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 ?

Perform a mail merge to send invitation, Question Elaborate the various...

Question Elaborate the various steps in performing a Mail Merge. Perform one mail merge operation for sending invitation for a conference which is being conducted in your organ

How is the ack request formed, QUESTION a) The handling of the INVITE t...

QUESTION a) The handling of the INVITE transaction in SIP is completely different from the handling of other transactions. The handling of the INVITE is one of the most complex

What is the basic model of cpu structure?, As there are many variations i...

As there are many variations in architecture between the different kinds of CPU, we shall begin my looking at an easy model of the structure. The basic model consists of five part

Write a long note on the viewfinder of a camera, Question 1 What are the d...

Question 1 What are the different kinds of editing? Explain them in detail Question 2 Write a long note on the viewfinder of a camera Question 3 Describe the various typ

Computers, Computers One of the most  important invention in the desig...

Computers One of the most  important invention in the design of digital  circuits  is that  of the general- purpose "stored program" computer or device. Computers are a partic

Time and space tradeoffs in search, Time and Space Tradeoffs in search-arti...

Time and Space Tradeoffs in search-artificial intelligence: In practice, you need to stop your agent at some stage if it has not searched a solution by then. However, if we can

Browser cookies, Browser Cookies: A cookie is a small message sent by ...

Browser Cookies: A cookie is a small message sent by the Web server to a your web client. This message is stored by the browser as a text file. The basic purpose of cookie is

One dimensional array, One dimensional array:  A one-dimensional arra...

One dimensional array:  A one-dimensional array  is a structured collection of elements  that can be accessed individually by specifying the position of a component with  ind

Computer definition ., what is the short and complete definition of compute...

what is the short and complete definition of computer

Third partial product of 13*11 in binary, third partial product of 13*11 in...

third partial product of 13*11 in binary

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