PCF2129A Datasheet, PDF (6/68 Pages) NXP Semiconductors – Integrated RTC, TCXO and quartz crystal

NXP Semiconductors
PCF2129A
Integrated RTC, TCXO and quartz crystal
• Address registers 1Ah and 1Bh are for internal use only.
• The registers Seconds, Minutes, Hours, Days, Months, and Years are all coded in
Binary Coded Decimal (BCD) format to simplify application use. Other registers are
either bit-wise or standard binary.
address register
00h
01h
02h
03h
...
19h
1Ah
1Bh
auto-increment
wrap around
001aaj398
Fig 3. Handling address registers
When one of the RTC registers is read, the content of all counters is temporarily frozen.
This prevents a faulty reading of the clock and calendar during a carry condition (see
Section 8.8.8).
Table 4. Register overview
Bit positions labeled as - are not implemented and will return 0 when read. Bits labeled as T must always be written with
logic 0. Bits labeled as X are undefined at power-on and unchanged by subsequent resets.
Address Register name Bit
Reset value
7
6
5
4
3
2
1
0
Control registers
00h
Control_1
EXT_ T
TEST
STOP TSF1 POR_ 12_24 MI
SI
OVRD
0000 0000
01h
Control_2
MSF WDTF TSF2 AF
T
TSIE AIE
T
0000 0000
02h
Control_3
PWRMNG[2:0]
BTSE BF
BLF BIE
BLIE 0000 0000
Time and date registers
03h
Seconds
OSF SECONDS (0 to 59)
1XXX XXXX
04h
Minutes
-
MINUTES (0 to 59)
- XXX XXXX
05h
Hours
-
-
AMPM HOURS (1 to 12) in 12 h mode
- - XX XXXX
HOURS (0 to 23) in 24 h mode
- - XX XXXX
06h
Days
-
-
DAYS (1 to 31)
- - XX XXXX
07h
Weekdays
-
-
-
-
-
WEEKDAYS (0 to 6)
- - - - - XXX
08h
Months
-
-
-
MONTHS (1 to 12)
- - - X XXXX
09h
Years
YEARS (0 to 99)
XXXX XXXX
Alarm registers
0Ah
Second_alarm AE_S SECOND_ALARM (0 to 59)
1XXX XXXX
0Bh
Minute_alarm AE_M MINUTE_ALARM (0 to 59)
1XXX XXXX
0Ch
Hour_alarm
AE_H -
AMPM HOUR_ALARM (1 to 12) in 12 h mode
1 - XX XXXX
HOUR_ALARM (0 to 23) in 24 h mode
1 - XX XXXX
0Dh
Day_alarm
AE_D -
DAY_ALARM (1 to 31)
1 - XX XXXX
0Eh
Weekday_alarm AE_W -
-
-
-
WEEKDAY_ALARM (0 to 6) 1 - - - - XXX
PCF2129A_1
Product data sheet
Rev. 01 — 13 January 2010
© NXP B.V. 2010. All rights reserved.
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