ASTEP  EQU  01H
       BSTEP  EQU  02H
       CSTEP  EQU  04H
       DsTEP  EQU  08H
       DLY_C  EQU  60H

       org   0000h
       ljmp  start
       org   0030h

      
START: MOV    DLY_C,#10H
       lJMP    LOOP
LOOP:  MOV    A,#ASTEP
       CPL    A
       MOV    P2,A
       CALL   DELAY
       MOV    A,#ASTEP+BsTEP
       CPL    A
       MOV    P2,A
       CALL   DELAY
       MOV    A,#BsTEP
       CPL    A
       MOV    P2,A
       CALL   DELAY
       MOV    A,#BsTEP+CsTEP
       CPL    A
       MOV    P2,A
       CALL   DELAY
       MOV    A,#CSTEP
       CPL    A
       MOV    P2,A
       CALL   DELAY
       MOV    A,#CSTEP+DSTEP
       CPL    A
       MOV    P2,A
       CALL   DELAY
       MOV    A,#DSTEP
       MOVX   @DPTR,A
       CALL   DELAY
       MOV    A,#DSTEP+ASTEP
       CPL    A
       MOV    P2,A
       CALL   DELAY
       MOV    A,DLY_C
       DEC    A
       CJNE   A,#1,NN1
       INC    A
NN1:   MOV    DLY_C,A
       LJMP   LOOP
LOOP1: MOV    A,#ASTEP+BSTEP
       CPL    A
       MOV    P2,A
       CALL   DELAY
       MOV    A,#BSTEP+CSTEP
       CPL    A
       MOV    P2,A
       CALL   DELAY
       MOV    A,#CSTEP+DSTEP
       CPL    A
       MOV    P2,A
       CALL   DELAY
       MOV    A,#DSTEP+ASTEP
       CPL    A
       MOV   P2,A
       CALL   DELAY
       MOV    A,DLY_C
       DEC    A
       CJNE   A,#2,NN2
       INC    A
NN2:   MOV    DLY_C,A
       JMP    LOOP1
LOOP2: MOV    A,#DSTEP
       CPL    A
       MOV    P2,A
       CALL   DELAY
       MOV    A,#CSTEP
       CPL    A
       MOV    P2,A
       CALL   DELAY
       MOV    A,#BSTEP
       CPL    A
       MOV    P2,A
       CALL   DELAY
       MOV    A,#ASTEP
       CPL    A
       MOV    P2,A 
       CALL   DELAY
       MOV    A,DLY_C
       CJNE   A,#3,NN3
       INC    A
NN3:   MOV    DLY_C,A
       JMP    LOOP2
DELAY: MOV    R6,DLY_C
DD1:   MOV    R5,68H
DD2:   MOV    R7,#0
       DJNZ   R7,$
       DJNZ   R5,DD2
       DJNZ   R6,DD1
       RET 
       END