Components of a computer system

• Control Unit

  • manages the fetch, decode, execute cycle
  • Controls the flow of data
• Fetch - instruction is fetched from memory into the register
• Execute - performs the required operation on data stored in registers or memory
• Decode - decodes the instruction to determine what operation needs to be performed
• Arithmetic Logic Unit

  • completes all calculations
  • performs logic operations (AND, OR, NOT)
  • Contains the accumulator register
• Cache

  • very fast memory, slower than registers but faster than RAM
  • Stores frequently used data
  • low capacity
  • expensive compared to RAM and secondary storage
  • Has different levels of memory