technology in action - fullerton college - student web serverstaff · · 2010-03-23integrated...

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Technology in Action

Chapter 9

Behind the Scenes:

A Closer Look at System Hardware

Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

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Binary Language

• Computers work in binary language.

• Consists of two numbers: 0 and 1

• Everything a computer does is broken

down into a series of 0s and 1s.

• Switches: Devices inside the

computer that can be flipped between

these two states: 1 or 0, on or off


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Switches

• Nonmechanical devices in computers that open and close circuits

• Types of electrical switches– Vacuum tubes

– Transistors• Solid state

Semiconductors

– Integrated circuits (very small transistors billions per square inch)

Vacuum Tube

Transistors

Integrated CircuitsCopyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

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• The on/off state of a switch represents one

bit of data.

• Bit (binary digit)

– On = 1

– Off = 0

OFF

0

Switches Representing Data

ON

1

01

OR = 1 bit


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The Binary Number System

• Describes a number as powers of 2

• Also referred to as base 2 numbering system

• Used to represent every piece of data stored in a computer: all of the numbers, letters, and instructions


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• Number systems are organized ways to represent numbers.

• Each number in one system has a corresponding number in another.

01011001 = 89Binary Base 10

128

2x64

64

2x32

32

2x16

16

2x8

8

2x4

4

2x2

2

2x1

1

Binary 0 1 0 1 1 0 0 1

Base

100 + 64 + 0 + 16 + 8 + 0 + 0 + 1 = 89


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• Any whole number can be precisely represented (max 18,446,744,073,709,600,000)

•Fractions may not be precise

•Same problem as decimal numbers, for

example:

•What is 2/3 ? .6666666666→∞

•Solution: round to precision desired


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Representing Letters

and Symbols

• American Standard Code for Information

Interchange (ASCII)

– 8 bits = 1 byte = alphanumeric character or

symbol

– 256 different combinations

• Unicode

– 16 bits equal 1 byte or character

– 65536 different combinations; used to

define all alphabetsCopyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

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ASCII Chart


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The CPU:

Processing Digital Information

• The brains of the

computer

• Different types of

CPUs– Intel and AMD chips: Used

in most Windows-based

PCs and most newer Apple

systems

– Some older Apple systems

use a different CPU design

• Differentiating CPUs

– Processing power

– Clock speed and

cache


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Graphics Processing Unit (GPU)

• Performs the same

work as a CPU

• Specialized to handle

– 3D graphics

– Image processing

– Video processing

• CPUs perform better

with a GPU handling

graphics computation.


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The CPU Machine Cycle

• Fetch– The next instruction is ―fetched‖ from its location in

RAM and moved to the CPU.

• Decode– The CPU circuitry is prepared to execute the

instruction.

• Execute– The instruction is executed.

• Store– The results are stored in memory or registers.

“Inside the Chip” by

Intel

Video Clip


../ppt_09_unit4_clip2_300.wmv

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The System Clock

• Located on the motherboard

• Controls the CPU’s processing cycles

• Clock cycle

– Pulse or tick

• Clock speed

– Number of pulses per second

– Measured in hertz--Hz, megahertz--MHz,

gigahertz--GHz


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The Future of RAM

• Magnetoresistive Random Access

Memory (MRAM)

– Uses magnetic plates to store data

• Nano Random Access Memory (NRAM)

– Uses carbon nanotubes to store data


• Something?? we don’t know about yet

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The Control Unit

• Manages the switches inside the CPU

• Is programmed by CPU designers to

remember the sequence of processing

stages for that CPU

• Moves each switch to its correct setting

(on or off)

• Then performs the work of that stage


The part of the CPU that:

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The Arithmetic Logic Unit (ALU)

• The Part of the CPU designed to perform

mathematical operations (addition,

subtraction, multiplication, division, etc.)

• Also performs logical OR, AND, and NOT

operations

• Is fed data from the CPU registers

– Word size: Number of bits a computer can

work with at a time (8, 16, 32, 64)


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Cache Memory-- more is better

• Small amount of very fast memory located on or near the CPU chip or both

• Stores recent or frequently used instructions and data

• Used for quick access by the CPU

• Different levels of cache—L1 on chip, L2 off


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RAM--main memory, holds the

programs to be executed

• Volatile: When you turn off your

computer, the data is erased.

• Several kinds of RAM exist.

• Each type of RAM has a different

design.

– Some types work at much faster speeds.

– Some transfer data more quickly.


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Types of RAM: DRAM-dynamic ram

• Most inexpensive and most basic type of RAM

• Loses its electrical charge; needs to be refreshed

• Many types of DRAM

– SDRAM: Synchronous DRAM

– DDR SDRAM: Double data rate of SDRAM

– DDR2 SDRAM: Twice as fast as DDR SDRAM

– Dual-Channel DDR2: Faster than DDR2


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Types of RAM: SRAM

• Static RAM (SRAM)

– Does not lose its electrical charge

– Faster than DRAM (on CPU chip)

– More expensive than DRAM

– Used only in locations like cache memory

– Used in thumb drives and other pseudo-disks


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• Bus– Electrical pathway used to move data between

components

– Local bus or front side bus (FSB): Connects the CPU with the memory

– Expansion bus: Connects the CPU with peripheral controllers

– Bus speed improves with technology

Buses: The CPU’s

Data Highway

01100010

0111001101001000

00100111


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Bus Performance

• Bus clock speed

– Rate of speed data moves from one location to another

– Measured in MHz (millions of clock cycles per second)

• Bus width

– The number of bits of data moved on a bus at any one

time

– Measured in bits

• 16 bits

• 32 bits (PCI)

• 64 bits (PCI)


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Types of Expansion Buses

• ISA and EISA

– Found on older computers

– Connect mouse, modem, and sound card

• PCI and PCI-x

– Faster than ISA and EISA

– Found on modern computers

– Connect network, modem, and sound cards

• AGP (accelerated graphics port)

– Used for three-dimensional graphics

– Connects the graphics card and memory


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Making Computers Faster

• Pipelining: The CPU processes more than

one instruction at a time

Fetch Decode Execute Store


Instruction 1

Instruction 2

Nonpipelined CPU





Instruction 1

Instruction 2

Instruction 3

Instruction 4

Pipelined CPU


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Making Computers Faster

• Overclocking (can overheat and damage)

• Dual processing– Two CPUs on the same system

– Each processor shares the workload

– Each could specialize—computing, communications

• Multi-core processing—sharing of workload, like graphics, I/O

• Hyperthreading—1 CPU doing 2 or more tasks at the same time, like math

• Parallel processing (Supercomputers)– Network (or cluster) of computers

– Each computer works on a portion of the problem simultaneously


technology in action - fullerton college - student web serverstaff · · 2010-03-23integrated...

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