Loading instructions, Basic Computer Science

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.
Posted Date: 5/4/2012 4:29:00 AM | Location : United States







Related Discussions:- Loading instructions, Assignment Help, Ask Question on Loading instructions, Get Answer, Expert's Help, Loading instructions Discussions

Write discussion on Loading instructions
Your posts are moderated
Related Questions
Paper System : When setting up a computer system you need to ask yourself 'Does the system you plan to operate work manually, i.e., on paper?' It is a popular misconception that t




Data Processing In any computer-based system, data storage and retrieval plays an important role. Data storage involves decision about the encoding of data, assignment o

Output Devices: Each output unit of computer system transmits information from the CPU and converts the electrical pulses to an appropriate output form. A printer, for example

Question 1 Write a note on advantages and disadvantages of Linux 2 Write a note on "File Permissions" on linux 3 Explain the usage of following Linux commands Cd kill

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

what is means with respect to software engineering?

Development of Personnel Computer Operating System: The next important breakthrough in computer use occurred in 1982, with the introduction of the IBM personal computer. The I