the problem is ram on chip extram access
mov auxr,#0h
mov p2,#2h
mov r0,#0a0h
mov a,#55h
movx @r0,a

Should write at the onchip extram address of 0x2a0 but writes at 0x0a0 according to data sheet page 30, will check for RD2 tomorrow if it functions same way.