Transcript Lecture 9

Technology In Action
© 2006 Prentice-Hall, Inc.
NEXT
SLIDE
1
Technology In Action Chapter 9
Technology In Action
Chapter 9
Behind the Scenes: Inside the System Unit
© 2006 Prentice-Hall, Inc.
NEXT
SLIDE
2
Technology In Action Chapter 9
Topics
•
•
•
•
•
•
•
Computer switches
Binary number system
Inside the CPU
Cache memory
Types of RAM
Computer buses
Creating faster CPUs
© 2006 Prentice-Hall, Inc.
NEXT
SLIDE
3
Technology In Action Chapter 9
Digital Data: Switches and Bits
• Electronic switches:
– Vacuum tubes
– Transistors
– Integrated circuits
ON
• Binary number system:
– Representing numbers
– Representing letters and symbols
OFF
 ASCII
 Unicode
© 2006 Prentice-Hall, Inc.
NEXT
SLIDE
4
Technology In Action Chapter 9
Electronic Switches
• Non-mechanical devices in computers that
open and close circuits
• Types of electronic switches:
– Vacuum tubes
– Transistors:
 Semiconductors
– Integrated circuits
 Microprocessors
Click here to view the video “The
Incredible Shrinking Circuit” by
Intel
© 2006 Prentice-Hall, Inc.
NEXT
SLIDE
5
Technology In Action Chapter 9
Computer Generations
• First-generation computers (1946-1958):
– UNIVAC
– Use vacuum tubes to store data
• Second-generation computers (1959-1964):
– Use transistors to store data
• Third-generation computers (1965-1970):
– Use integrated circuits
• Fourth-generation computers (1971-Today):
– Use a microprocessor chip
– Intel 4040, 1971
© 2006 Prentice-Hall, Inc.
LAST
SLIDE
7
Technology In Action Chapter 9
Switches Representing Data
• The on/off state of a switch represents
one bit of data
• Bit (binary digit):
OFF
ON
– On = 1
– Off = 0
OR
0
© 2006 Prentice-Hall, Inc.
= 1 bit
1
NEXT
SLIDE
8
Technology In Action Chapter 9
The Binary Number System
• Number systems:
– Organized ways to
represent numbers
64
2x32
32
2x16
Binary
2 digits 10
0 and 1
Base
10
9 2
16
8 digits 0 through
4
2x11
2x8
1000 2x4
100 2x210
10x100
10x10
1
10x1
Base 10
=
1011001
5832
© 2006 Prentice-Hall, Inc.
89
NEXT
SLIDE
9
Technology In Action Chapter 9
Representing Letters and Symbols
• American Standard Code for Information
Interchange (ASCII):
– 8 bits equal 1 byte
– 256 different combinations
– 1 byte equals an alphanumeric character or symbol
• Unicode:
– 16 bits equal 2 bytes
– 65000 differentON
combinations
OFF
– Used for all languages:
 English, Japanese, Chinese, etc.
© 2006 Prentice-Hall, Inc.
A
B
C
b
a
Click here to view an
ASCII Code chart
NEXT
SLIDE
10
Technology In Action Chapter 9
The CPU: Processing Digital
Information
• CPU components
• Types of CPUs
• What the CPU does:
– Machine cycle:
 System clock
 Cache memory
© 2006 Prentice-Hall, Inc.
NEXT
SLIDE
12
Technology In Action Chapter 9
The CPU
• Also known as a microprocessor or
processor
• Executes instructions
• Components include:
–
–
–
–
Control unit
Arithmetic logic unit (ALU)
Registers
Cache memory
© 2006 Prentice-Hall, Inc.
NEXT
SLIDE
13
Technology In Action Chapter 9
Types of CPUs
PROCESSOR
MANUFACTURER
TRANSISTORS
CLOCK
SPEED
• Athlon XP AMD 54.3 million 2.20 GHz
Athlon
XP
54.3 2.4
million
• Athlon
64FX AMDAMD
106 million
GHz 2.20 GHz
• Centrino
Intel 77AMD
million 1.70
GHz
Athlon
64FX
106 million
2.4 GHz
• Itanium 2 Intel 410
Centrino
Intel million
771.50
millionGHz 1.70 GHz
• Pentium 4 Intel 55 million 3.20 GHz
Itanium 2
Intel
410 million
1.50 GHz
• Pentium 4 Processor-M Intel 55 million 2.60
Pentium
Intel
55 million
3.20 GHz
GHz4
Pentium
4
Intel 57 million
55 million
2.60 GHz
• PowerPC
G4 Motorola
1.00 GHz
Processor-M
• PowerPC G5 IBM 58 million
2.00 GHz
PowerPC G4
Motorola
57 million
1.00 GHz
PowerPC G5
IBM
58 million
2.00 GHz
© 2006 Prentice-Hall, Inc.
NEXT
SLIDE
14
Technology In Action Chapter 9
The CPU’s Machine Cycle
• Also known as the processing cycle
• Fetch:
– The Control Unit searches cache memory and then RAM for
program instructions
– Instructions are moved to the Control Unit
• Decode:
– The Control Unit reads and prepares the program instructions
– The instructions are sent to the ALU
• Execute:
– The ALU performs the calculations
• Store:
– The results are stored in the registers
© 2006 Prentice-Hall, Inc.
Click here to view the
video “Inside the Chip”
by Intel
NEXT
SLIDE
15
Technology In Action Chapter 9
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)
© 2006 Prentice-Hall, Inc.
NEXT
SLIDE
17
Technology In Action Chapter 9
Cache Memory
• Small amount of memory located on the
CPU chip or near it:
– Level 1
– Level 2
• Stores recent or frequently used
instructions and data
• Used for quick access by the CPU
© 2006 Prentice-Hall, Inc.
NEXT
SLIDE
18
Technology In Action Chapter 9
Memory around CPU
© 2006 Prentice-Hall, Inc.
19
Technology In Action Chapter 9
RAM: The Next Level of Temporary
Storage
• Dynamic RAM (DRAM):
– Loses its electrical charge
– Needs to be refreshed
– SDRAM:
 Synchronous DRAM
– DDR SDRAM
 Double data rate SDRAM
– RDRAM:
 Rambus DRAM
• Static RAM (SRAM):
– Does not lose its electrical charge
– Faster than DRAM
– Cache memory
© 2006 Prentice-Hall, Inc.
NEXT
SLIDE
20
Technology In Action Chapter 9
Memory Levels
© 2006 Prentice-Hall, Inc.
21
Technology In Action Chapter 9
Buses: The CPU’s Data Highway
• Bus:
– Electrical pathway used to move data between
components
– Local bus:
 Connects the CPU with the memory
– Expansion bus:
 Connects the CPU with peripheral devices
01100010
01001000
01110011
00100111
© 2006 Prentice-Hall, Inc.
NEXT
SLIDE
22
Technology In Action Chapter 9
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
© 2006 Prentice-Hall, Inc.
NEXT
SLIDE
23
Technology In Action Chapter 9
Types of Expansion Buses
• ISA and EISA:
– Found on older computers
– Connects mouse, modem, and sound card
• PCI:
– Faster than ISA and EISA
– Found on modern computers
– Connects network, modem, and sound card
• AGP:
– Used for three-dimensional graphics
– Connects the graphics card and memory
© 2006 Prentice-Hall, Inc.
NEXT
SLIDE
24
Technology In Action Chapter 9
Making Computers Faster
• Pipelining:
– The CPU processes more than one instruction at a
time
Non-pipelined CPU
Instruction 1
Fetch
Decode
Execute
Store
Instruction 2
Fetch
Decode
Execute
Store
Pipelined CPU
Instruction 1
Fetch
Decode
Instruction 2
Fetch
Decode
Store
Execute
Store
Fetch
Decode
Execute
Store
Instruction 4
Fetch
Decode
Execute
Instruction 3
© 2006 Prentice-Hall, Inc.
Execute
Store
NEXT
SLIDE
25
Technology In Action Chapter 9
Making Computers Faster
• Dual processing:
– Two CPUs on the same
system
– Each processor shares
the workload
Dual processors
• Parallel processing:
– Network of computers
– Each computer works on
a portion of the problem
simultaneously
© 2006 Prentice-Hall, Inc.
NEXT
SLIDE
26
Technology In Action Chapter 9
Chapter 9 Summary Questions
• What is a switch and how does it work in a
computer?
• What is the binary number system and
what role does it play in computer
system?
• What is inside the CPU and how do these
components operate?
• How does a CPU process data and
instructions?
© 2006 Prentice-Hall, Inc.
NEXT
SLIDE
27
Technology In Action Chapter 9
Chapter 9 Summary Questions
• What is cache memory?
• What types of RAM are there?
• What is a bus and how does it function in
a computer system?
• How do manufacturers make CPUs so that
they run faster?
© 2006 Prentice-Hall, Inc.
LAST
SLIDE
28