Exiting A Low Energy Mode - Silicon Laboratories EFR32xG14 Wireless Gecko Reference Manual

10.3.3 Exiting a Low Energy Mode

A system in EM2 Deep Sleep and EM3 Stop can be woken up to EM0 Active through regular interrupt requests from active peripherals.
Since state and RAM retention is available, the EFR32 is fully restored and can continue to operate as before it went into the Low Ener-
gy Mode.
Wake-Up from EM4 Hibernate or EM4 Shutoff is performed through reset. Wake-Up from a specific module must be enabled in that
module's EM4WUEN register.
Enabled interrupts that can cause wake-up from a low energy mode are shown in
Modes on page 221. The wake-up triggers always return the EFR32 to EM0 Active/EM1 Sleep. Additionally, any reset source will re-
turn to EM0 Active. VMON-based EM4 Hibernate wake-ups also set the corresponding rise or fall interrupt flag. These flags serve as
the wake-up source for EM4 Hibernate and must be cleared by software on EM4 Hibernate exit. Not doing so will result in an immediate
wake-up after next EM4 Hibernate entry.
Peripheral
LEUART (Low Energy UART)
LETIMER
WDOG
LESENSE
LFXO
LFRCO
2
I C
ACMP
ADC
VDAC
PCNT
RTCC
VMON
EMU Temperature Sensor
CRYOTIMER
Pin Interrupts
RFSENSE
Reset Pin
Power
1 When using an external clock
2 Corresponding bit in the module's EM4WUEN must be set.
3 Only available on a subset of the pins. Refer to the data sheet for details.
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Table 10.3. EMU Wake-Up Triggers from Low Energy Modes
Wake-Up Trigger
Receive / transmit
Any enabled interrupt
Any enabled interrupt
Any enabled interrupt
Ready Interrupt
Ready Interrupt
Receive address recognition
Any enabled edge interrupt
SINGLE / SCAN FIFO events, window
comparator, and VREF overvoltage
Any enabled interrupt except
EM23ERRIF
Any enabled interrupt
Any enabled interrupt
Rising or falling edge on any moni-
tored power
Measured temperature outside the de-
fined limits
Timeout
Transition
RF signal detected
Assertion
Cycle Off/On
EMU - Energy Management Unit
Table 10.3 EMU Wake-Up Triggers from Low Energy
EM2 Deep EM3 Stop EM4 Hiber-
Sleep nate
Yes - -
Yes - -
Yes Yes -
Yes - -
Yes - -
Yes - -
Yes Yes -
Yes Yes -
Yes Yes -
Yes Yes -
Yes 1 -
Yes
Yes Yes
Yes
Yes Yes
Yes
Yes Yes
Yes
Yes Yes
Yes
Yes Yes
Yes
Yes Yes
Yes
Yes Yes Yes
Yes Yes Yes
Reference Manual
EM4 Shut-
off
-
-
-
-
-
-
-
-
-
-
-
2
2 -
2 -
2 2
Yes
23 23
Yes
2 2
Yes
Yes
Yes
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