CPU and Main Memory

• Control Unit

  • Decodes Instruction
  • Controls the fetching and writing of data
• Arithmetic Logic Unit

  • Executes the mathematical and logical instructions
  • Compares values held in registers
• Clock

  • controls the number of instructions carried out each second
  • Allows the CPU to synchronise operations
• Bus

  • Used to transfer data from one internal component of the CPU to another
• Cache

  • Very fast memory
  • close/on the CPU
  • stores frequently used data
• Register

  • Special purpose memory location on the CPU
  • used for specific purpose in Fetch Execute Cycle
• Explain how Main Memory is used

  • stores instructions and data whilst a program is being executed
  • each unique memory location in memory holds ond value
  • every memory location has a unique adress
  • Data and instructions are replaced in memory as needed