Low Power modes configuration functions.
More...
Low Power modes configuration functions.
==============================================================================
##### Low Power modes configuration functions #####
==============================================================================
[..] The devices feature three low-power modes:
(+) Sleep mode: Cortex-M4 core stopped, peripherals kept running.
(+) Stop mode: all clocks are stopped, regulator running, regulator in low power mode
(+) Standby mode: VCORE domain powered off
*** Sleep mode ***
==================
[..]
(+) Entry:
(++) The Sleep mode is entered by executing the WFE() or WFI() instructions.
(+) Exit:
(++) Any peripheral interrupt acknowledged by the nested vectored interrupt
controller (NVIC) can wake up the device from Sleep mode.
*** Stop mode ***
=================
[..] In Stop mode, all clocks in the VCORE domain are stopped, the PLL, the HSI,
the HSI14 and the HSE RC oscillators are disabled. Internal SRAM and register
contents are preserved.
The voltage regulator can be configured either in normal or low-power mode.
(+) Entry:
(++) The Stop mode is entered using the PWR_EnterSTOPMode(PWR_Regulator_LowPower,)
function with regulator in LowPower or with Regulator ON.
(+) Exit:
(++) Any EXTI Line (Internal or External) configured in Interrupt/Event mode
or any internal IPs (I2C, UASRT or CEC) wakeup event.
*** Standby mode ***
====================
[..] The Standby mode allows to achieve the lowest power consumption. It is based
on the Cortex-M4 deepsleep mode, with the voltage regulator disabled.
The VCORE domain is consequently powered off. The PLL, the HSI, the HSI14
oscillator and the HSE oscillator are also switched off. SRAM and register
contents are lost except for the Backup domain (RTC registers, RTC backup
registers and Standby circuitry).
[..] The voltage regulator is OFF.
(+) Entry:
(++) The Standby mode is entered using the PWR_EnterSTANDBYMode() function.
(+) Exit:
(++) WKUP pin rising edge, RTC alarm (Alarm A and Alarm B), RTC wakeup,
tamper event, time-stamp event, external reset in NRST pin, IWDG reset.
*** Auto-wakeup (AWU) from low-power mode ***
=============================================
[..] The MCU can be woken up from low-power mode by an RTC Alarm event, a tamper
event, a time-stamp event, or a comparator event, without depending on an
external interrupt (Auto-wakeup mode).
(+) RTC auto-wakeup (AWU) from the Stop mode
(++) To wake up from the Stop mode with an RTC alarm event, it is necessary to:
(+++) Configure the EXTI Line 17 to be sensitive to rising edges (Interrupt
or Event modes) using the EXTI_Init() function.
(+++) Enable the RTC Alarm Interrupt using the RTC_ITConfig() function
(+++) Configure the RTC to generate the RTC alarm using the RTC_SetAlarm()
and RTC_AlarmCmd() functions.
(++) To wake up from the Stop mode with an RTC Tamper or time stamp event, it
is necessary to:
(+++) Configure the EXTI Line 19 to be sensitive to rising edges (Interrupt
or Event modes) using the EXTI_Init() function.
(+++) Enable the RTC Tamper or time stamp Interrupt using the RTC_ITConfig()
function.
(+++) Configure the RTC to detect the tamper or time stamp event using the
RTC_TimeStampConfig(), RTC_TamperTriggerConfig() and RTC_TamperCmd()
functions.
(+) RTC auto-wakeup (AWU) from the Standby mode
(++) To wake up from the Standby mode with an RTC alarm event, it is necessary to:
(+++) Enable the RTC Alarm Interrupt using the RTC_ITConfig() function.
(+++) Configure the RTC to generate the RTC alarm using the RTC_SetAlarm()
and RTC_AlarmCmd() functions.
(++) To wake up from the Standby mode with an RTC Tamper or time stamp event, it
is necessary to:
(+++) Enable the RTC Tamper or time stamp Interrupt using the RTC_ITConfig()
function.
(+++) Configure the RTC to detect the tamper or time stamp event using the
RTC_TimeStampConfig(), RTC_TamperTriggerConfig() and RTC_TamperCmd()
functions.
(+) Comparator auto-wakeup (AWU) from the Stop mode
(++) To wake up from the Stop mode with an comparator 1 or comparator 2 wakeup
event, it is necessary to:
(+++) Configure the EXTI Line 21 for comparator 1 or EXTI Line 22 for comparator 2
to be sensitive to to the selected edges (falling, rising or falling
and rising) (Interrupt or Event modes) using the EXTI_Init() function.
(+++) Configure the comparator to generate the event.
| void PWR_EnterSleepMode |
( |
uint8_t |
PWR_SLEEPEntry | ) |
|
Enters Sleep mode.
- Note
- In Sleep mode, all I/O pins keep the same state as in Run mode.
- Parameters
-
| PWR_SLEEPEntry,: | specifies if SLEEP mode in entered with WFI or WFE instruction. This parameter can be one of the following values:
- PWR_SLEEPEntry_WFI: enter SLEEP mode with WFI instruction
- PWR_SLEEPEntry_WFE: enter SLEEP mode with WFE instruction
|
- Return values
-
| void PWR_EnterSTANDBYMode |
( |
void |
| ) |
|
Enters STANDBY mode.
- Note
- In Standby mode, all I/O pins are high impedance except for:
- Reset pad (still available)
- RTC_AF1 pin (PC13) if configured for Wakeup pin 2 (WKUP2), tamper, time-stamp, RTC Alarm out, or RTC clock calibration out.
- WKUP pin 1 (PA0) and WKUP pin 3 (PE6), if enabled.
- Parameters
-
- Return values
-
| void PWR_EnterSTOPMode |
( |
uint32_t |
PWR_Regulator, |
|
|
uint8_t |
PWR_STOPEntry |
|
) |
| |
Enters STOP mode.
- Note
- In Stop mode, all I/O pins keep the same state as in Run mode.
-
When exiting Stop mode by issuing an interrupt or a wakeup event, the HSI RC oscillator is selected as system clock.
-
When the voltage regulator operates in low power mode, an additional startup delay is incurred when waking up from Stop mode. By keeping the internal regulator ON during Stop mode, the consumption is higher although the startup time is reduced.
- Parameters
-
| PWR_Regulator,: | specifies the regulator state in STOP mode. This parameter can be one of the following values:
- PWR_Regulator_ON: STOP mode with regulator ON
- PWR_Regulator_LowPower: STOP mode with regulator in low power mode
|
| PWR_STOPEntry,: | specifies if STOP mode in entered with WFI or WFE instruction. This parameter can be one of the following values:
- PWR_STOPEntry_WFI: enter STOP mode with WFI instruction
- PWR_STOPEntry_WFE: enter STOP mode with WFE instruction
|
- Return values
-
1.8.3.1