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

Assignment Help:

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 :

1000_movsb.jpg


Related Discussions:- Movsw/movsb-string manipulation instruction-microprocessor

Segmentation, segmentation and overlapping in assemble language

segmentation and overlapping in assemble language

General terms for cache-microprocessor, General terms for Cache : Cac...

General terms for Cache : Cache Hits : When the cache consisted the information requested, the transaction is said to be a cache hit. Cache Miss : When the cache does n

Aaa-arithmetic instruction-microprocessor, AAA: ASCII Adjust after Additio...

AAA: ASCII Adjust after Addition operation the AAA instruction is executed after an ADD instruction that adds 2 ASCII coded operands to give a byte of outcome in the AL. The AAA i

Web services. , describes vertical and horizontal web services protocols. N...

describes vertical and horizontal web services protocols. Next, identify the similarities and differences between vertical and horizontal web services protocols. Finally, explain w

8237 modes-microprocessor, 8237 modes : Intel 8237 can be set to four d...

8237 modes : Intel 8237 can be set to four different type of style of transfer: 1) Single - One transfer at a time,  it allow processor access to the bus between transfers

Computes the integral square root - assembly program, Computes the integral...

Computes the integral square root: Problem: Square Root:   For this problem you will write a short assembly program that computes the integral square root of an input numb

Pointer(ptr)-assemblers directive-microprocessor, PTR : Pointer:- The p...

PTR : Pointer:- The pointer operator which is used to declare the type of a variable, label or memory operand. The operator PTR is prefixed by either WORD or BYTE. If the prefi

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