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 ?

How does a flash drive work?, Question 1 What is a desktop? Explain the...

Question 1 What is a desktop? Explain the Windows XP desktop? 2 How does a flash drive work? 3 Write the procedure for creating Macro 4 Explain the process of applyin

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

Software development, requirement analysis and specification for online vot...

requirement analysis and specification for online voting

Computer databases , COMPUTER DATABASES: As would be evident from the ...

COMPUTER DATABASES: As would be evident from the foregoing description, literature search is essentially a process of information retrieval. The term "Information Retrieval" w

Introduction Assembly Language, This web page looks at assembly languages i...

This web page looks at assembly languages in a common method. Specific illustrations of addressing modes and instructions from a variety of processors are used to demonstrate the g

Cryptography, Consider the one-time pad encryption scheme to encrypt a 1-bi...

Consider the one-time pad encryption scheme to encrypt a 1-bit message m, and assume m is chosen with uniform distribution from message space M={0,1}. Let E1 be the event "message

Concept of instruction, Concept of instruction: The CPU is a semicondu...

Concept of instruction: The CPU is a semiconductor integrated  circuit chip consisting of a large number of transistors. In personal computers, the CPU is also referred by the

Project, Identify three factors to consider in determining the competitive ...

Identify three factors to consider in determining the competitive value of information technology. Justify the selected factors. Of the factors selected, determine if each fact

Computer, identify application software from the list? ms excel linux inter...

identify application software from the list? ms excel linux internet explorer adobe photshop sound card driver window disk manger adobe dream weaver windows file explorer

Java, what is meant by deliverable in strus base applications

what is meant by deliverable in strus base applications

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