Transcript Lecture #9 -

Welcome to CMPE003
Personal Computer
Concepts: Hardware and
Software
Winter 2003
UC Santa Cruz
Instructor: Guy Cox
Midterm #1

This Wednesday – January 29
Chapters 1 – 4 and 8
 ~50 questions
 Multiple choice


Bring Scantron form
 #F-1712-ERI-L


(big & pink)
Bring #2 pencil
Bring your student ID

January 23, 2003
Required to take exam
2
Assignments
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Homework #3 – Due February 3
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Design your own Webpage 
Keep in mind --
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The world at large will see your page
Don’t put private or sensitive information on your
Webpage.
Details and sample – see class page –
http://www.soe.ucsc.edu/classes/cmpe003/Winter03/
January 23, 2003
3
The Central Processing Unit:
What Goes on Inside the
Computer
Chapter 4
Part b
Objectives
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Identify the components of the central processing
unit and how they work together and interact with
memory
Describe how program instructions are executed
by the computer
Explain how data is represented in the computer
Describe how the computer finds instructions and
data
Describe the components of a microcomputer
system unit’s motherboard
List the measures of computer processing speed
and explain the approaches that increase speed
January 23, 2003
5
Number systems
Binary Number: base 2
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on and off
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0,1
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ones=20, twos=21, fours=22, etc
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0000 0000 = 0 base 10
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0000 0001 = 1 base 10
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0000 0010 = 2 base 10
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0000 0011 = 3 base 10
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0000 1010 = 10 base 10
January 23, 2003
6
Binary Number System
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We have 10 fingers
...
1000
100
10
1
...
10^3
10^2
10^1
10^0
Computers have devices with 2 states
1
0
0
1
1
the binary number
2^4
2^3
2^2
2^1
2^0
place values
(1 * 2^4) + (0 * 2^3) + (0 * 2^2) + (1 * 2^1) + (1 * 2^0)
= 16 + 0 + 0 + 2 + 1 = 19
January 23, 2003
7
Hexadecimal Numbers
Hexadecimal Number: base 16
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alternative representation to binary
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0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F
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ones=160, sixteens=161, 256's=162, etc
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translation of hex into binary
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0000 0000 = 0 base 16 = 0 base 10
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0000 0001 = 1 base 16 = 1 base 10
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0000 1010 = A base 16 = 10 base 10
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0001 0000 = 10 base 16 = 16 base 10
January 23, 2003
8
Hexadecimal Table
0000
0
1000
8
0001
1
1001
9
0010
2
1010
A (10)
0011
3
1011
B (11)
0100
4
1100
C (12)
0101
5
1101
D (13)
0110
6
1110
E (14)
0111
7
1111
F (15)
January 23, 2003
9
Hexadecimal Example #1
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Hexadecimal (called ‘hex’) is often written
with a prefix of ‘0x’
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0xFF or 0xff
0xFF = 1111 1111
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= (0xF * 16^1) + (0xF * 16^0)
= (15 * 16) + (15 * 1)
= 240 + 15
= 255
January 23, 2003
10
Hexadecimal Example #2
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0x10 = 0001 0000
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= (0x1 * 16^1) + (0x0 * 16^0)
= (1 * 16) + (0 * 1)
= 16 + 0
= 16
0xA5 = 1010 0101
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January 23, 2003
= (0xA * 16^1) + (0x5 * 16^0)
= (10 * 16) + (5 * 1)
= 160 + 5
= 165
11
The System Unit: The Black Box
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Houses electronic components
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Motherboard
Storage devices
Connections
Some Apple Macintosh models have system unit
inside monitor
January 23, 2003
12
The System Unit: The Black Box
Motherboard
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Microprocessor chip
Memory chips
Connections to other parts of the
hardware
Additional chips may be added –
math coprocessor
January 23, 2003
13
The System Unit: The Black Box
Storage Devices
Hard drive
Floppy drive
CD-ROM drive
DVD-ROM drive
January 23, 2003
14
What is in our computer?
January 23, 2003
15
Microprocessor
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CPU etched on a chip
Chip size is ¼ x ¼ inch
Composed of silicon
Contains millions of transistors
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Electronic switches that can allow
current to pass through
January 23, 2003
16
Microprocessor Components
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Control Unit – CU
Arithmetic / Logic Unit – ALU
Registers
System clock
January 23, 2003
17
Building a Better Microprocessor
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Computers imprint circuitry onto microchips
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Cheaper
Faster
Perform functions of other hardware
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Math coprocessor is now part of microprocessor
Multimedia instructions are now part of microprocessor
January 23, 2003
18
Building a Better Microprocessor
The more functions that are combined on
a microprocessor:
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The faster the computer runs
The cheaper it is to make
The more reliable it is
January 23, 2003
19
Types of Microprocessors
Intel
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Pentium
Celeron
Xeon
Itanium
January 23, 2003
Intel-compatible
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Cyrix
AMD
20
Types of Microprocessors
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PowerPC
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Cooperative efforts of Apple, IBM, and Motorola
Used in Apple Macintosh family of PCs
Found in servers and embedded systems
Alpha
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Manufactured by Compaq (formerly DEC)
High-end servers and workstations
January 23, 2003
21
Semiconductor Memory
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Reliable
Compact
Low cost
Low power usage
Mass-produced economically
Volatile
Made up of tiny circuits, each able to
represent ‘0’ or ‘1’ (bits)
January 23, 2003
22
Semiconductor Memory: CMOS
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Complementary metal oxide semiconductor
(CMOS)
Uses little electricity
Used in PC to store hardware settings that are
needed to boot the computer
Retains information with current from battery
January 23, 2003
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RAM
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Keeps the instructions and data for current
program
Data in memory can be accessed randomly
Easy and speedy access
Volatile
Can be Erased
Written over
January 23, 2003
24
Types of RAM
SRAM (Static RAM)
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Retains contents as long as power is
maintained
Faster than DRAM
January 23, 2003
25
Types of RAM
DRAM (Dynamic RAM)
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Must be constantly refreshed
Used for most PC memory because of size and
cost
SDRAM (Synchronous DRAM)
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faster type of DRAM
RDRAM (Rambus DRAM)
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Faster than SDRAM
Expensive
January 23, 2003
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Adding RAM
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Purchase memory modules that are packaged
on circuit boards
SIMMS – Chips on one side
DIMMS – Chips on both sides
Maximum amount of RAM that can be installed
is based upon the motherboard design
January 23, 2003
27
ROM
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Programs and data that are permanently
recorded at the factory
Read-only
Cannot be changed by the user
Stores boot routine that is activated when
computer is turned on
Non-volatile
January 23, 2003
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PROM
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Programmable ROM
ROM burner can change instructions on
some type of ROM chips
January 23, 2003
29
Bus Line
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Paths that transport electrical signals
System bus
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Bus width
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Transports data between the CPU and memory
Number of bits of data that can be carried at a time
Normally the same as the CPUs word size
Speed measured in MHz
January 23, 2003
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Bus Line
Larger bus width
=
More powerful computer
CPU can transfer more
data at a time
=
Faster computer
CPU can reference larger
memory addresses
=
More memory available
CPU can support a greater number and variety of
instructions
January 23, 2003
31
Expansion Buses
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Connect the motherboard to expansion slots
Plug expansion boards into slots
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interface cards
adapter cards
Provides for external connectors / ports
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Serial
Parallel
January 23, 2003
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Expansion Buses
January 23, 2003
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PC Buses and Ports
ISA
Slow-speed devices like mouse, modem
PCI
High-speed devices like hard disks and network cards
AGP
Connects memory and graphics card for faster video
performance
USB
Supports “daisy-chaining” eliminating the need for
multiple expansion cards; hot-swappable
IEEE 1394
(FireWire)
High-speed bus connecting video equipment to the
computer
PC Card
PCMCIA
Credit card sized PC card devices normally found on
laptops
January 23, 2003
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What is in our computer?
January 23, 2003
35
Speed and Power
What makes a computer fast?
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Microprocessor speed
Bus line size
Availability of cache
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L1 & L2
Flash memory
RISC computers
Parallel processing
January 23, 2003
36
Computer Processing Speed
Time to execute an instruction
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Millisecond
Microsecond
Nanosecond
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Modern computers
Picosecond
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January 23, 2003
In the future
37
Microprocessor Speed
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Clock speed
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Number of instructions per second
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Megahertz (MHz)
Gigahertz (GHz)
Millions of Instructions Per Second (MIPS)
Performance of complex mathematical operations
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One million floating-point operations per second
(Megaflops – MFLOPS)
January 23, 2003
38
Cache
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Small block of very fast temporary memory
Speed up data transfer
Instructions and data used most frequently
or most recently
January 23, 2003
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Cache
P
R
O
C
E
S
S
O
R
Step 1
Processor
requests data
or instructions
January 23, 2003
Step 3
Transfer to main CPU and cache
R
Cache
A
M
Step 2
Go to address in main
memory and read
Next processor request
• Look first at cache
• Go to memory
40
Types of Cache
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Internal cache
 Level 1 (L1)
 Built into microprocessor
 Up to 128KB
External cache
 Level 2 (L2)
 Separate chips
 256KB or 512 KB
 SRAM technology
 Cheaper and slower than L1
 Faster and more expensive than memory
January 23, 2003
41
Flash Memory
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Nonvolatile RAM
Used in
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January 23, 2003
Cellular phones
Digital cameras
Digital music recorders
PDAs
42
Instruction Sets
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CISC Technology
Complex Instruction Set Computing
 Conventional computers
 Many of the instructions are not used
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RISC Technology
Reduced Instruction Set Computing
 Small subset of instructions
 Increases speed
 Programs with few complex instructions
 Graphics
 Engineering
January 23, 2003
43
Types of Processing
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Serial processing
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Execute one instruction at a time
Fetch, decode, execute, store
Parallel Processing
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Multiple processors used at the same time
Can perform trillions of floating-point instructions per
second (teraflops)
Ex: network servers, supercomputers
January 23, 2003
44
Types of Processing
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Pipelining
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Instruction’s action need not
be complete before the next
begins
Fetch instruction 1, begin to
decode and fetch instruction
2
Super Scalar
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Executes multiple
instructions per cycle
January 23, 2003
45
Midterm #1

This Wednesday – January 29
Chapters 1 – 4 and 8
 ~50 questions
 Multiple choice


Bring Scantron form
 #F-1712-ERI-L


(big & pink)
Bring #2 pencil
Bring your student ID

January 23, 2003
Required to take exam
46
January 23, 2003
47