无效有效地址计算 [英] invalid effective address calculation

问题描述

请看看下面的程序，错误是无效的有效地址计算，我已经提到，行，请告诉我，为什么它的无效有效地址计算
这里是节目
结果

  [组织的0x100]
JMP启动
数组1：DW 10,15,20,25,30,35,40,45,50,55
数组2：DW 15,10,20,35,40,30,55,50,25,45启动：MOV BX，0
    MOV CX，0
循环：MOV AX，[数组2 + BX]
        CMP AX，[数组1 + CX] //这里是错误无效的有效地址计算
        JNE NextElementOfArray1
NextElementOfArray2：加BX，2
                        CMP BX，20
            JE结束
                        MOV CX，0
            JMP环
NextElementOfArray1：加CX，2
                        CMP CX，20
            JE NextElementOfArray2
            JMP环
结束：MOV AX，0x4c00
    INT为0x21
 

解决方案

 启动：MOV BX，0
        MOV DX，0; ＆LT;  - 你的意思是MOV CX，0？
循环：MOV AX，[数组2 + BX]
        CMP AX，[数组1 + CX]
 

编辑：如果我没有记错， CX 寄存器不能用作指数

表2-1。 16位寻址与MODR / M字节形式

 有效地址模r MODR / M字节的/ M值（十六进制）[BX + SI]
[BX + DI]
[BP + SI]
[BP + DI]
[SI]
[二]
[BX]
[BX + SI] + disp8
[BX + DI] + disp8
[BP + SI] + disp8
[BP + DI] + disp8
[SI] + disp8
[二] + disp8
[BP] + disp8
[BX] + disp8
[BX + SI] + disp16
[BX + DI] + disp16
[BP + SI] + disp16
[BP + DI] + disp16
[SI] + disp16
[二] + disp16
[BP] + disp16
[BX] + disp16
 

Please look at the following program, the error is invalid effective address calculation and i have mentioned that line please tell me why its invalid effective address calculation here is the program

[org 0x100]
jmp start


array1: dw 10,15,20,25,30,35,40,45,50,55
array2: dw 15,10,20,35,40,30,55,50,25,45

start:  mov bx,0
    mov cx,0
loop:   mov ax,[array2+bx]
        cmp ax,[array1+cx]//here is the error invalid effective address calculation 
        jne NextElementOfArray1


NextElementOfArray2:    add bx,2
                        cmp bx,20       
            je end
                        mov cx,0
            jmp loop


NextElementOfArray1:    add cx,2        
                        cmp cx,20       
            je NextElementOfArray2   
            jmp loop
end:    mov ax,0x4c00
    int 0x21

解决方案

start:  mov bx,0
        mov dx,0 ; <-- did you mean "mov cx, 0" ?
loop:   mov ax,[array2+bx]
        cmp ax,[array1+cx]

Edit: If I recall correctly, cx register can not be used as an index.

Table 2-1. 16-Bit Addressing Forms with the ModR/M Byte

Effective Address Mod R/M Value of ModR/M Byte (in Hexadecimal)

[BX+SI]
[BX+DI]
[BP+SI]
[BP+DI]
[SI]
[DI]
[BX]
[BX+SI]+disp8
[BX+DI]+disp8
[BP+SI]+disp8
[BP+DI]+disp8
[SI]+disp8
[DI]+disp8
[BP]+disp8
[BX]+disp8
[BX+SI]+disp16
[BX+DI]+disp16
[BP+SI]+disp16
[BP+DI]+disp16
[SI]+disp16
[DI]+disp16
[BP]+disp16
[BX]+disp16

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