User Account

All Pages

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

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

Develop a schematic circuit diagram of system, Develop a suitable schematic...

Develop a suitable schematic circuit diagram of your system showing the interface between the PIC16F84 and the existing mains light & switch, including 5V derivation from the 240V

CONSTANTS, Ask question #MinimuWHAT ARE CONSTANTS AND WHAT DO THEY DO?m 100...

Ask question #MinimuWHAT ARE CONSTANTS AND WHAT DO THEY DO?m 100 words accepted#

Input output interface-microprocessor, I/O interface I/O  devices such ...

I/O interface I/O  devices such as displays and keyboards  establish  communication of computer with outside world. Devices may be interfaced in 2 ways Memory mapped I/O and I/

Basic microprocessor architecture and interface, Basic Microprocessor Archi...

Basic Microprocessor Architecture and Interface : Introduction: Intel launches its first 4-bit microprocessor 4004 in the year 1971 and 8-bit microprocessor 8008 in the y

Pointer and index registers-microprocessor, Pointer and Index Registers ...

Pointer and Index Registers The pointers contain offset within the specific segments. The pointers BP, IP and SP generally containoffsets within thedata, code and stack segment

Cache components-microprocessor, Cache components The cache sub-system ...

Cache components The cache sub-system may be divided into 3 functional blocks: Tag RAM, SRAM and theCache Controller. In real designs, these blocks can be implemented  by multi

Short-type-global-assemblers operator-microprocessor, SHORT  : The  SHO...

SHORT  : The  SHORT operator denoted to the assembler that only one byte is needed to code the displacement for a jump (for example displacement is within -128 to +127 bytes fr

Instruction word format, Displacement addressing technique

Displacement addressing technique

Addsub, Using the AddSub program from Ch3 under c:\Masm615\examples as a re...

Using the AddSub program from Ch3 under c:\Masm615\examples as a reference, write a program that subtracts three 16-bit integers using only registers. Insert a call DumpRegs statem

Write Your Message!

Captcha
Order Assignment

Featured Services

Order Now

Popular Subjects

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!

Submit Assignment

Academics

Major Subjects

Majors

Get In Touch

whatsapp: +91-977-207-8620

Phone: +91-977-207-8620

Email: [email protected]

TERMS & POLICIES

HELP & SUPPORT

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd