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 28 of 86
NXP Semiconductors
PCF2129
Accurate RTC with integrated quartz crystal for industrial applications
8.8.5 Register Weekdays
Although the association of the weekdays counter to the actual weekday is arbitrary, the
PCF2129 assumes that Sunday is 000 and Monday is 001 for the purpose of determining
the increment for calendar weeks.
[1] Definition may be reassigned by the user.
Table 30. Weekdays - weekdays register (address 07h) 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 - - - - - WEEKDAYS (0 to 6)
Reset
value
-----XXX
Table 31. Weekdays - weekdays register (address 07h) 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 Description
7 to 3 - - unused
2 to 0 WEEKDAYS 0 to 6 actual weekday value, see Table 32
Table 32. Weekday assignments
Day
[1]
Bit
2 1 0
Sunday 0 0 0
Monday 0 0 1
Tuesday 0 1 0
Wednesday 0 1 1
Thursday 1 0 0
Friday 1 0 1
Saturday110