0
votes

Need some help understanding this more or less. We are just getting into loops and OFFSET operands and would appreciate some help. So here are my instructions:


Write an assembly language program using the LOOP instruction with indirect addressing mode that calculating the first 12 values in the Fibonacci number sequence, {1, 1, 2, 3, 5, 8, 13, …}. Place each value in the EAX register and display it with a call DumpRegs statement inside the loop.

Please use the following variable definition: Fibonacci BYTE 1, 1, 10 DUP (?)

Insert the following statements immediately after the loop. They will display the hexadecimal contents of the target string: mov esi, OFFSET Fibonacci ; offset the variables mov ebx,1 ; byte format mov ecx, SIZEOF Fibonacci ; counter call dumpMem ; display the data in the memory

If your program works correctly, you will see the following sequence of hexadecimal bytes on the screen when the program runs: 01 01 02 03 05 08 0D 15 22 37 59 90


    .data

Fibonacci BYTE 1, 1, 10 DUP (?)

.code
main PROC

  L1:

  mov   esi, OFFSET Fibonacci       ; offset the variables
  mov   ebx,1               ; byte format
  mov   ecx, SIZEOF Fibonacci       ; counter
  call  dumpMem             ; display the data in the memory


    exit                    ;exits to Operating System
    main ENDP

END main

So I know I need to make a loop statement, but am completely stuck on how to begin it. Any advice will be greatly appreciated!

2

2 Answers

2
votes

I believe you just want to know how to create a loop in assembly. See the below for some examples:

x86 assembly programming loops with ecx and loop instruction versus jmp + j<condition>

1
votes
.586
.MODEL FLAT
INCLUDE io.h            ; header file for input/output
.STACK 4096


.DATA

resultLbl BYTE  "The result is", 0
sum     BYTE    11 DUP (?), 0

.CODE
_MainProc PROC

       mov eax,1
       mov ebx,1  ;  will store answer 
      dtoa  sum , eax
      output resultLbl , sum
      dtoa sum ,ebx 
      output  resultLbl ,sum
      mov ecx ,5
_for:
         mov edx , eax
     add edx , ebx
     dtoa sum ,edx
     output  resultLbl ,sum
     mov  eax ,ebx
     mov  ebx ,edx
     dec ecx
     cmp ecx , 0
     jne _for
     mov eax , 0
     ret


_MainProc ENDP
END