User Account

All Pages

define CISC and RISC ?, Basic Computer Science

Assignment Help:
Two competing architectures were developed for improving the architecture of the central processing unit, and different processors are conventional to each one. Both had their power and weaknesses, and as such also had supporters and detractors.
CISC: Complex Instruction Set Computers
Earlier developments were based in the order of the idea that making the CPU more complex and supporting a superior number of potential instructions would lead to amplified performance. This thought is at the root of CISC processors, such as the Intel x 86 ranges, which have very large instruction sets reaching up to and on top of three hundred separate instructions. They also have amplified complexity in other areas, with many more specialized addressing modes and registers also being implemented and variable length of the instruction codes themselves.
Performance was getting better here by allowing the generalization of program compilers, as the range of more advanced instructions available led to fewer refinements having to be made at the compilation process. But, the complexity of the processor hardware and architecture that resulted can cause such chips to be hard to understand and program for, and also means they can be exclusive to produce.
RISC: (Reduced Instruction Set Computers)
In conflict to CISC, the mid-1980s saw the beginnings of the RISC philosophy. The plan here was that the best way to get better performance would be to make simpler the processor workings as much as probable. RISC processors, for example the IBM PowerPC processor, have a greatly simplified and concentrated instruction set, numbering in the region of one hundred instructions or less. Addressing modes are basic back to four or less, and the length of the codes is fixed so as to allow standardization across the instruction set.
Changing the architecture to this extent means that fewer transistors are used to create the processors. This means that RISC chips are much cheaper to produce than their CISC counterparts. As well the reduced instruction set means that the processor can execute the instructions more rapidly, potentially allowing for greater speeds. However, only allowing such easy instructions means a greater burden is placed upon the software itself. Less instructions in the instruction set means a greater stress on the efficient writing of software with the instructions that are accessible. Supporters of the CISC architecture will point out that their processors are of good sufficient performance and cost to make such efforts not worth the problem.
CISC RISC
Large (100 to 300) Instruction Set Small (100 or less)
Complex (8 to 20) Addressing Modes Simple (4 or less)
Specialized Instruction Format Simple
Variable Code Lengths Fixed
Variable Execution Cycles Standard for most
Higher Cost / CPU Complexity Lower
Compilation Simplifies Processor design
Processor design Complicates Software

Related Discussions:- define CISC and RISC ?

Evolution of erp , Evolution of ERP  The origin of using computers for ...

Evolution of ERP  The origin of using computers for business, traces the following line of story. Originally, they were designed to support the repetitive and time consuming fu

Indexing and abstracting databases, Indexing and Abstracting Databases: ...

Indexing and Abstracting Databases: A study of growth of indexing and abstracting services over the years would show that during the past two centuries, these services have be

Expert system, Develop a simple expert system to pick ten stocks to conside...

Develop a simple expert system to pick ten stocks to consider. Create seven or more rules that could be used in such an expert system. Create five cases and use the rules

Telecommunication processors, brigde

brigde

Briefly explain the shutter speed, Question 1 Write a note on transition, ...

Question 1 Write a note on transition, transition types & Features Question 2 Describe the different types of lens used in film shooting Question 3 Briefly explain

COMPUTER, What is a computer??

What is a computer??

C, programm for fibonacci series

programm for fibonacci series

Geometric mean - algorithm, The geometric mean is obtained by multiplying a...

The geometric mean is obtained by multiplying all the four numbers and taking the fourth root of the product. Let x 1 ,x 2 ,x 3  and x 4  be the given four numbers then geometric

Batch processing, Batch Processing When the entire computer system is d...

Batch Processing When the entire computer system is dedicated to a single job, the system is said to be operating in Batch Processing mode. In this mode each program is run to

Formulate linear programming problem, Question (a) A firm produces four...

Question (a) A firm produces four products: P , Q , R , and S . Each unit of product P requires two hours of milling, one hour of assembly, and $10 worth of in-process in

Write Your Message!

Captcha
Order Assignment

Featured Services

Order Now

Popular Subjects

Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

Submit Assignment

Academics

Major Subjects

Majors

Get In Touch

whatsapp: +91-977-207-8620

Phone: +91-977-207-8620

Email: [email protected]

TERMS & POLICIES

HELP & SUPPORT

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd