ORG 0000H
LJMP START
ORG 0003H
LJMP INT
START: MOV SP,#60H
MOV TCON,#00H
MOV IP,#01H
MOV IE,#81H
RUN: MOV A,#0
LOOP:
MOV P2,A
MOV R5,#20
LCALL DELAY
CPL A
LJMP LOOP
INT :
PUSH ACC
PUSH PSW
CLR RS1
SETB RS0
CPL C
MOV A,#0FFH
MOV R4,#16
LOOPR:
RRC A
;cpl a
MOV P2,A
MOV R5,#20
CALL DELAY
DJNZ R4,LOOPR
POP PSW
POP ACC
RETI
DELAY:MOV R6,#20
S1: MOV R7,#248
DJNZ R7,$
DJNZ R6,S1
DJNZ R5,DELAY
RET
END