ST STM32F301 6 Series Reference Manual page 631

RM0366
24.6.6 RTC wake-up timer register (RTC_WUTR)
This register can be written only when WUTWF is set to 1 in RTC_ISR.
This register is write protected. The write access procedure is described in
write protection on page
Address offset: 0x14
Backup domain reset value: 0x0000 FFFF
System reset: not affected
31 30 29
Res. Res. Res. Res.
15 14 13
rw rw rw
Bits 31:16 Reserved, must be kept at reset value.
Bits 15:0 WUT[15:0]: Wake-up auto-reload value bits
611.
28 27 26 25
Res. Res. Res.
12 11 10 9
rw rw rw rw
When the wake-up timer is enabled (WUTE set to 1), the WUTF flag is set every (WUT[15:0]
+ 1) ck_wut cycles. The ck_wut period is selected through WUCKSEL[2:0] bits of the
RTC_CR register
When WUCKSEL[2] = 1, the wake-up timer becomes 17-bits and WUCKSEL[1] effectively
becomes WUT[16] the most-significant bit to be reloaded into the timer.
The first assertion of WUTF occurs (WUT+1) ck_wut cycles after WUTE is set. Setting
WUT[15:0] to 0x0000 with WUCKSEL[2:0] =011 (RTCCLK/2) is forbidden.
24 23 22
Res. Res. Res.
8 7 6
WUT[15:0]
rw rw rw
RM0366 Rev 5
Real-time clock (RTC)
RTC register
21 20 19 18
Res. Res. Res. Res.
5 4 3 2
rw rw rw rw
17 16
Res. Res.
1 0
rw rw
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