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

Determine whether the system is stable or causal, QUESTION (a) For each...

QUESTION (a) For each of the following systems, determine whether the system is (1) stable, (2) causal, (3) linear, (4) time invariant, (5) passive (i) Y[n] = x[-n] (ii)

Java, function of void

function of void

CAI, What is CAI? Explain its pitfalls

What is CAI? Explain its pitfalls

CAI, What is CAI? Explain its pitfalls.

What is CAI? Explain its pitfalls.

Define Function of OSI Layers, OSI Layers: Open Systems Interconnection mod...

OSI Layers: Open Systems Interconnection model is a reference model developed by International Organization for Standardization in 1984, as a conceptual structure of principles fo

On-line and realtime systems, On-line and Realtime Systems An on-line s...

On-line and Realtime Systems An on-line system means that input and output devices are directly connected to the CPU irrespective of geographical location. Thus the user can di

Explain briefly about gnome desktop, Question 1 Brief about the shells of ...

Question 1 Brief about the shells of Linux operating system Question 2 Explain briefly about GNOME desktop Question 3 Write note on the following Encryption Sig

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

Java, what is meant by deliverable in strus base applications

what is meant by deliverable in strus base applications

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