Logic Unit
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These work together with the RAM
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Transistors
Electronic component
 Applying voltage to one terminal affects
current flowing between other two
 Acts as a switch
 Can represent 0 or 1
 (more with logic gates
next week)
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Integrated Circuits
(Microchips, Silicon Chips)
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Millions of electronic components, e.g.
Transistors
Components very close (millions per mm!)
Small area (mm!)
‘Printed’ onto silicon using light
Low power (less heat)
Low cost
High performance
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Computer Architecture
CPU on an integrated circuit
 Control Unit co-ordinates activities
 Clock regulates activity at a set
speed (GHz)
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Arithmetic-Logic Unit
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Circuitary that performs operations on
data
 Integer arithmetic operations (addition,
subtraction, multiplication, division)
 Logic operations (next week)
Reads data from input registers
 Control unit tells it which operation
 Writes data to output registers
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Register Unit
Registers store data being worked on
by CPU
 Example: adding two numbers
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 Move numbers from memory to input
registers
 ALU writes answer to output register
 New data moved from register to memory
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Moving data around
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Bus moves data between CPU to
main memory
 Takes time to transfer data
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Cache stores recently used data in
CPU
 Faster than retrieval from main memory
 Avoids having to always use bus
 Much smaller than main memory
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Coprocessors
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Help main processor do special tasks
 e.g. graphics, sound, encryption
Designed to be faster at this one task
 Optional extra
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Parallel Processing
Core 2 Duo
The concept of using multiple
processors in the same computer
system
 One main processor examines the
problem and allocates portions to be
solved simultaneously
 The individual pieces are then
reassembled in the main processor
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Putting more on the chip
Technology allows more & more circuitry
on chip
 System on a chip: CPU + main
memory
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 Much faster bus transfer
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Multi-core: more than one CPU on
chip
 Can increase performance
 Often have shared cache
 Dual-core, quad-core etc.
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Neural networks
Digital computers process structured
data sequentially
 Neural networks process unstructured
information simultaneously
 Digital computers are faster and
accurate in numeric computation
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Neural Networks
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Neural networks are used where the
computer is required to function as a
human brain
 Playing chess
 Improving automobile engine efficiency
 Enabling improved vision technology
 Planning crop and rotation strategies
 Forecasting financial market fluctuations
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Example: New 13” Macbook
Intel Core 2 Duo
 Clock speed: 2.0 GHz or 2.4 GHz
 Two CPUs on chip
 3MB cache
 1066MHz bus
 2GB main memory
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Moore’s Law
Gordon Moore (1965)
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The complexity for minimum component
costs has increased at a rate of roughly a
factor of two per year... Certainly over the
short term this rate can be expected to
continue, if not to increase. Over the longer
term, the rate of increase is a bit more
uncertain, although there is no reason to
believe it will not remain nearly constant for
at least 10 years. That means by 1975, the
number of components per integrated
circuit for minimum cost will be 65,000. I
believe that such a large circuit can be built
on a single wafer.
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Moore’s Law
The number of transistors that can be
cheaply placed on an integrated circuit
doubles every two years
 Exponential growth in transistors-perchip
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 Related to increase in chip power
Roughly true since 1965
 Result of many technological advances
 Will approach physical limits at some
point
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Moore’s Law
Intel chips
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Summary
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Processor (CPU) made of millions of
transistors
Integrated circuits allow small powerful
CPUs
Control Unit, ALU, Registers, Bus, Cache
Co- and multi-core processors
Moore’s law: transistors on chip double in 2
yrs
Reading: Brookshear 2.1, White 5 & 6
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