我不断收到并解决我的汇编语言的错误

发布于 2024-12-13 02:38:13 字数 1238 浏览 0 评论 0原文

因此，我正在为以下内容创建一种汇编语言：

 X = 5
 Y = 7
 FOR I = 1 TO 9
    Y = Y + I
    IF T(I) = J(I) + X THEN J(I) = T(I) * 4 - Y
               ELSE J(I) = J(I) - T(I) 
END_FOR

并不断收到

"Address Error: Instruction at  418 accessing address  44f
Execution halted"

到目前为止我所拥有的代码是：

    ORG $400

    MOVEA   #T,A0
    MOVEA   #J,A1
    MOVE.B  #1,D0       //D0 is a counter to hold I
    MOVE    #5,D1       //X = 5
    MOVE    #7,D2       //Y = 7
NEXT    
    ADD D0,D2       //Y = Y + I
    MOVE    (A0),D3     
    MOVE    (A1),D4
    MOVE    D4,D5       //D5 is a temp copy of J(I)
    MOVE    D5,D1
    CMP D5,D3       //IF T(I) = J(I) + X
    BNE ELSE
    SUB D2,D3
    MULU    #4,D3
    MOVE    D3,(A1)     
    BRA END_LOOP
ELSE    
    SUB D3,D4       //J(I) = J(I) - T(i)
    MOVE    D4,(A1)
END_LOOP
    ADDA    #2,A0       //POINT TO NEXT ELEMENT IN T
    ADDA    #2,A1       //POINT TO NEXT ELEMENT IN J
    ADD #1,D0
    CMP #9,D0
    BNE NEXT
    MOVE.B  #4,D0
    TRAP    #15     //; halt simulator

* Variables and Strings
T   DC.B    6,2,5,4,9,7,3,1,0
J   DC.B    5,7,1,9,2,5,6,6,1

    END $400        //; last line of source

我忽略了什么？

原文

So I am creating an assembly language for the following:

 X = 5
 Y = 7
 FOR I = 1 TO 9
    Y = Y + I
    IF T(I) = J(I) + X THEN J(I) = T(I) * 4 - Y
               ELSE J(I) = J(I) - T(I) 
END_FOR

and keep recieving a

"Address Error: Instruction at  418 accessing address  44f
Execution halted"

The code I have so far is:

    ORG $400

    MOVEA   #T,A0
    MOVEA   #J,A1
    MOVE.B  #1,D0       //D0 is a counter to hold I
    MOVE    #5,D1       //X = 5
    MOVE    #7,D2       //Y = 7
NEXT    
    ADD D0,D2       //Y = Y + I
    MOVE    (A0),D3     
    MOVE    (A1),D4
    MOVE    D4,D5       //D5 is a temp copy of J(I)
    MOVE    D5,D1
    CMP D5,D3       //IF T(I) = J(I) + X
    BNE ELSE
    SUB D2,D3
    MULU    #4,D3
    MOVE    D3,(A1)     
    BRA END_LOOP
ELSE    
    SUB D3,D4       //J(I) = J(I) - T(i)
    MOVE    D4,(A1)
END_LOOP
    ADDA    #2,A0       //POINT TO NEXT ELEMENT IN T
    ADDA    #2,A1       //POINT TO NEXT ELEMENT IN J
    ADD #1,D0
    CMP #9,D0
    BNE NEXT
    MOVE.B  #4,D0
    TRAP    #15     //; halt simulator

* Variables and Strings
T   DC.B    6,2,5,4,9,7,3,1,0
J   DC.B    5,7,1,9,2,5,6,6,1

    END $400        //; last line of source

What am I overlooking?

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隱形的亼 2024-12-20 02:38:13

如果您更改所有 MOVE、ADD、SUB、CMP 至 MOVE.B、ADD.B、SUB.B、<代码>CMP.B。我假设为 .B，因为您的变量已声明为 DC.B。即使您没有收到错误，您也应该指定大小。注意需要更改的主要是访问内存的MOVE，原因如下，但它们都应该被指定。

无论如何，错误发生在：MOVE (A1),D4。如果您跟踪并查看寄存器，您将看到之前的类似指令 (MOVE (A0),D3) 将一个字而不是一个字节读入 D3 ：D3=00000602。它将 T 中的前两个字节读取到 D3 中。 MOVE (A1),D4 也想读取一个 WORD，这次是从 J 读取。

但是，由于您告诉汇编器 DC.B，它会对齐内存，以便您可以以字节（而不是字）的形式访问数组。由于您的 MOVE 指令等默认为 MOVE.W，您还可以将 DC.B 更改为 DC.W code>，错误就会消失。但不要这样做，只是向您展示错误发生的方式和原因，您应该按照我上面提到的方式指定大小。

另请注意，使用诸如 MULU 之类的指令，如果您只想将单个字节相乘，则应确保寄存器的较高字节被清零，因为它至少相乘每个操作数的 WORD。由于您没有将超过一个字节的任何内容移动到 D3 中，因此较高的字节无论如何都是 0。

另一件事，END $400 通常应该类似于 END START，即：

    ORG $1000
START:
...
END START

编辑：只是想我会指出（如果不是的话）已经很明显了）您应该修复 A0 和 A1 的增量，即。阅读 JustinP 的回答。

It'll execute without any errors (not sure if it does the right calculations but that's up to you since it's homework) if you change all your MOVE,ADD,SUB,CMP to MOVE.B, ADD.B, SUB.B, CMP.B. I'm assuming .B since your variables are declared DC.B. Even if you're not getting errors you should specify the size. Note the main ones that need changing are the MOVEs that access memory, for the reasons below, but they should all really be specified.

Anyway the error occurred at: MOVE (A1),D4. If you trace through and look at the registers you'll see the similar instruction before that (MOVE (A0),D3) was reading a WORD rather than a BYTE into D3: D3=00000602. It read the first two bytes from T into D3. MOVE (A1),D4 also wants to read a WORD, this time from J.

However, since you told the assembler to DC.B, it aligned the memory so that you can access your arrays as BYTEs as opposed to WORDs. Since your MOVE instructions and such were defaulting to MOVE.W, you could also change DC.B to DC.W, and the error would go away. Don't do that though, just showing you how and why the error occurs, you should specify the sizes as I mentioned above.

Also take note that with instructions like MULU, if you only want to multiply single BYTEs together you should make sure that the higher BYTEs of your register(s) are zeroed out, since it multiplies together at least a WORD from each operand. Since you haven't moved anything more than a BYTE into D3 the higher BYTEs are all 0 anyway.

Another thing, END $400 should usually be something like END START, ie: