Question

Write a simple C language code using MPLABX IDE that explains an operation then rewrite the same Code but using assembler code language and explain how the codes work.

Answer 1

C Code to find the sum of two 8-bit numbers:-

#include<stdio.h>

#include<conio.h>

int main(int argc, char* argv[]){

system("cls");

int x = 0x9;

int y = 0x2;

x = x + y;

printf("The Sum is: %x\n", x);

system("PAUSE");

return 0;

}

The Output is attached below:-

C\CHEGG GITAC++ Programs| Sum.exe The Sum is: b Press any key to continue .. .

The Assembly Code for the same C Code is given below:-

data segment
a db 09h ; load 09h to register a
b db 02h ; load 02h to register b
c dw ? ; store the sum in register c
data ends

code segment
assume cs:code,ds:data
start:
mov ax,data
mov ds,ax
mov al,a ; move the lower order 8 bitsof a to AL
mov bl,b ; move the lower order 8 bitsof b to BL
add al,bl ; add the two 8-bits and store the result back to AL
mov c,ax ; move the result stored in Register A to Register C
int 3
code ends
end start

The Output is attached below:-

E variables size: byte elements:1 edit show as: hex 09h 02h

Please let me know in case of any clarifications required. Thanks!