• Structure is the way in which components relate to each other
  • Function is the operation of individual components as part of the structure
  • All computer functions are:
    • Data processing: Computer must be able to process data which may take a wide variety of forms and the range of processing.
    • Data storage: Computer stores data either temporarily or permanently.
    • Data movement: Computer must be able to move data between itself and the outside world.
    • Control: There must be a control of the above three functions.

Fig: Functional view of a computer


           Fig: Data movement operation                              Fig: Storage Operation



        Fig: Processing from / to storage                         Fig: Processing from storage to i/o


  • Four main structural components:
    • Central processing unit (CPU)
    • Main memory
    • I / O
    • System interconnections
  • CPU structural components:
    • Control unit
    • Arithmetic and logic unit (ALU)
    • Registers
    • CPU interconnections