Difference Between Hardwired Control and Microprogrammed Control

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Difference Between Hardwired Control and Microprogrammed Control – The Hardwired control unit is implemented with the help of gates, flip-flops, decoders, etc. In the hardware, the inputs to the control unit are the instruction register, flags, timing signals, etc. This organization can be very complicated if we have to make the control unit large. The Microprogrammed control unit is implemented using a programming approach. A sequence of micro operations is carried out by executing a program consisting of micro-instructions. In this organization, any modifications or changes can be made by updating the microprogram in the control memory by the programmer.

Let’s see the Difference between Hardwired Control and Microprogrammed Control using the table given below.

Hardwired ControlMicroprogrammed Control
Technology is circuit based.Technology is software based.
It is implemented through flip-flops, gates, decoders, etc.Microinstructions generate signals to control the execution of instructions.
Fixed instruction format.Variable instruction format (16-64 bits per instruction).
Instructions are register based.Instructions are not register-based.
ROM is not used.ROM is used.
It is used in RISC.It is used in CISC.
Faster decoding.Slower decoding.
Difficult to modify.Easily modified.
The chip area is less.The chip area is large.
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