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

Command processor and user interface, Command Processor and User Interface:...

Command Processor and User Interface: To the user, the most important and visible services provided by the OS is the user interface and the capabilities that it provides to ex

What is vpn? explain the vpn protocols, Question 1 What is IT auditing? Di...

Question 1 What is IT auditing? Discuss the three phases involved in the IT auditing Question 2 List and explain the two types of load balancing methods Question 3

Disadvantages of manual records, Disadvantages of Manual Records  ...

Disadvantages of Manual Records  More manpower is required to record/storelretrieve the data.   Bulky paper records take up more space and this problem increases with

Distinguish between the following javascript built-in method, QUESTION ...

QUESTION (a) Draw an annotated diagram explaining how data is transmitted to web servers during a standard form submit event. (b) What in your opinion makes a bad web site?

What is a Process and process mangemen in operating system? , A process is ...

A process is a chronological program in execution. The constituents of a process are the following: • The object program to be executed ( described the program text in UNIX) • Th

What is the definition of instructiion set?, For a processor to be able ...

For a processor to be able to process an instruction, it requires to be able to determine what the instruction is asking to be carried out. For this to take place, the CPU requires

Data communication & net centric computing, Suppose there are exactly five ...

Suppose there are exactly five packet switches (Figure 4) between a sending host and a receiving host connected by a virtual circuit line (shown as dotted line in figure 4). The tr

Why we need data mining? Give an example to illustrate your, Why we need da...

Why we need data mining? Give an example to illustrate your answer.

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