Detailed Description

Energy Management Unit (EMU) Peripheral API.

This module contains functions to control the EMU peripheral of Silicon Labs 32-bit MCUs and SoCs. The EMU handles the different low energy modes in Silicon Labs microcontrollers.

Data Structures
struct	EMU_EM23Init_TypeDef

Macros
#define	EMU_EM23INIT_DEFAULT

Enumerations
enum	EMU_BODMode_TypeDef { emuBODMode_Active, emuBODMode_Inactive }

enum	EMU_PowerConfig_TypeDef { emuPowerConfig_DcdcToDvdd }

Functions
void	EMU_DCDCConductionModeSet (EMU_DcdcConductionMode_TypeDef conductionMode, bool rcoDefaultSet)
	Set DCDC LN regulator conduction mode. More...

bool	EMU_DCDCInit (const EMU_DCDCInit_TypeDef *dcdcInit)
	Configure DCDC regulator. More...

void	EMU_DCDCLnRcoBandSet (EMU_DcdcLnRcoBand_TypeDef band)
	Set DCDC Low-noise RCO band. More...

void	EMU_DCDCModeSet (EMU_DcdcMode_TypeDef dcdcMode)
	Set DCDC regulator operating mode. More...

void	EMU_DCDCOptimizeSlice (uint32_t em0LoadCurrent_mA)
	Optimize DCDC slice count based on the estimated average load current in EM0. More...

bool	EMU_DCDCOutputVoltageSet (uint32_t mV, bool setLpVoltage, bool setLnVoltage)
	Set DCDC output voltage. More...

bool	EMU_DCDCPowerOff (void)
	Power off the DCDC regulator. More...

void	EMU_EM23Init (const EMU_EM23Init_TypeDef *em23Init)
	Update EMU module with Energy Mode 2 and 3 configuration. More...

__STATIC_INLINE void	EMU_EM2Block (void)
	Block entering EM2 or higher number energy modes.

__STATIC_INLINE void	EMU_EM2UnBlock (void)
	Unblock entering EM2 or higher number energy modes.

__STATIC_INLINE void	EMU_EnterEM1 (void)
	Enter energy mode 1 (EM1).

void	EMU_EnterEM2 (bool restore)
	Enter energy mode 2 (EM2). More...

void	EMU_EnterEM3 (bool restore)
	Enter energy mode 3 (EM3). More...

void	EMU_EnterEM4 (void)
	Enter energy mode 4 (EM4). More...

__STATIC_INLINE void	EMU_Lock (void)
	Lock the EMU in order to protect its registers against unintended modification. More...

void	EMU_MemPwrDown (uint32_t blocks)
	Power down memory block. More...

void	EMU_RamPowerDown (uint32_t start, uint32_t end)
	Power down RAM memory blocks. More...

void	EMU_Restore (void)
	Restore CMU HF clock select state, oscillator enable and voltage scaling (if available) after EMU_EnterEM2() or EMU_EnterEM3() are called with the restore parameter set to false. Calling this function is equivalent to calling EMU_EnterEM2() or EMU_EnterEM3() with the restore parameter set to true, but it allows the application to evaluate the wakeup reason before restoring state.

__STATIC_INLINE void	EMU_Unlock (void)
	Unlock the EMU so that writing to locked registers again is possible.

void	EMU_UpdateOscConfig (void)
	Update EMU module with CMU oscillator selection/enable status. More...

Macro Definition Documentation

#define EMU_EM23INIT_DEFAULT

Value:

{                                                                                                               \
  false,                                                /* Reduced voltage regulator drive strength in EM2/3 */ \
}

Default initialization of EM2 and 3 configuration

Definition at line 404 of file em_emu.h.

Enumeration Type Documentation

enum EMU_BODMode_TypeDef

BOD threshold setting selector, active or inactive mode

Enumerator
emuBODMode_Active	Configure BOD threshold for active mode
emuBODMode_Inactive	Configure BOD threshold for inactive mode

Definition at line 121 of file em_emu.h.

enum EMU_PowerConfig_TypeDef

Power configurations. DCDC-to-DVDD is currently the only supported mode.

Enumerator
emuPowerConfig_DcdcToDvdd	DCDC is connected to DVDD

Definition at line 155 of file em_emu.h.

Function Documentation

void EMU_DCDCConductionModeSet	(	EMU_DcdcConductionMode_TypeDef	conductionMode,
		bool	rcoDefaultSet
	)

Set DCDC LN regulator conduction mode.

Parameters

[in]	conductionMode	DCDC LN conduction mode.
[in]	rcoDefaultSet	The default DCDC RCO band for the conductionMode will be used if true. Otherwise the current RCO configuration is used.

Definition at line 1813 of file em_emu.c.

References EMU, EMU_DCDCLnRcoBandSet(), EMU_DCDCModeSet(), and EMU_DCDCOptimizeSlice().

bool EMU_DCDCInit ( const EMU_DCDCInit_TypeDef * dcdcInit )

Configure DCDC regulator.

Note: If the power circuit is configured for NODCDC as described in Section 11.3.4.3 of the Reference Manual, do not call this function. Instead call EMU_DCDCPowerOff().

Parameters

[in] dcdcInit DCDC initialization structure

Returns: True if initialization parameters are valid

Definition at line 1869 of file em_emu.c.

References BUS_RegBitWrite(), EMU, EMU_DCDCModeSet(), EMU_DCDCOptimizeSlice(), and EMU_DCDCOutputVoltageSet().

void EMU_DCDCLnRcoBandSet ( EMU_DcdcLnRcoBand_TypeDef band )

Set DCDC Low-noise RCO band.

Parameters

[in] band RCO band to set.

Definition at line 2260 of file em_emu.c.

References BUS_RegBitRead(), EMU, and EMU_DCDCOptimizeSlice().

Referenced by EMU_DCDCConductionModeSet().

void EMU_DCDCModeSet ( EMU_DcdcMode_TypeDef dcdcMode )

Set DCDC regulator operating mode.

Parameters

[in] dcdcMode DCDC mode

Definition at line 1760 of file em_emu.c.

References BUS_RegBitWrite(), and EMU.

Referenced by EMU_DCDCConductionModeSet(), EMU_DCDCInit(), and EMU_EnterEM4().

void EMU_DCDCOptimizeSlice ( uint32_t em0LoadCurrent_mA )

Optimize DCDC slice count based on the estimated average load current in EM0.

Parameters

[in] em0LoadCurrent_mA Estimated average EM0 load current in mA.

Definition at line 2184 of file em_emu.c.

References EMU.

Referenced by EMU_DCDCConductionModeSet(), EMU_DCDCInit(), and EMU_DCDCLnRcoBandSet().

bool EMU_DCDCOutputVoltageSet	(	uint32_t	mV,
		bool	setLpVoltage,
		bool	setLnVoltage
	)

Set DCDC output voltage.

Parameters

[in] mV Target DCDC output voltage in mV

Returns: True if the mV parameter is valid

Definition at line 2020 of file em_emu.c.

References DEVINFO, EMU, SL_MAX, and SL_MIN.

Referenced by EMU_DCDCInit().

bool EMU_DCDCPowerOff ( void )

Power off the DCDC regulator.

This function powers off the DCDC controller. This function should only be used if the external power circuit is wired for no DCDC. If the external power circuit is wired for DCDC usage, then use EMU_DCDCInit() and set the DCDC in bypass mode to disable DCDC.

Returns: Return false if the DCDC could not be disabled.

Definition at line 2288 of file em_emu.c.

References EMU.

void EMU_EM23Init ( const EMU_EM23Init_TypeDef * em23Init )

Update EMU module with Energy Mode 2 and 3 configuration.

Parameters

[in] em23Init Energy Mode 2 and 3 configuration structure

Definition at line 1078 of file em_emu.c.

References EMU_EM23Init_TypeDef::em23VregFullEn, EMU, and EMU_CTRL_EMVREG.

void EMU_EnterEM2 ( bool restore )

Enter energy mode 2 (EM2).

When entering EM2, the high frequency clocks are disabled, ie HFXO, HFRCO and AUXHFRCO (for AUXHFRCO, see exception note below). When re-entering EM0, HFRCO is re-enabled and the core will be clocked by the configured HFRCO band. This ensures a quick wakeup from EM2.

However, prior to entering EM2, the core may have been using another oscillator than HFRCO. The restore parameter gives the user the option to restore all HF oscillators according to state prior to entering EM2, as well as the clock used to clock the core. This restore procedure is handled by SW. However, since handled by SW, it will not be restored before completing the interrupt function(s) waking up the core!

Note: If restoring core clock to use the HFXO oscillator, which has been disabled during EM2 mode, this function will stall until the oscillator has stabilized. Stalling time can be reduced by adding interrupt support detecting stable oscillator, and an asynchronous switch to the original oscillator. See CMU documentation. Such a feature is however outside the scope of the implementation in this function.

: If HFXO is re-enabled by this function, and NOT used to clock the core, this function will not wait for HFXO to stabilize. This must be considered by the application if trying to use features relying on that oscillator upon return.

: If a debugger is attached, the AUXHFRCO will not be disabled if enabled upon entering EM2. It will thus remain enabled when returning to EM0 regardless of the restore parameter.

: If HFXO autostart and select is enabled by using CMU_HFXOAutostartEnable(), the starting and selecting of the core clocks will be identical to the user independently of the value of the restore parameter when waking up on the wakeup sources corresponding to the autostart and select setting.

: If voltage scaling is supported, the restore parameter is true and the EM0 voltage scaling level is set higher than the EM2 level, then the EM0 level is also restored.

Parameters

[in]

restore

true - restore oscillators, clocks and voltage scaling, see function details.
false - do not restore oscillators and clocks, see function details.

: The restore option should only be used if all clock control is done via the CMU API.

Definition at line 480 of file em_emu.c.

References SystemCoreClockUpdate().

Referenced by CAPLESENSE_Sleep(), UTIL_sleep(), and UTIL_waitForEvent().

void EMU_EnterEM3 ( bool restore )

Enter energy mode 3 (EM3).

When entering EM3, the high frequency clocks are disabled by HW, ie HFXO, HFRCO and AUXHFRCO (for AUXHFRCO, see exception note below). In addition, the low frequency clocks, ie LFXO and LFRCO are disabled by SW. When re-entering EM0, HFRCO is re-enabled and the core will be clocked by the configured HFRCO band. This ensures a quick wakeup from EM3.

However, prior to entering EM3, the core may have been using another oscillator than HFRCO. The restore parameter gives the user the option to restore all HF/LF oscillators according to state prior to entering EM3, as well as the clock used to clock the core. This restore procedure is handled by SW. However, since handled by SW, it will not be restored before completing the interrupt function(s) waking up the core!

Note: If restoring core clock to use an oscillator other than HFRCO, this function will stall until the oscillator has stabilized. Stalling time can be reduced by adding interrupt support detecting stable oscillator, and an asynchronous switch to the original oscillator. See CMU documentation. Such a feature is however outside the scope of the implementation in this function.

: If HFXO/LFXO/LFRCO are re-enabled by this function, and NOT used to clock the core, this function will not wait for those oscillators to stabilize. This must be considered by the application if trying to use features relying on those oscillators upon return.

: If a debugger is attached, the AUXHFRCO will not be disabled if enabled upon entering EM3. It will thus remain enabled when returning to EM0 regardless of the restore parameter.

: If voltage scaling is supported, the restore parameter is true and the EM0 voltage scaling level is set higher than the EM3 level, then the EM0 level is also restored.

Parameters

[in]

restore

true - restore oscillators, clocks and voltage scaling, see function details.
false - do not restore oscillators and clocks, see function details.

: The restore option should only be used if all clock control is done via the CMU API.

Definition at line 597 of file em_emu.c.

References CMU, CMU_Lock(), CMU_LOCK_LOCKKEY_LOCKED, CMU_OSCENCMD_LFRCODIS, CMU_OSCENCMD_LFXODIS, CMU_Unlock(), and SystemCoreClockUpdate().

void EMU_EnterEM4 ( void )

Enter energy mode 4 (EM4).

Note: Only a power on reset or external reset pin can wake the device from EM4.

Definition at line 705 of file em_emu.c.

References _EMU_CTRL_EM4CTRL_MASK, _EMU_CTRL_EM4CTRL_SHIFT, EMU, EMU_BASE, EMU_DCDCModeSet(), and EMU_Unlock().

Referenced by UTIL_shutdown().

__STATIC_INLINE void EMU_Lock ( void )

Lock the EMU in order to protect its registers against unintended modification.

Note: If locking the EMU registers, they must be unlocked prior to using any EMU API functions modifying EMU registers, excluding interrupt control and regulator control if the architecture has a EMU_PWRCTRL register. An exception to this is the energy mode entering API (EMU_EnterEMn()), which can be used when the EMU registers are locked.

Definition at line 916 of file em_emu.h.

References EMU, and EMU_LOCK_LOCKKEY_LOCK.

Referenced by RMU_ResetCauseClear().

void EMU_MemPwrDown ( uint32_t blocks )

Power down memory block.

Parameters

[in] blocks Specifies a logical OR of bits indicating memory blocks to power down. Bit 0 selects block 1, bit 1 selects block 2, etc. Memory block 0 cannot be disabled. Please refer to the reference manual for available memory blocks for a device.

Note: Only a POR reset can power up the specified memory block(s) after powerdown.

Deprecated:: This function is deprecated, use EMU_RamPowerDown() instead which maps a user provided memory range into RAM blocks to power down.

Definition at line 825 of file em_emu.c.

References _EMU_MEMCTRL_MASK, and EMU.

void EMU_RamPowerDown	(	uint32_t	start,
		uint32_t	end
	)

Power down RAM memory blocks.

This function will power down all the RAM blocks that are within a given range. The RAM block layout is different between device families, so this function can be used in a generic way to power down a RAM memory region which is known to be unused.

This function will only power down blocks which are completely enclosed by the memory range given by [start, end).

Here is an example of how to power down all RAM blocks except the first one. The first RAM block is special in that it cannot be powered down by the hardware. The size of this first RAM block is device specific see the reference manual to find the RAM block sizes.

1 EMU_RamPowerDown(SRAM_BASE, SRAM_BASE + SRAM_SIZE);

Note: Only a POR reset can power up the specified memory block(s) after powerdown.

Parameters

[in]	start	The start address of the RAM region to power down. This address is inclusive.
[in]	end	The end address of the RAM region to power down. This address is exclusive. If this parameter is 0, then all RAM blocks contained in the region from start to the upper RAM address will be powered down.

Definition at line 870 of file em_emu.c.

References EMU, RAM_MEM_BASE, SRAM_BASE, and SRAM_SIZE.

void EMU_UpdateOscConfig ( void )

Update EMU module with CMU oscillator selection/enable status.

Deprecated:: Oscillator status is saved in EMU_EnterEM2() and EMU_EnterEM3().

Definition at line 958 of file em_emu.c.

Detailed Description

Data Structures

Macros

Enumerations

Functions

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation