
DocID024597 Rev 5
RM0351
Real-time clock (RTC)
1230
38.6.3 RTC
control
register (RTC_CR)
Address offset: 0x08
Backup domain reset value: 0x0000 0000
System reset: not affected
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Res.
Res.
Res.
Res.
Res.
Res.
Res.
ITSE
COE
OSEL[1:0]
POL
COSEL
BKP
SUB1H ADD1H
rw
rw
rw
rw
rw
rw
rw
w
w
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
TSIE
WUTIE ALRBIE ALRAIE
TSE
WUTE ALRBE ALRAE
Res.
FMT
BYPS
HAD
REFCKON TSEDGE
WUCKSEL[2:0]
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
Bits 31:25 Reserved, must be kept at reset value.
Bit 24
ITSE
: timestamp on internal event enable
0: internal event timestamp disabled
1: internal event timestamp enabled
Bit 23
COE
: Calibration output enable
This bit enables the RTC_CALIB output
0: Calibration output disabled
1: Calibration output enabled
Bits 22:21
OSEL[1:0]
: Output selection
These bits are used to select the flag to be routed to RTC_ALARM output
00: Output disabled
01: Alarm A output enabled
10: Alarm B output enabled
11: Wakeup output enabled
Bit 20
POL
: Output polarity
This bit is used to configure the polarity of RTC_ALARM output
0: The pin is high when ALRAF/ALRBF/WUTF is asserted (depending on OSEL[1:0])
1: The pin is low when ALRAF/ALRBF/WUTF is asserted (depending on OSEL[1:0]).
Bit 19
COSEL
: Calibration output selection
When COE=1, this bit selects which signal is output on RTC_CALIB.
0: Calibration output is 512 Hz (with default prescaler setting)
1: Calibration output is 1 Hz (with default prescaler setting)
These frequencies are valid for RTCCLK at 32.768 kHz and prescalers at their default values
(PREDIV_A=127 and PREDIV_S=255). Refer to
Section 38.3.15: Calibration clock output
Bit 18
BKP
: Backup
This bit can be written by the user to memorize whether the daylight saving time change has
been performed or not.