assemblyeasy68k

Adding two hex values in assembly language (EASy68K)

I want to create a program that adds two hex values together using ADD.B, ADD.W, and ADD.L and see what the differences are. I'm new to assembly programming, so I can't seem to get it quite right. There are no errors, but when I run the program, no result is displayed. There also doesn't seem to be any value stored in register D3. Can anyone tell me what I am doing wrong? Thanks a lot for any help.

START   ORG     $1000       Program starts at loc $1000
        MOVE    $374D1FC4,D2     [D0] <- $374D1FC4
        MOVE    $F22C4663,D3    [D1] <- $F22C4663
        ADD.B   D2,D3           [D1] <- [D0] + [D1] 
*       ADD.W   D2,D3           [D1] <- [D0] + [D1]
*       ADD.L   D2,D3           [D1] <- [D0] + [D1]
        MOVE    D3,R
* The following three instructions will display [R] to Output Window
* Task number 3 of trap #15 is to display D1.L as a signed decimal
    MOVE    R,D1    [D1] <- R
    EXT.L   D1  Extend sign bit to presreve the sign
    MOVE    #3,D0   Assign task number to [D0]
    TRAP    #15 Ask "OS" to perform the task

    STOP    #$2700  Stop execution

* Data section
R   DS.W    1   int R;
    END START
Solution

  • Easy68K gives you a hint about what the problem is when you try to run the program: "Address Error: Instruction at 1006 accessing address f22c4663".

    These lines:

        MOVE    $374D1FC4,D2     [D0] <- $374D1FC4
    MOVE    $F22C4663,D3     [D1] <- $F22C4663

    should be changed to:

        MOVE    #$374D1FC4,D2     [D0] <- $374D1FC4
    MOVE    #$F22C4663,D3     [D1] <- $F22C4663

    assuming that you wanted to load the immediate values $374D1FC4 and $F22C4663.