STMicroelectronics STM32F405, Reference Manual

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RM0090 Real-time clock (RTC)
828
26.6.5 RTC prescaler register (RTC_PRER)
Address offset: 0x10
Backup domain reset value: 0x007F 00FF
System reset: not affected
Note: This register must be written in initialization mode only. The initialization must be performed
in two separate write accesses. Refer to
Calendar initialization and configuration on
page 794
This register is write protected. The write access procedure is described in RTC register
write protection on page 794 .
26.6.6 RTC wakeup timer register (RTC_WUTR)
Address offset: 0x14
Backup domain reset value: 0x0000 FFFF
System reset: not affected
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
Reserved
PREDIV_A[6:0]
rw rw rw rw rw rw rw
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Res.
PREDIV_S[14:0]
rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw
Bits 31:24 Reserved
Bit 23 Reserved, must be kept at reset value.
Bits 22:16 PREDIV_A[6:0] : Asynchronous prescaler factor
This is the asynchronous division factor:
ck_apre frequency = RTCCLK frequency/(P1)
Bit 15 Reserved, must be kept at reset value.
Bits 14:0 PREDIV_S[14:0] : Synchronous prescaler factor
This is the synchronous division factor:
ck_spre frequency = ck_apre frequency/(P1)
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
Reserved
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
WUT[15:0]
rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw