here is my code

    [ORG 0x0100]
    
    jmp  start
    
    even: dw 16,18,20,22,24,26,28,30,32    
    avg:  dw 0
    
average:     
a1: add  ax, [bx]    
    add  bx, 2    
    loop a1    
    ret
    
start:    
    mov ax,0    
    mov bx,even    
    mov cx,8    
    call average    
    mov bx,9    
    div ax    
    mov avg,ax    
    mov ax, 0x4c00  ;terminate program    
    int 0x21

I do not know why I am getting this error.

CodePudding user response：

invalid combination of opcode and operand

If this is NASM, then mov avg,ax needs to become mov [avg], ax to avoid the error.
If this were MASM, then mov bx,even needs to become mov bx, OFFSET even for correct results.

You got errors!

• The array has 9 elements but you process only 8 with mov cx,8.
• Eventhough you prepare for a division by 9 with mov bx,9, you execute div ax which is wrong.
• The word-sized division requires zeroing DX beforehand

start:    
    mov ax, 0    
    mov bx, even    
    mov cx, 9    
    call average    
    mov bx, 9
    xor dx, dx    
    div bx
    mov [avg], ax    
    mov ax, 0x4C00  ;terminate program    
    int 0x21