MOV DPTR, #1000H
MOV R7, #0
MOV R6, #0
MOV R5, #100
LADD:
MOVX A, @DPTR
INC DPTR
ADD A, R6
MOV R6, A
CLR A
ADDC A, R7
MOV R7, A
DJNZ R5, LADD
RET