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

., why first generation computers are better than fourth generation compute...

why first generation computers are better than fourth generation computers

Obtain the truth table and a boolean expression, Problem 1. Convert the...

Problem 1. Convert the following number system 12.34 (8) to binary number system 23BC.0A (16) to decimal number system 456.012 (16) to Octal number system 123

Flowchart, 1. The volume of a pyramid is taken from the formula: V = 1/3 x ...

1. The volume of a pyramid is taken from the formula: V = 1/3 x AREA OF BASE x ALTITUDE Given the dimensions of a pyramid, calculate the cost of materials for making that pyrami

Explain Process States and Process Control Block (PCB), Process States Thr...

Process States Throughout the lifespan of a process, its execution position may be in one of four states: (linked with each state is generally a queue on which the process resides)

Read only memory (rom), Read only memory (rom): The problem with RAM is...

Read only memory (rom): The problem with RAM is that its memory is volatile, i.e. it loses all its data when the power supply is removed.  A non-volatile memory is a permanent

Digital design system, Manipulate the following Boolean expression in such ...

Manipulate the following Boolean expression in such a way so that it can be implemented using exclusive-OR and AND gates only. AB''CD'' + A ''BCD'' + AB''C''D + A''BC''D

Computer, hitory and genration of computer

hitory and genration of computer

Cryptography, Assume |s1|=|s2|=n and consider the functions defined, for an...

Assume |s1|=|s2|=n and consider the functions defined, for any s1 and s2, as: (a) G1(s1,s2)=s1 xor s2, (b) G2(s1,s2)=(s1, s2, s1 xor s2). We have that: A. G1 and G2 are pseudo-ra

Merchant problem, Pebble Merchant Problem Description There is a pebble mer...

Pebble Merchant Problem Description There is a pebble merchant. He sells the pebbles, that are used for shining the floor. His main duty is to take the length of the room’s sides.

What is the use of system bus ?, The system bus is a cable which carries da...

The system bus is a cable which carries data communication among the major components of the computer, as well as the microprocessor. Not all of the communication that uses the bus

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