StrNCpyAsm, Assembly Language

Assignment Help:
;StrNCpyAsm - copy zero terminated string2 to zero terminated string1,
; but copy no more than count (parameter) characters
; or the length of string2, whichever comes first
; entry: - addStr1 contains the address of string1
; - addStr2 contains the address of string2
; - count contains the max number of characters to copy
; exit: NONE (no return value so do not use edi to return an address)
;
; Note: StrNCpyAsm does not zero terminate the copied string
; unless the 0 is within count characters copied.
;
; example1: char str1[]= {''h'',''e'',''l'',''l'',''o'','' '',''w'',''o'',''r'',''l'',''d'',0};
; char str2[]= {''G'',''o'',''o'',''d'',''-'',''b'',''y'',''e'',0};
; StrNCpyAsm(str1,str2,4);//terminating 0 not copied since only 4 characters copied
; ;//and terminating 0 not within the 4 characters
; after copy str1 contains: ''G'',''o'',''o'',''d'',''o'','' '',''w'',''o'',''r'',''l'',''d'',0
;
; example2: use str1 and str2 from example1
;
; StrNCpyAsm(str1,str2,9); //terminating 0 copied since terminating 0
; //within 9 characters copied
; str1 contains: ''G'',''o'',''o'',''d'',''-'',''b'',''y'',''e'',0,''l'',''d'',0
;
; example3: use str1 and str2 from example1
;
; StrNCpyAsm(str1,str2,20);//copy 20 characters upto and including 0,
; //whichever comes first
; //only 9 characters including 0 copied
; after copy str1 contains: ''G'',''o'',''o'',''d'',''-'',''b'',''y'',''e'',0,''l'',''d'',0
;
; The above is how you would call StrNCpyAsm from C++.
;
; To call StrNCpyAsm from an asm function use:
;
; push 20 ;max num of characters to copy
; push str2Add ;address of string 2
; push str1Add ;address of string 1
; call StrNCpyAsm
; ;no add esp, 12 needed because stack cleaup automatically done
;
;Do not use a loop in this function.
;Choose 2 instructions from the following string instructions to use:
; rep, repe, repne, movsb,stosb,cmpsb,scasb
;
; hint1: use StrLenAsm to get the number of characters in str2
; hint2: the length returned by StrLenAsm does not include terminating 0
; hint3: copy the lesser of the length of the string (including terminating 0)
; or count characters
;copy to ecx the lesser of count or the length of string2 (including terminating 0)
; Please note for the above, you need the length of string2 including terminating 0.
; StrLenAsm returns the length not including terminating 0
;populate esi and edi with the correct values
;clear the direction flag
;use rep and movsb to copy
;
;

StrNCpyAsm PROC uses eax esi edi ecx , ;save registers used
addStr1:DWORD, ;address of string1
addStr2:DWORD, ;address of string2
count:DWORD ;max chars to copy

Related Discussions:- StrNCpyAsm

Timing diagram of minimum mode, give the explaination of timing diagram min...

give the explaination of timing diagram minimum mode memory write cycle

8086 program, program to arrange a given set of numbers in descending order...

program to arrange a given set of numbers in descending order

Bitwise logical and shift operations, Part A: Bitwise Logical and Shift Op...

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

Stand alone system - assembly language program, Develop an assembly languag...

Develop an assembly language program for the system and simulate it using MPLAB. From this produce a demo program (in Assembly language) that will run on the MatrixMultimedia Devel

Dma hardware (8237 dmac)-microprocessor, DMA Hardware (8237 DMAC) : ...

DMA Hardware (8237 DMAC) :   1)Processor contain HOLD/HOLD Acknowledge lines to interact with 8237 o   DMAC can achieve control of ISA bus by asserting HOLD o   P

Convert into hex pairs, Convert 751 to hex and show what it would look like...

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

Software interrupts-microprocessor, Software Interrupts Software interr...

Software Interrupts Software interrupts are the result of an INT instruction in an executed program.  It may be assumed as a programmer triggered event that immediately stops e

Write a program, write a program that calculates the fibonacci series: exce...

write a program that calculates the fibonacci series: except for the first two numbers in the sequence

Evolution of microprocessor , EVOLUTION OF MICROPROCESSOR : ...

EVOLUTION OF MICROPROCESSOR : The digital circuits and systems may be broken into two part: 1) Sequential Circuit and 2) Combinational Circuits     Norm

Multiplication using shift and add instruction, Multiply two numbers by usi...

Multiply two numbers by using shift and rotate instruction

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