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 ?

., why first generation computers are better than fourth generation compute...

why first generation computers are better than fourth generation computers

Login, Login Because the information on a network is sharable, network...

Login Because the information on a network is sharable, networks are very susceptible to unauthorized intruders. In order to prevent unauthorized access to use the services o

Arithmetic and control unit, micro routine

micro routine

Construct a conditional profits table, Question (a) A dairy wants to de...

Question (a) A dairy wants to determine the quantity of butter it should produce to meet the demand. Past records have shown the following demand pattern:

C, A palindrome is a string that reads the same from both the ends. Given a...

A palindrome is a string that reads the same from both the ends. Given a string S convert it to a palindrome by doing character replacement. Your task is to convert S to palindrome

Data type, Data Type:  Data Type: Anything that is processed by a comp...

Data Type:  Data Type: Anything that is processed by a computer is called data. There are different types of data that can be given to the computer for processing. A  data typ

Compare between file processing system and dbms, Problem a. Compare bet...

Problem a. Compare between file processing system and DBMS >>This is a comparison of DBMS with file processing system which the answer has to be searched from the GOOGLE an

Data autonomous transmission, DATA AUTONOMOUS TRANSMISSION: This could ...

DATA AUTONOMOUS TRANSMISSION: This could be the possible replacement for the ARINC 429 standard and will be annotated the standard - ARINC 629. In the DATAC system, the contro

Explain how cpu responses to an interrupts, Problem 1. Explain the diff...

Problem 1. Explain the different categories of instructions. Explanation of 4 categories 2. Explain the steps to be followed for the addition of floating point numb

Uninformed search strategies, Uninformed Search Strategies: To be able ...

Uninformed Search Strategies: To be able to undertake a regular search, our entire agent ought to know is the starting state, the possible operators and how to check whether th

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