Question

PROGRAMMING ASSIGNMENT:

Write a fully-commented program for the HC12 board, including appropriate directives and labels for memory operands and constants. The program should do the following:

• The program should start execution at address $2000.

• Use directives to create an array of N=20 unsigned 8-bit decimal values: 15,20,14,13,17,9,10,5,18,7,19,8,1,3,4,11,2,6,12,16 stored in contiguous memory at locations start at $1000.

• Sort given numbers in a descending order.

• Store sorted numbers at memory locations starting from $1000. *assembly programming language*

Answer 1

section   .text
global _start ;must be declared for linker (ld)
Begin:
mov ax, data
mov ds, ax
mov es, ax
mov bx, OFFSET N
mov cx, 20
mov dx, cx
L1:
mov si, 0
mov ax, si
inc ax
mov di, ax
mov dx, cx
L2:
mov al, [bx][si]
cmp al, [bx][di]
jg L4
L3:
inc si
inc di
dec dx
cmp dx, 00
je L1
jg L2
L4:
mov al, [bx][si]
mov ah, [bx][di]
mov [bx][si], ah
mov [bx][di], al
inc si
inc di   
dec dx
cmp dx, 00
je L1
jg L2
Exit:
mov ax, 1000
int 21h
  
_start:   ;tells linker entry point
mov   edx,len ;message length
mov   ecx,msg ;message to write
mov   ebx,1 ;file descriptor (stdout)
mov   eax,4 ;system call number (sys_write)
int   0x80 ;call kernel
  
mov   eax,1 ;system call number (sys_exit)
int   0x80 ;call kernel

section   .data
N times 20 DW 15,20,14,13,17,9,10,5,18,7,19,8,1,3,4,11,2,6,12,16