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

Hashing, what is double hashing

what is double hashing

Matrices, code to add two matrices

code to add two matrices

The pentium-micro processor, The Pentium   The next member of the Intel ...

The Pentium   The next member of the Intel family of microprocessors was the Pentium, introduced in the year 1993. With the Pentium, Intel broke its custom of numeric model name

NASM assembly language programming, NASM assembly language program: Consid...

NASM assembly language program: Consider a sequence of 19 strictly positive decimal digits, most likely stored in an array. There are obviously duplicates, and the sequence is un

8088 associated with 8259 a-microprocessor, For an 8088 the 2 addresses lin...

For an 8088 the 2 addresses linked with an 8259A are normally consecutive, and the AO line is associated to the AO pin, but because there are just 8 data pins on the 8259A and the

Control transfer or branching instruction-microprocessor, Control Transfer ...

Control Transfer or Branching Instruction Control transfer instructions transfer the flow of execution of the program to a new address specified in the instruction indirectly o

Cache controller-microprocessor, Cache controller The cache controller ...

Cache controller The cache controller is the mind of the cache.  Its responsibilities include:  performing the  snarfs and snoops, updating the  TRAM  and SRAM and implementing

Introduction to evaluation, This unit introduces the topic of evaluating in...

This unit introduces the topic of evaluating interactive products. It is a short unit as evaluation is discussed in more detail in Block 4. Its brevity should give you additional t

Motorola 68000 series, Motorola 68000 Series : 68000microprocessor is a...

Motorola 68000 Series : 68000microprocessor is a 16 bit processor that has addressing space of 65536 locations, each of which holds a 64-bits word; In order to address those lo

8086, Write a program to mask bits D3D2D1D0 and to set bits D5D4 and to inv...

Write a program to mask bits D3D2D1D0 and to set bits D5D4 and to invert bits D7D6 of ax register

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