Rtc Functional Description; Rtc Block Diagram; Figure 227. Rtc Block Diagram - STMicroelectronics STM32F05 series Reference Manual

Real-time clock (RTC)
24.3

RTC functional description

24.3.1

RTC block diagram

Figure 227. RTC block diagram

RTC_TAMP2
RTC_TAMP1
RTC_TS
RTC_REFIN
LSE (32.768 Hz)
HSE/32
LSI
RTCCLK
RTC_CALR
Smooth
calibration
The RTC includes:
●
One alarm
●
Two tamper events
●
Five 32-bit backup registers
●
Alternate function outputs: RTC_OUT which selects one of the following two outputs:
–
–
●
Alternate function inputs:
–
–
–
–
536/742
Backup registers
and RTC tamper
control registers
ck_apre
RTC_PRER
(default 256 Hz)
Asynchronous
7-bit prescaler
(default = 128)
512 Hz
Alarm A
RTC_ALRMAR
RTC_ALRMASSR
RTC_CALIB: 512 Hz or 1Hz clock output (with an LSE frequency of 32.768 kHz).
This output is enabled by setting the COE[23] bit in the RTC_CR register.
RTC_ALARM: Alarm A. This output is selected by configuring the OSEL[1:0] bits
in the RTC_CR register.
RTC_TS : timestamp event
RTC_TAMP1: tamper1 event detection
RTC_TAMP2: tamper2 event detection
RTC_REFIN: 50 or 60 Hz reference clock input
Doc ID 018940 Rev 1
RTC_PRER
Synchronous
15-bit prescaler
(default = 256)
Shadow register
RTC_SSR
RTC_CALIB
1 Hz
RTC_ALARM
Time stamp
registers
ck_spre
(default 1 Hz)
Calendar
Shadow registers
RTC_TR,
RTC_DR
Output
control
=
RM0091
TAMPxF
TSF
RTC_OUT
ALRAF
MS19901V1