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

Define baud rate, Define baud rate The rate of data transfer in serial...

Define baud rate The rate of data transfer in serial data communication is signified in bps. Bits per second (bps) is the rate of transfer of information bits. Baud is the num

Define the programmable logic devices (pld), Define the Programmable logic ...

Define the Programmable logic devices (PLD)? In the world of digital electronic systems there are three essential kinds of devices 1.memory, 2.microprocessors, and 3.logic. The

TITLE: Signals for digital communications, DETERMINE ANALYTICALY IF THE SIG...

DETERMINE ANALYTICALY IF THE SIGNAL IS PERIODIC OR NOT - X[n] = 4Cos(Pi n)

Significance of having less memory references, Q. What is the significance ...

Q. What is the significance of having less memory references? As the time needed for memory reference is more than that of a register reference so increased number of memory r

Difference between visual basic, Visual basic is useful if you are planning...

Visual basic is useful if you are planning to make the programs from scratch. This language helps you in producing Active x controls, exe files, etc. Visual script is a powerful t

Explain the graphic display system, Q. Explain the graphic display system? ...

Q. Explain the graphic display system? The function of your graphic display system is to display bit-mapped graphics on your monitor.  The image displayed on your system so com

Where the trunks lines are run, Trunks are the lines that run between? ...

Trunks are the lines that run between? Trunks are the lines which run in between switching stations.

Write the game using writing functions, The year is 2199. For many generati...

The year is 2199. For many generations, the robotic Cyleth have faithfully served humanity. However, under the direction of the computerized superintelligence Skyweb, they have tur

Define hypertext verses hypermedia briefly, Define Hypertext verses Hyperme...

Define Hypertext verses Hypermedia briefly. Hypertext is fundamentally the same as regular text- this can be stored, read, searched or edited along with a significant exception

What is artificial intelligence language processing, Artificial intelligenc...

Artificial intelligence language processing (AILP) is a field of computer science and linguistics concerned with the interactions among computers and human (natural) languages; it

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