PCNT - Pulse Counter
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 |
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struct | PCNT_Init_TypeDef |
Initialization structure.
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struct | PCNT_TCC_TypeDef |
TCC initialization structure.
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Functions |
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uint32_t | PCNT_CounterGet (PCNT_TypeDef *pcnt) |
Get pulse counter value.
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uint32_t | PCNT_AuxCounterGet (PCNT_TypeDef *pcnt) |
Get auxiliary counter value.
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void | PCNT_CounterReset (PCNT_TypeDef *pcnt) |
Reset PCNT counters and TOP register.
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void | PCNT_CounterTopSet (PCNT_TypeDef *pcnt, uint32_t count, uint32_t top) |
Set the counter and top values.
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void | PCNT_CounterSet (PCNT_TypeDef *pcnt, uint32_t count) |
Set counter value.
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void | PCNT_Enable (PCNT_TypeDef *pcnt, PCNT_Mode_TypeDef mode) |
Set PCNT operational mode.
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bool | PCNT_IsEnabled (PCNT_TypeDef *pcnt) |
Returns if the PCNT module is enabled or not.
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void | PCNT_FreezeEnable (PCNT_TypeDef *pcnt, bool enable) |
PCNT register synchronization freeze control.
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void | PCNT_Init (PCNT_TypeDef *pcnt, const PCNT_Init_TypeDef *init) |
Initialize the pulse counter.
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void | PCNT_PRSInputEnable (PCNT_TypeDef *pcnt, PCNT_PRSInput_TypeDef prsInput, bool enable) |
Enable/disable the selected PRS input of PCNT.
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void | PCNT_TCCConfiguration (PCNT_TypeDef *pcnt, const PCNT_TCC_TypeDef *config) |
Set Triggered Compare and Clear configuration.
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void | PCNT_IntClear (PCNT_TypeDef *pcnt, uint32_t flags) |
Clear one or more pending PCNT interrupts.
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void | PCNT_IntDisable (PCNT_TypeDef *pcnt, uint32_t flags) |
Disable one or more PCNT interrupts.
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void | PCNT_IntEnable (PCNT_TypeDef *pcnt, uint32_t flags) |
Enable one or more PCNT interrupts.
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uint32_t | PCNT_IntGet (PCNT_TypeDef *pcnt) |
Get pending PCNT interrupt flags.
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uint32_t | PCNT_IntGetEnabled (PCNT_TypeDef *pcnt) |
Get enabled and pending PCNT interrupt flags.
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void | PCNT_IntSet (PCNT_TypeDef *pcnt, uint32_t flags) |
Set one or more pending PCNT interrupts from SW.
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void | PCNT_Reset (PCNT_TypeDef *pcnt) |
Reset PCNT to the same state that it was in after a hardware reset.
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uint32_t | PCNT_TopBufferGet (PCNT_TypeDef *pcnt) |
Get pulse counter top buffer value.
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void | PCNT_TopBufferSet (PCNT_TypeDef *pcnt, uint32_t val) |
Set top buffer value.
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uint32_t | PCNT_TopGet (PCNT_TypeDef *pcnt) |
Get pulse counter top value.
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void | PCNT_TopSet (PCNT_TypeDef *pcnt, uint32_t val) |
Set the top value.
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void | PCNT_Sync (PCNT_TypeDef *pcnt, uint32_t mask) |
Wait for an ongoing sync of register(s) to low-frequency domain to complete.
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Macros |
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#define | PCNT0_CNT_SIZE (16) |
PCNT0 Counter register size.
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#define | PCNT_MODE_DISABLE 0xFF |
PCNT mode disable.
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#define | PCNT_CNT_EVENT_NONE 0xFF |
PCNT count event is none.
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#define | DEFAULT_DEBUG_HALT |
Default Debug.
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#define | DEFAULT_MODE pcntModeDisable , |
Default Mode.
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#define | DEFAULT_HYST false, |
Default Hysteresis.
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#define | DEFAULT_CDIR true, |
Default counter direction.
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#define | DEFAULT_CNTEV pcntCntEventUp , |
Default count event.
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#define | DEFAULT_AUXCNTEV pcntCntEventNone , |
Default auxiliary count event.
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#define | DEFAULT_PRS_CH pcntPRSCh0 , |
Default selected PRS channel as S0IN and S1IN.
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#define | PCNT_INIT_DEFAULT |
Default configuration for PCNT initialization structure.
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#define | PCNT_TCC_DEFAULT |
TCC Default.
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Enumerations |
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enum |
PCNT_Mode_TypeDef
{
pcntModeDisable = _PCNT_CTRL_MODE_DISABLE, pcntModeOvsSingle = _PCNT_CTRL_MODE_OVSSINGLE, pcntModeExtSingle = _PCNT_CTRL_MODE_EXTCLKSINGLE, pcntModeExtQuad = _PCNT_CTRL_MODE_EXTCLKQUAD } |
Mode selection.
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enum |
PCNT_CntEvent_TypeDef
{
pcntCntEventBoth = _PCNT_CTRL_CNTEV_BOTH, pcntCntEventUp = _PCNT_CTRL_CNTEV_UP, pcntCntEventDown = _PCNT_CTRL_CNTEV_DOWN, pcntCntEventNone = _PCNT_CTRL_CNTEV_NONE } |
Counter event selection.
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enum |
PCNT_PRSSel_TypeDef
{
pcntPRSCh0 = 0, pcntPRSCh1 = 1, pcntPRSCh2 = 2, pcntPRSCh3 = 3 } |
PRS sources for
s0PRS
and
s1PRS
.
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enum |
PCNT_PRSInput_TypeDef
{
pcntPRSInputS0 = 0, pcntPRSInputS1 = 1 } |
PRS inputs of PCNT.
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enum |
PCNT_TCCMode_TypeDef
{
tccModeDisabled = _PCNT_CTRL_TCCMODE_DISABLED, tccModeLFA = _PCNT_CTRL_TCCMODE_LFA, tccModePRS = _PCNT_CTRL_TCCMODE_PRS } |
Default configuration for PCNT initialization structure.
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enum |
PCNT_TCCPresc_Typedef
{
tccPrescDiv1 = _PCNT_CTRL_TCCPRESC_DIV1, tccPrescDiv2 = _PCNT_CTRL_TCCPRESC_DIV2, tccPrescDiv4 = _PCNT_CTRL_TCCPRESC_DIV4, tccPrescDiv8 = _PCNT_CTRL_TCCPRESC_DIV8 } |
Prescaler values for LFA compare and clear events.
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enum |
PCNT_TCCComp_Typedef
{
tccCompLTOE = _PCNT_CTRL_TCCCOMP_LTOE, tccCompGTOE = _PCNT_CTRL_TCCCOMP_GTOE, tccCompRange = _PCNT_CTRL_TCCCOMP_RANGE } |
Compare modes for TCC module.
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Function Documentation
◆ PCNT_CounterGet()
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inline |
Get pulse counter value.
- Parameters
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[in] pcnt
Pointer to PCNT peripheral register block.
- Returns
- Current pulse counter value.
◆ PCNT_AuxCounterGet()
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inline |
Get auxiliary counter value.
- Parameters
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[in] pcnt
Pointer to PCNT peripheral register block.
- Returns
- Current auxiliary counter value.
◆ PCNT_CounterReset()
void PCNT_CounterReset | ( | PCNT_TypeDef * |
pcnt
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) |
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 an external clock.) The SYNCBUSY bit will however be set, leading to a synchronization in the LF domain, with, in reality, no changes.
- Parameters
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[in] pcnt
A pointer to the PCNT peripheral register block.
◆ PCNT_CounterTopSet()
void PCNT_CounterTopSet | ( | PCNT_TypeDef * |
pcnt,
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uint32_t |
count,
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uint32_t |
top
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Set the 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 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.
- Parameters
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[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.
◆ PCNT_CounterSet()
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inline |
Set counter value.
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.
- Parameters
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[in] pcnt
Pointer to PCNT peripheral register block. [in] count
Value to set in counter register.
◆ PCNT_Enable()
void PCNT_Enable | ( | PCNT_TypeDef * |
pcnt,
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PCNT_Mode_TypeDef |
mode
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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 an external clock is used for the PCNT module, since stall time may be undefined.
- Parameters
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[in] pcnt
A pointer to the PCNT peripheral register block. [in] mode
An operational mode to use for PCNT.
◆ PCNT_IsEnabled()
bool PCNT_IsEnabled | ( | PCNT_TypeDef * |
pcnt
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Returns if the PCNT module is enabled or not.
Notice that this function does not do any configuration.
- Parameters
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[in] pcnt
A pointer to the PCNT peripheral register block.
- Returns
- Returns TRUE if the module is enabled.
◆ PCNT_FreezeEnable()
void PCNT_FreezeEnable | ( | PCNT_TypeDef * |
pcnt,
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bool |
enable
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) |
PCNT register synchronization freeze control.
Some PCNT registers require synchronization into the low-frequency (LF) domain. The freeze feature allows for several 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 the LF domain to complete (normally synchronization will not be in progress). However, for this reason, when using freeze mode, modifications of registers requiring the LF synchronization should be done within one freeze enable/disable block to avoid unnecessary stalling.
- Parameters
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[in] pcnt
A pointer to the 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.
◆ PCNT_Init()
void PCNT_Init | ( | PCNT_TypeDef * |
pcnt,
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const PCNT_Init_TypeDef * |
init
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Initialize the 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 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.
- Parameters
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[in] pcnt
A pointer to the PCNT peripheral register block. [in] init
A pointer to the initialization structure.
◆ PCNT_PRSInputEnable()
void PCNT_PRSInputEnable | ( | PCNT_TypeDef * |
pcnt,
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PCNT_PRSInput_TypeDef |
prsInput,
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bool |
enable
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Enable/disable the selected PRS input of PCNT.
Notice that this function does not do any configuration.
- Parameters
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[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.
◆ PCNT_TCCConfiguration()
void PCNT_TCCConfiguration | ( | PCNT_TypeDef * |
pcnt,
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const PCNT_TCC_TypeDef * |
config
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) |
Set Triggered Compare and Clear configuration.
This function will configure the PCNT TCC (Triggered Compare and Clear) module. This module can, upon a configurable trigger source, compare the current counter value with the configured TOP value. Upon match, the counter will be reset and the TCC PRS output and TCC interrupt flag will be set.
Since there is a comparison with the TOP value, the counter will not stop counting nor wrap when hitting the TOP value, but it will keep on counting until its maximum value. Then, it will not wrap, but stop counting and set the overflow flag.
- Parameters
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[in] pcnt
A pointer to the PCNT peripheral register block. [in] config
A pointer to the configuration structure to be applied.
◆ PCNT_IntClear()
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inline |
Clear one or more pending PCNT interrupts.
- Parameters
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[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).
◆ PCNT_IntDisable()
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inline |
Disable one or more PCNT interrupts.
- Parameters
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[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 PCNT module (PCNT_IF_nnn).
◆ PCNT_IntEnable()
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inline |
Enable one or more PCNT interrupts.
- 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.
- 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 PCNT module (PCNT_IF_nnn).
◆ PCNT_IntGet()
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inline |
Get pending PCNT interrupt flags.
- Note
- The event bits are not cleared by the use of this function.
- Parameters
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[in] pcnt
Pointer to PCNT peripheral register block.
- Returns
- PCNT interrupt sources pending. A bitwise logic OR combination of valid interrupt flags for PCNT module (PCNT_IF_nnn).
◆ PCNT_IntGetEnabled()
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inline |
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
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[in] pcnt
Pointer to PCNT peripheral register block.
- Returns
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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).
◆ PCNT_IntSet()
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inline |
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 PCNT module (PCNT_IF_nnn).
◆ PCNT_Reset()
void PCNT_Reset | ( | PCNT_TypeDef * |
pcnt
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) |
Reset PCNT to the same state that it was in after a hardware 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 initialization.
- Note
- The ROUTE register is NOT reset by this function to allow for centralized setup of this feature.
- Parameters
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[in] pcnt
A pointer to the PCNT peripheral register block.
◆ PCNT_TopBufferGet()
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inline |
Get pulse counter top buffer value.
- Parameters
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[in] pcnt
Pointer to PCNT peripheral register block.
- Returns
- Current pulse counter top buffer value.
◆ PCNT_TopBufferSet()
void PCNT_TopBufferSet | ( | PCNT_TypeDef * |
pcnt,
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uint32_t |
val
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) |
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 an external clock is used for the PCNT module since stall time may be undefined.
- Parameters
-
[in] pcnt
A pointer to the PCNT peripheral register block. [in] val
A value to set in the top buffer register.
◆ PCNT_TopGet()
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inline |
Get pulse counter top value.
- Parameters
-
[in] pcnt
Pointer to PCNT peripheral register block.
- Returns
- Current pulse counter top value.
◆ PCNT_TopSet()
void PCNT_TopSet | ( | PCNT_TypeDef * |
pcnt,
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uint32_t |
val
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) |
Set the 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 an external clock is used for the PCNT module since stall time may be undefined.
- Parameters
-
[in] pcnt
A pointer to the PCNT peripheral register block. [in] val
A value to set in the top register.
◆ PCNT_Sync()
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inline |
Wait for an ongoing sync of register(s) to low-frequency domain to complete.
- Parameters
-
[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.
Macro Definition Documentation
◆ PCNT0_CNT_SIZE
#define PCNT0_CNT_SIZE (16) |
PCNT0 Counter register size.
PCNT0 counter is 16 bits.
◆ PCNT_MODE_DISABLE
#define PCNT_MODE_DISABLE 0xFF |
PCNT mode disable.
◆ PCNT_CNT_EVENT_NONE
#define PCNT_CNT_EVENT_NONE 0xFF |
PCNT count event is none.
◆ DEFAULT_DEBUG_HALT
#define DEFAULT_DEBUG_HALT |
Default Debug.
◆ DEFAULT_MODE
#define DEFAULT_MODE pcntModeDisable , |
Default Mode.
Disabled by default.
◆ DEFAULT_HYST
#define DEFAULT_HYST false, |
Default Hysteresis.
Hysteresis disabled.
◆ DEFAULT_CDIR
#define DEFAULT_CDIR true, |
Default counter direction.
Counter direction is given by CNTDIR.
◆ DEFAULT_CNTEV
#define DEFAULT_CNTEV pcntCntEventUp , |
Default count event.
Regular counter counts up on upcount events.
◆ DEFAULT_AUXCNTEV
#define DEFAULT_AUXCNTEV pcntCntEventNone , |
Default auxiliary count event.
Auxiliary counter doesn't respond to events.
◆ DEFAULT_PRS_CH
#define DEFAULT_PRS_CH pcntPRSCh0 , |
Default selected PRS channel as S0IN and S1IN.
PRS channel 0 selected as S0IN and as S1IN.
◆ PCNT_INIT_DEFAULT
#define PCNT_INIT_DEFAULT |
Default configuration for PCNT initialization structure.
◆ PCNT_TCC_DEFAULT
#define PCNT_TCC_DEFAULT |
TCC Default.
Enumeration Type Documentation
◆ PCNT_Mode_TypeDef
enum PCNT_Mode_TypeDef |
Mode selection.
◆ PCNT_CntEvent_TypeDef
Counter event selection.
Note: unshifted values are being used for enumeration because multiple configuration structure members use this type definition.
◆ PCNT_PRSSel_TypeDef
enum PCNT_PRSSel_TypeDef |
◆ PCNT_PRSInput_TypeDef
◆ PCNT_TCCMode_TypeDef
enum PCNT_TCCMode_TypeDef |
Default configuration for PCNT initialization structure.
Modes for Triggered Compare and Clear module.
◆ PCNT_TCCPresc_Typedef
Prescaler values for LFA compare and clear events.
Only has effect when TCC mode is LFA.
◆ PCNT_TCCComp_Typedef
enum PCNT_TCCComp_Typedef |
Compare modes for TCC module.