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					                                                    Chamchamal Tech. institute



                       Computer organization


Computer: - Is a machine which is automatically accepts, processes and
out put data.

Information: - Is represented by words, number, sounds, measurement,
etc & in a form which is meaningful to people. before a computer or other
machine can process it , information has to be prepared or encoded into a
form that the machine can accept.

Data: - The result of encoding information in to a machine readable
form. When the input data been processed and further data has out put
this out put data is decoded back into information as shown below.



                              I/P                 O/P
Information     Preparation          Processing        Printing     Information
                 Encoding     Data                Data Decoding



Computer system consists of several interacting part these part classified
as either. Hardware (H/W) and software (s/w).

Hardware: - Is the physical equipment that consist the computer system.

Software: - Is the set of instruction. (Programs)That tells the hardware
how to solve problem & perform various task.

    Usually (H/W) is contrasted with software)

Computer organization: - Is the study of the internal structure of the
computer system. That is the resource that are available, the purpose they
serve, and relation ship between them.




                                       1                     Hemin S. Abdullah
                                                 Chamchamal Tech. institute


         The computer revolution:-

         Since, 1971 the microprocessor has revolutionized the computer
field.

   – Computer were universally very large, very expensive, and almost
     none were owned be individuals.
   – In 1981 IBM entered as small computer and were called “Home
     computer ” and which was based on the Intel( 8088)

Today computer have become work house computer for business and
industry as well as individual.

    The (80X86):

In (1978) also called (80X 86) families include the (8086) the evolution
stage.
The first generation of the (80X86) family includes the (8086) and the
(8088).

   – the (8086 / 8088) and (80186) developed in 1978
   – The 8086 was the first of the (80X86).

   1- The (8086) was 16-bit data bus represented significant adapter
      from the early 8-bit device.
   2- The number of address line increased to the 220 =(1 MB)
   3- Memory location =(1 MB)
   4- The clock frequency 5MHz

    the 8088 essentially an (8086) 16-bit internal data bus

   – The 80186 supported functions such as clock generator, system
     control, interrupt, control (DMA).
   – the clock frequency 12.5MHz


    The 80286 introduced in 1982 an the memory address line = 224
   – Memory location =(16 MB)

    The 80386 introduced in 1985 when the first Intel 32-bit and 32-bit
     address bus DX version and SX version 232
   – Memory location = 4 GB
   – The frequency is 16 to 25 MHz

                                      2                   Hemin S. Abdullah
                                            Chamchamal Tech. institute



 The 80486 in 1989 it is very fast SRAM and DRAM

- The clock frequency 66 MHz.

   Pentium introduced in 1993
–   32-bit address bus
–   32-bit register.
–   Cash memory 8-KByte
–   Clock frequency 60-66 MHz.

 Pentium pro code name = P6.
– Introduced in 1995
– The clock speed up to 200 MHz.

   Pentium II
-   Introduced as 1997
–   Intel MMX Technology
–   The clock speed 450 MHz.
   In the 1998 Pentium II family included Celeron processor designed
    for PC market the clock speed 400 MHz.


   Pentium III
–   Introduced as 1999
–   It designed for costumer and business
–   The enhance is 3D imaging and video.
–   Frequency speed up to 1 GHz.

 Pentium IV
– Introduced as 2000
– The performance increased than 1.30GHz, 1.40, GHz, 1.50 GHz,
  1.70 GHz, 1.90 GHz, 2.0 GHz, and 2.2 GHz.

 The new Generation is Pentium IV LGA.




                                 3                   Hemin S. Abdullah
                                                 Chamchamal Tech. institute


Hardware:-

   - There are four main component



           CPU                             Main memory


                  System Interconnection




                         I/O Unit




   5- (CPU):- (central processing unit) is the main part of the computer.
      It operates at a higher speed than the rest of the computer system.

          It consist of :-

   a. control unit (CU)
   b. the arithmetic logic unit (ALU)
   c. Immediate access store(IAS)
Organized by
          KR How do you pick a processor for your system?
                 Performance & Cost
    How to measure performance?
       – Clock speed is one measure of computer “power”, but it
is not always directly proportional to the performance level.
       – The type of microprocessor, the bus architecture, and
the nature of the instruction set, all make a difference.
– examples : P4 3.06 GHz, P4 3.0B GHz, P4 3.0C GHz
– Check for bus speed and cache size as well.




                                     4                    Hemin S. Abdullah
                                                Chamchamal Tech. institute


 6- Main memory: - stores data & program instructions for immediate
    access by the CPU.

 7- I/O:- movies data & information between the computer & the
    external environment (peripherals )

 8- System interconnection: - provides way for communication
    among CPU, main memory & I/O.

  Software: - Is general term for program which written to help
   computer users.

 There are two basic types of software.

 1- System software.
 2- Application software.


                                  Backing
                                   Store

        I/P                                                             O/P
       Device                                                          Device



                     CPU
 Data flow
                                      Control unit


Control signal
                            IAS                      ALU




                 The layout of typical computer




                                  5                        Hemin S. Abdullah
                                                 Chamchamal Tech. institute

              CPU
                                                            ALU
                                         Clock
                     Control
                      Unit               Register




                                    IAS Memory


                         Central processing unit


    Input devices:-
Tasks programs and data in machine readable form & send them to the
processing unit, e.g. keyboard, mouse, scanner, plotter, microphone.

   a. Control unit:- When the computer is running the control unit
      repeatically interprets (decoded) instruction quickly one after
      another, after each instruction is decoded.


   b. Arithmetic & Logic unit:- The (ALU) is the key processing
      element of the microprocessor. It is directed by the control unit to
      perform arithmetic operation, such as addition and subtraction and
      logic operation such as Not, And, Or, Xor.

   c. Immediate access store (IAS) :- Is the main working store of the
      computer it is used with the control unit at a higher speed without
      using any mechanical movement? It is also called working store or
      main store. Store is called memory.

    Backing store: - is a mean of storing large amount of data outside
     of CPU. It used for long term storage of data and program e.g.
     floppy disc, CD, flash memory.

    Registers:- Temporary storage device that hold control
     information, address, instruction, data and intermediate result.


                                    6                     Hemin S. Abdullah
                                                        Chamchamal Tech. institute


             Clock:- generates, prissily timed electronic pulse that synchronized
              the processor with other component of the system.




        1) A signal to select                             2) An instruction fetch
        location in memory                                        memory




                                         Control unit


        3) A signal to the ALU specify                          4) A signal
        which operation to perform                                 indicated
                                                                   the state of
                                                                   result From
                                                                  the ALU
                                     The Control Unit



Unit by
             Unite              Size                      Number of Bit
 write
  ‫بت‬          Bit                1                               1
 ‫بايت‬        Byte                8                               8
‫كيلو بايت‬   kilobyte            1024                           1024
‫ ميجابايت‬megabyte           1048576                         1024× 1024
‫جيجابايت‬    gigabyte      1073741824                    1024 × 1024 × 1024
‫تيرابايت‬    terabyte    1099511627776                1024 × 1024 × 1024 × 1024
                        1.125899906843
‫بيتا بايت‬   petabyte                             1024 × 1024 × 1024 × 1024 × 1024
                             e+15
                        1.152921504607
‫إكسابايت‬    exabyte                          1024 × 1024 × 1024 × 1024 × 1024 × 1024
                             e+18
                        1.180591620717       1024 × 1024 × 1024 × 1024 × 1024 × 1024 ×
‫زيتابايت‬    zitabyte
                             e+21                              1024
                        1.208925819615       1024 × 1024 × 1024 × 1024 × 1024 × 1024 ×
‫يوبابايت‬    yobabyte
                             e+24                           1024 × 1024


                                            7                    Hemin S. Abdullah
                                              Chamchamal Tech. institute


Main memory:-

There are two type of internal memory.

1- Random access memory (read/write memory (RAM))
2- Read only memory (ROM)

  1. RAM: - As the name implies RAM allows data and instruction to
     be both retrieve (i.e. read) and stores (i.e. wrote). RAM is the
     computer temporary storage compartments.
  – A user can read the data stored there as well as write new data to
     replace what is there
  – RAM is usually volatile i.e. the content are lost when the power is
     turned off ,is one of the rezones that we need backing or secondary
     storage
  – The more RAM in the computer the more power full the program
     can be run.


  2 - ROM: - the content of ROM (program and data) fixed when the
  memory chips (ICs) are manufactured and can not be changed during
  normal operation of the computer.
  – The advantage of ROM is that it is non volatile because it content
      are permanent they do not disappear when the computer is turned
      off.
  – The content of ROM can be read and used, but they can not be
      changed by the users without using special equipments.
  – ROMs are not be altered e.g. microcomputer might have, basic
      interpreting program and it is calculator might have program for
      calculation of several mathematical operation, like square, root.




                                   8                   Hemin S. Abdullah

				
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posted:10/18/2011
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