ORG 0000H

LJMP MAIN

ORG 0030H

MAIN:

MOV A,#0FEH

MOV B,#0FFH

MOV P1,A

MOV P0,B

MOV R2,#14

LOOP:

LCALL DELAY

RLC A

XCH A,B

RLC A

MOV C,ACC.6

XCH A,B

MOV ACC.0,C

MOV P1,A

MOV P0,B

DJNZ R2,LOOP

MOV R2,#3

LOOP1:

MOV P0,#00H

MOV P1,#00H

LCALL DELAY

MOV P1,#0FFH

MOV P0,#0FFH

DELAY

DJNZ R2,LOOP1

SJMP $

DELAY:

MOV R6,#200

DLY:

MOV R7,#250

DJNZ R7,$

DJNZ R6,DLY

RET

END