1     /*
2         DS12887 on 51 mcu
3         designed by zl0801
4        
5         zhaoliang0801@dl.cn
6         2007-5-16 16:22
7
8     /*
9     register description
10
11    REGISTER A
12    MSB                                                     LSB
13    BIT 7   BIT 6   BIT 5   BIT 4   BIT 3   BIT 2   BIT 1   BIT 0
14    UIP     DV2     DV1     DV0     RS3     RS2     RS1     RS0
15
16        Update In Progress (UIP) : The time, calendar,
17    and alarm information in RAM is fully available
18    for access when the UIP bit is zero.
19       
20        DV2     DV1     DV0      : A pattern of 010 is the
21    only combination of bits that will turn the oscillator on
22    and allow the RTC to keep time.
23
24
25    REGISTER B
26    MSB                                                     LSB
27    BIT 7   BIT 6   BIT 5   BIT 4   BIT 3   BIT 2   BIT 1   BIT 0
28    SET     PIE     AIE     UIE     SQWE    DM      24/12   DSE
29
30        SET     :   When the SET bit is written to a one, any update transfer
31    is inhibited and the program can initialize the time and
32    calendar bytes without an update occurring in the midst
33    of initializing.
34
35
36        DM  Data Mode (DM)  :   A one in DM signifies binary data
37    while a zero in DM specifies Binary Coded Decimal
38    (BCD) data.
39
40        24/12   : A one indicates the 24¨Chour mode and a zero indicates
41    the 12¨Chour mode.
42
43    */
44
45    #include
46    #include
47
48    /*************************/
49    #define     TM_SEC      XBYTE[0xFF00]
50    #define     TM_MIN      XBYTE[0xFF02]
51    #define     TM_HOU      XBYTE[0xFF04]
52<