Question

Difference between hard warewire and microprogram control unit

Answer 1

The control hardware can be viewed as a state machine that changes from one state to another in every clock cycle, depending on the contents of the instruction register, the condition codes and the external inputs. The outputs of the state machine are the control signals. The sequence of the operation carried out by this machine is determined by the wiring of the logic elements and hence named as “hardwired”.



Micro-programmed Control Unit –

The control signals associated with operations are stored in special memory units inaccessible by the programmer as Control Words.

Control signals are generated by a program are similar to machine language programs.

Micro-programmed control unit is slower in speed because of the time it takes to fetch microinstructions from the control memory.