Microcodes are something that is present in control unit section of CPU. It resides in control store part of i.e. like a high speed ROM in control unit of CPU.
Control unit decodes instruction from code and call the particular instruction of microcode.
Microinstruction from microcode are large in size like around 50bit or more... because they generate the required signals based on its each bit to ALU.
Microcodes system is only used in CISC based architectures. It is used instead of hardwire circuit bcz, it reduces the job of designing complex "control unit" circuit in CISC.
RISC uses Hardwired control unit circuit. Previously, the job of writing assembly code for RISC processor was time consuming as it required LOAD and STORE instruction for every simple job like "Addition of two numbers"
RISC architecture assembly code takes more space on RAM as compared to CISC.
But as years passed, the compilers became so improved that, no more assembly level programming is mandatory. Hence, in RISC architecture based system, more emphasis is given on software side i.e. more emphasis given on building intelligent compiler.
Control unit decodes instruction from code and call the particular instruction of microcode.
Microinstruction from microcode are large in size like around 50bit or more... because they generate the required signals based on its each bit to ALU.
Microcodes system is only used in CISC based architectures. It is used instead of hardwire circuit bcz, it reduces the job of designing complex "control unit" circuit in CISC.
RISC uses Hardwired control unit circuit. Previously, the job of writing assembly code for RISC processor was time consuming as it required LOAD and STORE instruction for every simple job like "Addition of two numbers"
RISC architecture assembly code takes more space on RAM as compared to CISC.
But as years passed, the compilers became so improved that, no more assembly level programming is mandatory. Hence, in RISC architecture based system, more emphasis is given on software side i.e. more emphasis given on building intelligent compiler.
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