LEDRED   BIT  P2.0
LEDYELLOW BIT P2.1
ORG  0000H
LJMP START
ORG  0030H
START:
      MOV  R0,#3
      MOV  R7,#5
S1:
      CLR  LEDRED
      CALL DELAY2
      SETB LEDRED
      CALL DELAY2
      DJNZ R0,S1
      JMP  S2
      RETI
S2:
      CLR  LEDYELLOW
      CALL DELAY1
      SETB LEDYELLOW
      CALL DELAY1
      DJNZ R7,S2
     JMP S
DELAY1:MOV  R3,#05H
DEL1:MOV  R2,#0FFH
DEL2:MOV  R1,#0FFH
DEL3:DJNZ  R1,DEL3;275*3us=825us
     DJNZ  R2,DEL2;0.825ms*275=226ms
     DJNZ  R3,DEL1;225ms*5=1125ms
     RETI
DELAY2:MOV   R6,#09H
DEL4:MOV  R5,#0FFH
DEL5:MOV  R4,#0FFH
DEL6:DJNZ R4,DEL6;275*3=825us
     DJNZ R5,DEL5;0.825ms*275=226ms
     DJNZ R6,DEL4;225ms*9=2025ms
     RETI
S:   
     END