
Power control (PWR)
RM0453
244/1454
RM0453 Rev 2
The table below details how to exit the LPSleep mode.
6.5.7 Stop
0
mode
The Stop 0 mode is based on the CPU Deep-Sleep mode combined with the peripheral
clock gating. The voltage regulator is configured in main regulator mode. In Stop 0 mode, all
clocks in the V
CORE
domain are stopped.PLL, MSI, HSI16 and HSE32 oscillators are
disabled. Some peripherals with the wakeup capability (I2Cx (x = 1, 3), USARTx (x = 1, 2)
and LPUART1) can switch on HSI16 to receive a frame, and switch off HSI16 after receiving
the frame if it is not a wakeup frame. In this case, the HSI16 clock is propagated only to the
peripheral requesting it.
SRAM1, SRAM2 and register contents are preserved.
The BOR is always available in Stop 0 mode. The consumption is increased when
thresholds higher than V
BOR0
are used.
The BOR and PDR can be activated to sample periodically the supply voltage. This option
enabled by setting the ULPEN bit of the PWR_CR3 register allows decreasing the current
consumption in this mode, but any drop of the voltage below the operating conditions
between two active periods of the supply detector results in a non-generation of PDR reset.
I/O states in Stop 0 mode
In the Stop 0 mode, all I/O pins keep the same state as in the Run mode.
Table 50. LPSleep
LPSleep mode
Description
Mode entry
LPSleep mode is entered from the LPRun mode.
WFI (wait for interrupt) or WFE (wait for event) while:
– SLEEPDEEP = 0
– No interrupt (for WFI) or event (for WFE) is pending
Refer to the Cortex system control register.
LPSleep mode is entered from the LPRun mode.
On return from ISR while:
– SLEEPDEEP = 0 and
– SLEEPONEXIT = 1
– No interrupt is pending
Refer to the Cortex system control register.
Mode exit
If WFI or return from ISR was used for entry
Interrupt: refer to
, and
If WFE was used for entry and SEVONPEND = 0:
If WFE was used for entry and SEVONPEND = 1:
Interrupt even when disabled in NVIC: refer to
,
and
After exiting the LPSleep mode, the MCU is in LPRun mode.
Wakeup latency
None