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

Pin functions of 8086-microprocessor, Pin functions for the minimum mode o...

Pin functions for the minimum mode operation of 8086 are following: 1) M/I/O -Memory/IO: This is a status line logically equivalent to S2 in maximum mode. When it is low, it

Dec-arithmetic instruction-microprocessor, DEC:  Decrement :- The decremen...

DEC:  Decrement :- The decrement instruction subtracts 1 from the contents of the particular memory location or register. All the conditions code flags except carry flag are affec

Using straight line method for depreciation, Request a depreciation of the...

Request a depreciation of the item, year of purchase, cost of item, number of years to be depreciated (estimated life ) and,the method of depreciation . Method of depreciation sh

Data copy/transfer instructions-microprocessor, Data copy/transfer Instruct...

Data copy/transfer Instructions MOV: This data transfer instruction transfers data from one register or memory location to another register or memory location. The source can

Flag register-microprocessor, Flag Register : 8086 has a 16-bit flag r...

Flag Register : 8086 has a 16-bit flag register which is divided into 2 parts, viz. (a)machine control flagsand (b)condition code or status flags. The condition code flag regi

8086 alp, to find the matrix addition

to find the matrix addition

Internal hardware-interrupts-microprocessor, Internal Hardware-Interrupts ...

Internal Hardware-Interrupts Internal hardware-interrupts are the outcome of sure situations that occur during the execution of a program, for example. Divide by 0. The interru

#title., BINARY TO GRAY CONVERSION

BINARY TO GRAY CONVERSION

Aam-arithmetic instruction-microprocessor, AAM: ASCII Adjust for Multiplic...

AAM: ASCII Adjust for Multiplication after execution. This instruction converts the product available in the AL into unpacked BCD format.  This follows a multiplication   instruct

Write an assembly language program, You are to write an assembly language p...

You are to write an assembly language program called subfaq.s that computes the generalized subfactorial function of nonnegative integer inputs i0 and n. The generalized subfactori

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