Microprogramming for Multicycle Control
  • macroinstruction - an instruction at the assembly or machine code level
  • A microinstruction
    • causes a set of control signals that can be asserted during each cycle.
    • determines which microinstruction should be executed next.
      • Increment the address of the current microinstruction to obtain the address of the next microinstruction.
      • Jump to another microinstruction.
      • Choose the next microinstruction based on the control unit input (dispatch).
  • Each macroinstruction is implemented by executing a sequence of microinstructions.
Chapter 5: The Processor: Datapath and Control - 31 of 35