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 ?

Ipx for lan, explain ipx for lan and spx

explain ipx for lan and spx

Android database file not loading on real device, i have an android app whi...

i have an android app which uses a database file called question db which is stored in the assets file. I have tried a database example called android application development but f

Data mining, Process of Data mining Data mining is an iterative process t...

Process of Data mining Data mining is an iterative process that typically involves the following phases: Problem definition A data mining project starts with the understanding o

Application packages, APPLICATION PACKAGES : There are two options. You ca...

APPLICATION PACKAGES : There are two options. You can either write your own program or buy an applications package, i.e. a proprietary program, 'off-the-shelf. The former option i

Syntax of a Macro, The divisions which make a macro are: • Declaration of t...

The divisions which make a macro are: • Declaration of the macro Code of the macro Macro termination directive The assertion of the macro is done the following way: Name Macro [par

Introduction to microprocessor, The microprocessor is at times referred to ...

The microprocessor is at times referred to as the ''brain'' of the personal computer, and is responsible for the processing of the instructions which creates computer software. It

Decision table , No charges are reimbursed to the patient until the deducti...

No charges are reimbursed to the patient until the deductible has been met. Hospital visits are reimbursed at 80% and Lab visits are reimbursed at 70%. Doctor''s office visits are

Briefly explain main parts of the camera, Question 1 Briefly explain main ...

Question 1 Briefly explain main parts of the Camera Question 2 Write a note on: Ripple Edit Tool, Rate Stretch Tool & Track Selection Tool Question 3 What is Pixel

Spreadsheet development, Basic steps/tasks involved in spreadsheets develop...

Basic steps/tasks involved in spreadsheets development

Flowcharts, flowchart that display yhe students average scores for 3 quizze...

flowchart that display yhe students average scores for 3 quizzes.Assume that there are 3 sections having 5 student each.Valid number is 1-100 for the quizzes.Enter an invalid numbe

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