RM0376 Datasheet, PDF (147/968 Pages) STMicroelectronics – This reference manual targets application developers

RM0376
Power control (PWR)
The devices feature five low-power modes:
• Low-power run mode: regulator in low-power mode, limited clock frequency, limited
number of peripherals running (refer to Section 6.3.4)
• Sleep mode: Cortex^®-M0+ core stopped, peripherals kept running (refer to
Section 6.3.7)
• Low-power sleep mode: Cortex^®-M0+core stopped, limited clock frequency, limited
number of peripherals running, regulator in low-power mode, Flash stopped ((refer to
Section 6.3.8))
• Stop mode (all clocks are stopped, regulator running, regulator in low-power mode
(refer to Section 6.3.9)
• Standby mode: V_CORE domain powered off ((refer to Section 6.3.10))
In addition, the power consumption in Run mode can be reduced by one of the following
means:
• Slowing down the system clocks
• Gating the clocks to the APBx and AHBx peripherals when they are unused.
Table 29. Summary of low-power modes
Mode name
Entry
Wakeup
Effect on V_CORE
domain clocks
Effect on
V_DD
domain
clocks
Voltage regulator
Low-power
run
LPSDSR and
LPRUN bits +
Clock setting
The regulator is forced in
Main regulator (1.8 V)
None
None
In low-power
mode
Sleep
(Sleep now or
Sleep-on-exit)
WFI or Return
from ISR
WFE
Any interrupt
Wakeup event
CPU CLK OFF
no effect on other
clocks or analog
clock sources
None
ON
Low-power
sleep (Sleep
now or Sleep-
on-exit)
LPSDSR bits +
WFI or Return
from ISR
LPSDSR bits +
WFE
Any interrupt
Wakeup event
CPU CLK OFF
no effect on other
clocks or analog
clock sources,
Flash CLK OFF
None
In low-power
mode
Stop
Standby
PDDS, LPSDSR
bits +
SLEEPDEEP bit +
WFI, Return from
ISR or WFE
Any EXTI line (configured
in the EXTI registers,
internal and external lines)
PDDS bit +
SLEEPDEEP bit +
WFI, Return from
ISR or WFE
WKUP pin rising edge,
RTC alarm (Alarm A or
Alarm B), RTC Wakeup
event, RTC tamper event,
RTC timestamp event,
external reset in NRST
pin, IWDG reset
All V_CORE
domain clocks
OFF
HSI16
and HSE
and MSI
oscillators
OFF
ON, in low-power
mode (depending
on PWR_CR)
OFF
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