ORG    00H
        JMP    START
        ORG    0BH
        JMP    TIM0
START:  MOV    TMOD,#00000001B
        MOV    IE,#10000010B
        JB     P3.4,$
        MOV    31H,#00
START0:
        MOV    30H,#LOW SONG
NEXT:   MOV    A,30H
        MOV    DPTR,#TABLE
        MOVC   A,@A+DPTR
        MOV    R2,A
        JZ     END0
        ANL    A,#OFH
        MOV    R5,A
        MOV    A,R2
        SWAP   A
        ANL    A,#0FH
        JNZ    SING
        CLR    TRO
        JMP    D1
SING:   DEC    A
        MOV    22H,A
        RL     A
        MOV    DPTR,#TABLE
        MOVC   A,@A+DPTR
        MOV    TH0,A
        MOV    21H,A
        MOV    A,22H
        RL     A
        INC    A
        MOVC   A,@A+DPTR
        MOV    TL0,A
        MOV    20H,A
        SETB   TR0
D1:     CALL   DELAY
        INC    30H
        JMP    NEXT
END0:   CLR    TR0
        MOV    A,31H
        XRL    A,#00H
        JNZ    END1
        JB     P3.4,$
        CALL   DELAY1
        JNB    P3.4,$
        INC    31H
        MOV    30H,#LOW  SONG1
        JMP    NEXT
END1:
        MOV    A,31H
        XRL    A,#01H
        JNZ    END2
        JB     P3.4,$
        CALL   DELAY1
        JNB    P3.4,$
        INC    31H
        MOV    30H,#LOW  SONG2
        JMP    NEXT
END2:
       MOV     A,31H
       XRL     A,#02H
       JNZ     END3
       JB      P3.4,$
       CALL    DELAY1       JNB     P3.4,$
       INC     31H
       MOV     30H,#LOW  SONG3
       JMP     NEXT
END3:
       MOV     A,31H
       XRL     A,#03H
       JNZ     END4
       JB      P3.4,$
       CALL    DELAY1       JNB     P3.4,$
       INC     31H
       MOV     30H,#LOW  SONG4
       JMP     NEXT
END4:
       MOV     A,31H
       XRL     A,#04H
       JNZ     END5
       JB      P3.4,$
       CALL    DELAY1       JNB     P3.4,$
       INC     31H
       MOV     30H,#LOW  SONG5
       JMP     NEXT
END5:
       JMP     START
TIM0:  PUSH    ACC
       PUSH    PSW
       SETB    RS0
       CLR     RS1
       MOV     TL0,20H
       MOV     TH0,21H
       CPL     P1.0
       POP     PSW
       POP     ACC
       RETI
DELAY: MOV     R7,#02       ；125毫秒
D2:    MOV     R4,#125
D3:    MOV     R3,#248
       DJNZ    R3,$
       DJNZ    R4,D3
       DJNZ    R7,D2
       DJNZ    R5,DELAY     ；决定节拍
DELAY1:MOV     R4,#20
D4     MOV     R3,#248
       DJNZ    R3,$
       DJNZ    R4,D4
       RET
       ORG     300H
TABLE:
       DW     64260,64400,64524,64580
       DW     64684,64777,64820,64898
       DW     64968,65630,65058,65110
       DW     65151,65178,65217
SONG:  ;第一首  哈巴狗
       ;1
       DB     42H,42H,42H,52H,64H,04H
       DB     62H,62H,62H,72H,84H,04H
       DB     92H,92H,82H,72H,64H,04H
       ;2   
       DB     42H,42H,42H,52H,64H,04H
       DB     62H,62H,62H,72H,84H,04H
       DB     92H,92H,82H,72H,64H,04H
       DB     00H
SONG1: ;第二首  生日快乐
       ;1
       DB     82H,01H,81H,94H,84H
       DB     0B4H,0A4H,04H
       DB     82H,01H,81H,94H,84H
       DB     0C4H,0A4H,04H
       ;2
       DB     82H,01H,81H,0F4H,0D4H
       DB     0B4H,0A4H,94H
       DB     0E2H,01H,0E1H,0D4H,0B4H
       DB     0C4H,0B4H,04H
       DB     00H
SONG2: ;第三首  不倒翁
       ;1
       DB     84H,94H,88H
       DB     64H,54H,68H
       DB     84H,64H,54H,44H
       DB     62H,82H,42H,62H,58H
       ;2
       DB     84H,94H,88H
       DB     64H,54H,68H
       DB     84H,64H,54H,44H
       DB     52H,42H,52H,62H,48H
       DB     00H
SONG3: ;第四首  妹妹背着洋娃娃
       ;1
       DB     84H,02H,82H,64H,54H
       DB     64H,54H,48H
       DB     64H,02H,52H,44H,24H
       DB     14H,24H,18H
       ;2
       DB     24H,02H,22H,42H,24H
       DB     44H,54H,68H
       DB     54H,64H,48H
       DB     00H
SONG4: ;第五首  两只老虎
       ;1
       DB     44H,54H,64H,44H
       DB     44H,54H,64H,44H
       DB     64H,74H,88H
       DB     64H,74H,88H
       ;2
       DB     82H,92H,82H,72H,64H,44H
       DB     82H,92H,82H,72H,64H,44H
       DB     44H,84H,48H
       DB     44H,14H,48H
       DB     00H
SONG5: ;第六首  三只小猫
       ;1
       DB     62H,82H,82H,62H,98H
       DB     92H,0B2H,0B2H,82H,98H
       DB     62H,82H,82H,52H,98H
       DB     92H,0B2H,0B2H,82H,98H
       ;2
       DB     62H,82H,82H,62H,92H,92H,94H
       DB     92H,0B2H,0B2H,92H,84H,94H
       DB     0B8H,0B4H,04H
       DB     
       END
原来程序是按一下给T0一个低电平，P1.0输出音乐，再给T0一个低电平，就播放下一首。
我现在需要把它改为这样的：
    状态1：给P1.0一个高电平，P2.0输出一个高电平（触发一个9013用的），P2.1输出音乐信号，音乐自动一首接一首播放下去,播放期间高/低电平对P1.0均无效，等音乐播放完毕1秒钟左右后才生效，即有高电平输入，P2.0、P2.1又有输出。
    状态2：给P1.2高电平，P2.0、P2.1一直输出，音乐循环播放，P1.2高电平一消失，P2.0、P2.1停止输出。