设array是10个元素的数组，每个元素8位数据。试用子程序计算数组元素的校验和，并将结果存入变量result中。所谓校验和是指不记进位的累加用于检查信息的正确性

子程序的参数传递：

1.用寄存器传递参数
data segment
   count equ 10
   array db 12h,25h,0f0h,0a3h,3,68h,71h,0cah,0ffh,90h
   result db ?
data ends
code segment
assume cs:code,ds:data
start:
   mov bx,offset array
   mov cx,count
   call checksuma
   mov result,al
   mov ah,4ch
   int 21h
checksuma proc
   xor al,al
suma:add al,[bx]
   inc bx
   loop suma
   ret
checksuma endp
code ends
end start

2.使用变量传递参数

data segment
   count equ 10
   array db 12h,25h,0f0h,0a3h,3,68h,71h,0cah,0ffh,90h
   result db ?
data ends
code segment
assume cs:code,ds:data
start:
   call checksuma
   mov ah,4ch
   int 21h
checksuma proc
   push ax
   push bx
   push cx
   xor al,al
   mov bx,offset array
   mov cx,count
suma:add al,[bx]
   inc bx
   loop suma
   mov result,al
   pop cx
   pop bx
   pop ax
   ret
checksuma endp
code ends
end start

3.使用堆栈传递参数

data segment
   count equ 10
   array db 12h,25h,0f0h,0a3h,3,68h,71h,0cah,0ffh,90h
   result db ?
data ends
code segment
assume cs:code,ds:data
start:
   mov ax,offset array
   push ax
   mov ax,count
   push ax
   call checksuma
   add sp,4;主程序平衡堆栈
   mov result,al
   mov ah,4ch
   int 21h
checksuma proc
   push bp
   mov bp,sp
   push bx
   push cx
   mov bx,[bp+6];数组的偏移地址
   mov cx,[bp+4];数组的元素个数
   xor al,al
suma:add al,[bx]
   inc bx
   loop suma
   pop cx
   pop bx
   pop bp
   ret
checksuma endp
code ends
end start