anthony morris

von Neumann Architecture

von Neumann architecture


  • Name honors John von Neumann
  • Idea probably originated with J. Presper Eckert and John Mauchly


  • Units processing information are separate from the units storing information
  • Five components:
    • Memory unit (computer memory)
      • Holds both data and instructions
    • Arithmetic logic unit
      • Capable of performing arithmetic and logic operations on data
      • Pairs with the control unit to make the cpu
    • Input unit
      • Moves data from outside world --> inside the computer
      • Keyboard, mouse, scanners, etc.
    • Output unit
      • Moves results from inside the computer --> outside world
      • Screens, printers, etc.
    • Control unit


Data flow through a von Neumann machine

  • Components are connected by a bus
  • Collection of wires
  • Data travels through
  • Bus width is the amount of bits a bus can simultaneously transfer
  • Each bus has:
    • Address
      • Used to select memory location or device to which data will go or be taken from
    • Data
      • Flows over bus between CPU/memory/IO
    • Control
      • Used to manage flow of addresses and data

Computer Science Computing Systems