The Central Processing Unit: What goes on Inside the Computer

About This Presentation

Title:

The Central Processing Unit: What goes on Inside the Computer

Description:

Chapter 4 The Central Processing Unit: What goes on Inside the Computer –

Number of Views:203

Avg rating:3.0/5.0

Slides: 40

Provided by: KarenV153

Learn more at: https://www.cs.nmsu.edu

Category:

more less

Transcript and Presenter's Notes

Title: The Central Processing Unit: What goes on Inside the Computer

1
Chapter 4

The Central Processing Unit What goes on Inside
the Computer

2
Components of the CPU

Control Unit (CU)
Directs system operations
Communicates with the ALU and memory
Arithmetic Logic Unit (ALU)
Performs calculations

3
ALU Operations

Arithmetic operations
Addition ()
Subtraction(-)
Multiplication ()
Division ()
Logical operations
Equal-to ()
Less-than (lt)
Greater-than (gt)

4
Components of the CPU

Registers
Temporary storage
High speed
Not part of memory
System clock
Controls speed of processing
Does not keep date/time

5
Instruction Execution

Machine cycle
Fetch get an instruction
Decode interpret, then get data from memory
Execute perform the instruction
Store move the result to memory or a register

6
Data Representation

Bit (Binary Digit)
ON (1)
OFF (0)
Byte
8 bits
Stores one character
Word
Number of bits processed at one time
The size of a register
32 or 64 bits for PCs

7
Coding Schemes

Assigns a number to each characters
ASCII 1 byte per character
Used on PCs and larger computers
256 possible characters
EBCDIC 1 byte per character
Used on IBM mainframes
256 possible characters

8
Coding Schemes

Unicode 2 bytes per character
Allows characters from languages other than
English
Used by Java, a programming language for the web
65,536 possible characters

9
Memory Types

RAM
Random Access Memory
Volatile lost if the power goes off
Often called main memory
ROM
Read Only Memory
Non-volatile
Required for booting the computer

10
Memory Types

CMOS RAM
Stores info about computer hardware
Requires battery power

11
Memory

Each location has unique address
Fast access regardless of location
Programmers use names instead of address numbers

12
Memory and Storage Capacities

Kilobyte (KB or K) approx. one thousand bytes
Exactly 1024 bytes
Megabyte (MB) approx. one million bytes
Gigabyte (GB) - One billion bytes
Terabyte - One trillion bytes

13
System Unit

the box or case that houses the electronic
components of the computer
Inside the system unit you find
CPU
Memory
Motherboard
Power supply
And much more

14
System Units Motherboard

CPU
Memory
Expansion slots
Connections to other components

15
Microprocessors

Intel
Pentium
Celeron
Xeon, Itanium
Intel-compatible
Cyrix, AMD
Non-Intel
PowerPC
Alpha

16
System Bus

Copper lines on the motherboard
For example, from memory to CPU
Transports data and instructions
Bus width
Bus speed

17
Expansion Buses

Expansion boards
Ports
Serial ports
Parallel ports
Universal Serial Bus (USB)
PC Card Bus

18
Measuring Computer Time

Millisecondone thousandth of a second
Microsecondone millionth of a second
Nanosecondone billionth of a second
Picosecondone trillionth of a second

19
Computer Processor Speed

The frequency of pulses from the system clock
MHz megahertz, one million pulses (ticks) per
second
GHz gigahertz, one billion pulses per second
The higher the number, the faster the CPU can
process instructions.

20
PC Processor Speed

Common processor frequencies
1.53 Gigahertz ( 1,530,000,000 ticks per second )
1.8 GHz
2.2 GHz
2.8 GHz

21
Cache

Very fast memory
Stores frequently used instructions
Level 1 - Built into the processor chip
Level 2 - Separate chips
Usually 256 KB or 512 KB
Cheaper than level 1
Most PCs have Level 2 cache

22
Flash Memory

Nonvolatile RAM
Uses
Cellular phones
Digital cameras
Handheld computers

23
Some of the factors affecting overall speed of a
computer

CPU speed
Amount and speed of RAM
Speed and size of bus lines
Amount and speed of L1 and L2 cache
Register size (Word size)

24
Shopping for a Computer

Decide what software you will need.
What do you want to do with the computer?
Email? Web browsing?
Word Processing? Spreadsheet?
Make CDs? Edit photos or movies?
???

25
Shopping for a Computer

2. Determine the types of hardware needed for
the software. Make a list of hardware
specifications.
Email, Web browsing, and other Internet related
software requires a modem or other hardware to
connect to the Internet.

26
Shopping for a Computer

Word processing, spreadsheet, and presentation
graphics dont require a super-fast processor or
much memory.
Want to print your document?
You will need a printer.

27
Shopping for a Computer

Large databases, lots of music files, photos, or
videos require a large amount of hard drive space
and a lot of memory.
Want to make your own music CDs?
You need a writable CD drive.

28
Shopping for a Computer

If you use statistical or mathematical, photo
editing, or video editing software, youll need a
fast processor and a lot of memory.
Want to watch movies on your computer? Youll
need a DVD drive and a fast processor.

29
Shopping for a Computer

3. Set a price range.
Typical PCs sell from 500 to 2000
Some software will come with the system, but you
may need to purchase additional software to meet
your needs.
The cheapest computer is usually not the best
choice.

30
Shopping for a Computer

4. Learn about manufacturers, their
reputations, service and support provided, etc.
Instructors Top 5
Hewlett-Packard (Compaq)
Dell
Gateway
IBM
Sony

31
Shopping for a Computer

5. Compare available systems
Sunday paper ads
Store flyers
TV ads
Manufacturers web sites
Watch the fine print. after rebates, monitor
sold separately, when you sign up for MSN, are
common.

32
This Weeks Ad