8051 Assembly Address Based 8 bit Addition program

ORG 0000H

MOV DPTR, #0030H

MOVX A, @DPTR

MOV R0, A

INC DPTR

MOVX A, @DPTR

ADD A, R0

MOV DPTR, #0090H

MOVX @DPTR, A

MOV PCON, #02H