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 ?

What is Assembly Language?, Assembly language is fundamentally the local la...

Assembly language is fundamentally the local language of your computer. In principle the processor of your machine understands machine code (consisting of ones and zeroes). But wit

Computerised systems, Computerised Systems : You would have realized by no...

Computerised Systems : You would have realized by now that computing systems are most useful for manipulating information. Any organisation and management of information basically

Why learning of Assembly language is beneficial?, The first reason to work ...

The first reason to work with assembler is that it offers the opportunity of knowing more the operation of your PC, which permits the development of software in a more constant man

Explain the different types of addressing modes, Question 1 What are the d...

Question 1 What are the different stages of evolution of Computer Architecture? Explain in detail Question 2 What are the components of Instruction Set architecture? Discu

If staement, if statement with explanation

if statement with explanation

Need of artificial intelligence, Need of artificial intelligence: Artif...

Need of artificial intelligence: Artificial Intelligence may be seen as just the latest tool in the philosopher's toolbox for answering these all questions about the behavior o

CAI, EXPLAIN CAI? AND ITS PITFALLS

EXPLAIN CAI? AND ITS PITFALLS

Internet searching, Internet searching:  The Internet consists of mill...

Internet searching:  The Internet consists of millions of private/public/academic/business and government networks having local to global scope. It has billions of web pages o

Oop, evolution of oop

evolution of oop

Overview of a computer system, Overview of a Computer System The...

Overview of a Computer System There are three major elements in every computer solution. They are:     Data     Hardware     Software Hardware + Softwa

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