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

Combining goals and design principles, The Set Book assignment should enabl...

The Set Book assignment should enable you to begin talking about the usability of interactive products in terms of a variety of parameters. Instead of simply saying 'nice cell phon

Application to calculate the diameter, Write an application to calculate th...

Write an application to calculate the diameter, circumference, and area of a circle with a radius input by the user. Assign the radius float variable and then output the radius wit

What are the advantages of carrying out simulations, What are the Advantage...

What are the Advantages of carrying out simulations -  saves cost (instead of doing the real thing) -  Safer (scenarios tried out on the simulation first before used in real

One node at the highest level in the structure, There can be more than one ...

There can be more than one node at the highest level in the structure. False.  One can describe only single node at the highest level in the structure on LDB

Define critical mass and critical volume, Q. Define critical mass and criti...

Q. Define critical mass and critical volume? The minimum size in which at least one neutron is available for further fission reaction. The throng of the fissile material at the

Desirable characteristics of an electronic market place, What are the desir...

What are the desirable characteristics of an Electronic Market Place?  Characteristics of an Electronic Market Place:  a. Its electronic, the business center is not a phys

Determine Boolean identities using Boolean algebra, Prove the following ide...

Prove the following identities   a. A ‾B ‾C‾ + A ‾BC ‾ + AB ‾C ‾ + ABC ‾ = C ‾ b. AB + ABC + A ‾ B + AB ‾C = B + AC Ans. a. LHS = A'B'C' + A'BC' + AB'C' + ABC' =

Big – endian and little- endian representations, Explain Big - Endian and L...

Explain Big - Endian and Little- Endian representations Ans: The Big- endian is used where lower byte addresses are used for the more significant bytes (leftmost bytes) of the

Explain public key encryption, Public Key Encryption A cryptographic sy...

Public Key Encryption A cryptographic system that uses two-keys-a public  key known to everyone and a private or secret key known only to the recipient of the message. An si

Communication between memory and the processor, How are instructions sent b...

How are instructions sent between memory and the processor? Both the instruction pointer (IP) and program counter (PC) utilized to holds the memory address of the next inst

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