PCNT - Pulse Counter#
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.
Modules#
Enumerations#
Mode selection.
Counter event selection.
Typedefs#
PRS sources for s0PRS
and s1PRS
.
Functions#
Reset PCNT counters and TOP register.
Set PCNT operational mode.
Returns if the PCNT module is enabled or not.
Set the counter and top values.
Enable/disable the selected PRS input of PCNT.
Initialize the pulse counter.
Reset PCNT to the same state that it was in after a hardware reset.
Set the filter configuration.
Set top buffer value.
Set the top value.
Get the pulse counter value.
Get the auxiliary counter value.
Set a counter value.
Clear one or more pending PCNT interrupts.
Disable one or more PCNT interrupts.
Enable one or more PCNT interrupts.
Get pending PCNT interrupt flags.
Get enabled and pending PCNT interrupt flags.
Set one or more pending PCNT interrupts from SW.
Lock PCNT registers.
Unlock PCNT registers.
Get the pulse counter top buffer value.
Get the pulse counter top value.
Wait for an ongoing sync of register(s) to low-frequency domain to complete.
Start the main PCNT counter.
Stop the main PCNT counter.
Start the auxiliary PCNT counter.
Stop the auxiliary PCNT counter.
Macros#
PCNT0 Counter register size.
PCNT mode disable.
PCNT count event is none.
Default Debug.
Default Mode.
Default Hysteresis.
Default counter direction.
Default count event.
Default auxiliary count event.
Default selected PRS channel as S0IN and S1IN.
Default configuration for PCNT initialization structure.
Default configuration for PCNT initialization structure.
Enumeration Documentation#
PCNT_Mode_TypeDef#
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). |
pcntModeOvsQuad1 | LFACLK oversampling quadrature decoder 1X mode (available in EM0-EM2). |
pcntModeOvsQuad2 | LFACLK oversampling quadrature decoder 2X mode (available in EM0-EM2). |
pcntModeOvsQuad4 | LFACLK oversampling quadrature decoder 4X mode (available in EM0-EM2). |
114
of file platform/emlib/inc/em_pcnt.h
PCNT_CntEvent_TypeDef#
PCNT_CntEvent_TypeDef
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. |
142
of file platform/emlib/inc/em_pcnt.h
PCNT_PRSInput_TypeDef#
PCNT_PRSInput_TypeDef
PRS inputs of PCNT.
Enumerator | |
---|---|
pcntPRSInputS0 | |
pcntPRSInputS1 | PRS input 0. |
235
of file platform/emlib/inc/em_pcnt.h
Typedef Documentation#
PCNT_PRSSel_TypeDef#
typedef unsigned int PCNT_PRSSel_TypeDef
PRS sources for s0PRS
and s1PRS
.
230
of file platform/emlib/inc/em_pcnt.h
Variable Documentation#
initCntEvent#
PCNT_CntEvent_TypeDef initCntEvent
73
of file platform/emlib/src/em_pcnt.c
initAuxCntEvent#
PCNT_CntEvent_TypeDef initAuxCntEvent
74
of file platform/emlib/src/em_pcnt.c
Function Documentation#
PCNT_CounterReset#
void PCNT_CounterReset (PCNT_TypeDef * pcnt)
Reset PCNT counters and TOP register.
[in] | pcnt | A pointer to the PCNT peripheral register block. |
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 an external clock.) The SYNCBUSY bit will however be set, leading to a synchronization in the LF domain, with, in reality, no changes.
119
of file platform/emlib/src/em_pcnt.c
PCNT_Enable#
void PCNT_Enable (PCNT_TypeDef * pcnt, PCNT_Mode_TypeDef mode)
Set PCNT operational mode.
[in] | pcnt | A pointer to the PCNT peripheral register block. |
[in] | mode | An operational mode to use for PCNT. |
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 an external clock is used for the PCNT module, since stall time may be undefined.
160
of file platform/emlib/src/em_pcnt.c
PCNT_IsEnabled#
bool PCNT_IsEnabled (PCNT_TypeDef * pcnt)
Returns if the PCNT module is enabled or not.
[in] | pcnt | A pointer to the PCNT peripheral register block. |
Notice that this function does not do any configuration.
Returns
Returns TRUE if the module is enabled.
221
of file platform/emlib/src/em_pcnt.c
PCNT_CounterTopSet#
void PCNT_CounterTopSet (PCNT_TypeDef * pcnt, uint32_t count, uint32_t top)
Set the counter and top values.
[in] | pcnt | A pointer to the PCNT peripheral register block. |
[in] | count | A value to set in the counter register. |
[in] | top | A value to set in the top register. |
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 an external clock is used for the PCNT module, since stall time may be undefined. The counter should normally only be set when operating in (or about to enable) pcntModeOvsSingle mode.
256
of file platform/emlib/src/em_pcnt.c
PCNT_PRSInputEnable#
void PCNT_PRSInputEnable (PCNT_TypeDef * pcnt, PCNT_PRSInput_TypeDef prsInput, bool enable)
Enable/disable the selected PRS input of PCNT.
[in] | pcnt | A pointer to the 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. |
Notice that this function does not do any configuration.
367
of file platform/emlib/src/em_pcnt.c
PCNT_Init#
void PCNT_Init (PCNT_TypeDef * pcnt, const PCNT_Init_TypeDef * init)
Initialize the pulse counter.
[in] | pcnt | A pointer to the PCNT peripheral register block. |
[in] | init | A pointer to the initialization structure. |
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 the external pin clock usage mode is chosen. The pulse counter clock for the selected instance must also be enabled prior to initialization.
Notice that pins used by the PCNT module must be properly configured by the user explicitly through setting the ROUTE register 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 a delay.
512
of file platform/emlib/src/em_pcnt.c
PCNT_Reset#
void PCNT_Reset (PCNT_TypeDef * pcnt)
Reset PCNT to the same state that it was in after a hardware reset.
[in] | pcnt | A pointer to the PCNT peripheral register block. |
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 initialization.
Note
The ROUTE register is NOT reset by this function to allow for centralized setup of this feature.
805
of file platform/emlib/src/em_pcnt.c
PCNT_FilterConfiguration#
void PCNT_FilterConfiguration (PCNT_TypeDef * pcnt, const PCNT_Filter_TypeDef * config, bool enable)
Set the filter configuration.
[in] | pcnt | A pointer to the PCNT peripheral register block. |
[in] | config | A pointer to the configuration structure to be applied. |
[in] | enable | Indicates whether to enable or disable filtering. |
This function will configure the PCNT input filter when the PCNT mode is configured to take an LFA-derived clock as an input clock.
877
of file platform/emlib/src/em_pcnt.c
PCNT_TopBufferSet#
void PCNT_TopBufferSet (PCNT_TypeDef * pcnt, uint32_t val)
Set top buffer value.
[in] | pcnt | A pointer to the PCNT peripheral register block. |
[in] | val | A value to set in the top buffer register. |
Note
This function may stall until synchronization to low-frequency domain is completed. For that reason, it should normally not be used when an external clock is used for the PCNT module since stall time may be undefined.
1001
of file platform/emlib/src/em_pcnt.c
PCNT_TopSet#
void PCNT_TopSet (PCNT_TypeDef * pcnt, uint32_t val)
Set the top value.
[in] | pcnt | A pointer to the PCNT peripheral register block. |
[in] | val | A value to set in the top register. |
Note
This function will stall until synchronization to low-frequency domain is completed. For that reason, it should normally not be used when an external clock is used for the PCNT module since stall time may be undefined.
1026
of file platform/emlib/src/em_pcnt.c
PCNT_CounterGet#
uint32_t PCNT_CounterGet (PCNT_TypeDef * pcnt)
Get the pulse counter value.
[in] | pcnt | Pointer to the PCNT peripheral register block. |
Returns
Current pulse counter value.
496
of file platform/emlib/inc/em_pcnt.h
PCNT_AuxCounterGet#
uint32_t PCNT_AuxCounterGet (PCNT_TypeDef * pcnt)
Get the auxiliary counter value.
[in] | pcnt | Pointer to the PCNT peripheral register block. |
Returns
Current auxiliary counter value.
512
of file platform/emlib/inc/em_pcnt.h
PCNT_CounterSet#
void PCNT_CounterSet (PCNT_TypeDef * pcnt, uint32_t count)
Set a counter value.
[in] | pcnt | Pointer to the PCNT peripheral register block. |
[in] | count | Value to set in counter register. |
Pulse counter is disabled while changing counter value and re-enabled (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.
542
of file platform/emlib/inc/em_pcnt.h
PCNT_IntClear#
void PCNT_IntClear (PCNT_TypeDef * pcnt, uint32_t flags)
Clear one or more pending PCNT interrupts.
[in] | pcnt | Pointer to the 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). |
579
of file platform/emlib/inc/em_pcnt.h
PCNT_IntDisable#
void PCNT_IntDisable (PCNT_TypeDef * pcnt, uint32_t flags)
Disable one or more PCNT interrupts.
[in] | pcnt | Pointer to the PCNT peripheral register block. |
[in] | flags | PCNT interrupt sources to disable. Use a bitwise logic OR combination of valid interrupt flags for PCNT module (PCNT_IF_nnn). |
599
of file platform/emlib/inc/em_pcnt.h
PCNT_IntEnable#
void PCNT_IntEnable (PCNT_TypeDef * pcnt, uint32_t flags)
Enable one or more PCNT interrupts.
[in] | pcnt | Pointer to the PCNT peripheral register block. |
[in] | flags | PCNT interrupt sources to enable. Use a bitwise logic OR combination of valid interrupt flags for PCNT module (PCNT_IF_nnn). |
Note
Depending on the use, a pending interrupt may already be set prior to enabling the interrupt. To ignore a pending interrupt, consider using PCNT_IntClear() prior to enabling the interrupt.
624
of file platform/emlib/inc/em_pcnt.h
PCNT_IntGet#
uint32_t PCNT_IntGet (PCNT_TypeDef * pcnt)
Get pending PCNT interrupt flags.
[in] | pcnt | Pointer to the PCNT peripheral register block. |
Note
The event bits are not cleared by the use of this function.
Returns
PCNT interrupt sources pending. A bitwise logic OR combination of valid interrupt flags for PCNT module (PCNT_IF_nnn).
647
of file platform/emlib/inc/em_pcnt.h
PCNT_IntGetEnabled#
uint32_t PCNT_IntGetEnabled (PCNT_TypeDef * pcnt)
Get enabled and pending PCNT interrupt flags.
[in] | pcnt | Pointer to thePCNT peripheral register block. |
Useful for handling more interrupt sources in the same interrupt handler.
Note
The event bits are not cleared by the use of this function.
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).
673
of file platform/emlib/inc/em_pcnt.h
PCNT_IntSet#
void PCNT_IntSet (PCNT_TypeDef * pcnt, uint32_t flags)
Set one or more pending PCNT interrupts from SW.
[in] | pcnt | Pointer to the PCNT peripheral register block. |
[in] | flags | PCNT interrupt sources to set to pending. Use a bitwise logic OR combination of valid interrupt flags for PCNT module (PCNT_IF_nnn). |
696
of file platform/emlib/inc/em_pcnt.h
PCNT_Lock#
void PCNT_Lock (PCNT_TypeDef * pcnt)
Lock PCNT registers.
[in] | pcnt | Pointer to the PCNT peripheral register block. |
Note
When PCNT registers are locked PCNT_CFG, PCNT_EN, PCNT_SWRST, PCNT_CMD, PCNT_CTRL, PCNT_OVSCTRL, PCNT_CNT, PCNT_TOP, and PCNT_TOPB registers cannot be written to.
717
of file platform/emlib/inc/em_pcnt.h
PCNT_Unlock#
void PCNT_Unlock (PCNT_TypeDef * pcnt)
Unlock PCNT registers.
[in] | pcnt | Pointer to thePCNT peripheral register block. |
731
of file platform/emlib/inc/em_pcnt.h
PCNT_TopBufferGet#
uint32_t PCNT_TopBufferGet (PCNT_TypeDef * pcnt)
Get the pulse counter top buffer value.
[in] | pcnt | Pointer to the PCNT peripheral register block. |
Returns
Current pulse counter top buffer value.
749
of file platform/emlib/inc/em_pcnt.h
PCNT_TopGet#
uint32_t PCNT_TopGet (PCNT_TypeDef * pcnt)
Get the pulse counter top value.
[in] | pcnt | Pointer to the PCNT peripheral register block. |
Returns
Current pulse counter top value.
770
of file platform/emlib/inc/em_pcnt.h
PCNT_Sync#
void PCNT_Sync (PCNT_TypeDef * pcnt, uint32_t mask)
Wait for an ongoing sync of register(s) to low-frequency domain to complete.
[in] | pcnt | A pointer to the PCNT peripheral register block. |
[in] | mask | A bitmask corresponding to SYNCBUSY register defined bits indicating registers that must complete any ongoing synchronization. |
792
of file platform/emlib/inc/em_pcnt.h
PCNT_StartMainCnt#
void PCNT_StartMainCnt (PCNT_TypeDef * pcnt)
Start the main PCNT counter.
[in] | pcnt | A pointer to the PCNT peripheral register block. |
This function will send a start command to the PCNT peripheral. The PCNT peripheral will use some LF clock ticks before the command is executed. The PCNT_Sync() function can be used to wait for the start command to be executed.
Note
This function requires the PCNT to be enabled.
825
of file platform/emlib/inc/em_pcnt.h
PCNT_StopMainCnt#
void PCNT_StopMainCnt (PCNT_TypeDef * pcnt)
Stop the main PCNT counter.
[in] | pcnt | A pointer to the PCNT peripheral register block. |
This function will send a stop command to the PCNT peripheral. The PCNT peripheral will use some LF clock ticks before the command is executed. The PCNT_Sync() function can be used to wait for the stop command to be executed.
Note
This function requires the PCNT to be enabled.
847
of file platform/emlib/inc/em_pcnt.h
PCNT_StartAuxCnt#
void PCNT_StartAuxCnt (PCNT_TypeDef * pcnt)
Start the auxiliary PCNT counter.
[in] | pcnt | A pointer to the PCNT peripheral register block. |
This function will send a start command to the PCNT peripheral. The PCNT peripheral will use some LF clock ticks before the command is executed. The PCNT_Sync() function can be used to wait for the start command to be executed.
Note
This function requires the PCNT to be enabled.
869
of file platform/emlib/inc/em_pcnt.h
PCNT_StopAuxCnt#
void PCNT_StopAuxCnt (PCNT_TypeDef * pcnt)
Stop the auxiliary PCNT counter.
[in] | pcnt | A pointer to the PCNT peripheral register block. |
This function will send a stop command to the PCNT peripheral. The PCNT peripheral will use some LF clock ticks before the command is executed. The PCNT_Sync() function can be used to wait for the stop command to be executed.
Note
This function requires the PCNT to be enabled.
891
of file platform/emlib/inc/em_pcnt.h
Macro Definition Documentation#
PCNT0_CNT_SIZE#
#define PCNT0_CNT_SIZEValue:
(16)
PCNT0 Counter register size.
PCNT0 counter is 16 bits.
55
of file platform/emlib/inc/em_pcnt.h
PCNT_MODE_DISABLE#
#define PCNT_MODE_DISABLEValue:
0xFF
PCNT mode disable.
78
of file platform/emlib/inc/em_pcnt.h
PCNT_CNT_EVENT_NONE#
#define PCNT_CNT_EVENT_NONEValue:
0xFF
PCNT count event is none.
80
of file platform/emlib/inc/em_pcnt.h
DEFAULT_DEBUG_HALT#
#define DEFAULT_DEBUG_HALTValue:
true,
Default Debug.
317
of file platform/emlib/inc/em_pcnt.h
DEFAULT_MODE#
#define DEFAULT_MODEValue:
pcntModeDisable,
Default Mode.
Disabled by default.
323
of file platform/emlib/inc/em_pcnt.h
DEFAULT_HYST#
#define DEFAULT_HYSTValue:
false,
Default Hysteresis.
Hysteresis disabled.
327
of file platform/emlib/inc/em_pcnt.h
DEFAULT_CDIR#
#define DEFAULT_CDIRValue:
true,
Default counter direction.
Counter direction is given by CNTDIR.
334
of file platform/emlib/inc/em_pcnt.h
DEFAULT_CNTEV#
#define DEFAULT_CNTEVValue:
pcntCntEventUp,
Default count event.
Regular counter counts up on upcount events.
341
of file platform/emlib/inc/em_pcnt.h
DEFAULT_AUXCNTEV#
#define DEFAULT_AUXCNTEVValue:
pcntCntEventNone,
Default auxiliary count event.
Auxiliary counter doesn't respond to events.
348
of file platform/emlib/inc/em_pcnt.h
DEFAULT_PRS_CH#
#define DEFAULT_PRS_CHValue:
0u,
Default selected PRS channel as S0IN and S1IN.
357
of file platform/emlib/inc/em_pcnt.h
PCNT_INIT_DEFAULT#
#define PCNT_INIT_DEFAULTValue:
Default configuration for PCNT initialization structure.
363
of file platform/emlib/inc/em_pcnt.h
PCNT_FILTER_DEFAULT#
#define PCNT_FILTER_DEFAULTValue:
Default configuration for PCNT initialization structure.
395
of file platform/emlib/inc/em_pcnt.h