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

Define the elements of contlor unit , The three main elements of the con...

The three main elements of the control unit are: 1. Decoder this is used to decode the instructions that create a program when they are being processed, and to establish in what ac

Bandwidth, Bandwidth: Bandwidth is the second concept important for tr...

Bandwidth: Bandwidth is the second concept important for transmission. This concept can be explained with the help of the traffic network mentioned earlier. If there is a two-

Write a program to solve a maze 10x10, write a program to solve a 10x10 maz...

write a program to solve a 10x10 maze. prompt the user for an input text file containing ten rows(ten characters on each row). Use following characters in the input file: * startin

E - R diagram, draw the e r diagram for irctc rail ticket reservation onlin...

draw the e r diagram for irctc rail ticket reservation online

Definition of procedure, A procedure is a compilation of instructions to wh...

A procedure is a compilation of instructions to which we can express the flow of our program, and once the execution of these instructions is over power is given back to the next l

Write short notes on joint fiction reserve, QUESTION (i) Write short no...

QUESTION (i) Write short notes on each of the following: a) Shelf reading b) Joint Fiction Reserve c) London and South-Eastern Library Region d) Document access

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