Energy Modes - Silicon Laboratories EFR32xG14 Wireless Gecko Reference Manual

10.3.1 Energy Modes

EFR32 features six main energy modes, referred to as Energy Mode 0 (EM0 Active) through Energy Mode 4 (EM4 Shutoff). The Cor-
tex-M4 is only available for program execution in EM0 Active. In EM0 Active/EM1 Sleep any peripheral function can be enabled. EM2
Deep Sleep through EM4 Shutoff, also referred to as low energy modes, provide a significantly reduced energy consumption while still
allowing a rich set of peripheral functionality. The following
ent energy modes.
Current Mode
EM0 Active
EM1 Sleep
EM2 Deep Sleep
EM3 Stop
EM4 Hibernate
EM4 Shutoff
1 Peripheral wake-up from EM2/3 to EM1 and then automatically back to EM2/3 when done.
The LESENSE, ADC, RAC, and LEUART have the ability to temporarily wake up the part from either EM2 Deep Sleep or EM3 Stop to
EM1 Sleep in order to transfer data. Once completed, the part is automatically placed back into the EM2 Deep Sleep or EM3 Stop
mode.
The Core can always request to go to EM1 Sleep with the WFI or WFE command during EM0 Active. The core will be prevented from
entering EM2 Deep Sleep or EM3 Stop if the RAC is transferring data or if Flash is programming or erasing.
An overview of supported energy modes and available functionality is shown in
For each energy mode, the system will typically default to its lowest power configuration, with non-essential clocks and peripherals disa-
bled. Functionality may be then selectively enabled by software.
Wake-up time to EM0 Active/EM1 Sleep
Core Active
Debug
Digital logic and system RAM retained
Flash Memory Access
LDMA (Linked DMA Controller)
RAC (Radio Controller)
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Table 10.1 table on page 215
Table 10.1. Energy Mode Transitions
EM Transition Action
Enter EM0 Ac- Enter EM1
tive Sleep
Sleep (WFI,
WFE)
IRQ
IRQ Peripheral
wake up req
IRQ Peripheral
wake up req
Wake Up
Wake Up
Table 10.2. EMU Energy Mode Overview
EM0
Active/EM1
Sleep
-
Yes, in EM0
only
Available
Yes
Available
Available
Available
shows the possible transitions between differ-
Enter EM2 EnterEM3
Deep Sleep Stop
Deep Sleep Deep Sleep
(WFI, WFE) (WFI, WFE)
Peripheral Peripheral
1
wake up done wake up done
1
1
Table 10.2 EMU Energy Mode Overview on page
EM2 Deep EM3 Stop
Sleep
1 1
3 µs 3 µs
- -
2
See Note See Note
Yes Yes
- -
3
Available Available
4 -
Available
Reference Manual
EMU - Energy Management Unit
EnterEM4 Hi- Enter EM4
bernate Shutoff
EM4 Entry EM4 Entry
1
EM4 Hiber- EM4 Shutoff
nate
1
90 µs 90 µs
- -
2 - -
- -
- -
3 - -
- -
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