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 34 of 86
NXP Semiconductors
PCF2129
Accurate RTC with integrated quartz crystal for industrial applications
8.9.3 Register Hour_alarm
[1] Hour mode is set by the bit 12_24 in register Control_1.
8.9.4 Register Day_alarm
Table 42. Hour_alarm - hour alarm register (address 0Ch) 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 AE_H - AMPM HOUR_ALARM (1 to 12) in 12-hour mode
HOUR_ALARM (0 to 23) in 24-hour mode
Reset
value
1 - XXXXXX
Table 43. Hour_alarm - hour alarm register (address 0Ch) 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
7 AE_H 0 - hour alarm is enabled
1 - hour alarm is disabled
6- --unused
12-hour mode
[1]
5 AMPM 0 - indicates AM
1 - indicates PM
4 HOUR_ALARM 0 to 1 ten’s place hour alarm information coded in BCD format when in
12-hour mode
3to0 0to9 unit place
24-hour mode
[1]
5 to 4 HOUR_ALARM 0 to 2 ten’s place hour alarm information coded in BCD format when in
24-hour mode
3to0 0to9 unit place
Table 44. Day_alarm - day alarm register (address 0Dh) 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 AE_D - DAY_ALARM (1 to 31)
Reset
value
1 - XXXXXX
Table 45. Day_alarm - day alarm register (address 0Dh) 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
7 AE_D 0 - day alarm is enabled
1 - day alarm is disabled
6- --unused
5 to 4 DAY_ALARM 0 to 3 ten’s place day alarm information coded in BCD format
3to0 0to9 unit place