Assembly language (arrays)

问题

I'm new to assembly language and everything seems a little complicated.

I'm programming an old MCU (68hc11), I'm trying to migrate from C language to assembly code using the 68hc11 instructions.

I want to solve 2 different situations:

FIRST CASE

I want to write a program in assembly that counts the number of POSITIVE, NEGATIVE, and ZERO values that exist inside a given array. DO NOTE that all values inside ARRAY could be all positive or all negative or all zeros,do you get me? So I should define the size of the variables that will store the quantity properly.

NOTE: The end of the array is: ARRAY+QUANTITY-1

Array: contains some random values

QUANTITY: represent the highest number of elements that the ARRAY can hold

I wrote this program in C:

int A[15], pos, neg, nul, i;

[...]

pos = 0;
neg = 0;
nul = 0;

for (i = 0; i < 15; i++) {
    if (A[i] > 0) {
        pos++;
    }
    if (A[i] < 0) {
        neg++;
    }
    if (A[i] == 0) {
        nul++;
    }
}

Now, I want to translate that but in assembly (I GOT STUCK IN HERE)

RWM         EQU $0
ROM         EQU   $C000
VRESET      EQU   $FFFE

QUANTITY    EQU 800 ;MEANS THE MAXIMUM AMOUNT OF VALUES THAT THE ARRAY WILL CONTAIN

            ORG RWM

POSITIVE        RMB 2
NEGATIVE        RMB 2
ZEROS           RMB 2

            ORG ROM
START:




END         BRA END

ARRAY       DW    78,554,-44,-4,2547,0,-3,0,1,7,8,

        ORG VRESET
        DW  START

------------------------------------------------------------------------------------------------------

SECOND CASE

I want to obtain the absolute values of all the elements that are stored in a specific array.

ABSOLUTE will contain the absolute values of the elements stored in ARRAY (the size of ABSOLUTE must be related to the amount of elements inside ARRAY)

In C it looks like this:

#include <stdio.h>

#define SIZE 16

int absolute(int array[], int ray[], int N)
{
  for (int i=0; i<N; i++)
    ray[i] = array[i] * (array[i]<0?-1:1);
}

int main()
{
  int array[SIZE] = {0,1,2,3,-4,5,6,7,-8,9,-10,11,12,13,14,20};
  int ray[SIZE];

  absolute(array,ray,SIZE);
  for (int i = 0; i < SIZE; i++ )
    printf("The absolute value of %3i is %3i\n", array[i],ray[i]);
  return 0;
}

Assembly should look like this (i got stuck in here)

RWM      EQU        $0
ROM      EQU     $C000
RESET    EQU     $FFFE

         ORG    RWM
ABSOLUTE RMB    ;i must dfine a size depending on the amount of elements inside ARRAY

        ORG     ROM
Start:      


END     BRA END

ARRAY   DW   4,144,447,-14,-555,-1147

        ORG RESET
        DW  Start

Can help me to make it work using the corresponding HC11 instructions?.

PS: I use these instructions: INSTRUCTIONS

来源：https://stackoverflow.com/questions/62337005/assembly-language-arrays

标签

assembly

68hc11