Datasheet

PCF2129 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2014. All rights reserved.
Product data sheet Rev. 7 — 19 December 2014 27 of 86
NXP Semiconductors
PCF2129
Accurate RTC with integrated quartz crystal for industrial applications
8.8.3 Register Hours
[1] Hour mode is set by the bit 12_24 in register Control_1 (see Ta ble 7).
8.8.4 Register Days
[1] If the year counter contains a value which is exactly divisible by 4, including the year 00, the RTC compensates for leap years by adding
a 29
th
day to February.
Table 26. Hours - hours register (address 05h) bit allocation
Bit positions labeled as - are not implemented and return 0 when read. Bits labeled as X are undefined at power-on and
unchanged by subsequent resets.
Bit 7 6 5 4 3 2 1 0
Symbol - - AMPM HOURS (1 to 12) in 12-hour mode
HOURS (0 to 23) in 24-hour mode
Reset
value
- - XXXXXX
Table 27. Hours - hours register (address 05h) bit description
Bit positions labeled as - are not implemented and return 0 when read. Bits labeled as X are undefined at power-on and
unchanged by subsequent resets.
Bit Symbol Value Place value Description
7to6 - - - unused
12-hour mode
[1]
5 AMPM 0 - indicates AM
1 - indicates PM
4 HOURS 0 to 1 ten’s place actual hours coded in BCD format when in 12-hour
mode
3to0 0to9 unit place
24-hour mode
[1]
5 to 4 HOURS 0 to 2 ten’s place actual hours coded in BCD format when in 24-hour
mode
3to0 0to9 unit place
Table 28. Days - days register (address 06h) bit allocation
Bit positions labeled as - are not implemented and return 0 when read. Bits labeled as X are undefined at power-on and
unchanged by subsequent resets.
Bit 7 6 5 4 3 2 1 0
Symbol - - DAYS (1 to 31)
Reset
value
- - XXXXXX
Table 29. Days - days register (address 06h) bit description
Bit Symbol Value Place value Description
7to6 - - - unused
5to4 DAYS
[1]
0 to 3 ten’s place actual day coded in BCD format
3to0 0to9 unit place