
RM0453 Rev 2
225/1454
RM0453
Power control (PWR)
275
Figure 20. Brownout reset waveform
1. The reset temporization t
RSTTEMPO
is present only for the BOR lowest threshold (V
BOR0
).
6.2.2
Programmable voltage detector (PVD)
The PVD can be used to monitor V
DD
by comparing it to a threshold selected by the
PLS[2:0] bits in the
PWR control register 2 (PWR_CR2)
.
PVD can also be used to monitor a voltage level on the PVD_IN pin. In this case the voltage
level on PVD_IN is compared to the internal VREFINT level.
PVD is enabled by setting the PVDE bit.
A PVDO flag is available in the
Power status register 2 (PWR_SR2)
to indicate if V
DD
or the
voltage level on PVD_IN is higher or lower than the PVD threshold. This event is internally
connected to the EXTI line 16 and can generate an interrupt if enabled through the EXTI
registers.
The PVD output interrupt can be generated when V
DD
or voltage level on PVD_IN drops
below the PVD threshold and/or when V
DD
or voltage level on PVD_IN rises above the PVD
threshold depending on EXTI line 16 rising/falling edge configuration. As an example, the
service routine can perform emergency shutdown tasks.
The PVD can be configured to monitor the V
DD
supply level needed for the sub-GHz radio
operation. For this, the PVD must select its lowest level and PVD and the wakeup must be
enabled in EWPVD. Only a voltage drop below the PVD level generates a wakeup event.
BOR0 level cannot be disabled. The other BOR levels can be enabled by user option. When
enabled, BOR is active in all power modes except in Shutdown.
MS44480V1
V
DD
t
nPwr
hysteresis
BORH
rise
BORH
fall