Stop 1 Mode; Table 24. Stop 0 Mode - ST STM32L4x6 Reference Manual

RM0351
(RCC_CFGR). The MSI oscillator is selected as system clock if the bit STOPWUCK is
cleared. The wakeup time is shorter when HSI16 is selected as wakeup system clock. The
MSI selection allows wakeup at higher frequency, up to 48 MHz.
When the voltage regulator operates in low-power mode, an additional startup delay is
incurred when waking up from Stop 0 mode with HSI16. By keeping the internal regulator
ON during Stop 0 mode, the consumption is higher although the startup time is reduced.
When exiting the Stop 0 mode, the MCU is either in Run mode (Range 1 or Range 2
depending on VOS bit in PWR_CR1) or in Low-power run mode if the bit LPR is set in the
PWR_CR1 register.
Stop 0 mode
Mode entry
Mode exit
Wakeup latency
5.3.7

Stop 1 mode

The Stop 1 mode is the same as Stop 0 mode except that the main regulator is OFF, and
only the low-power regulator is ON. Stop 1 mode can be entered from Run mode and from
Low-power run mode.

Table 24. Stop 0 mode

WFI (Wait for Interrupt) or WFE (Wait for Event) while:
– SLEEPDEEP bit is set in Cortex
– No interrupt (for WFI) or event (for WFE) is pending
– LPMS = "000" in PWR_CR1
On Return from ISR while:
– SLEEPDEEP bit is set in Cortex
– SLEEPONEXIT = 1
– No interrupt is pending
– LPMS = "000" in PWR_CR1
Note: To enter Stop 0 mode, all EXTI Line pending bits (in
register 1 (EXTI_PR1)), and the peripheral flags generating wakeup
interrupts must be cleared. Otherwise, the Stop 0 mode entry
procedure is ignored and program execution continues.
If WFI or Return from ISR was used for entry
Any EXTI Line configured in Interrupt mode (the corresponding EXTI
Interrupt vector must be enabled in the NVIC). The interrupt source can
be external interrupts or peripherals with wakeup capability. Refer to
Table 42: STM32L4x6 vector
If WFE was used for entry and SEVONPEND = 0:
Any EXTI Line configured in event mode. Refer to
Wakeup event management.
If WFE was used for entry and SEVONPEND = 1:
Any EXTI Line configured in Interrupt mode (even if the corresponding
EXTI Interrupt vector is disabled in the NVIC). The interrupt source can
be external interrupts or peripherals with wakeup capability. Refer
toTable 42: STM32L4x6 vector
Wakeup event: refer to
Longest wakeup time between: MSI or HSI16 wakeup time and Flash
wakeup time from Stop 0 mode.
DocID024597 Rev 3
Description
®
-M4 System Control register
®
-M4 System Control register
table.
table.
Section 12.3.2: Wakeup event management
Power control (PWR)
Pending
Section 12.3.2:
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