Detailed Description

Pulse Counter (PCNT) Peripheral API.

This module contains functions to control the PCNT peripheral of Silicon Labs 32-bit MCUs and SoCs. The PCNT decodes incoming pulses. The module has a quadrature mode which may be used to decode the speed and direction of a mechanical shaft.

Data Structures
struct	PCNT_Init_TypeDef

Macros
#define	PCNT0_CNT_SIZE (8) /* PCNT0 counter is 8 bits. */

#define	PCNT1_CNT_SIZE (8) /* PCNT1 counter is 8 bits. */

#define	PCNT2_CNT_SIZE (8) /* PCNT2 counter is 8 bits. */

#define	PCNT_INIT_DEFAULT

Enumerations
enum	PCNT_Mode_TypeDef { pcntModeDisable = _PCNT_CTRL_MODE_DISABLE, pcntModeOvsSingle = _PCNT_CTRL_MODE_OVSSINGLE, pcntModeExtSingle = _PCNT_CTRL_MODE_EXTCLKSINGLE, pcntModeExtQuad = _PCNT_CTRL_MODE_EXTCLKQUAD }

Functions
__STATIC_INLINE uint32_t	PCNT_CounterGet (PCNT_TypeDef *pcnt)
	Get pulse counter value. More...

void	PCNT_CounterReset (PCNT_TypeDef *pcnt)
	Reset PCNT counters and TOP register. More...

__STATIC_INLINE void	PCNT_CounterSet (PCNT_TypeDef *pcnt, uint32_t count)
	Set counter value. More...

void	PCNT_CounterTopSet (PCNT_TypeDef *pcnt, uint32_t count, uint32_t top)
	Set counter and top values. More...

void	PCNT_Enable (PCNT_TypeDef *pcnt, PCNT_Mode_TypeDef mode)
	Set PCNT operational mode. More...

void	PCNT_FreezeEnable (PCNT_TypeDef *pcnt, bool enable)
	PCNT register synchronization freeze control. More...

void	PCNT_Init (PCNT_TypeDef pcnt, const PCNT_Init_TypeDef init)
	Init pulse counter. More...

__STATIC_INLINE void	PCNT_IntClear (PCNT_TypeDef *pcnt, uint32_t flags)
	Clear one or more pending PCNT interrupts. More...

__STATIC_INLINE void	PCNT_IntDisable (PCNT_TypeDef *pcnt, uint32_t flags)
	Disable one or more PCNT interrupts. More...

__STATIC_INLINE void	PCNT_IntEnable (PCNT_TypeDef *pcnt, uint32_t flags)
	Enable one or more PCNT interrupts. More...

__STATIC_INLINE uint32_t	PCNT_IntGet (PCNT_TypeDef *pcnt)
	Get pending PCNT interrupt flags. More...

__STATIC_INLINE uint32_t	PCNT_IntGetEnabled (PCNT_TypeDef *pcnt)
	Get enabled and pending PCNT interrupt flags. More...

__STATIC_INLINE void	PCNT_IntSet (PCNT_TypeDef *pcnt, uint32_t flags)
	Set one or more pending PCNT interrupts from SW. More...

void	PCNT_Reset (PCNT_TypeDef *pcnt)
	Reset PCNT to same state as after a HW reset. More...

__STATIC_INLINE uint32_t	PCNT_TopBufferGet (PCNT_TypeDef *pcnt)
	Get pulse counter top buffer value. More...

void	PCNT_TopBufferSet (PCNT_TypeDef *pcnt, uint32_t val)
	Set top buffer value. More...

__STATIC_INLINE uint32_t	PCNT_TopGet (PCNT_TypeDef *pcnt)
	Get pulse counter top value. More...

void	PCNT_TopSet (PCNT_TypeDef *pcnt, uint32_t val)
	Set top value. More...

Macro Definition Documentation

#define PCNT0_CNT_SIZE (8) /* PCNT0 counter is 8 bits. */

PCNT0 Counter register size.

Definition at line 60 of file em_pcnt.h.

Referenced by PCNT_CounterTopSet(), PCNT_Init(), and PCNT_TopSet().

#define PCNT1_CNT_SIZE (8) /* PCNT1 counter is 8 bits. */

PCNT1 Counter register size.

Definition at line 67 of file em_pcnt.h.

Referenced by PCNT_CounterTopSet(), PCNT_Init(), and PCNT_TopSet().

#define PCNT2_CNT_SIZE (8) /* PCNT2 counter is 8 bits. */

PCNT2 Counter register size.

Definition at line 72 of file em_pcnt.h.

Referenced by PCNT_CounterTopSet(), PCNT_Init(), and PCNT_TopSet().

#define PCNT_INIT_DEFAULT

Value:

{                                                                                 \
  pcntModeDisable,                          /* Disabled by default. */            \
  _PCNT_CNT_RESETVALUE,                     /* Default counter HW reset value. */ \
  _PCNT_TOP_RESETVALUE,                     /* Default counter HW reset value. */ \
  false,                                    /* Use positive edge. */              \
  false,                                    /* Up-counting. */                    \
  false                                     /* Filter disabled. */                \
}

Default config for PCNT init structure.

Definition at line 237 of file em_pcnt.h.

Enumeration Type Documentation

enum PCNT_Mode_TypeDef

Mode selection.

Enumerator
pcntModeDisable	Disable pulse counter.
pcntModeOvsSingle	Single input LFACLK oversampling mode (available in EM0-EM2).
pcntModeExtSingle	Externally clocked single input counter mode (available in EM0-EM3).
pcntModeExtQuad	Externally clocked quadrature decoder mode (available in EM0-EM3).

Definition at line 81 of file em_pcnt.h.

Function Documentation

__STATIC_INLINE uint32_t PCNT_CounterGet ( PCNT_TypeDef * pcnt )

Get pulse counter value.

Default config for PCNT init structure.

Parameters

[in] pcnt Pointer to PCNT peripheral register block.

Returns: Current pulse counter value.

Definition at line 385 of file em_pcnt.h.

References PCNT_TypeDef::CNT.

void PCNT_CounterReset ( PCNT_TypeDef * pcnt )

Reset PCNT counters and TOP register.

Note: Notice that special SYNCBUSY handling is not applicable for the RSTEN bit of the control register, so we don't need to wait for it when only modifying RSTEN. (It would mean undefined wait time if clocked by external clock.) The SYNCBUSY bit will however be set, leading to a synchronization in the LF domain, with in reality no changes.

Parameters

[in] pcnt Pointer to PCNT peripheral register block.

Definition at line 146 of file em_pcnt.c.

References _PCNT_CTRL_RSTEN_SHIFT, BUS_RegBitWrite(), and PCNT_TypeDef::CTRL.

__STATIC_INLINE void PCNT_CounterSet	(	PCNT_TypeDef *	pcnt,
		uint32_t	count
	)

Set counter value.

The pulse counter is disabled while changing counter value, and reenabled (if originally enabled) when counter value has been set.

Note: This function will stall until synchronization to low frequency domain is completed. For that reason, it should normally not be used when using an external clock to clock the PCNT module, since stall time may be undefined in that case. The counter should normally only be set when operating in (or about to enable) pcntModeOvsSingle mode.

Parameters

[in]	pcnt	Pointer to PCNT peripheral register block.
[in]	count	Value to set in counter register.

Definition at line 431 of file em_pcnt.h.

References PCNT_CounterTopSet(), and PCNT_TypeDef::TOP.

void PCNT_CounterTopSet	(	PCNT_TypeDef *	pcnt,
		uint32_t	count,
		uint32_t	top
	)

Set counter and top values.

The pulse counter is disabled while changing these values, and reenabled (if originally enabled) when values have been set.

Note: This function will stall until synchronization to low frequency domain is completed. For that reason, it should normally not be used when using an external clock to clock the PCNT module, since stall time may be undefined in that case. The counter should normally only be set when operating in (or about to enable) pcntModeOvsSingle mode.

Parameters

[in]	pcnt	Pointer to PCNT peripheral register block.
[in]	count	Value to set in counter register.
[in]	top	Value to set in top register.

Definition at line 182 of file em_pcnt.c.

References _PCNT_CTRL_MODE_MASK, PCNT_TypeDef::CMD, PCNT_TypeDef::CTRL, PCNT0, PCNT0_CNT_SIZE, PCNT1, PCNT1_CNT_SIZE, PCNT2, PCNT2_CNT_SIZE, PCNT_CMD_LCNTIM, PCNT_CMD_LTOPBIM, PCNT_CTRL_MODE_DISABLE, PCNT_SYNCBUSY_CMD, PCNT_SYNCBUSY_CTRL, PCNT_SYNCBUSY_TOPB, and PCNT_TypeDef::TOPB.

Referenced by PCNT_CounterSet(), and PCNT_Init().

void PCNT_Enable	(	PCNT_TypeDef *	pcnt,
		PCNT_Mode_TypeDef	mode
	)

Set PCNT operational mode.

Notice that this function does not do any configuration. Setting operational mode is normally only required after initialization is done, and if not done as part of initialization. Or if requiring to disable/reenable pulse counter.

Note: This function may stall until synchronization to low frequency domain is completed. For that reason, it should normally not be used when using an external clock to clock the PCNT module, since stall time may be undefined in that case.

Parameters

[in]	pcnt	Pointer to PCNT peripheral register block.
[in]	mode	Operational mode to use for PCNT.

Definition at line 284 of file em_pcnt.c.

References _PCNT_CTRL_MODE_MASK, _PCNT_CTRL_MODE_SHIFT, PCNT_TypeDef::CTRL, and PCNT_SYNCBUSY_CTRL.

void PCNT_FreezeEnable	(	PCNT_TypeDef *	pcnt,
		bool	enable
	)

PCNT register synchronization freeze control.

Some PCNT 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 PCNT 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]	pcnt	Pointer to PCNT 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 371 of file em_pcnt.c.

References PCNT_TypeDef::FREEZE, PCNT_FREEZE_REGFREEZE, and PCNT_TypeDef::SYNCBUSY.

void PCNT_Init	(	PCNT_TypeDef *	pcnt,
		const PCNT_Init_TypeDef *	init
	)

Init pulse counter.

This function will configure the pulse counter. The clock selection is configured as follows, depending on operational mode:

pcntModeOvsSingle - Use LFACLK.
pcntModeExtSingle - Use external PCNTn_S0 pin.
pcntModeExtQuad - Use external PCNTn_S0 pin.

Notice that the LFACLK must be enabled in all modes, since some basic setup is done with this clock even if external pin clock usage mode is chosen. The pulse counter clock for the selected instance must also be enabled prior to init.

Notice that pins used by the PCNT module must be properly configured by the user explicitly through setting the ROUTE register, in order for the PCNT to work as intended.

Writing to CNT will not occur in external clock modes (EXTCLKQUAD and EXTCLKSINGLE) because the external clock rate is unknown. The user should handle it manually depending on the application

TOPB is written for all modes but in external clock mode it will take 3 external clock cycles to sync to TOP

Note: Initializing requires synchronization into the low frequency domain. This may cause some delay.

Parameters

[in]	pcnt	Pointer to PCNT peripheral register block.
[in]	init	Pointer to initialization structure used to initialize.

Definition at line 435 of file em_pcnt.c.

References _PCNT_CTRL_MODE_MASK, _PCNT_CTRL_MODE_SHIFT, _PCNT_CTRL_RSTEN_SHIFT, BUS_RegBitWrite(), PCNT_TypeDef::CMD, CMU_PCNTClockExternalSet(), PCNT_Init_TypeDef::countDown, PCNT_Init_TypeDef::counter, PCNT_TypeDef::CTRL, PCNT_Init_TypeDef::filter, PCNT_Init_TypeDef::mode, PCNT_Init_TypeDef::negEdge, PCNT0, PCNT0_CNT_SIZE, PCNT1, PCNT1_CNT_SIZE, PCNT2, PCNT2_CNT_SIZE, PCNT_CMD_LTOPBIM, PCNT_CounterTopSet(), PCNT_CTRL_CNTDIR_DOWN, PCNT_CTRL_EDGE_NEG, PCNT_CTRL_FILT, PCNT_CTRL_MODE_DISABLE, PCNT_CTRL_RSTEN, PCNT_SYNCBUSY_CTRL, pcntModeExtQuad, pcntModeExtSingle, pcntModeOvsSingle, PCNT_Init_TypeDef::top, and PCNT_TypeDef::TOPB.

__STATIC_INLINE void PCNT_IntClear	(	PCNT_TypeDef *	pcnt,
		uint32_t	flags
	)

Clear one or more pending PCNT interrupts.

Parameters

[in]	pcnt	Pointer to PCNT peripheral register block.
[in]	flags	Pending PCNT interrupt source to clear. Use a bitwise logic OR combination of valid interrupt flags for the PCNT module (PCNT_IF_nnn).

Definition at line 464 of file em_pcnt.h.

References PCNT_TypeDef::IFC.

__STATIC_INLINE void PCNT_IntDisable	(	PCNT_TypeDef *	pcnt,
		uint32_t	flags
	)

Disable one or more PCNT interrupts.

Parameters

[in]	pcnt	Pointer to PCNT peripheral register block.
[in]	flags	PCNT interrupt sources to disable. Use a bitwise logic OR combination of valid interrupt flags for the PCNT module (PCNT_IF_nnn).

Definition at line 480 of file em_pcnt.h.

References PCNT_TypeDef::IEN.

__STATIC_INLINE void PCNT_IntEnable	(	PCNT_TypeDef *	pcnt,
		uint32_t	flags
	)

Enable one or more PCNT interrupts.

Note: Depending on the use, a pending interrupt may already be set prior to enabling the interrupt. Consider using PCNT_IntClear() prior to enabling if such a pending interrupt should be ignored.

Parameters

[in]	pcnt	Pointer to PCNT peripheral register block.
[in]	flags	PCNT interrupt sources to enable. Use a bitwise logic OR combination of valid interrupt flags for the PCNT module (PCNT_IF_nnn).

Definition at line 501 of file em_pcnt.h.

References PCNT_TypeDef::IEN.

__STATIC_INLINE uint32_t PCNT_IntGet ( PCNT_TypeDef * pcnt )

Get pending PCNT interrupt flags.

Note: The event bits are not cleared by the use of this function.

Parameters

[in] pcnt Pointer to PCNT peripheral register block.

Returns: PCNT interrupt sources pending. A bitwise logic OR combination of valid interrupt flags for the PCNT module (PCNT_IF_nnn).

Definition at line 520 of file em_pcnt.h.

References PCNT_TypeDef::IF.

__STATIC_INLINE uint32_t PCNT_IntGetEnabled ( PCNT_TypeDef * pcnt )

Get enabled and pending PCNT 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] pcnt Pointer to PCNT peripheral register block.

Returns

Pending and enabled PCNT interrupt sources. The return value is the bitwise AND combination of

the OR combination of enabled interrupt sources in PCNT_IEN_nnn register (PCNT_IEN_nnn) and
the OR combination of valid interrupt flags of the PCNT module (PCNT_IF_nnn).

Definition at line 546 of file em_pcnt.h.

References PCNT_TypeDef::IEN, and PCNT_TypeDef::IF.

__STATIC_INLINE void PCNT_IntSet	(	PCNT_TypeDef *	pcnt,
		uint32_t	flags
	)

Set one or more pending PCNT interrupts from SW.

Parameters

[in]	pcnt	Pointer to PCNT peripheral register block.
[in]	flags	PCNT interrupt sources to set to pending. Use a bitwise logic OR combination of valid interrupt flags for the PCNT module (PCNT_IF_nnn).

Definition at line 570 of file em_pcnt.h.

References PCNT_TypeDef::IFS.

void PCNT_Reset ( PCNT_TypeDef * pcnt )

Reset PCNT to same state as after a HW reset.

Notice the LFACLK must be enabled, since some basic reset is done with this clock. The pulse counter clock for the selected instance must also be enabled prior to init.

Note: The ROUTE register is NOT reset by this function, in order to allow for centralized setup of this feature.

Parameters

[in] pcnt Pointer to PCNT peripheral register block.

Definition at line 644 of file em_pcnt.c.

References _PCNT_CTRL_RESETVALUE, _PCNT_CTRL_RSTEN_SHIFT, _PCNT_IEN_RESETVALUE, _PCNT_IFC_MASK, _PCNT_TOPB_RESETVALUE, BUS_RegBitWrite(), CMU_PCNTClockExternalSet(), PCNT_TypeDef::CTRL, PCNT_TypeDef::IEN, PCNT_TypeDef::IFC, PCNT_CTRL_RSTEN, PCNT_SYNCBUSY_CTRL, and PCNT_TopBufferSet().

__STATIC_INLINE uint32_t PCNT_TopBufferGet ( PCNT_TypeDef * pcnt )

Get pulse counter top buffer value.

Parameters

[in] pcnt Pointer to PCNT peripheral register block.

Returns: Current pulse counter top buffer value.

Definition at line 587 of file em_pcnt.h.

References PCNT_TypeDef::TOPB.

void PCNT_TopBufferSet	(	PCNT_TypeDef *	pcnt,
		uint32_t	val
	)

Set top buffer value.

Note: This function may stall until synchronization to low frequency domain is completed. For that reason, it should normally not be used when using an external clock to clock the PCNT module, since stall time may be undefined in that case.

Parameters

[in]	pcnt	Pointer to PCNT peripheral register block.
[in]	val	Value to set in top buffer register.

Definition at line 788 of file em_pcnt.c.

References PCNT_SYNCBUSY_TOPB, and PCNT_TypeDef::TOPB.

Referenced by PCNT_Reset().

__STATIC_INLINE uint32_t PCNT_TopGet ( PCNT_TypeDef * pcnt )

Get pulse counter top value.

Parameters

[in] pcnt Pointer to PCNT peripheral register block.

Returns: Current pulse counter top value.

Definition at line 604 of file em_pcnt.h.

References PCNT_TypeDef::TOP.

void PCNT_TopSet	(	PCNT_TypeDef *	pcnt,
		uint32_t	val
	)

Set top value.

Note: This function will stall until synchronization to low frequency domain is completed. For that reason, it should normally not be used when using an external clock to clock the PCNT module, since stall time may be undefined in that case.

Parameters

[in]	pcnt	Pointer to PCNT peripheral register block.
[in]	val	Value to set in top register.

Definition at line 814 of file em_pcnt.c.

References PCNT_TypeDef::CMD, PCNT0, PCNT0_CNT_SIZE, PCNT1, PCNT1_CNT_SIZE, PCNT2, PCNT2_CNT_SIZE, PCNT_CMD_LTOPBIM, PCNT_SYNCBUSY_CMD, PCNT_SYNCBUSY_TOPB, and PCNT_TypeDef::TOPB.

Detailed Description

Data Structures

Macros

Enumerations

Functions

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation