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