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 ?

Explain digital multiplexers, Problem 1 Perform the following conversio...

Problem 1 Perform the following conversion a. (ABE) 16 =() 2 b. (101011) 2 =() 10 2 Explain how full adder adds three bits 3 Explain digital multiplexers

Spidering or web crawling, Spidering or Web crawling: Spider or Web c...

Spidering or Web crawling: Spider or Web crawler is a computer program that browses the web pages of WWW in a systematic, automated manner. Search Engines use spider for gett

Explain the construction of hard drive, Question 1 Classify and explain th...

Question 1 Classify and explain the different types of computers Question 2 List and explain the commonly used input devices Question 3 What is binary number system? Exp

Computer architecture, Write control sequence for adding the content of the...

Write control sequence for adding the content of the memory location whose address is at memory location pointed by immediate number NUM to register R1. Assume the number NUM is pr

Data base software, Data Base Software: Another major type of applicat...

Data Base Software: Another major type of application comes under the heading database software; which allows for the collection of, searching for and manipulation of informat

Cpu scheduler, Selects among the processes in memory which are ready to exe...

Selects among the processes in memory which are ready to execute & allocates the CPU to one of them CPU scheduling decisions can be taken place when a process: A. Terminates B. Swi

Acting Rationally - artificial intelligence, Acting Rationally: Al Capo...

Acting Rationally: Al Capone was finally convicted for tax evasion. Were the police acting rationally? To answer this, we must first look at how the performance of police force

Computer programming, outline and explain in detail any 10 application area...

outline and explain in detail any 10 application areas of vb.net

What is blu-ray disk, Question 1 Explain the configuration steps involved ...

Question 1 Explain the configuration steps involved in CMOS setup Date and time Error halt Floppy drive A Halt on Hard disk C HDD Delay Keyboard Memory

Introduction to computer technology, excel grade book

excel grade book

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