Loading instructions, Basic Computer Science

Assignment Help:
They are particular register instructions. They are used to load bytes or sequences of bytes onto a register.
LODS (LODSB) (LODSW)
LAHF
LDS
LEA
LES
LODS (LODSB) (LODSW) INSTRUCTION
Goal: To load sequences of a byte or a word into the accumulator.
Syntax:
LODS
This instruction takes the sequence found on the address specified by SI, loads it to the AL (or AX) register and adds or subtracts , depending on the state of DF, to SI if it is a bytes transfer or if it is a words transfer.
MOV SI, OFFSET VAR1
LODS
The first line loads the VAR1 address on SI and the second line receives the content of that locality to the AL register.
• The LODSB and LODSW commands are used likewise, the first one loads a byte and the second one a word (it uses the whole AX register).
LAHF INSTRUCTION
Goal: It transfers the full content of the flags to the AH register.
Syntax:
LAHF
This instruction is helpful to make sure the state of the flags through the execution of our program.
LDS INSTRUCTION
Goal: used to load the register of the data segment
Syntax:
LDS destiny, source
The source operator must be a dual word in memory. The word related with the largest address is transferred to DS, in other words it is taken as the segment address. The word associated with the lesser address is the displacement address and it is deposited in the register indicated as destiny.
LEA INSTRUCTION
Goal: To load the address of the source operator
Syntax:
LEA destiny, source
The source operator must be situated in memory, and its displacement is placed on the index register or specified pointer in destiny.

Related Discussions:- Loading instructions

Hotel database, Create a database,show all ojectives and give a fruitful in...

Create a database,show all ojectives and give a fruitful introduction and also state how it will be implemented

Challenges in building information system, discuss the three major challeng...

discuss the three major challenges in building information system in an organization

Unix Shell, Write a shell script, change-lines, which will substitute a str...

Write a shell script, change-lines, which will substitute a string for a replacement string for each occurance of the string in files specified. The original file will be saved,

What is the delay of the filter, QUESTION We wish to use the Kaiser win...

QUESTION We wish to use the Kaiser window method to design a discrete-time filter with generalized linear phase that meets specifications of the following form:

Concept in programming language, CONCEPT IN PROGRAMMING LANGUAGE: A Pr...

CONCEPT IN PROGRAMMING LANGUAGE: A Programming Language is used to design and describe a set of instructions and computations to be executed by a computer. To do programming,

Programming, how to use pseudocode to write a hotel reservation program

how to use pseudocode to write a hotel reservation program

Disk output, Disk output : You will already have decided whether to u...

Disk output : You will already have decided whether to use a hard disk or floppies for storing data. An important point of disk management is to ensure a secure method of kee

Perverse software, Perverse software: Perverse software is a program w...

Perverse software: Perverse software is a program which causes hindrances in other programs execution in such a way resulting in modification or complete destruction of data w

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

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