Overview

The MCUXpresso SDK provides a driver for the General Purpose Timer (GPT) of MCUXpresso SDK devices.

Function groups

The gpt driver supports the generation of PWM signals, input capture, and setting up the timer match conditions.

Initialization and deinitialization

The function GPT_Init() initializes the gpt with specified configurations. The function GPT_GetDefaultConfig() gets the default configurations. The initialization function configures the restart/free-run mode and input selection when running.

The function GPT_Deinit() stops the timer and turns off the module clock.

Typical use case

GPT interrupt example

Set up a channel to trigger a periodic interrupt after every 1 second. Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/gpt

Data Structures
struct	gpt_config_t
	Structure to configure the running mode. More...

Enumerations
enum	gpt_clock_source_t { kGPT_ClockSource_Off = 0U, kGPT_ClockSource_Periph = 1U, kGPT_ClockSource_HighFreq = 2U, kGPT_ClockSource_Ext = 3U, kGPT_ClockSource_LowFreq = 4U, kGPT_ClockSource_Osc = 5U }
	List of clock sources. More...

enum	gpt_input_capture_channel_t { kGPT_InputCapture_Channel1 = 0U, kGPT_InputCapture_Channel2 = 1U }
	List of input capture channel number. More...

enum	gpt_input_operation_mode_t { kGPT_InputOperation_Disabled = 0U, kGPT_InputOperation_RiseEdge = 1U, kGPT_InputOperation_FallEdge = 2U, kGPT_InputOperation_BothEdge = 3U }
	List of input capture operation mode. More...

enum	gpt_output_compare_channel_t { kGPT_OutputCompare_Channel1 = 0U, kGPT_OutputCompare_Channel2 = 1U, kGPT_OutputCompare_Channel3 = 2U }
	List of output compare channel number. More...

enum	gpt_output_operation_mode_t { kGPT_OutputOperation_Disconnected = 0U, kGPT_OutputOperation_Toggle = 1U, kGPT_OutputOperation_Clear = 2U, kGPT_OutputOperation_Set = 3U, kGPT_OutputOperation_Activelow = 4U }
	List of output compare operation mode. More...

enum	gpt_interrupt_enable_t { kGPT_OutputCompare1InterruptEnable = GPT_IR_OF1IE_MASK, kGPT_OutputCompare2InterruptEnable = GPT_IR_OF2IE_MASK, kGPT_OutputCompare3InterruptEnable = GPT_IR_OF3IE_MASK, kGPT_InputCapture1InterruptEnable = GPT_IR_IF1IE_MASK, kGPT_InputCapture2InterruptEnable = GPT_IR_IF2IE_MASK, kGPT_RollOverFlagInterruptEnable = GPT_IR_ROVIE_MASK }
	List of GPT interrupts. More...

enum	gpt_status_flag_t { kGPT_OutputCompare1Flag = GPT_SR_OF1_MASK, kGPT_OutputCompare2Flag = GPT_SR_OF2_MASK, kGPT_OutputCompare3Flag = GPT_SR_OF3_MASK, kGPT_InputCapture1Flag = GPT_SR_IF1_MASK, kGPT_InputCapture2Flag = GPT_SR_IF2_MASK, kGPT_RollOverFlag = GPT_SR_ROV_MASK }
	Status flag. More...

Driver version
#define	FSL_GPT_DRIVER_VERSION (MAKE_VERSION(2, 0, 2))

Initialization and deinitialization
void	GPT_Init (GPT_Type base, const gpt_config_t initConfig)
	Initialize GPT to reset state and initialize running mode. More...

void	GPT_Deinit (GPT_Type *base)
	Disables the module and gates the GPT clock. More...

void	GPT_GetDefaultConfig (gpt_config_t *config)
	Fills in the GPT configuration structure with default settings. More...

Software Reset
static void	GPT_SoftwareReset (GPT_Type *base)
	Software reset of GPT module. More...

Clock source and frequency control
static void	GPT_SetClockSource (GPT_Type *base, gpt_clock_source_t source)
	Set clock source of GPT. More...

static gpt_clock_source_t	GPT_GetClockSource (GPT_Type *base)
	Get clock source of GPT. More...

static void	GPT_SetClockDivider (GPT_Type *base, uint32_t divider)
	Set pre scaler of GPT. More...

static uint32_t	GPT_GetClockDivider (GPT_Type *base)
	Get clock divider in GPT module. More...

static void	GPT_SetOscClockDivider (GPT_Type *base, uint32_t divider)
	OSC 24M pre-scaler before selected by clock source. More...

static uint32_t	GPT_GetOscClockDivider (GPT_Type *base)
	Get OSC 24M clock divider in GPT module. More...

Timer Start and Stop
static void	GPT_StartTimer (GPT_Type *base)
	Start GPT timer. More...

static void	GPT_StopTimer (GPT_Type *base)
	Stop GPT timer. More...

Read the timer period
static uint32_t	GPT_GetCurrentTimerCount (GPT_Type *base)
	Reads the current GPT counting value. More...

GPT Input/Output Signal Control
static void	GPT_SetInputOperationMode (GPT_Type *base, gpt_input_capture_channel_t channel, gpt_input_operation_mode_t mode)
	Set GPT operation mode of input capture channel. More...

static gpt_input_operation_mode_t	GPT_GetInputOperationMode (GPT_Type *base, gpt_input_capture_channel_t channel)
	Get GPT operation mode of input capture channel. More...

static uint32_t	GPT_GetInputCaptureValue (GPT_Type *base, gpt_input_capture_channel_t channel)
	Get GPT input capture value of certain channel. More...

static void	GPT_SetOutputOperationMode (GPT_Type *base, gpt_output_compare_channel_t channel, gpt_output_operation_mode_t mode)
	Set GPT operation mode of output compare channel. More...

static gpt_output_operation_mode_t	GPT_GetOutputOperationMode (GPT_Type *base, gpt_output_compare_channel_t channel)
	Get GPT operation mode of output compare channel. More...

static void	GPT_SetOutputCompareValue (GPT_Type *base, gpt_output_compare_channel_t channel, uint32_t value)
	Set GPT output compare value of output compare channel. More...

static uint32_t	GPT_GetOutputCompareValue (GPT_Type *base, gpt_output_compare_channel_t channel)
	Get GPT output compare value of output compare channel. More...

static void	GPT_ForceOutput (GPT_Type *base, gpt_output_compare_channel_t channel)
	Force GPT output action on output compare channel, ignoring comparator. More...

GPT Interrupt and Status Interface
static void	GPT_EnableInterrupts (GPT_Type *base, uint32_t mask)
	Enables the selected GPT interrupts. More...

static void	GPT_DisableInterrupts (GPT_Type *base, uint32_t mask)
	Disables the selected GPT interrupts. More...

static uint32_t	GPT_GetEnabledInterrupts (GPT_Type *base)
	Gets the enabled GPT interrupts. More...

Status Interface
static uint32_t	GPT_GetStatusFlags (GPT_Type *base, gpt_status_flag_t flags)
	Get GPT status flags. More...

static void	GPT_ClearStatusFlags (GPT_Type *base, gpt_status_flag_t flags)
	Clears the GPT status flags. More...

Data Structure Documentation

struct gpt_config_t

Data Fields
gpt_clock_source_t	clockSource
	clock source for GPT module. More...

uint32_t	divider
	clock divider (prescaler+1) from clock source to counter. More...

bool	enableFreeRun
	true: FreeRun mode, false: Restart mode. More...

bool	enableRunInWait
	GPT enabled in wait mode. More...

bool	enableRunInStop
	GPT enabled in stop mode. More...

bool	enableRunInDoze
	GPT enabled in doze mode. More...

bool	enableRunInDbg
	GPT enabled in debug mode. More...

bool	enableMode
	true: counter reset to 0 when enabled; false: counter retain its value when enabled. More...

Field Documentation

gpt_clock_source_t gpt_config_t::clockSource

uint32_t gpt_config_t::divider

bool gpt_config_t::enableFreeRun

bool gpt_config_t::enableRunInWait

bool gpt_config_t::enableRunInStop

bool gpt_config_t::enableRunInDoze

bool gpt_config_t::enableRunInDbg

bool gpt_config_t::enableMode

Enumeration Type Documentation

enum gpt_clock_source_t

Note: Actual number of clock sources is SoC dependent

Enumerator
kGPT_ClockSource_Off	GPT Clock Source Off.
kGPT_ClockSource_Periph	GPT Clock Source from Peripheral Clock.
kGPT_ClockSource_HighFreq	GPT Clock Source from High Frequency Reference Clock.
kGPT_ClockSource_Ext	GPT Clock Source from external pin.
kGPT_ClockSource_LowFreq	GPT Clock Source from Low Frequency Reference Clock.
kGPT_ClockSource_Osc	GPT Clock Source from Crystal oscillator.

enum gpt_input_capture_channel_t

Enumerator
kGPT_InputCapture_Channel1	GPT Input Capture Channel1.
kGPT_InputCapture_Channel2	GPT Input Capture Channel2.

enum gpt_input_operation_mode_t

Enumerator
kGPT_InputOperation_Disabled	Don't capture.
kGPT_InputOperation_RiseEdge	Capture on rising edge of input pin.
kGPT_InputOperation_FallEdge	Capture on falling edge of input pin.
kGPT_InputOperation_BothEdge	Capture on both edges of input pin.

enum gpt_output_compare_channel_t

Enumerator
kGPT_OutputCompare_Channel1	Output Compare Channel1.
kGPT_OutputCompare_Channel2	Output Compare Channel2.
kGPT_OutputCompare_Channel3	Output Compare Channel3.

enum gpt_output_operation_mode_t

Enumerator
kGPT_OutputOperation_Disconnected	Don't change output pin.
kGPT_OutputOperation_Toggle	Toggle output pin.
kGPT_OutputOperation_Clear	Set output pin low.
kGPT_OutputOperation_Set	Set output pin high.
kGPT_OutputOperation_Activelow	Generate a active low pulse on output pin.

enum gpt_interrupt_enable_t

Enumerator
kGPT_OutputCompare1InterruptEnable	Output Compare Channel1 interrupt enable.
kGPT_OutputCompare2InterruptEnable	Output Compare Channel2 interrupt enable.
kGPT_OutputCompare3InterruptEnable	Output Compare Channel3 interrupt enable.
kGPT_InputCapture1InterruptEnable	Input Capture Channel1 interrupt enable.
kGPT_InputCapture2InterruptEnable	Input Capture Channel1 interrupt enable.
kGPT_RollOverFlagInterruptEnable	Counter rolled over interrupt enable.

enum gpt_status_flag_t

Enumerator
kGPT_OutputCompare1Flag	Output compare channel 1 event.
kGPT_OutputCompare2Flag	Output compare channel 2 event.
kGPT_OutputCompare3Flag	Output compare channel 3 event.
kGPT_InputCapture1Flag	Input Capture channel 1 event.
kGPT_InputCapture2Flag	Input Capture channel 2 event.
kGPT_RollOverFlag	Counter reaches maximum value and rolled over to 0 event.

Function Documentation

void GPT_Init	(	GPT_Type *	base,
		const gpt_config_t *	initConfig
	)

Parameters

base	GPT peripheral base address.
initConfig	GPT mode setting configuration.

void GPT_Deinit ( GPT_Type * base )

Parameters

base	GPT peripheral base address.

void GPT_GetDefaultConfig ( gpt_config_t * config )

The default values are:

*    config->clockSource = kGPT_ClockSource_Periph;
*    config->divider = 1U;
*    config->enableRunInStop = true;
*    config->enableRunInWait = true;
*    config->enableRunInDoze = false;
*    config->enableRunInDbg = false;
*    config->enableFreeRun = false;
*    config->enableMode  = true;
* 

Parameters

config Pointer to the user configuration structure.

static void GPT_SoftwareReset ( GPT_Type * base )

inlinestatic

Parameters

base	GPT peripheral base address.

static void GPT_SetClockSource	(	GPT_Type *	base,
		gpt_clock_source_t	source
	)

inlinestatic

Parameters

base	GPT peripheral base address.
source	Clock source (see gpt_clock_source_t typedef enumeration).

static gpt_clock_source_t GPT_GetClockSource ( GPT_Type * base )

inlinestatic

Parameters

base	GPT peripheral base address.

Returns: clock source (see gpt_clock_source_t typedef enumeration).

static void GPT_SetClockDivider	(	GPT_Type *	base,
		uint32_t	divider
	)

inlinestatic

Parameters

base	GPT peripheral base address.
divider	Divider of GPT (1-4096).

static uint32_t GPT_GetClockDivider ( GPT_Type * base )

inlinestatic

Parameters

base	GPT peripheral base address.

Returns: clock divider in GPT module (1-4096).

static void GPT_SetOscClockDivider	(	GPT_Type *	base,
		uint32_t	divider
	)

inlinestatic

Parameters

base	GPT peripheral base address.
divider	OSC Divider(1-16).

static uint32_t GPT_GetOscClockDivider ( GPT_Type * base )

inlinestatic

Parameters

base	GPT peripheral base address.

Returns: OSC clock divider in GPT module (1-16).

static void GPT_StartTimer ( GPT_Type * base )

inlinestatic

Parameters

base	GPT peripheral base address.

static void GPT_StopTimer ( GPT_Type * base )

inlinestatic

Parameters

base	GPT peripheral base address.

static uint32_t GPT_GetCurrentTimerCount ( GPT_Type * base )

inlinestatic

Parameters

base	GPT peripheral base address.

Returns: Current GPT counter value.

static void GPT_SetInputOperationMode	(	GPT_Type *	base,
		gpt_input_capture_channel_t	channel,
		gpt_input_operation_mode_t	mode
	)

inlinestatic

Parameters

base	GPT peripheral base address.
channel	GPT capture channel (see gpt_input_capture_channel_t typedef enumeration).
mode	GPT input capture operation mode (see gpt_input_operation_mode_t typedef enumeration).

static gpt_input_operation_mode_t GPT_GetInputOperationMode	(	GPT_Type *	base,
		gpt_input_capture_channel_t	channel
	)

inlinestatic

Parameters

base	GPT peripheral base address.
channel	GPT capture channel (see gpt_input_capture_channel_t typedef enumeration).

Returns: GPT input capture operation mode (see gpt_input_operation_mode_t typedef enumeration).

static uint32_t GPT_GetInputCaptureValue	(	GPT_Type *	base,
		gpt_input_capture_channel_t	channel
	)

inlinestatic

Parameters

base	GPT peripheral base address.
channel	GPT capture channel (see gpt_input_capture_channel_t typedef enumeration).

Returns: GPT input capture value.

static void GPT_SetOutputOperationMode	(	GPT_Type *	base,
		gpt_output_compare_channel_t	channel,
		gpt_output_operation_mode_t	mode
	)

inlinestatic

Parameters

base	GPT peripheral base address.
channel	GPT output compare channel (see gpt_output_compare_channel_t typedef enumeration).
mode	GPT output operation mode (see gpt_output_operation_mode_t typedef enumeration).

static gpt_output_operation_mode_t GPT_GetOutputOperationMode	(	GPT_Type *	base,
		gpt_output_compare_channel_t	channel
	)

inlinestatic

Parameters

base	GPT peripheral base address.
channel	GPT output compare channel (see gpt_output_compare_channel_t typedef enumeration).

Returns: GPT output operation mode (see gpt_output_operation_mode_t typedef enumeration).

static void GPT_SetOutputCompareValue	(	GPT_Type *	base,
		gpt_output_compare_channel_t	channel,
		uint32_t	value
	)

inlinestatic

Parameters

base	GPT peripheral base address.
channel	GPT output compare channel (see gpt_output_compare_channel_t typedef enumeration).
value	GPT output compare value.

static uint32_t GPT_GetOutputCompareValue	(	GPT_Type *	base,
		gpt_output_compare_channel_t	channel
	)

inlinestatic

Parameters

base	GPT peripheral base address.
channel	GPT output compare channel (see gpt_output_compare_channel_t typedef enumeration).

Returns: GPT output compare value.

static void GPT_ForceOutput	(	GPT_Type *	base,
		gpt_output_compare_channel_t	channel
	)

inlinestatic

Parameters

base	GPT peripheral base address.
channel	GPT output compare channel (see gpt_output_compare_channel_t typedef enumeration).

static void GPT_EnableInterrupts	(	GPT_Type *	base,
		uint32_t	mask
	)

inlinestatic

Parameters

base	GPT peripheral base address.
mask	The interrupts to enable. This is a logical OR of members of the enumeration gpt_interrupt_enable_t

static void GPT_DisableInterrupts	(	GPT_Type *	base,
		uint32_t	mask
	)

inlinestatic

Parameters

base	GPT peripheral base address
mask	The interrupts to disable. This is a logical OR of members of the enumeration gpt_interrupt_enable_t

static uint32_t GPT_GetEnabledInterrupts ( GPT_Type * base )

inlinestatic

Parameters

base	GPT peripheral base address

Returns: The enabled interrupts. This is the logical OR of members of the enumeration gpt_interrupt_enable_t

static uint32_t GPT_GetStatusFlags	(	GPT_Type *	base,
		gpt_status_flag_t	flags
	)

inlinestatic

Parameters

base	GPT peripheral base address.
flags	GPT status flag mask (see gpt_status_flag_t for bit definition).

Returns: GPT status, each bit represents one status flag.

static void GPT_ClearStatusFlags	(	GPT_Type *	base,
		gpt_status_flag_t	flags
	)

inlinestatic

Parameters

base	GPT peripheral base address.
flags	GPT status flag mask (see gpt_status_flag_t for bit definition).

Overview

Function groups

Initialization and deinitialization

Typical use case

GPT interrupt example

Data Structures

Enumerations

Driver version

Initialization and deinitialization

Software Reset

Clock source and frequency control

Timer Start and Stop

Read the timer period

GPT Input/Output Signal Control

GPT Interrupt and Status Interface

Status Interface

Data Structure Documentation

Data Fields

Field Documentation

Enumeration Type Documentation

Function Documentation