How are comparisons done in 8086 assembly language, Computer Engineering

Assignment Help:

Q. How are comparisons done in 8086 assembly language?

There is a compare instruction CMP. Though this instruction just sets the flags on comparing two operands (both 16 bits and 8 bits). Compare instruction just subtracts value of source from destination without storing result however setting the flag at the time of the process. Normally only 3 comparisons are more important. These are:

Result of comparison    Flag(s) affected

Destination < source    Carry flag = 1

Destination = source    Zero flag = 1

Destination > source    Carry = 0, Zero = 0

Let us look at 3 illustration which show how flags are set when numbers are compared. In illustration 1 BL is less than 10 so carry flag is set. In illustration 2 the zero flag is set since both operands are equal. In illustration 3 the destination (BX) is greater than source so both zero and carry flags are clear.

Example 1: 

 MOV BL, 02h 

 CMP BL, 10h; Carry flag = 1

Example 2:

 MOV AX, F0F0h

 MOV DX, F0F0h

 CMP AX, DX; Zero flag = 1

Example 3:

MOV BX, 200H

CMP BX, 0; Zero and Carry flags = 0


Related Discussions:- How are comparisons done in 8086 assembly language

How 2-domain name servers contain exactly same set of names, Does it makes ...

Does it makes sense for two domain name servers to contain exactly the same set of names? Why? Yes. This is very advantageous for two domain servers having similar set of names

Concept development of project, Concept Development Journal General In...

Concept Development Journal General Information: Once you have researched and gained some insight into the topic you must then begin developing your ideas and your conceptua

Two services that are used to deal with communication, Explain about the tw...

Explain about the two services that are used to deal with communication. Message Service: Used by the application servers to change short internal messages, all system commu

Working on dreamweaver, Write your text, format text, insert picture throug...

Write your text, format text, insert picture through Object window or INSERT -> IMAGE. Insert Menu provides you all features which are available under the Object window. Modify men

Equivalences & rewrite rules - artificial intelligence, Equivalences & Rewr...

Equivalences & Rewrite Rules - artificial intelligence: Along with allowing us to verify trivial theorems, tautologies make us able to establish that definite sentences are say

Procedures relating to the deployment of the server, Edith & Associates is ...

Edith & Associates is a modern law firm. They have an Internet Link that is an ADSL 8MB links from JJNET. The server they are to deploy will the main service giving  server and wil

What is model, What is model?  A universe together with an assignment o...

What is model?  A universe together with an assignment of relations to relation symbol is known as a model.  A model M is a tuple (U, P1, P2..Pk), where U is the universe and P

Components of information super highway infrastructure, Explain the compone...

Explain the components of Information Super Highway Infrastructure. The Information Superhighway is more than the Internet. It is a sequence of components, having the collectio

Pvm communication model, Q. PVM communication model? A nonblocking rece...

Q. PVM communication model? A nonblocking receive as soon as returns with either data or a flag that data hasn't arrived while a blocking receive returns only when data is in r

Write Your Message!

Captcha
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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd