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

Ddition, Write a program that performs the addition, subtraction, multiplic...

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

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

Das-arithmetic instruction-microprocessor, DAS: Decimal Adjust after Subtr...

DAS: Decimal Adjust after Subtraction:- This instruction converts the result of subtraction operation of 2 packed BCD numbers to a valid BCD number. The subtraction operation has

Program that will display a list of the decades , Write an assembly languag...

Write an assembly language program that will display (print) a list of the Decades 2010, 2020, 2030... 2100 to the screen using a while loop.

Quarters, There are two parts to this assignment. The first part has you r...

There are two parts to this assignment. The first part has you reading 4 integers representing; #QUARTERS, #DIMES, #NICKELS & #PENNIES, respectively. Your program should compute t

Signal descriptions of 8086-microprocessor, Signal descriptions of 8086 : ...

Signal descriptions of 8086 : described below are common for the maximum andminimum mode bothdata lines AD15 -AD0: These are the time multiplexed andmemory I/O address. Addre

A/D conversions, A/D conversion: Basic tasks: (a) Write a program that wil...

A/D conversion: Basic tasks: (a) Write a program that will read and display the analog voltage on pin PE7 approximately once every second. (b) Write a program that will read and d

Assignment, You have to write a subroutine (assembly language code using NA...

You have to write a subroutine (assembly language code using NASM) for the following equation.

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

Architecture of file transfer, Explain the architecture of the file transfe...

Explain the architecture of the file transfer protocol ftp in terms of clients, servers, sockets

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