检测点 11.4

流风逸雪

assume cs:code

code segment

start:        
        mov ax,0
        push ax
        popf ;以上三步相当于把标志位全部置0
        mov ax,0fff0h
        add ax,0010h;执行完后(ax)=0,NV UP DI PL ZR NA PE CY
        pushf ;这里往内存里push 0047H，也就是flag的值
        pop ax;(ax)=0047H,(al)=01000111b
        and al,11000101b;(al)=45H=01000101b,(ah)=00000000b,NV UP DI PL NZ NA PO NC
        and ah,00001000b;(ah)=00000000b,(ax)=45H
code ends
end start