Question

This is a three-part question. If you want it piecemeal, then let me know.

a) Why do CISC processors tend to use micro-programming?

b) Why do RISC processors not use micro-programming?

c) What is the main advantage provided by a micro-programmed system?

Answer 1

Answer)

A) CISC architecture mostly uses the microcode rom and microprogramming for decoding the complex variable-length instruction as micro-ops that are being fed to that of the reorder buffer as well as for execution units via the reservation station.

B) Microprogramming was implemented as a form of microcode that helps in governing the control logic to CPU and is an important aspect of the design which would be virtually meant for microprocessor and helps to implement some of the instruction to that of the hardware cost or the design standpoint wherein mostly some of the microcode is used for some of the architecture.

So some part of microprogramming is being used in any of the processors that is for RISC or CISC.

But as RISC architecture executes the instruction in a single clock cycle whereas microprogramming takes many operations in sequence

C) Some of the main advantages being provided by that of the micro-programmed system is that it is much cheaper and error occurrence is much lesser. There is much more flexibility for accomodating with that of the new instructions and is much easier for decoding as well as for sequencing which could be done and is much easier for handling the complex instruction set.

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