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STM32F3xx microcontroller low-power overview

24

The wakeup time from low-power modes contributes a lot in the power optimization and the

application flexibility. A trade-off has to be done between the low-power modes

consumption and the correspondent wakeup time.

Table 4 gives examples of wake up from low-power mode timing in STM32F3xx

microcontrollers.

Table 3. Wake up from low-power mode sources

Mode name

Entry

Wakeup sources

Wakeup pins

Sleep

WFI

Any interrupt

All I/O

WFE

Wakeup event

Comparator can wake up from Sleep (up to

7 EXTI lines in STM32F303xB/C/D/E,

STM32F358xx and STM32F398xx)

Stop

PDDS, LPDS bits +

SLEEPDEEP bit +

WFI or WFE

Any EXTI line (configured in the EXTI

registers, internal and external lines)

•

U(S)ART

•

Comparator

•

I2C

•

1. For EXTI lines connected internally to these peripherals refer to EXTI lines mapping section in the

reference manuals.

2. CEC Available only in STM32F37xxx.

Standby

PDDS bit +

SLEEPDEEP bit +

WFI or WFE

WKUPx pins (x = 1, 2, 3), RTC alarm, RTC

tamper event, external reset in NRST pin,

IWDG reset

PA0

PC13

3. PE6 works as wakeup pin only in STM32F303/302xB/C/D/E.

Table 4. Wake up from low-power mode timing examples

Parameter

Condition

Unit

STM32F302x6/8

STM32F303xB/C STM32F373xx

Wake up from Sleep

6

CPU clock

cycles

Wake up from Stop

Regulator in Run

mode

3.8

3.6

3.6

µs

Regulator in low-

power modes

5.7

5.4

5.4

Wake up from

Standby

LSI and IWDG OFF

53.1

51.7

42.7