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

What is software quality assuranc, Software QA includes the whole software ...

Software QA includes the whole software development PROCESS - improving and monitoring the process, making sure that any agreed-upon standards and processes are followed, and ensur

How future environment changes can be predicted - simulation, How future cl...

How future climate/environment changes can be predicted -  Information over time is fed into a weather/climate model -  based on changes in weather patterns, carries out a s

Interrupt - driven input-output, Q. Interrupt - Driven Input-output? Pr...

Q. Interrupt - Driven Input-output? Problem with programmed I/O is that processor has to wait a long time for I/O interface to see whether a device is free or waits until compl

Linq file extension, What is the LINQ file extension that interacts with Co...

What is the LINQ file extension that interacts with Code Behind objects. Ans) its .dbml

Using aspx view engine, When using aspx view engine, to have a steady look ...

When using aspx view engine, to have a steady look and feel, across all pages of the application, we can build use of asp.net master pages. What is asp.net master pages equal, when

Describe about remote-load latency problem, Q. Describe about Remote-load L...

Q. Describe about Remote-load Latency Problem? When one processor requires some remote loading of data from other nodes then processor has to wait for these two remote load ope

What is the role of certifying authority, What is the Role of Certifying Au...

What is the Role of Certifying Authority? A certificate authority is a body, that is either public or private, that seeks to fill the requirement for trusted third-party servic

Definition of a micro controllers, Before we take a detailed look about the...

Before we take a detailed look about the Motorola 68HC11 series of micro controllers it is useful to define what is meant by a micro controller. As the name suggests a micro contro

Define emulation, Define emulation. Given a computer with a particular ...

Define emulation. Given a computer with a particular instruction set, it is possible to explain additional machine instructions and execute them with extra micro routines. Emul

Explain the matlab mathematical function library?, This is a huge collectio...

This is a huge collection of computational algorithms ranging from elementary functions like sum, sine, cosine, and difficult arithmetic, to more sophisticated functions like matri

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