Datasheet

PCF8563 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
Product data sheet Rev. 10 — 3 April 2012 11 of 50
NXP Semiconductors
PCF8563
Real-time clock/calendar
The VL flag is intended to detect the situation when V
DD
is decreasing slowly, for example
under battery operation. Should the oscillator stop or V
DD
reach V
low
before power is
re-asserted, then the VL flag is set. This will indicate that the time may be corrupted.
8.4.2 Register Minutes
8.4.3 Register Hours
8.4.4 Register Days
[1] The PCF8563 compensates for leap years by adding a 29th day to February if the year counter contains a
value which is exactly divisible by 4, including the year 00.
8.4.5 Register Weekdays
Table 10. Minutes - minutes register (address 03h) bit description
Bit Symbol Value Place value Description
7 - - - unused
6 to 4 MINUTES 0 to 5 ten’s place actual minutes coded in BCD format
3 to 0 0 to 9 unit place
Table 11. Hours - hours register (address 04h) bit description
Bit Symbol Value Place value Description
7 to 6 - - - unused
5 to 4 HOURS 0 to 2 ten’s place actual hours coded in BCD format
3to0 0to9 unit place
Table 12. Days - days register (address 05h) bit description
Bit Symbol Value Place value Description
7 to 6 - - - unused
5to4 DAYS
[1]
0 to 3 ten’s place actual day coded in BCD format
3to0 0to9 unit place
Table 13. Weekdays - weekdays register (address 06h) bit description
Bit Symbol Value Description
7 to 3 - - unused
2 to 0 WEEKDAYS 0 to 6 actual weekday values, see Table 14