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Do all WKUP pins work for Standby mode for STM32F072 ?

mvonahnen
Associate III
Posted on May 29, 2018 at 23:32

The documentation for the STM32 F072 is inconsistent:

Section 3.5.4:

'

•

Standby mode

The Standby mode is used to achieve the lowest power consumption. The internal

voltage regulator is switched off so that the entire 1.8 V domain is powered off. The

PLL, the HSI RC and the HSE crystal oscillators are also switched off. After entering

Standby mode, SRAM and register contents are lost except for registers in the RTC

domain and Standby circuitry.

The device exits Standby mode when an external reset (NRST pin), an IWDG reset, a

rising edge on the WKUP pins, or an RTC event occurs.'

Section 6.3.6:

'6.3.6 Wakeup time from low-power mode

The wakeup times given in

Table 36

are the latency between the event and the execution of

the first user instruction. The device goes in low-power mode after the WFE (Wait For

Event) instruction, in the case of a WFI (Wait For Interruption) instruction, 16 CPU cycles

must be added to the following timings due to the interrupt latency in the Cortex M0

architecture.

The SYSCLK clock source setting is kept unchanged after wakeup from Sleep mode.

During wakeup from Stop or Standby mode, SYSCLK takes the default setting: HSI 8 MHz.

The wakeup source from Sleep and Stop mode is an EXTI line configured in event mode.

The wakeup source from Standby mode is the WKUP1 pin (PA0).'

My assumption is that the since the part has multiple WKUP pins that any of them can wake up the part from Standby and that Section 6.3.6 is just a carryover from an older part with one WKUP pin, but I would like to know definitely that I can use all of the WKUP pins to come out of standby

1 REPLY 1
Imen.D
ST Employee
Posted on May 30, 2018 at 11:37

Hello

Von_Ahnen.Michael

,

Measurement in the datasheet were down with this precise WKUP1

but ALL of the

WKUP pins w

ork for Standby mode.

WKUP pins are design precisely to wake up from standby.

With Regards,

Imen.

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Thanks
Imen