Chapter 4 The Components of the System Unit

1
Chapter 4The Components of the System Unit
2
Chapter 4 Objectives
????????????????????????? System
?????????????? expansion slots and adapter cards
???????????? Motherboard
????????? Port ??? Adapter
????????????????? Processor
?????????????????? Mobile Computer
????????? Memory (???????????)
3
The System Unit

• What is the system unit? (?????????)

• Case that contains electronic components of the
  computer used to process data
• ???????????????? ???????????????????
  ????????????????????????????????????????????????
  ?????????
• Sometimes called the chassis (??????)

4
The System Unit

• What are common components inside the system
  unit?
• ??????????????? ???????????)

• Processor (?????????????????)

• Memory (???????????????)
• Adapter cards (Card ?????????)
• Sound card
• Modem card
• Video card
• Network card
• Ports (???????)
• Drive bays (????????? Drive)
• Power supply (???????????)

5
The System Unit

• What is the motherboard? (???????????)

• Main circuit board in system unit
  (????????????????????????????????)
• Contains adapter cards, processor chips,
  andmemory chips (????????????????????????????????
  ????????????????????????????????????)
• Also called system board

6
The System Unit
dual inline packages (DIP) holds memory
chips ???????????

• What is a chip ???? chip set?

• Integrated circuits contain many microscopic
  pathways capable of carrying electrical current
• (?????????????????????????????? ???????????????
• ????????????????????????????????????????????????
• ???????????)
• Chips are packaged so they can be attached to a
  circuit board
• (???????????????????? ???????????????????????????
  ????????????????)

pin grid array (PGA) package holds processor
chips ????????????
7
Processor

• What is the central processing unit (CPU)?
  (?????????????????)
• (??? ?????????????????????????????????????????????
  ??????????????????????? )

• Interprets and carries out basic instructions
  that operate a computer (?????????????????????????
  ????????????????)
• ??????????

• Control unit directs and coordinates operations
  in computer
• ??????????? (control unit) ???????????????????????
  

• Arithmetic logic unit (ALU) performs arithmetic,
  comparison, and logical operations (??????????
  (ALU) ???????????????????????????????????????????)
  

• Also called the processor (???????????)

8
Processor

• What is the central processing unit (CPU)?
  (?????????????????)
• (??? ?????????????????????????????????????????????
  ??????????????????????? )

CPU ??????????????????????????
???????????????????????????????????? ???????????
(Memory) ???????????????????????????????? CPU
??????????????????????????????????????????????????
??????? ?????????????????????????????????????????
???????
Arithmetic Logic Unit (ALU)
Control Unit
Memory
InputDevices
OutputDevices
Data
Information
StorageDevices
9
Processor

• What is a machine cycle? (??????????????????)

• Four operations of the CPU comprise a machine
  cycle

Step 1. Fetch Obtain program instruction or
data item from memory
Step 2. Decode Translate instruction into
commands
Step 4. Store Write result to memory
Step 3. Execute Carry out command
10
Processor

• What is a machine cycle? (??????????????????)

• Four operations of the CPU comprise a machine
  cycle
• (??????????????? ?????????? 4 ??????? ?????
  ??????)

1 ??????????????????? (fetches) ????????????????
2 ???????????????????? (decodes) ??? Control
Unit ??????????? ALU
3 ALU ???????? (executes) ??????????
4 ??????????????????????????(stored)
?????????????
????????????????????????????? ?????????????
11
Processor

• What is pipelining?

• CPU begins fetching second instruction before
  completing machine cycle for first instruction
• (????????????????????????????????????????????????
  ???????????????? ???????????? ????????????? 1
  ??????????????? ??????????????????????????????? 2
  ???? ????????????????????????????
  ???????????????????????????????? ???????????
  ????????????????????)
• Results in faster processing (????????????????????
  ?????????????????)

12
Processor

• What is a register? (??????????)

• Temporary high-speed storage area that holds
  data and instructions (??????????????? CPU
  ??????????? ?????????????????????????????????????
  ????????????? ????????????????????????????????????
  ???????????)

Stores location from where instruction was
fetched (?????????????????????????)
Stores instruction while it is being
decoded(????????????????????????????)
Stores data while ALU computes it
(?????????????????????????????)
Stores results of calculation ???????????????????
????
13
Processor

• What is the system clock? (???????????????????)

• Controls timing of all computer operations
• (????????????????????????????????????????????????
  ?)
• ??????????????????????????????? 1 ????????????
• ??????????????????????????????????????

Each tick is a clock cycle (????????????????????
??)
Pace of system clock is clock speed Most clock
speeds are in the gigahertz (GHz) range (1 GHz
one billion ticks of system clock per second)
Processor speed can also be measured in
millions of instructions per second
(MIPS) (????????????????????????????????)
??????????? GHz (???????????????????????????????
)
14
Processor

• How do personal computer processors compare?
• (??????? Processor ???????????????? PC)

15
Processor

• Which processor should you select?
  (???????????????)

• The faster the processor, the more expensive the
  computer

16
Processor

• What are heat sinks, heat pipes, and liquid
  cooling?

• Liquid coolinguses a continuous flow of fluids
  to transfer heat away

• Heat sinkcomponent with fins that cools
  processor (?????????????????????????????? CPU)

• Heat pipesmaller device for notebook computers
  (????????? Notebook ?????????? Heat pipe
  ??????????????
• ???????????????? PC)

???????????????????????? http//www.overclockzon
e.com/article.html
17
Processor

• What is parallel processing?

• ???????????????????????? ?????????????????????????
  ????????????????? ???? processor ??????? 1
  ?????????????????????? ???
• ??????????????????????????
• ???????????????????????????????
  ??????????????????????????? Supercomputer ????
  ????????????????????????????

Control Processor
Results combined
18
Data Representation

• How do computers represent data?
  (????????????????)

• Most computers are digital (??????????????????????
  ???????????????? ?????????????????)

• Recognize only two discrete states on or off
• (????? ??????/????)
• Use a binary system to recognize two states
• (???????????????? (Binary System)
  ???????????????? 0 ?????? 1)

• Use Number system with two unique digits 0 and
  1, called bits (?????? 0 ???? 1 ???????? ??? ???
  (Binary Digit Bit)

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Data Representation

• What is a byte?

• Eight bits grouped together as a unit
• (?????????????????? 1 ???????????????????????????
  ? ??? 8 ??? ????????? 1 ????)
• Provides enough different combinations of 0s and
  1s to represent 256 individual characters
  (??????????????? 256 ????????
• Numbers (??????)
• Uppercase and lowercase letters (????????)
• Punctuation marks (???????????
• ????????????)

20
Data Representation

• What are three popular coding systems to
  represent data?

• ASCIIAmerican Standard Code for Information
  Interchange
• (??????? ?????? ???????? ??????????? ?????
  ?????? ???????????????????????????????????????????
  ??????????????????????????????????????????????????
  ???? ??????????????????????????????????
  ?????????? ASCII ????????? 256 ???)
• EBCDICExtended Binary Coded Decimal Interchange
  Code
• (????????????????????????????????????????????????
  ????????? 256 ???? ???????????????????????????????
  ???????????????????????? ??? Zone bits ???
  Numeric bits)
• Unicode - ??????????????????? 16 ???
  ??????????????????????? 65,536 ???
  ??????????????????????????????????????????????????
  ??????????????????? ???? ??????????????????????
  ????????????????????????????????? ?

p. 192 Fig. 4-15
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Data Representation

• How is a letter converted to binary form and back?

Step 2.An electronic signal for the capital
letter D is sent to the system unit.
Step 3.The signal for the capital letter D is
converted to its ASCII binary code (01000100) and
is stored in memory for processing.
22
Memory

• What is memory? (???????????????)

• ????????????????????????????????????????????????
  ??????????????????????????????????????????????????
  ??????????????????????????????????????
• ?????????????/??????? ??????? 1 ?????????
• ??????????????????????????????????????????????????
  ?????????????????????

23
Memory

• How is memory measured? (??????????????????)

• By number of bytes available for storage

- Kilobyte (KB) ?????? 1,024 ???? ( 210 ???? )
- Megabyte (MB) ?????? 1,048,576 ???? ( 220 ????
) ???????????????????????????? - Gigabyte (GB)
?????? 1,073,741,824 ???? ( 230 ???? ) -
Terabyte (TB) ?????? 1,078,036,791,296 ???? ( 240
????)
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Memory

• What is random access memory (RAM)?

• ???????????????????????????????????????????
  ?????????????? (Processor) ???????????????????????
  ?
• ???????????????????????????? ????????????????????
  ??????????????????????????????????????????????????
  ???
• ?????????????????????????????????????????????????
  ????????????????

Memory chips that can be read from and written
to by processor
Also called main memory or primary storage
Most RAM is volatile, it is lost when
computers power is turned off
The more RAM a computer has, the faster it
responds
25
Memory

• How do program instructions transfer in and out
  of RAM?

Step 1. When you start the computer, certain
operating system files are loaded into RAM from
the hard disk. The operating system displays the
user interface on the screen.
Operating system interface
Operating system instructions
Step 2. When you start a Web browser, the
programs instructions are loaded into RAM from
the hard disk. The Web browser window is
displayed on the screen.
Web browser instructions
Web browser window
Step 3. When you start a word processing program,
the programs instructions are loaded into RAM
from the hard disk. The word processing program,
along with the Web Browser and certain operating
system instructions are in RAM. The word
processing program window is displayed on the
screen.
Word processing program instructions
Word processing program window
Step 4. When you quit a program, such as the Web
browser, its program instructions are removed
from RAM. The Web browser is no longer displayed
on the screen.
Web browser program instructions are removed from
RAM
Web browser window is no longer displayed on
desktop
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Memory

• What are two basic types of RAM chips? (?????????
  RAM)

Static RAM (SRAM)
Dynamic RAM (DRAM)
Future Magneto resistive RAM (MRAM)
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Memory

• What are two basic types of RAM chips? (?????????
  RAM)

• Static RAM (SRAM) ????????????????????????????????
  ??????????????????? ??????????????????? SRAM
  ??????????????????? ??????????????????????????????
  ??????????????? ????????????????
• Dynamic RAM (DRAM) ???????????????????????????????
  ??????????????????????????????????????????????????
  ????????????????????????????????????????????????
  0 ???1 ????????????????????????
  ?????????????????????????? ??????
• (2.1) SDRAM ???? Synchronous DRAM ???? ????????
  ??????????????????????????????????????????????????
  ????????? ??????????????????????????????
  ??????????? (MHz)
• (2.2) DDR SDRAM ???? Double Data Rate SDRAM ????
  ???????????????? ???????????? ????????????????????
  ???????? 200MHz ??????????????????????????????????
  ??????????? 2 ???? ??? ???????????????????????????
  ??????????????????????? ??????????????????????????
  ??????????????????????????????????????????????????
  

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Memory
dual inline memory module

• Where does memory reside?
• (?????????????????????????????)

• Resides on small circuit board called memory
  module ???????????????????
• ??????????????????? ????????????????
  ???????????????????????????????????
• Memory slots on motherboard hold memory modules
  (????????????????????????????????????????????)

memory chip
memory slot
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Memory

• How much RAM does an application require?
• ??????? RAM ????????????????? ??????????

• Software package typically indicates RAM
  requirements
• For optimal performance, you need more than
  minimum specifications

30
Memory

• How much RAM do you need? (??????? RAM
  ????????????)

• Depends on type of applications you intend to
  runon your computer

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Memory
http//www.byxtreme.com/Article/cache.html

• What is cache? ??????????????

• Helps speed computer processes by storing
  frequently used instructions and data
  ???????????????????????????????????????????????
  ?????????
• ?????????? Cache ????????????? CPU ???
  ??????????????? (RAM) ???????????????? ????
  ??????????????????????????????????
  ??????????????????
• ??????????????????????????????????????????????????
  ?????????????????? (RAM) ?????????????????

• L1 cache ???????????? CPU ?????????????????
• L2 cache ??????????????????????????
  ??????????????? CPU ?????????????????? L1
• L2 advanced transfer cache ?????????????????????
  L2 cache ???? ??????????????????????????????
  ?????? CPU ??????????
• L3 cache ????????????????? ???????????????????
  CPU

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Memory

• What is read-only memory (ROM)?
  ?????????????????????? ??????????????????
  ????????????????????????????? ????????????????????
  ??????????????????????????????????????
  ????????????????? ?????? ?????????????????????????
  ?? ???????????????????????????????????????????
  "????" ??? ???????????????????????????????????????
  ?? ?????????????????????? ???????????????????????
  ??? ?????????????????????????????????????????????
  ???????????????????????

Nonvolatile memory, it is not lost when
computers power is turned off
Memory chips that store permanent data and
instructions
?????????????????????????
???????????????????????????????
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Memory

• What is read-only memory (ROM)?
  ?????????????????????? ROM ????????????
• ?????????? (???????????) ???????? ROM
  ??????????????? ???????????????????
  ???????????????
• ?????????????????????? ROM ???

??????????? ?????????????? ROM) ??????????? 3
??????

• Firmware ????????????????? ?????????????
  ????????????? ???? ????????? ??????
  ?????????????? ?????????????????
  ??????????????????????????? ??????????????????????
  ????????????????
• PROM (programmable read-only memory)
  ?????????????? (ROM) ?????????????? ???????????
  ????????????????????????????
• EEPROM (electrically erasable programmable
  read-only memory) ?????????????? (ROM)
  ??????????????????????????????????????????????????
  ?????????????? ?????????????????????????????

34
Memory

• What is CMOS? ???????????????????

35
Memory

• What is flash memory? (???????????????)

• ????????????????? ??????????" (Nonvolatile)
  ???????????????????????????????????????
• ????????????????????????????????????? ????
  ??????????????, ????????????, PDAs, ???????????
  MP3, Printers

36
???????????????????????????? CPU ???????????????
37
Memory

• What is access time? ?????????????
  ???????????????????????

• ??????????????????????????????????????????????????
  ???????????????????

• ????????????????? (1 ??????????????? ns)

• It takes 1/10 of a second to blink your eye a
  computer can perform up to 10 million operations
  in same amount of time (?????????????????????? 1
  ???????????? 1/10 ?????? ?????????????????????????
  ?????? 10 ?????????? ?????????????????)

38
Expansion Slots and Adapter Cards

• What is an adapter card? (interface card)

• Enhances system unit or provides connections to
  external devices called peripherals ???????
  ??????????????????????? ??????????????????????????
  ?????????????????????? (peripheral)
  ??????????????????????????????????????????????????
  ?? adapter ???????????????????? upgrade
  ??????????? ???? ?????????????????????????????????
  ??????????????????????????????
• Also called an expansion card

39
Expansion Slots and Adapter Cards

• What is an expansion slot ? ??????????????????????
  ?????????????????

• An opening, or socket on the motherboard that can
  hold an adapter card (????????????????????????????
  ??????????????????????????
  ??????????????????????????????????????????)
• With Plug and Play, ?????????????????????????????
  ???
• ???? Card ??????????????????????
• Driver ????????????????????????
• ?????? ??????????????????

40
Expansion Slots and Adapter Cards

• What are PC cards and flash memory cards?

• A PC card ??????????????????????????????????
  ??????????????????????????????????????????????????
  ???????????????? Notebook ???? ???????????????????
  , ???????????, Sound Card, Fax/Modem

• A flash memory card ??????????????????????????????
  ????????? Mobile Computer ?????????? PC ??? ????
  USB Flash Drive

• Hot plugging ??????????????????????? PC Card ???
  Flash memory Card ????????????????????????????????
  ???????????

41
Ports and Connectors

• What are ports (???????) and connectors?
  (????????????)

• Port ?????????????????????????????????????
  (System Unit)????????????????
• Connector ????????????????????????????????????????
  ???????????????
• ???????????? ????????????????? ?????????? male
  and female

42
Ports and Connectors

• What are different types of connectors?
  (?????????????????????)

43
Ports and Connectors

• What is a serial port? (??????????)

• Transmits one bit of data at a time
• (??????????????????? 1 ???)
• Connects slow-speed devices, such as mouse,
  keyboard, modem
• (???????????????????? ????????? ?????????)

44
Ports and Connectors

• What is a parallel port? (????????)

• Connects devices that can transfer more than one
  bit at a time, such as a printer
• (??????????????????? 1 ????
• ???????????????????????????????????)

45
Ports and Connectors

• What are USB ports?

USB (universal serial bus) port
???????????????????????????? ?????? 127 ???
?????????????????????????????????
46
Ports and Connectors

• What are special-purpose ports? (Port
  ???????????????????????????)

• FireWire port ???? ????? IEEE 1394
  ?????????????????????????????????????? ??
• ????????????????????????????????? 400 Mbps
  ?????????????????????????????????? USB
• ??????????????????????????????????????????????????
  ???????? (DV Camera)
• MIDI (Musical Instrument Digital Interface) port
  ?????????????????????????????????????
• SCSI (small computer system interface) port
  ?????????????????????????????? SCSI
  ????????????????????????? computer ???? External
  Harddisk, scanner
• IrDA (Infrared Data Association) port
  ????????????????????????????
• Bluetooth port ??????????????????????????
  Mobile PCs, Mobile Phones ??????????????????????
  ???

47
Buses

• What is a bus? (??????????-???????????????)

• ??????????????????????????????????????????????????
  ??????????????????????????????????????????????????
  ??????

• System bus (???????) ?????????????????????????????
  (CPU)???????????????? (RAM)
• Bus width determines number of bits transmitted
  at one time
• (??????????????????????????? ????????????????????
  ??????)
• Word size ????????? ??? ??????????????????????????
  1 ????????? ???? word size ??? ?????????????????

48
Buses

• What is an expansion bus? (???????????)

• Allows processor to communicate with peripherals
• ????????????????????????????????????????

FireWire Bus
PCIBus
AGPBus
USBBus
49
Bays

• What is a bay?

• Open area inside system unit used to install
  additional equipment
• (???????????????????????????????????????)
• Drive bays typically hold disk drives
• (????????????????? ???????? ?????????)
• ?????????????????????????????????? Harddisk,
  CD,DVD-ROM Drive

50
Power Supply

• What is a power supply? (????????????????)

51
Mobile Computers and Devices

• What is a mobile computer? (??????????????????)

• Notebook, weighing between 2.5 and 8 pounds, or
  mobile device such as a PDA

52
Mobile Computers and Devices

• What ports are on a notebook computer?
• Port ????? ????????????????????? Notebook
  ???????????????

http//pclab.nectec.or.th/Documents/Support/Articl
e/Notebook.pdf
53
Mobile Computers and Devices

• What ports are on a tablet PC?
• Port ????? ??? Tablet PC

54
Putting It All Together

• What are suggested processor, clock speed, and
  RAM requirements based on the needs of various
  types of users?

55
Summary of the Components of the System Unit
Components of the system unit
Sequence of operations that occur when a computer
executes an instruction
How memory stores data, instructions,and
information
Comparison of various personal computer
processors on the market today
Chapter 4 Complete