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NUC126
Aug. 08, 2018
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Rev 1.03
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(RTC_INTSTS[0]) will be set to 1 and the RTC alarm interrupt signal assert if the alarm interrupt
enable ALMIEN (RTC_INTEN[0]) is enabled.
The RTC controller also provides alarm mask function which controlled in RTC_TAMSK and
RTC_CAMSK registers. User can mask the specified digit and generate periodic interrupt without
changing the alarm match condition in RTC_TALM and RTC_CALM registers in each alarm interrupt
service routine.
6.14.5.9 Daylight Saving Time
The RTC controller also provides RTC_DSTCTL register to store the control settings of daylight saving
time application. User can read RTC_DSTCTL value to check current RTC date/time counter runs in
daylight saving time mode or normal mode.
6.14.5.10 Application Note
1. All data in RTC_TIME, RTC_CAL, RTC_TALM and RTC_CALM registers are expressed in
BCD format.
2. User has to make sure that the loaded values are reasonable in specified fields. For example,
load RTC_CAL as 201a (year), 13 (month), 00 (day), or RTC_CAL does not match with
RTC_WEEKDAY, etc.
3. Registers value after core power and RTC battery power, both first powered on are shown in
Register
Default Value
RTC_INIT
0
RTC_RWEN
0
RTC_FREQADJ
0x00200000
RTC_CAL
15/8/8 (year/month/day)
RTC_TIME
00:00:00 (hour:minute:second)
RTC_CALM
00/00/00 (year/month/day)
RTC_TALM
00:00:00 (hour:minute:second)
RTC_CLKFMT
1 (24-hour mode)
RTC_WEEKDAY
6 (Saturday)
RTC_INTEN
0
RTC_INTSTS
0
RTC_LEAPYEAR
0
RTC_TICK
0
RTC_DSTCTL
0
Table 6.14-3 Registers Default Value After Powered On
4. In RTC_CAL and RTC_CALM registers
, only 2 BCD digits are used to express “year”. The 2
BCD digits of xy means 20xy, rather than 19xy or 21xy.
5. Example of 12-Hour Time Setting
If current RTC time is PM12:59:30 in 12-hour time scale mode, the RTC_TIME setting should
be:
RTC_TIME[21:16]: 0x32 (0x12+0x20)