Movsw/movsb-string manipulation instruction-microprocessor, Assembly Language

MOVSW/MOVSB : Move String Word or String Byte: Imagine a string of bytes, stored in a set  of consecutive memory locations is to be moved to another set of  the destination locations. Starting byte of the source string is located in the memory location whose address can be computed by using DS (data segment) and SI (source index) contents. Starting address of the destination locations where this string has to be relocated is given by ES (extra segment) and Dl (destination index) contents. Starting address of the source string is 10H*DS+[SI],  whereas the starting  address of the destination  string is 10H*ES+[DI].  The MOVSB/MOVSW instruction therefore, moves a string of bytes/ words pointed to by DS: SI pair (source) to the memory location pointed to by ES: Dl pair (destination).  The REP instruction prefix is utilized with MOVS instruction to repeat it by a value given in the register counter (CX). The length of word string or byte string ought to be stored in register CX register. Flags are remaining unaffected by this instruction.

After the MOVS instruction is executed, the index registers are automatically updated and register CX is decremented. The decrementing or incrementing of the pointers, for example DI and Sl depend on the direction flag DF. If flag DF is 0, the index registers are incremented, or else, they are decremented, in all casa of the string manipulation instructions. Following string of instructions explain the execution of the MOVS instruction.

Example :


Posted Date: 10/12/2012 3:27:51 AM | Location : United States

Related Discussions:- Movsw/movsb-string manipulation instruction-microprocessor, Assignment Help, Ask Question on Movsw/movsb-string manipulation instruction-microprocessor, Get Answer, Expert's Help, Movsw/movsb-string manipulation instruction-microprocessor Discussions

Write discussion on Movsw/movsb-string manipulation instruction-microprocessor
Your posts are moderated
Related Questions
Type of Microprocessor : Microprocessors fall into 3 categories: Single Chip Microcomputers: - Contains RWM, ROM, microprocessor, I/O port, timer and clock. General pu

write an assembly language program that has two subroutines : one for encrypting alphabates of a string and second fo decrypting the encoded string . in encryption simply converta

Part A: Bitwise Logical and Shift Operations Create a SPARC assembly language program that extracts a bit-field from the contents of register %l0. The position of the rightmos

External Hardware-Interrupts External hardware-interrupts are generated by controllers of external devices or coprocessors and are connected to the processor pin for Non Mask a

to find the matrix addition

AAD: ASCII Adjust for Division though the names of these 2 instructions (AAM and AAD) seem to be same, there is many difference between their functions. The AAD instruction conver

how to add 111 and 333 in assembly language

$NOMOD51 $NOSYMBOLS ;***************************************************************************** ; Spring 2013 Project ; ; FILE NAME : Project.ASM ; DATE : 3/30/20

this is my first project i dont know where to start

LODS : Load String Byte or String Word:- The LODS instruction loads AL/AX register by the content of a string pointed to by DS:SI register pair. The SI is automatically modifie