PCNT
[EM_Library]

Pulse Counter (PCNT) Peripheral API. More...

Collaboration diagram for PCNT:

Data Structures

struct  PCNT_Init_TypeDef

Defines

#define PCNT0_CNT_SIZE   (16)
#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
}
enum  PCNT_CntEvent_TypeDef {
  pcntCntEventBoth = _PCNT_CTRL_CNTEV_BOTH,
  pcntCntEventUp = _PCNT_CTRL_CNTEV_UP,
  pcntCntEventDown = _PCNT_CTRL_CNTEV_DOWN,
  pcntCntEventNone = _PCNT_CTRL_CNTEV_NONE
}
enum  PCNT_PRSSel_TypeDef {
  pcntPRSCh0 = 0,
  pcntPRSCh1 = 1,
  pcntPRSCh2 = 2,
  pcntPRSCh3 = 3
}
enum  PCNT_PRSInput_TypeDef {
  pcntPRSInputS0 = 0,
  pcntPRSInputS1 = 1
}

Functions

__STATIC_INLINE uint32_t PCNT_CounterGet (PCNT_TypeDef *pcnt)
 Get pulse counter value.
__STATIC_INLINE uint32_t PCNT_AuxCounterGet (PCNT_TypeDef *pcnt)
 Get auxiliary counter value.
void PCNT_CounterReset (PCNT_TypeDef *pcnt)
 Reset PCNT counters and TOP register.
void PCNT_CounterTopSet (PCNT_TypeDef *pcnt, uint32_t count, uint32_t top)
 Set counter and top values.
__STATIC_INLINE void PCNT_CounterSet (PCNT_TypeDef *pcnt, uint32_t count)
 Set counter value.
void PCNT_Enable (PCNT_TypeDef *pcnt, PCNT_Mode_TypeDef mode)
 Set PCNT operational mode.
void PCNT_FreezeEnable (PCNT_TypeDef *pcnt, bool enable)
 PCNT register synchronization freeze control.
void PCNT_Init (PCNT_TypeDef *pcnt, const PCNT_Init_TypeDef *init)
 Init pulse counter.
void PCNT_PRSInputEnable (PCNT_TypeDef *pcnt, PCNT_PRSInput_TypeDef prsInput, bool enable)
 Enable/disable the selected PRS input of PCNT.
__STATIC_INLINE void PCNT_IntClear (PCNT_TypeDef *pcnt, uint32_t flags)
 Clear one or more pending PCNT interrupts.
__STATIC_INLINE void PCNT_IntDisable (PCNT_TypeDef *pcnt, uint32_t flags)
 Disable one or more PCNT interrupts.
__STATIC_INLINE void PCNT_IntEnable (PCNT_TypeDef *pcnt, uint32_t flags)
 Enable one or more PCNT interrupts.
__STATIC_INLINE uint32_t PCNT_IntGet (PCNT_TypeDef *pcnt)
 Get pending PCNT interrupt flags.
__STATIC_INLINE uint32_t PCNT_IntGetEnabled (PCNT_TypeDef *pcnt)
 Get enabled and pending PCNT interrupt flags.
__STATIC_INLINE void PCNT_IntSet (PCNT_TypeDef *pcnt, uint32_t flags)
 Set one or more pending PCNT interrupts from SW.
void PCNT_Reset (PCNT_TypeDef *pcnt)
 Reset PCNT to same state as after a HW reset.
__STATIC_INLINE uint32_t PCNT_TopBufferGet (PCNT_TypeDef *pcnt)
 Get pulse counter top buffer value.
void PCNT_TopBufferSet (PCNT_TypeDef *pcnt, uint32_t val)
 Set top buffer value.
__STATIC_INLINE uint32_t PCNT_TopGet (PCNT_TypeDef *pcnt)
 Get pulse counter top value.
void PCNT_TopSet (PCNT_TypeDef *pcnt, uint32_t val)
 Set top value.

Detailed Description

Pulse Counter (PCNT) Peripheral API.


Define Documentation

#define PCNT0_CNT_SIZE   (16)

PCNT Counter register sizes.

Definition at line 63 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. */                             \
    false,                                    /* Hysteresis disabled. */                         \
    true,                                     /* Counter direction is given by CNTDIR. */        \
    pcntCntEventUp,                           /* Regular counter counts up on upcount events. */ \
    pcntCntEventNone,                         /* Auxiliary counter doesn't respond to events. */ \
    pcntPRSCh0,                               /* PRS channel 0 selected as S0IN. */              \
    pcntPRSCh0                                /* PRS channel 0 selected as S1IN. */              \
  }

Default config for PCNT init structure.

Definition at line 221 of file em_pcnt.h.


Enumeration Type Documentation

Counter event selection. Note: unshifted values are being used for enumeration because multiple configuration structure members use this type definition.

Enumerator:
pcntCntEventBoth 

Counts up on up-count and down on down-count events.

pcntCntEventUp 

Only counts up on up-count events.

pcntCntEventDown 

Only counts down on down-count events.

pcntCntEventNone 

Never counts.

Definition at line 98 of file em_pcnt.h.

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 78 of file em_pcnt.h.

PRS inputs of PCNT.

Enumerator:
pcntPRSInputS1 

PRS input 0.

Definition at line 139 of file em_pcnt.h.

PRS sources for s0PRS and s1PRS.

Enumerator:
pcntPRSCh0 

PRS channel 0.

pcntPRSCh1 

PRS channel 1.

pcntPRSCh2 

PRS channel 2.

pcntPRSCh3 

PRS channel 3.

Definition at line 117 of file em_pcnt.h.


Function Documentation

__STATIC_INLINE uint32_t PCNT_AuxCounterGet ( PCNT_TypeDef *  pcnt  ) 

Get auxiliary counter value.

Parameters:
[in] pcnt Pointer to PCNT peripheral register block.
Returns:
Current auxiliary counter value.

Definition at line 269 of file em_pcnt.h.

__STATIC_INLINE uint32_t PCNT_CounterGet ( PCNT_TypeDef *  pcnt  ) 

Get pulse counter value.

Parameters:
[in] pcnt Pointer to PCNT peripheral register block.
Returns:
Current pulse counter value.

Definition at line 252 of file em_pcnt.h.

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 142 of file em_pcnt.c.

References BITBAND_Peripheral().

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__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 301 of file em_pcnt.h.

References PCNT_CounterTopSet().

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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 178 of file em_pcnt.c.

References PCNT0_CNT_SIZE.

Referenced by PCNT_CounterSet(), and PCNT_Init().

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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 280 of file em_pcnt.c.

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 373 of file em_pcnt.c.

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:

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 437 of file em_pcnt.c.

References PCNT_Init_TypeDef::auxCntEvent, BITBAND_Peripheral(), CMU_PCNTClockExternalSet(), PCNT_Init_TypeDef::cntEvent, PCNT_Init_TypeDef::countDown, PCNT_Init_TypeDef::counter, PCNT_Init_TypeDef::filter, PCNT_Init_TypeDef::hyst, PCNT_Init_TypeDef::mode, PCNT_Init_TypeDef::negEdge, PCNT0_CNT_SIZE, PCNT_CounterTopSet(), pcntCntEventBoth, pcntCntEventDown, pcntCntEventNone, pcntCntEventUp, pcntModeExtQuad, pcntModeExtSingle, pcntModeOvsSingle, PCNT_Init_TypeDef::s0PRS, PCNT_Init_TypeDef::s1CntDir, PCNT_Init_TypeDef::s1PRS, and PCNT_Init_TypeDef::top.

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__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 329 of file em_pcnt.h.

__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 346 of file em_pcnt.h.

__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 368 of file em_pcnt.h.

__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 388 of file em_pcnt.h.

__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 415 of file em_pcnt.h.

__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 440 of file em_pcnt.h.

void PCNT_PRSInputEnable ( PCNT_TypeDef *  pcnt,
PCNT_PRSInput_TypeDef  prsInput,
bool  enable 
)

Enable/disable the selected PRS input of PCNT.

Notice that this function does not do any configuration.

Parameters:
[in] pcnt Pointer to PCNT peripheral register block.
[in] prsInput PRS input (S0 or S1) of the selected PCNT module.
[in] enable Set to true to enable, false to disable the selected PRS input.

Definition at line 312 of file em_pcnt.c.

References BITBAND_Peripheral(), and pcntPRSInputS1.

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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 645 of file em_pcnt.c.

References BITBAND_Peripheral(), CMU_PCNTClockExternalSet(), and PCNT_TopBufferSet().

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__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 458 of file em_pcnt.h.

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 698 of file em_pcnt.c.

Referenced by PCNT_Reset().

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__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 475 of file em_pcnt.h.

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 724 of file em_pcnt.c.

References PCNT0_CNT_SIZE.