SOUTH_RED EQU P1.0
SOUTH_YELLOW EQU P1.1
SOUTH_GREEN EQU P1.2
EAST_RED EQU P1.3
EAST_YELLOW EQU P1.4
EAST_GREEN EQU P1.5
SECOND_FLAG BIT 00H
TIME_COUNT0 DATA 30H
TIME_COUNT1 DATA 31H
STATUS_FLAG DATA 32H
SECOND_COUNT DATA 33H
ORG 000H
LJMP MAIN
ORG 000BH
LJMP T0_INT
ORG 0100H
MAIN:MOV SP,#60H
     LCALL INIT
     LCALL  T0_INT
LOOP:
JNB  SECOND_FLAG,LOOP
LCALL STATUS_CHANGE
CLR  SECOND_FLAG
SJMP LOOP
STATUS_CHANGE:MOV A,STATUS_FLAG
              ADD A,STATUS_FLAG
              MOV DPTR,#STATUS_PROC_TABLE
              JMP @A+DPTR
STATUS_PROC_TABLE:AJMP STATUS1
                  AJMP STATUS2
                  AJMP STATUS3
                  AJMP STATUS4
STATUS1:DJNZ  SECOND_COUNT,STATUS1_EXIT
        MOV  SECOND_COUNT,#10
        MOV  STATUS_FLAG,#01H
STATUS1_EXIT:
RET
STATUS2:DJNZ     SECOND_COUNT,STATUS2_EXIT
        MOV      SECOND_COUNT,#40
        MOV      STATUS_FLAG,#02H
        SETB     SOUTH_RED
        CLR      SOUTH_YELLOW
        SETB     SOUTH_GREEN
        CLR      EAST_RED
        SETB     EAST_YELLOW
        SETB     EAST_GREEN
        RET
STATUS2_EXIT:
     CPL  SOUTH_GREEN
RET
STATUS3:DJNZ     SECOND_COUNT,STATUS3_EXIT
        MOV      SECOND_COUNT,#10
        MOV      STATUS_FLAG,#03H
STATUS3_EXIT:
RET
STATUS4:DJNZ    SECOND_COUNT,STATUS4_EXIT
        MOV     SECOND_COUNT,#60
        MOV     STATUS_FLAG,#00H
        CLR     SOUTH_RED
        SETB    SOUTH_YELLOW
        SETB    SOUTH_GREEN
        SETB    EAST_RED
        CLR     EAST_YELLOW
        SETB    EAST_GREEN
        RET
STATUS4_EXIT:CPL  EAST_GREEN
RET
INIT:SETB SOUTH_RED
     SETB SOUTH_YELLOW
     CLR  SOUTH_GREEN
     CLR EAST_RED
     SETB EAST_YELLOW
     SETB EAST_GREEN
     MOV TIME_COUNT0,#250
     MOV TIME_COUNT1,#8
     MOV SECOND_COUNT,#60
     MOV STATUS_FLAG,#00H
     CLR SECOND_FLAG
     RET
T0_INT:DJNZ TIME_COUNT0,T0_INT_EXIT
       MOV TIME_COUNT0,#250
       DJNZ TIME_COUNT1,T0_INT_EXIT
       MOV     TIME_COUNT1,#8
       SETB SECOND_FLAG
T0_INT_EXIT:
RETI
T0_INT_INIT:
  MOV TMOD,#02H
  MOV TL0,#06H
  MOV TH0,#06H
  MOV TCON,#10H
  SETB EA
  SETB ET0
  RET
END

頂！！
我建議你現在不要寫這么長的程序，先把基本的如中斷，定時，流水燈等等！！
加油，我也是初學者！