ST STM32F301 6 Series Reference Manual page 78

Power control (PWR)
When the RTC domain is supplied by V
functions are available:
•
PC13, PC14, and PC15 can be used as GPIO pins
•
PC13, PC14, and PC15 can be configured by RTC or LSE (refer to
functional description on page
Note: Because the switch only sinks a limited amount of current (3 mA), the use of GPIOs PC13 to
PC15 in output mode is restricted: the speed has to be limited to 2 MHz with a maximum
load of 30 pF and these I/Os must not be used as a current source (for example, to drive an
an LED).
When the RTC domain is supplied by V
is not present), the following functions are available:
•
PC13, PC14, and PC15 can be controlled only by RTC or LSE (refer to
RTC functional description on page
6.1.3 Voltage regulator
The voltage regulator is always enabled after Reset. It works in three different modes
depending on the application modes.
•
In Run mode, the regulator supplies full power to the 1.8 V domain (core, memories,
and digital peripherals).
•
In Stop mode the regulator supplies low-power to the 1.8 V domain, preserving the
contents of registers and SRAM.
•
In Standby Mode, the regulator is powered off. The contents of the registers and SRAM
are lost except for the Standby circuitry and the RTC Domain.
In the STM32F318x8 devices, the voltage regulator is bypassed and the microcontroller
must be powered from a nominal V
6.2 Power supply supervisor
6.2.1 Power on reset (POR)/power down reset (PDR)
The device has an integrated power-on reset (POR) and power-down reset (PDR) circuits,
which are always active and ensure proper operation above a threshold of 2 V.
The device remains in Reset mode when the monitored supply voltage is below a specified
threshold, V
•
The POR monitors only the V
arrive first and be greater than or equal to V
•
The PDR monitors both the V
is designed with V
can be disabled (by programming a dedicated VDDA_MONITOR option bit) to reduce
the power consumption.
For more details on the power on /power down reset threshold, refer to the electrical
characteristics section in the datasheet.
78/874
, without the need for an external reset circuit.
POR/PDR
higher than or equal to V
DDA
RM0366 Rev 5
(analog switch connected to V
DD
606)
(analog switch connected to V
BAT
606)
= 1.8 V ± 8% voltage.
DD
supply voltage. During the startup phase V
DD
.
DD
and V supply voltages. However, if the application
DD DDA
, the V
DD
), the following
DD
Section 24.3: RTC
because V
BAT
Section 24.3:
DDA
power supply supervisor
DDA
RM0366
DD
must