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

C programming program, I wrote a program that adds up 5x5 matrices by colum...

I wrote a program that adds up 5x5 matrices by column and row. Now i have to use pointers to rewrite the same code how would do that

Algorithm - programming language, Algorithm : Once a problem has been defi...

Algorithm : Once a problem has been defined precisely, a procedure or process must be designed to produce the required output from the given input. Since a computer is a machine t

Microwave transmission, Microwave Transmission: Using space as transmi...

Microwave Transmission: Using space as transmission medium, microwave emanates from an origination point on earth, such as telephone exchange, where many individual messages h

TREES, construct a tree where preorder is ABCDFGE

construct a tree where preorder is ABCDFGE

7489 ttl ram device, The 7489 TTL Ram Device: The 7489 TTL Ram package ...

The 7489 TTL Ram Device: The 7489 TTL Ram package has 64 memory cells, each cell is capable of holding a single bit of data.  The cells are organised into locations, and each l

Operating systems, Operating Systems: The operating system is the soft...

Operating Systems: The operating system is the software that mediates between the applications programs and a level of instructions nearer to the machine's operations. In othe

Probability, Mike sells on the average 15 newspapers per week (Monday – Fri...

Mike sells on the average 15 newspapers per week (Monday – Friday). Find the probability that 2.1 In a given week he will sell all the newspapers [7] 2.2 In a given day he will sel

History , when was the first computer made

when was the first computer made

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