王爽 汇编11.10(2)编程用串传送指令，将F000H段中最后的16个字节复制到data段中

assume cs:code,ds:data

data segment    
    db 16 dup(0)
data ends

code segment
start:  mov    ax,0f000h
        mov ds,ax
        mov si,0ffffh    ;ds:si指向f000:ffff
        mov ax,data    
        mov es,ax
        mov di,15        ;es:di指向data:15
        mov cx,16        ;(cx0)=16,rep循环16次
        
        std              ;设置df=1,反向传递
        rep movsb
        
        mov ax,4c00h
        int 21h
code ends
end start