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What is The Difference Between RISC and CISC Architecture?

written 7.6 years ago by nikhilkumar11061998 • 0

modified 3.8 years ago by krithikkm200 • 10

RISC - Reduced Instruction Set Computer

CISC - Complex Instruction Set Computer

Show detailed comparison between RISC and CISC Architecture

computer organization and architecture

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written 7.5 years ago by yashbeer ★ 11k

Sr No.	RISC	CISC
1	RISC processors have simple instructions taking about one clock cycle. The average clock cycle per instruction (CPI) is 1.5	CSIC processor has complex instructions that take up multiple clocks for execution. The average clock cycle per instruction (CPI) is in the range of 2 and 15
2	Performance is optimized with more focus on software	Performance is optimized with more focus on hardware.
3	It has no memory unit and uses a separate hardware to implement instructions..	It has a memory unit to implement complex instructions
4	It has a hard-wired unit of programming.	It has a microprogramming unit.
5	The instruction set is reduced i.e. it has only a few instructions in the instruction set. Many of these instructions are very primitive.	The instruction set has a variety of different instructions that can be used for complex operations.
6	The instruction set has a variety of different instructions that can be used for complex operations.	CISC has many different addressing modes and can thus be used to represent higher-level programming language statements more efficiently.
7	Complex addressing modes are synthesized using the software.	CISC already supports complex addressing modes.
8	Multiple register sets are present	Only has a single register set
9	RISC processors are highly pipelined	They are normally not pipelined or less pipelined
10	The complexity of RISC lies with the compiler that executes the program	The complexity lies in the microprogram
11	Execution time is very less	Execution time is very high
12	Code expansion can be a problem	Code expansion is not a problem
13	Decoding of instructions is simple.	Decoding of instructions is complex.
14	It does not require external memory for calculations	It requires external memory for calculations
15	The most common RISC microprocessors are Alpha, ARC, ARM, AVR, MIPS, PA-RISC, PIC, Power Architecture, and SPARC.	Examples of CISC processors are the System/360, VAX, PDP-11, Motorola 68000 family, AMD and Intel x86 CPUs.
16	RISC architecture is used in high-end applications such as video processing, telecommunications and image processing.	CISC architecture is used in low-end applications such as security systems, home automation, etc.

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