PCA21125 Datasheet, PDF (8/42 Pages) NXP Semiconductors – SPI-bus Real-Time Clock and calendar

NXP Semiconductors
PCA21125
SPI-bus Real-Time Clock and calendar
8.3.3 Register Hours
Table 10. Hours - hours register (address 04h) bit description
Bit
Symbol
Value Description
7 to 6 -
0
unused
12 hour mode^[1]
5
AMPM
0
indicates AM
1
indicates PM
4 to 0 HOURS
0 to 1 ten’s place
3 to 0
0 to 9 unit place
24 hour mode^[1]
5 to 4 HOURS
0 to 2 ten’s place
3 to 0
0 to 9 unit place
[1] Hour mode is set by bit 12_24 in register Control_1 (see Table 5).
8.3.4 Register Days
Table 11. Days - days register (address 05h) bit description
Bit Symbol Value Place value Description
7 to 6 -
-
-
unused
5 to 4 DAYS^[1] 0 to 3 ten’s place actual day coded in BCD format
3 to 0
0 to 9 unit place
[1] The PCA21125 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.
8.3.5 Register Weekdays
Table 12. 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 13
Table 13. 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
Saturday
1
1
0
[1] Definition may be re-assigned by the user.
PCA21125_1
Product data sheet
Rev. 01 — 16 November 2009
© NXP B.V. 2009. All rights reserved.
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