莱鸟求助！汇编基础问题！

assume cs:code, ds:data, ss:stack

data segment
dw 0123h, 0456h, 0789h, 0abch, 0defh, 0fedh, 0cbah, 0987h
data ends

stack segment
dw 0, 0, 0, 0, 0, 0, 0, 0
stack ends

code segment

start: mov ax, data
mov ds, ax

mov ax, stack
mov ss, ax
mov sp, 16

mov bx, 0
mov cx, 8
s1: push ds:[bx]
add bx, 2
loop s1

mov bx, 0
mov cx, 8
s2: pop ds:[bx]
add bx, 2
loop s2

mov ax, 4c00h　　　/* 在debug中为什么执行不到这里就结束了*/
int 21h

code ends

end start