String manipulation instruction-microprocessor, Assembly Language

String Manipulation Instruction

A series of words or data bytes are available in memory at consecutive locations, to be mention to individually or collectively, are known as byte strings or word strings or byte strings. For instance, a string of characters can be located in consecutive memory locations, where each character can be represented by its ASCII equivalent. For mention to a string, two parameters are needed,

(a) Length of the string and

(b) Starting or ending address of the string.

The length of a string is generally stored as count in the CX register. In case of 8085, same structures may be set up by counter and the pointer arrangements.  The counters and pointers can be modified at each iteration until the needed condition for proceeding further is satisfied. Instead, the 8086 supports a set of more powerful instructions for string manipulations.  In case of 8086 string instructions, the decrementing or incrementing of the pointer depends on the direction flag (DF) status. If it is a byte string operation then the index registers are updated by one. Instead, if it is a word string operation then the index registers are updated by two. The counter in both of the cases is decremented by one. It consisits of REP, MOVSW/MOVSB, CMPS, SCAS, LODS, STOS.

 

Posted Date: 10/12/2012 3:19:22 AM | Location : United States







Related Discussions:- String manipulation instruction-microprocessor, Assignment Help, Ask Question on String manipulation instruction-microprocessor, Get Answer, Expert's Help, String manipulation instruction-microprocessor Discussions

Write discussion on String manipulation instruction-microprocessor
Your posts are moderated
Related Questions
Program Translation Sequence Developing a software program to accomplish a particular task, the implementer chooses an appropriate language, develops the algorithm (a sequence

Convert 751 to hex and show what it would look like stored at TheNumber WORD ? (hint: answer in hex pairs)

INC: Increment : - This instruction increments the contents of the particular memory or register location by the value 1. All the condition code flags are affected except the carry

errorlevel -302 ;prevents error code for this chipset __config 0x373A ;chip config PIC spec page 146 processor 16F877A ;chipset reset code

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

Linking a program The DOS linking program LINK.EXE links the different object modules of function library routines and source program to produce an integrated executable code o

ADD:  Add :- This instruction adds an immediate contents of a memory location specified in the a register ( source ) or instruction to the contents of another register (destinat

ROL : Rotate Left without Carry: This instruction rotates the content of the destination operand to the left by the specified count bit-wise excluding the carry. The most signific

Write a program that performs the addition, subtraction, multiplications, division of the given operands. Perform BCD operation for addition and subtraction.

I can get it to copy the string but can''t get it to reverse it.