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 Router. Explain Network Router, A router is a device which has play...

A router is a device which has played an important role in the development and existence of the Internet. Routers are designed to transmit data from other network users to specific

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

Discuss on segmentation, Question 1 What is an operating system? Explain i...

Question 1 What is an operating system? Explain its functions Question 2 Discuss round-robin scheduling Question 3 Discuss on segmentation Question 4 What are the s

Functions, each of the following functions has the form f(x ) = (ax+b) mod ...

each of the following functions has the form f(x ) = (ax+b) mod n. assume that each function has type N base n arrow N base n, so that we can think of f as a cipher for an alphabet

Digital camera , Digital Camera: A Digital camera is an electronic dev...

Digital Camera: A Digital camera is an electronic device which takes video or still photographs or both, digitally by recording images via an electronic image sensor. Digital

Explain the characteristics of leasing, Question 1 Give the classification...

Question 1 Give the classification of Client/Server software architectures Question 2 Explain the characteristics of Leasing Question 3 Write a note on Activator interfa

Software engineering, how will a poorly conducted feasibility study affect ...

how will a poorly conducted feasibility study affect an implemented system

ICT IN BUSINESS, Explain how ICT can be used for achievement of each of the...

Explain how ICT can be used for achievement of each of the following business objectives, illustrating your answer with examples: 1. Customer intimacy 2. Low-cost leadership

What is mixing, Question 1 Briefly explain waveform Characteristics ...

Question 1 Briefly explain waveform Characteristics Question 2 Write a note on: types of Microphones Question 3 Briefly explain Magnetic Properties of Audiotape

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

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