Write this ARM assemble language program, Basic Computer Science

Assignment Help:
Programming Assignment
CS252 Spring 2014

Write an ARM assembly language subroutine that performs according to the following specification (Caesar cypher).

Given a mixed case alphabetic string from the C driver program, convert it to all upper case and create a new string for return to the C program. The new string has the characters from the old string replaced by upper case characters from the alphabet offset by the given amount in the alphabet.

If the character string is ‘Abc’ with an offset of -3 the new string would be ‘XYZ’. For characters in the alphabet such as ‘mno’, the alphabet is ‘JKL’. The beginning of the alphabet is wrapped to the end.

To convert a character to upper case, AND the character with 0xDF. Do not process the space character (leave it as a space) or the NULL byte terminator but be sure to include the NULL byte in the new string.

The C driver code:
/* C code for cipher */
#include
#include

extern char * cypher( char * s, int offset ) ;

int main( int argc, char * argv[] )
{
?char string[] = "The quick brown fox jumped over the lazy dog" ;
?char * result ;
?int offset = -5 ;

?result = cypher( string, offset ) ;
?printf( "Original:%s\n", string ) ;
?printf( "Coded: %s\n", result ) ;
?
?exit( 0 ) ;
}

The assembly routines definition is:
?extern char * cypher( char * s, int offset )
?where?char * s is the pointer to the string,
?int offset is the integer distance to move
?returns a pointer to a string.

To determine the length of the string in order to reserve space for the new string use the library routine strlen. Register a1 contains a pointer to the string to measure and on return register a1 has the number of characters in the string. You need to add one to this result since strlen does not account for the null byte at the end.
You can pass this length to the malloc library routine to obtain space for the new string.

Related Discussions:- Write this ARM assemble language program

Input and output devices, Input and Output Devices : The most common input...

Input and Output Devices : The most common input devices that you will see in your PC are the keyboard and the mouse. The keyboard of the computer looks like the keyboard o

How is python Using Blank Lines and Waiting for the User, A line holds onl...

A line holds only whitespace, probably with a comment, is identified as a blank line, and Python completely avoids it. In an interrelated interpreter session, you need to enter an

Enterprise resource planning, ENTERPRISE RESOURCE PLANNING What ...

ENTERPRISE RESOURCE PLANNING What has football got to do with it? asks management guru Michael Hammer in his latest best seller Beyond Reengineering. The answer is almos

Innovation, role of an system analyst as an innovator

role of an system analyst as an innovator

Define jumps and loops , The unconditional jumps in a written program in a...

The unconditional jumps in a written program in assembler language are specified by the jmp instruction; a jump is to moves the flow of the execution of a program by sending the co

Defining micro-operations, Problem 1. What are Micro-operations? Explai...

Problem 1. What are Micro-operations? Explain Micro operations of the Fetch cycle. Defining Micro-operations Its explanation of the fetch cycle 2. Differen

Explain data movement ?, In any program it is essential to move the data in...

In any program it is essential to move the data in the memory and in the CPU registers; there are a number of ways to do this: it can copy data in the memory to a number of registe

Programmable rom (prom) , PROGRAMMABLE ROM (PROM): The user can program...

PROGRAMMABLE ROM (PROM): The user can program a PROM after purchase.  Each memory bit element in the PROM contains a nichrome or silicon link that acts as a fuse.  The user can

Data transmission, DATA TRANSMISSION: When we talk on the telephone we...

DATA TRANSMISSION: When we talk on the telephone we generally transmit a message to someone else. The message is made up of words that we speak into the telephone instrument.

Explain the concept of knowledge discovery in database, Question 1 Explain...

Question 1 Explain the concept of knowledge discovery in database Question 2 Discuss the following types of Multidimensional Data Models                    Stars, Snowflakes and

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