clr a
	mov r0, a
	mov p2, a
	cpl a
lp0:	movx @r0, a  ;P2 = 0
	djnz r0, lp0
	inc p2
lp1:	movx @r0, a  ;P2 = 1
	djnz r0, lp1
	inc p2
lp2:	movx @r0, a  ;P2 = 2
	djnz r0, lp2
	inc p2
lp3:	movx @r0, a  ;P2 = 3
	djnz r0, lp3