Datasheet

PCF8523 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
Product data sheet Rev. 6 — 17 September 2013 21 of 78
NXP Semiconductors
PCF8523
Real-Time Clock (RTC) and calendar
8.6.2 Register Minutes
8.6.3 Register Hours
[1] Hour mode is set by bit 12_24 in register Control_1 (see Table 7).
8.6.4 Register Days
[1] If the year counter contains a value, which is exactly divisible by 4 (including the year 00), the PCF8523
compensates for leap years by adding a 29
th
day to February.
Fig 12. OS flag
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Table 14. Minutes - minutes register (address 04h) 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 15. Hours - hours register (address 05h) bit description
Bit Symbol Value Place value Description
7 to 6 - - - unused
12 hour mode
[1]
5 AMPM 0 - indicates AM
1 - indicates PM
4 HOURS 0 to 1 ten’s place actual hours in 12 hour mode
coded in BCD format
3 to 0 0 to 9 unit place
24 hour mode
[1]
5 to 4 HOURS 0 to 2 ten’s place actual hours in 24 hour mode
coded in BCD format
3to0 0to9 unit place
Table 16. Days - days register (address 06h) 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