EFM32 Gecko Software Documentation  efm32g-doc-5.1.2
LETIMER

Detailed Description

Low Energy Timer (LETIMER) Peripheral API.

This module contains functions to control the LETIMER peripheral of Silicon Labs 32-bit MCUs and SoCs. The LETIMER is a down-counter that can keep track of time and output configurable waveforms.

Data Structures

struct  LETIMER_Init_TypeDef
 

Macros

#define LETIMER_INIT_DEFAULT
 

Enumerations

enum  LETIMER_RepeatMode_TypeDef {
  letimerRepeatFree = _LETIMER_CTRL_REPMODE_FREE,
  letimerRepeatOneshot = _LETIMER_CTRL_REPMODE_ONESHOT,
  letimerRepeatBuffered = _LETIMER_CTRL_REPMODE_BUFFERED,
  letimerRepeatDouble = _LETIMER_CTRL_REPMODE_DOUBLE
}
 
enum  LETIMER_UFOA_TypeDef {
  letimerUFOANone = _LETIMER_CTRL_UFOA0_NONE,
  letimerUFOAToggle = _LETIMER_CTRL_UFOA0_TOGGLE,
  letimerUFOAPulse = _LETIMER_CTRL_UFOA0_PULSE,
  letimerUFOAPwm = _LETIMER_CTRL_UFOA0_PWM
}
 

Functions

uint32_t LETIMER_CompareGet (LETIMER_TypeDef *letimer, unsigned int comp)
 Get LETIMER compare register value. More...
 
void LETIMER_CompareSet (LETIMER_TypeDef *letimer, unsigned int comp, uint32_t value)
 Set LETIMER compare register value. More...
 
__STATIC_INLINE uint32_t LETIMER_CounterGet (LETIMER_TypeDef *letimer)
 Get LETIMER counter value. More...
 
void LETIMER_Enable (LETIMER_TypeDef *letimer, bool enable)
 Start/stop LETIMER. More...
 
void LETIMER_FreezeEnable (LETIMER_TypeDef *letimer, bool enable)
 LETIMER register synchronization freeze control. More...
 
void LETIMER_Init (LETIMER_TypeDef *letimer, const LETIMER_Init_TypeDef *init)
 Initialize LETIMER. More...
 
__STATIC_INLINE void LETIMER_IntClear (LETIMER_TypeDef *letimer, uint32_t flags)
 Clear one or more pending LETIMER interrupts. More...
 
__STATIC_INLINE void LETIMER_IntDisable (LETIMER_TypeDef *letimer, uint32_t flags)
 Disable one or more LETIMER interrupts. More...
 
__STATIC_INLINE void LETIMER_IntEnable (LETIMER_TypeDef *letimer, uint32_t flags)
 Enable one or more LETIMER interrupts. More...
 
__STATIC_INLINE uint32_t LETIMER_IntGet (LETIMER_TypeDef *letimer)
 Get pending LETIMER interrupt flags. More...
 
__STATIC_INLINE uint32_t LETIMER_IntGetEnabled (LETIMER_TypeDef *letimer)
 Get enabled and pending LETIMER interrupt flags. More...
 
__STATIC_INLINE void LETIMER_IntSet (LETIMER_TypeDef *letimer, uint32_t flags)
 Set one or more pending LETIMER interrupts from SW. More...
 
uint32_t LETIMER_RepeatGet (LETIMER_TypeDef *letimer, unsigned int rep)
 Get LETIMER repeat register value. More...
 
void LETIMER_RepeatSet (LETIMER_TypeDef *letimer, unsigned int rep, uint32_t value)
 Set LETIMER repeat counter register value. More...
 
void LETIMER_Reset (LETIMER_TypeDef *letimer)
 Reset LETIMER to same state as after a HW reset. More...
 

Macro Definition Documentation

#define LETIMER_INIT_DEFAULT
Value:
{ \
true, /* Enable timer when init complete. */ \
false, /* Stop counter during debug halt. */ \
false, /* Do not start counting on RTC COMP0 match. */ \
false, /* Do not start counting on RTC COMP1 match. */ \
false, /* Do not load COMP0 into CNT on underflow. */ \
false, /* Do not load COMP1 into COMP0 when REP0 reaches 0. */ \
0, /* Idle value 0 for output 0. */ \
0, /* Idle value 0 for output 1. */ \
letimerUFOANone, /* No action on underflow on output 0. */ \
letimerUFOANone, /* No action on underflow on output 1. */ \
letimerRepeatFree /* Count until stopped by SW. */ \
}

Default config for LETIMER init structure.

Definition at line 115 of file em_letimer.h.

Referenced by MIC_init().

Enumeration Type Documentation

Repeat mode.

Enumerator
letimerRepeatFree 

Count until stopped by SW.

letimerRepeatOneshot 

Count REP0 times.

letimerRepeatBuffered 

Count REP0 times, if REP1 has been written to, it is loaded into REP0 when REP0 is about to be decremented to 0.

letimerRepeatDouble 

Run as long as both REP0 and REP1 are not 0. Both REP0 and REP1 are decremented when counter underflows.

Definition at line 59 of file em_letimer.h.

Underflow action on output.

Enumerator
letimerUFOANone 

No output action.

letimerUFOAToggle 

Toggle output when counter underflows.

letimerUFOAPulse 

Hold output one LETIMER clock cycle when counter underflows.

letimerUFOAPwm 

Set output idle when counter underflows, and active when matching COMP1.

Definition at line 79 of file em_letimer.h.

Function Documentation

uint32_t LETIMER_CompareGet ( LETIMER_TypeDef letimer,
unsigned int  comp 
)

Get LETIMER compare register value.

Parameters
[in]letimerPointer to LETIMER peripheral register block
[in]compCompare register to get, either 0 or 1
Returns
Compare register value, 0 if invalid register selected.

Definition at line 129 of file em_letimer.c.

References LETIMER_TypeDef::COMP0, and LETIMER_TypeDef::COMP1.

void LETIMER_CompareSet ( LETIMER_TypeDef letimer,
unsigned int  comp,
uint32_t  value 
)

Set LETIMER compare register value.

Note
The setting of a compare register requires synchronization into the low frequency domain. If the same register is modified before a previous update has completed, this function will stall until the previous synchronization has completed. This only applies to the Gecko Family, see comment in the LETIMER_Sync() internal function call.
Parameters
[in]letimerPointer to LETIMER peripheral register block
[in]compCompare register to set, either 0 or 1
[in]valueInitialization value (<= 0x0000ffff)

Definition at line 176 of file em_letimer.c.

References _LETIMER_COMP0_COMP0_MASK, _LETIMER_COMP0_COMP0_SHIFT, LETIMER_TypeDef::COMP0, LETIMER_TypeDef::COMP1, LETIMER_SYNCBUSY_COMP0, and LETIMER_SYNCBUSY_COMP1.

Referenced by MIC_init().

__STATIC_INLINE uint32_t LETIMER_CounterGet ( LETIMER_TypeDef letimer)

Get LETIMER counter value.

Parameters
[in]letimerPointer to LETIMER peripheral register block.
Returns
Current LETIMER counter value.

Definition at line 164 of file em_letimer.h.

References LETIMER_TypeDef::CNT.

void LETIMER_Enable ( LETIMER_TypeDef letimer,
bool  enable 
)

Start/stop LETIMER.

Note
The enabling/disabling of the LETIMER modifies the LETIMER CMD register which requires synchronization into the low frequency domain. If this register is modified before a previous update to the same register has completed, this function will stall until the previous synchronization has completed. This only applies to the Gecko Family, see comment in the LETIMER_Sync() internal function call.
Parameters
[in]letimerPointer to LETIMER peripheral register block.
[in]enabletrue to enable counting, false to disable.

Definition at line 231 of file em_letimer.c.

References LETIMER_TypeDef::CMD, LETIMER_CMD_START, LETIMER_CMD_STOP, and LETIMER_SYNCBUSY_CMD.

void LETIMER_FreezeEnable ( LETIMER_TypeDef letimer,
bool  enable 
)

LETIMER register synchronization freeze control.

Some LETIMER registers require synchronization into the low frequency (LF) domain. The freeze feature allows for several such registers to be modified before passing them to the LF domain simultaneously (which takes place when the freeze mode is disabled).

Note
When enabling freeze mode, this function will wait for all current ongoing LETIMER synchronization to LF domain to complete (Normally synchronization will not be in progress.) However for this reason, when using freeze mode, modifications of registers requiring LF synchronization should be done within one freeze enable/disable block to avoid unecessary stalling.
Parameters
[in]letimerPointer to LETIMER peripheral register block.
[in]enable
  • true - enable freeze, modified registers are not propagated to the LF domain
  • false - disables freeze, modified registers are propagated to LF domain

Definition at line 278 of file em_letimer.c.

References LETIMER_TypeDef::FREEZE, LETIMER_FREEZE_REGFREEZE, and LETIMER_TypeDef::SYNCBUSY.

Referenced by LETIMER_Reset().

void LETIMER_Init ( LETIMER_TypeDef letimer,
const LETIMER_Init_TypeDef init 
)

Initialize LETIMER.

Note that the compare/repeat values must be set separately with LETIMER_CompareSet() and LETIMER_RepeatSet(). That should probably be done prior to the use of this function if configuring the LETIMER to start when initialization is completed.

Note
The initialization of the LETIMER modifies the LETIMER CTRL/CMD registers which require synchronization into the low frequency domain. If any of those registers are modified before a previous update to the same register has completed, this function will stall until the previous synchronization has completed. This only applies to the Gecko Family, see comment in the LETIMER_Sync() internal function call.
Parameters
[in]letimerPointer to LETIMER peripheral register block.
[in]initPointer to LETIMER initialization structure.

Definition at line 327 of file em_letimer.c.

References _LETIMER_CTRL_REPMODE_SHIFT, _LETIMER_CTRL_UFOA0_SHIFT, _LETIMER_CTRL_UFOA1_SHIFT, LETIMER_Init_TypeDef::bufTop, LETIMER_TypeDef::CMD, LETIMER_Init_TypeDef::comp0Top, LETIMER_TypeDef::CTRL, LETIMER_Init_TypeDef::debugRun, LETIMER_Init_TypeDef::enable, LETIMER_CMD_START, LETIMER_CMD_STOP, LETIMER_CTRL_BUFTOP, LETIMER_CTRL_COMP0TOP, LETIMER_CTRL_DEBUGRUN, LETIMER_CTRL_OPOL0, LETIMER_CTRL_OPOL1, LETIMER_CTRL_RTCC0TEN, LETIMER_CTRL_RTCC1TEN, LETIMER_STATUS_RUNNING, LETIMER_SYNCBUSY_CMD, LETIMER_SYNCBUSY_CTRL, LETIMER_Init_TypeDef::out0Pol, LETIMER_Init_TypeDef::out1Pol, LETIMER_Init_TypeDef::repMode, LETIMER_Init_TypeDef::rtcComp0Enable, LETIMER_Init_TypeDef::rtcComp1Enable, LETIMER_TypeDef::STATUS, LETIMER_Init_TypeDef::ufoa0, and LETIMER_Init_TypeDef::ufoa1.

Referenced by MIC_init().

__STATIC_INLINE void LETIMER_IntClear ( LETIMER_TypeDef letimer,
uint32_t  flags 
)

Clear one or more pending LETIMER interrupts.

Parameters
[in]letimerPointer to LETIMER peripheral register block.
[in]flagsPending LETIMER interrupt source to clear. Use a bitwise logic OR combination of valid interrupt flags for the LETIMER module (LETIMER_IF_nnn).

Definition at line 189 of file em_letimer.h.

References LETIMER_TypeDef::IFC.

__STATIC_INLINE void LETIMER_IntDisable ( LETIMER_TypeDef letimer,
uint32_t  flags 
)

Disable one or more LETIMER interrupts.

Parameters
[in]letimerPointer to LETIMER peripheral register block.
[in]flagsLETIMER interrupt sources to disable. Use a bitwise logic OR combination of valid interrupt flags for the LETIMER module (LETIMER_IF_nnn).

Definition at line 206 of file em_letimer.h.

References LETIMER_TypeDef::IEN.

__STATIC_INLINE void LETIMER_IntEnable ( LETIMER_TypeDef letimer,
uint32_t  flags 
)

Enable one or more LETIMER interrupts.

Note
Depending on the use, a pending interrupt may already be set prior to enabling the interrupt. Consider using LETIMER_IntClear() prior to enabling if such a pending interrupt should be ignored.
Parameters
[in]letimerPointer to LETIMER peripheral register block.
[in]flagsLETIMER interrupt sources to enable. Use a bitwise logic OR combination of valid interrupt flags for the LETIMER module (LETIMER_IF_nnn).

Definition at line 228 of file em_letimer.h.

References LETIMER_TypeDef::IEN.

__STATIC_INLINE uint32_t LETIMER_IntGet ( LETIMER_TypeDef letimer)

Get pending LETIMER interrupt flags.

Note
The event bits are not cleared by the use of this function.
Parameters
[in]letimerPointer to LETIMER peripheral register block.
Returns
LETIMER interrupt sources pending. A bitwise logic OR combination of valid interrupt flags for the LETIMER module (LETIMER_IF_nnn).

Definition at line 248 of file em_letimer.h.

References LETIMER_TypeDef::IF.

__STATIC_INLINE uint32_t LETIMER_IntGetEnabled ( LETIMER_TypeDef letimer)

Get enabled and pending LETIMER interrupt flags.

Useful for handling more interrupt sources in the same interrupt handler.

Note
The event bits are not cleared by the use of this function.
Parameters
[in]letimerPointer to LETIMER peripheral register block.
Returns
Pending and enabled LETIMER interrupt sources. The return value is the bitwise AND combination of
  • the OR combination of enabled interrupt sources in LETIMER_IEN_nnn register (LETIMER_IEN_nnn) and
  • the OR combination of valid interrupt flags of the LETIMER module (LETIMER_IF_nnn).

Definition at line 275 of file em_letimer.h.

References LETIMER_TypeDef::IEN, and LETIMER_TypeDef::IF.

__STATIC_INLINE void LETIMER_IntSet ( LETIMER_TypeDef letimer,
uint32_t  flags 
)

Set one or more pending LETIMER interrupts from SW.

Parameters
[in]letimerPointer to LETIMER peripheral register block.
[in]flagsLETIMER interrupt sources to set to pending. Use a bitwise logic OR combination of valid interrupt flags for the LETIMER module (LETIMER_IF_nnn).

Definition at line 300 of file em_letimer.h.

References LETIMER_TypeDef::IFS.

uint32_t LETIMER_RepeatGet ( LETIMER_TypeDef letimer,
unsigned int  rep 
)

Get LETIMER repeat register value.

Parameters
[in]letimerPointer to LETIMER peripheral register block
[in]repRepeat register to get, either 0 or 1
Returns
Repeat register value, 0 if invalid register selected.

Definition at line 417 of file em_letimer.c.

References LETIMER_TypeDef::REP0, and LETIMER_TypeDef::REP1.

void LETIMER_RepeatSet ( LETIMER_TypeDef letimer,
unsigned int  rep,
uint32_t  value 
)

Set LETIMER repeat counter register value.

Note
The setting of a repeat counter register requires synchronization into the low frequency domain. If the same register is modified before a previous update has completed, this function will stall until the previous synchronization has completed. This only applies to the Gecko Family, see comment in the LETIMER_Sync() internal function call.
Parameters
[in]letimerPointer to LETIMER peripheral register block
[in]repRepeat counter register to set, either 0 or 1
[in]valueInitialization value (<= 0x0000ffff)

Definition at line 464 of file em_letimer.c.

References _LETIMER_REP0_REP0_MASK, _LETIMER_REP0_REP0_SHIFT, LETIMER_SYNCBUSY_REP0, LETIMER_SYNCBUSY_REP1, LETIMER_TypeDef::REP0, and LETIMER_TypeDef::REP1.

Referenced by MIC_init().

void LETIMER_Reset ( LETIMER_TypeDef letimer)

Reset LETIMER to same state as after a HW reset.

Note
The ROUTE register is NOT reset by this function, in order to allow for centralized setup of this feature.
Parameters
[in]letimerPointer to LETIMER peripheral register block.

Definition at line 520 of file em_letimer.c.

References _LETIMER_COMP0_RESETVALUE, _LETIMER_COMP1_RESETVALUE, _LETIMER_CTRL_RESETVALUE, _LETIMER_IEN_RESETVALUE, _LETIMER_IFC_MASK, _LETIMER_REP0_RESETVALUE, _LETIMER_REP1_RESETVALUE, LETIMER_TypeDef::CMD, LETIMER_TypeDef::COMP0, LETIMER_TypeDef::COMP1, LETIMER_TypeDef::CTRL, LETIMER_TypeDef::IEN, LETIMER_TypeDef::IFC, LETIMER_CMD_CLEAR, LETIMER_CMD_CTO0, LETIMER_CMD_CTO1, LETIMER_CMD_STOP, LETIMER_FreezeEnable(), LETIMER_TypeDef::REP0, and LETIMER_TypeDef::REP1.