Complex Instruction Set Computer (CISC)

The Microprocessors using CISC architecture have many instruction built into it. This saves the processing time for performing tasks. The time is saved because the required instructions are available in the microprocessor itself and it does not have to retrieve the instruction from the program stored in the external memory, such as the RAM.

                            The CISC architecture helps the microprocessor to speed up the execution of programs requiring instruction. However, the instruction built into the microprocessor affects the performance of the microprocessor. This is because more time is taken to process the instruction and also the space available on the microprocessor for processing reduces. To overcome this problem, more transistors need to be built into the microprocessor to maintain the speed of microprocessor. This type of processor is useful for general purpose computing. It is generally used in personal computers (PCs).

   

                         ReducedInstruction Set Computer (RISC) :-