Overview

The MCUXpresso SDK provides a driver for the Signal Frequency Analyser (SFA) of MCUXpresso SDK devices.

Function groups

The SFA driver supports operating the module to measure clock frequency, clock period and time between triggers.

Initialization and Deinitialization

The function SFA_Init() enables the SFA clock. The function SFA_Deinit() clears each conters and status flags, disables SFA, gates the SFA clock. The function SFA_GetDefaultConfig() gets the default configurations. The function SFA_EnableCUTPin() controls the connection of the CUT to an external pin.

Status

Provides functions to get and clear the SFA status.

Interrupt

Provides functions to enable/disable SFA interrupts.

SFA measurement Operations

The function SFA_InstallCallback() installs the callback function to be called when measure finish. The function SFA_SetMeasureConfig() sets the measurement options. The function SFA_MeasureBlocking() starts measure sequence in blocking mode. The funciton SFA_MeasureNonBlocking() starts measure sequence in nonblocking mode. The function SFA_AbortMeasureSequence() aborts measure sequence. The funciton SFA_CalculateFrequencyOrPeriod() calculates the frequency or period based on the reference clock frequency.

Control CUT counter

The function SFA_GetCUTCounter() gets current counts of the CUT counter. The function SFA_SetCUTTargetCount() sets the target counts for the CUT. The function SFA_GetCUTTargetCount() gets the target counts of the CUT. The function SFA_SetCUTLowLimitClockCount() sets CUT low limit clock count. The function SFA_GetCUTLowLimitClockCount() Gets CUT low limit clock count. The function SFA_SetCUTHighLimitClockCount() sets CUT high limit clock count. The function SFA_GetCUTHighLimitClockCount() Gets CUT high limit clock count.

Control REF counter

The function SFA_GetREFCouner() get current counts of the REF counter. The function SFA_SetREFTargetCount() sets the target counts for the CUT. The function SFA_GetREFTargetCount() gets the target counts of the CUT. The function SFA_GetREFStartCount() gets the saved REF count when measurement starts. The function SFA_GetREFEndCount() gets the saved REF count when measurement ends. The function SFA_SetREFLowLimitClockCount() sets REF low limit clock count. The function SFA_GetREFLowLimitClockCount() Gets REF low limit clock count. The function SFA_SetREFHighLimitClockCount() sets REF high limit clock count. The function SFA_GetREFHighLimitClockCount() Gets REF high limit clock count.

Data Structures
struct	sfa_config_t
	Structure with setting to initialize the SFA module. More...

Typedefs
typedef void(*	sfa_callback_t )(status_t status)
	sfa measure completion callback function pointer type More...

Enumerations
enum	{ kStatus_SFA_MeasurementCompleted = MAKE_STATUS(kStatusGroup_SFA, 0U), kStatus_SFA_ReferenceCounterTimeout = MAKE_STATUS(kStatusGroup_SFA, 1U), kStatus_SFA_CUTCounterTimeout = MAKE_STATUS(kStatusGroup_SFA, 2U), kStatus_SFA_CUTClockFreqLessThanMinLimit = MAKE_STATUS(kStatusGroup_SFA, 3U), kStatus_SFA_CUTClockFreqGreaterThanMaxLimit = MAKE_STATUS(kStatusGroup_SFA, 4U) }
	SFA status return codes. More...

enum	_sfa_status_flags { kSFA_RefStoppedFlag = SFA_CNT_STAT_REF_STOPPED_MASK, kSFA_CutStoppedFlag = SFA_CNT_STAT_CUT_STOPPED_MASK, kSFA_MeasurementStartedFlag = SFA_CNT_STAT_MEAS_STARTED_MASK, kSFA_ReferenceCounterTimeOutFlag = SFA_CNT_STAT_REF_CNT_TIMEOUT_MASK, kSFA_InterruptRequestFlag = SFA_CNT_STAT_SFA_IRQ_MASK, kSFA_FreqGreaterThanMaxInterruptFlag = SFA_CNT_STAT_FREQ_GT_MAX_IRQ_MASK, kSFA_FreqLessThanMinInterruptFlag = SFA_CNT_STAT_FREQ_LT_MIN_IRQ_MASK }
	List of SFA status flags. More...

enum	_sfa_interrupts_enable { kSFA_InterruptEnable = SFA_CTRL_SFA_IRQ_EN_MASK, kSFA_FreqGreaterThanMaxInterruptEnable = SFA_CTRL2_FREQ_GT_MAX_IRQ_EN_MASK, kSFA_FreqLessThanMinInterruptEnable = SFA_CTRL2_FREQ_LT_MIN_IRQ_EN_MASK }
	List of SFA interrupt. More...

enum	sfa_measurement_mode_t { kSFA_FrequencyMeasurement0 = 0U, kSFA_FrequencyMeasurement1 = 1U, kSFA_CUTPeriodMeasurement = 2U, kSFA_TriggerBasedMeasurement = 3U }
	List of SFA measurement mode(Please check the mode configuration according to the manual). More...

enum	sfa_cut_select_t
	List of CUT which is connected to the CUT counter (Please refer to the manual for configuration).

enum	sfa_ref_select_t
	List of REF which is connected to the REF counter (Please refer to the manual for configuration).

enum	sfa_trigger_start_select_t
	List of Signal MUX for Trigger Based Measurement Start.

enum	sfa_trigger_end_select_t
	List of Signal MUX for Trigger Based Measurement End.

enum	sfa_trigger_start_polarity_t { kSFA_TriggerStartPolarityRiseEdge = 0U, kSFA_TriggerStartPolarityFallEdge = 1U }
	List of Trigger Start Polarity. More...

enum	sfa_trigger_end_polarity_t { kSFA_TriggerEndPolarityRiseEdge = 0U, kSFA_TriggerEndPolarityFallEdge = 1U }
	List of Trigger End Polarity. More...

Driver version
#define	FSL_SFA_DRVIER_VERSION (MAKE_VERSION(2, 1, 0))
	SFA driver version 2.1.0.

Initialization and Deinitialization.
void	SFA_GetDefaultConfig (sfa_config_t *config)
	Fill the SFA configuration structure with default settings. More...

void	SFA_Init (SFA_Type *base)
	Initialize SFA. More...

void	SFA_Deinit (SFA_Type *base)
	Clear counter, disable SFA and gate the SFA clock. More...

static void	SFA_EnableCUTPin (SFA_Type *base, bool enable)
	Control the connection of the clock under test to an external pin. More...

Status Interface
static uint32_t	SFA_GetStatusFlags (SFA_Type *base)
	Get SFA status flags. More...

void	SFA_ClearStatusFlag (SFA_Type *base, uint32_t mask)
	Clear the SFA status flags. More...

Interrupts Interface
static void	SFA_EnableInterrupts (SFA_Type *base, uint32_t mask)
	Enable the selected SFA interrupt. More...

static void	SFA_DisableInterrupts (SFA_Type *base, uint32_t mask)
	Disable the selected SFA interrupt. More...

Control SFA Measurement sequence.
static uint8_t	SFA_GetMode (SFA_Type *base)
	Get SFA measurement mode. More...

static uint8_t	SFA_GetCUTPredivide (SFA_Type *base)
	Get CUT predivide value. More...

void	SFA_InstallCallback (SFA_Type *base, sfa_callback_t function)
	Install the callback function to be called when IRQ happens or measurement completes. More...

void	SFA_SetMeasureConfig (SFA_Type base, const sfa_config_t config)
	Set Measurement options with the passed in configuration structure. More...

status_t	SFA_MeasureBlocking (SFA_Type *base)
	Start SFA measurement in blocking mode. More...

void	SFA_MeasureNonBlocking (SFA_Type *base)
	Start measure sequence in NonBlocking mode. More...

void	SFA_AbortMeasureSequence (SFA_Type *base)
	Abort SFA measurement sequence. More...

uint32_t	SFA_CalculateFrequencyOrPeriod (SFA_Type *base, uint32_t refFrequency)
	Calculate the frequency or period. More...

Control CUT counter
static uint32_t	SFA_GetCUTCounter (SFA_Type *base)
	Get current count of the clock under test. More...

static void	SFA_SetCUTTargetCount (SFA_Type *base, uint32_t count)
	Set the target count for the clock under test. More...

static uint32_t	SFA_GetCUTTargetCount (SFA_Type *base)
	Get the target count of the clock under test. More...

static void	SFA_SetCUTLowLimitClockCount (SFA_Type *base, uint32_t count)
	Set CUT low limit clock count. More...

static uint32_t	SFA_GetCUTLowLimitClockCount (SFA_Type *base)
	Get CUT low limit clock count. More...

static void	SFA_SetCUTHighLimitClockCount (SFA_Type *base, uint32_t count)
	Set CUT high limit clock count. More...

static uint32_t	SFA_GetCUTHighLimitClockCount (SFA_Type *base)
	Get CUT high limit clock count. More...

Control REF counter
static uint32_t	SFA_GetREFCounter (SFA_Type *base)
	Get current count of the reference clock. More...

static void	SFA_SetREFTargetCount (SFA_Type *base, uint32_t count)
	Set the target count for the reference clock. More...

static uint32_t	SFA_GetREFTargetCount (SFA_Type *base)
	Get the target count of the reference clock. More...

static uint32_t	SFA_GetREFStartCount (SFA_Type *base)
	Get saved reference clock counter which is loaded when measurement start. More...

static uint32_t	SFA_GetREFEndCount (SFA_Type *base)
	Get saved reference clock counter which is loaded when measurement complete. More...

static void	SFA_SetREFLowLimitClockCount (SFA_Type *base, uint32_t count)
	Set REF low limit clock count. More...

static uint32_t	SFA_GetREFLowLimitClockCount (SFA_Type *base)
	Get REF low limit clock count. More...

static void	SFA_SetREFHighLimitClockCount (SFA_Type *base, uint32_t count)
	Set REF high limit clock count. More...

static uint32_t	SFA_GetREFHighLimitClockCount (SFA_Type *base)
	Get REF high limit clock count. More...

Data Structure Documentation

struct sfa_config_t

This structure holds configuration setting for the SFA peripheral. To initialize this structure to reasonable defaults, call the SFA_GetDefaultConfig() function and pass a pointer to your configuration structure instance.

Data Fields
sfa_measurement_mode_t	mode
	measurement mode

sfa_cut_select_t	cutSelect
	Select clock connected to the clock under test counter.

sfa_ref_select_t	refSelect
	Selcet REF connected the bus clock.

uint8_t	prediv
	Integer divide of the Input CUT signal.

sfa_trigger_start_select_t	trigStart
	Select the signal will be used to end a trigger based measurement.

sfa_trigger_start_polarity_t	startPolarity
	Select the polarity of the start trigger signal.

sfa_trigger_end_select_t	trigEnd
	Select the signal will be used to commence a trigger based measurement.

sfa_trigger_end_polarity_t	endPolarity
	Select the polarity of the end trigger signal.

bool	enableTrigMeasurement
	false: The measurement will start by default with a dummy write to the CUT counter; true : The measurement will start after receiving a dummy write to the REF_CNT followed by receiving the trigger edge

bool	enableCUTPin
	Control the connection of the clock under test to an external pin. More...

uint32_t	refTarget
	Reference counter target counts.

uint32_t	cutTarget
	CUT counter target counts.

Field Documentation

bool sfa_config_t::enableCUTPin

Typedef Documentation

typedef void(* sfa_callback_t)(status_t status)

This callback can be used in non blocking IRQHandler. Specify the callback you want in the call to SFA_InstallCallback().

Parameters

base	SFA peripheral base address.
status	The runtime measurement status. kStatus_SFA_MeasurementCompleted: The measurement completes. kStatus_SFA_ReferenceCounterTimeout: Reference counter timeout happenes. kStatus_SFA_CUTCounterTimeout: CUT counter timeout happenes.

Enumeration Type Documentation

anonymous enum

enumeration _sfa_status

Enumerator
kStatus_SFA_MeasurementCompleted	Measurement completed.
kStatus_SFA_ReferenceCounterTimeout	Reference counter timeout.
kStatus_SFA_CUTCounterTimeout	CUT counter timeout.
kStatus_SFA_CUTClockFreqLessThanMinLimit	CUT clock frequency less than minimum limit.
kStatus_SFA_CUTClockFreqGreaterThanMaxLimit	CUT clock frequency greater than maximum limit.

enum _sfa_status_flags

The following status register flags can be cleared on any write to REF_CNT.

kSFA_RefStoppedFlag
kSFA_CutStoppedFlag
kSFA_MeasurementStartedFlag
kSFA_ReferenceCounterTimeOutFlag
kSFA_InterruptRequestFlag
kSFA_FreqGreaterThanMaxInterruptFlag
kSFA_FreqLessThanMinInterruptFlag

Note: These enums are meant to be OR'd together to from a bit mask.

Enumerator
kSFA_RefStoppedFlag	Reference counter stopped flag.
kSFA_CutStoppedFlag	CUT counter stopped flag.
kSFA_MeasurementStartedFlag	Measurement Started flag.
kSFA_ReferenceCounterTimeOutFlag	Reference counter time out flag.
kSFA_InterruptRequestFlag	SFA interrupt request flag.
kSFA_FreqGreaterThanMaxInterruptFlag	FREQ_GT_MAX interrupt flag.
kSFA_FreqLessThanMinInterruptFlag	FREQ_LT_MIN interrupt flag.

enum _sfa_interrupts_enable

Enumerator
kSFA_InterruptEnable	SFA interrupt enable.
kSFA_FreqGreaterThanMaxInterruptEnable	FREQ_GT_MAX interrupt enable.
kSFA_FreqLessThanMinInterruptEnable	FREQ_LT_MIN interrupt enable.

enum sfa_measurement_mode_t

Enumerator
kSFA_FrequencyMeasurement0	Frequency measurement performed with REF frequency > CUT frequency.
kSFA_FrequencyMeasurement1	Frequency measurement performed with REF frequency < CUT frequency.
kSFA_CUTPeriodMeasurement	CUT period measurement performed.
kSFA_TriggerBasedMeasurement	Trigger based measurement performed.

enum sfa_trigger_start_polarity_t

Enumerator
kSFA_TriggerStartPolarityRiseEdge	Rising edge will begin the measurement sequence.
kSFA_TriggerStartPolarityFallEdge	Falling edge will begin the measurement sequence.

enum sfa_trigger_end_polarity_t

Enumerator
kSFA_TriggerEndPolarityRiseEdge	Rising edge will end the measurement sequence.
kSFA_TriggerEndPolarityFallEdge	Falling edge will end the measurement sequence.

Function Documentation

void SFA_GetDefaultConfig ( sfa_config_t * config )

The default values are:

*      config->mode = kSFA_FrequencyMeasurement0;
*      config->cutSelect = kSFA_CUTSelect0;
*      config->refSelect = kSFA_REFSelect0;
*      config->prediv = 0U;
*      config->trigStart = kSFA_TriggerStartSelect0;
*      config->startPolarity = kSFA_TriggerStartPolarityRiseEdge;
*      config->trigEnd = kSFA_TriggerEndSelect0;
*      config->endPolarity = kSFA_TriggerEndPolarityRiseEdge;
*      config->enableTrigMeasurement = false;
*      config->enableCUTPin = false;
*      config->cutTarget = 0xffffU;
*      config->refTarget = 0xffffffffU;
* 

Parameters

config Pointer to the user configuration structure.

void SFA_Init ( SFA_Type * base )

Parameters

base	SFA peripheral base address.

void SFA_Deinit ( SFA_Type * base )

Parameters

base	SFA peripheral base address.

static void SFA_EnableCUTPin	(	SFA_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	SFA peripheral base address.
enable	true: connect the clock under test and external pin. false: Disconnect the clock under test and external pin.

static uint32_t SFA_GetStatusFlags ( SFA_Type * base )

inlinestatic

Parameters

base	SFA peripheral base address.

void SFA_ClearStatusFlag	(	SFA_Type *	base,
		uint32_t	mask
	)

Parameters

base	SFA peripheral base address.
mask	SFA status flag mask (see _sfa_status_flags for bit definition).

static void SFA_EnableInterrupts	(	SFA_Type *	base,
		uint32_t	mask
	)

inlinestatic

Parameters

base	SFA peripheral base address.
mask	The interrupt to enable (see _sfa_interrupts_enable for definition).

static void SFA_DisableInterrupts	(	SFA_Type *	base,
		uint32_t	mask
	)

inlinestatic

Parameters

base	SFA peripheral base address.
mask	The interrupt to disable (see _sfa_interrupts_enable for definition).

static uint8_t SFA_GetMode ( SFA_Type * base )

inlinestatic

Parameters

base	SFA peripheral base address.

static uint8_t SFA_GetCUTPredivide ( SFA_Type * base )

inlinestatic

Parameters

base	SFA peripheral base address.

void SFA_InstallCallback	(	SFA_Type *	base,
		sfa_callback_t	function
	)

Parameters

base	SFA peripheral base address.
function	the SFA measure completed callback function.

void SFA_SetMeasureConfig	(	SFA_Type *	base,
		const sfa_config_t *	config
	)

Parameters

base	SFA peripheral base address.
config	SFA configuration structure.

status_t SFA_MeasureBlocking ( SFA_Type * base )

Parameters

base	SFA peripheral base address.

Return values

kStatus_SFA_MeasurementCompleted	SFA measure completes.
kStatus_SFA_ReferenceCounterTimeout	reference counter timeout error happens.
kStatus_SFA_CUTCounterTimeout	CUT counter time out happens.

void SFA_MeasureNonBlocking ( SFA_Type * base )

This function performs nonblocking measurement by enabling sfa interrupt (Please enable the FreqGreaterThanMax and FreqLessThanMin interrupts individually as needed). The callback function must be installed before invoking this function.

Note: This function has different functions for different instances.

Parameters

base	SFA peripheral base address.

void SFA_AbortMeasureSequence ( SFA_Type * base )

Parameters

base	SFA peripheral base address.

uint32_t SFA_CalculateFrequencyOrPeriod	(	SFA_Type *	base,
		uint32_t	refFrequency
	)

Parameters

base	SFA peripheral base address.
refFrequency	The reference clock frequency(BUS clock recommended).

static uint32_t SFA_GetCUTCounter ( SFA_Type * base )

inlinestatic

Parameters

base	SFA peripheral base address.

static void SFA_SetCUTTargetCount	(	SFA_Type *	base,
		uint32_t	count
	)

inlinestatic

Parameters

base	SFA peripheral base address.
count	target count for CUT.

static uint32_t SFA_GetCUTTargetCount ( SFA_Type * base )

inlinestatic

Parameters

base	SFA peripheral base address.

static void SFA_SetCUTLowLimitClockCount	(	SFA_Type *	base,
		uint32_t	count
	)

inlinestatic

Parameters

base	SFA peripheral base address.
count	low limit count for CUT clock.

static uint32_t SFA_GetCUTLowLimitClockCount ( SFA_Type * base )

inlinestatic

Parameters

base	SFA peripheral base address.

static void SFA_SetCUTHighLimitClockCount	(	SFA_Type *	base,
		uint32_t	count
	)

inlinestatic

Parameters

base	SFA peripheral base address.
count	high limit count for CUT clock.

static uint32_t SFA_GetCUTHighLimitClockCount ( SFA_Type * base )

inlinestatic

Parameters

base	SFA peripheral base address.

static uint32_t SFA_GetREFCounter ( SFA_Type * base )

inlinestatic

Parameters

base	SFA peripheral base address.

static void SFA_SetREFTargetCount	(	SFA_Type *	base,
		uint32_t	count
	)

inlinestatic

Parameters

base	SFA peripheral base address.
count	target count for reference clock.

static uint32_t SFA_GetREFTargetCount ( SFA_Type * base )

inlinestatic

Parameters

base	SFA peripheral base address.

static uint32_t SFA_GetREFStartCount ( SFA_Type * base )

inlinestatic

Parameters

base	SFA peripheral base address.

static uint32_t SFA_GetREFEndCount ( SFA_Type * base )

inlinestatic

Parameters

base	SFA peripheral base address.

static void SFA_SetREFLowLimitClockCount	(	SFA_Type *	base,
		uint32_t	count
	)

inlinestatic

Parameters

base	SFA peripheral base address.
count	low limit count for REF clock.

static uint32_t SFA_GetREFLowLimitClockCount ( SFA_Type * base )

inlinestatic

Parameters

base	SFA peripheral base address.

static void SFA_SetREFHighLimitClockCount	(	SFA_Type *	base,
		uint32_t	count
	)

inlinestatic

Parameters

base	SFA peripheral base address.
count	high limit count for REF clock.

static uint32_t SFA_GetREFHighLimitClockCount ( SFA_Type * base )

inlinestatic

Parameters

base	SFA peripheral base address.

Overview

Function groups

Initialization and Deinitialization

Status

Interrupt

SFA measurement Operations

Control CUT counter

Control REF counter

Data Structures

Typedefs

Enumerations

Driver version

Initialization and Deinitialization.

Status Interface

Interrupts Interface

Control SFA Measurement sequence.

Control CUT counter

Control REF counter

Data Structure Documentation

Data Fields

Field Documentation

Typedef Documentation

Enumeration Type Documentation

Function Documentation