• Once the configuration of a computer and its microprogrammed control unit is established, the designer’s task is to generate the microcode for the control memory.
  • This microcode generation is called microprogramming.
  • The block diagram of the computer is shown in Below Fig:
  • Two memory units
    • A main memory for storing instructions and data
    • A control memory for storing the microprogram
  • Four registers are associated with the processor unit
    • Program counter PC, address register AR, data register DR, accumulator register AC
  • The control unit has a control address register CAR and a subroutine register SBR.
  • The control memory and its register are organized as a microprogrammed control unit, as shown in Fig. 3-2.
  • The transfer of information among the registers in the processor is done through multiplexers rather than a common bus.

                     Fig 3-4: Computer hardware configuration