ST STM32L4+ Series Reference Manual page 1594

Real-time clock (RTC) applied to STM32L4P5xx and STM32L4Q5xx only
The triggers outputs can be used as triggers for other peripherals.
47.3.3 GPIOs controlled by the RTC and TAMP
The GPIOs included in the Battery Backup Domain (V
peripherals providing functions on these I/Os, whatever the GPIO configuration.
Both RTC and TAMP peripherals provide functions on these I/Os (refer to
Tamper and backup registers (TAMP) applied to STM32L4P5xx and STM32L4Q5xx
RTC_OUT1, RTC_TS and TAMP_IN1 are mapped on the same pin (PC13). The RTC and
TAMP functions mapped on PC13 are available in all low-power modes and in V
The output mechanism follows the priority order shown in
PC13 Pin function
TAMPALRM output
Push-Pull
TAMPALRM
output
Open-Drain
CALIB output PP
1594/2301
Table 321. PC13 configuration
01 or
10 or
11
00
01 or
10 or
11
01 or
10 or
11
No pull 00
01 or
10 or
11
01 or
(2)
10 or
11
Internal
00
pull-up
01 or
10 or
11
00
RM0432 Rev 6
) are directly controlled by the
BAT
Table
0
Don't Don't
1
care care
1
0
Don't Don't
1
care care
1
0
Don't Don't
1
care care
1
0 1 0
Section 48:
BAT
321.
(1)
Don't
0 0
care
Don't
1 0
care
Don't
1 1
care
Don't Don't Don't
care care care
RM0432
only).
mode.
Don't
care
Don't
care
Don't
care
Don't
care