Overview

The KSDK provides a driver for the PIT module of Kinetis devices.

Files
file	fsl_pit.h

Data Structures
struct	pit_config_t
	PIT config structure. More...

Enumerations
enum	pit_chnl_t { kPIT_Chnl_0 = 0U, kPIT_Chnl_1, kPIT_Chnl_2, kPIT_Chnl_3 }
	List of PIT channels. More...

enum	pit_interrupt_enable_t { kPIT_TimerInterruptEnable = PIT_TCTRL_TIE_MASK }
	List of PIT interrupts. More...

enum	pit_status_flags_t { kPIT_TimerFlag = PIT_TFLG_TIF_MASK }
	List of PIT status flags. More...

Driver version
#define	FSL_PIT_DRIVER_VERSION (MAKE_VERSION(2, 0, 0))
	Version 2.0.0.

Initialization and deinitialization
void	PIT_Init (PIT_Type base, const pit_config_t config)
	Ungates the PIT clock, enables the PIT module and configures the peripheral for basic operation. More...

void	PIT_Deinit (PIT_Type *base)
	Gate the PIT clock and disable the PIT module. More...

static void	PIT_GetDefaultConfig (pit_config_t *config)
	Fill in the PIT config struct with the default settings. More...

Interrupt Interface
static void	PIT_EnableInterrupts (PIT_Type *base, pit_chnl_t channel, uint32_t mask)
	Enables the selected PIT interrupts. More...

static void	PIT_DisableInterrupts (PIT_Type *base, pit_chnl_t channel, uint32_t mask)
	Disables the selected PIT interrupts. More...

static uint32_t	PIT_GetEnabledInterrupts (PIT_Type *base, pit_chnl_t channel)
	Gets the enabled PIT interrupts. More...

Status Interface
static uint32_t	PIT_GetStatusFlags (PIT_Type *base, pit_chnl_t channel)
	Gets the PIT status flags. More...

static void	PIT_ClearStatusFlags (PIT_Type *base, pit_chnl_t channel, uint32_t mask)
	Clears the PIT status flags. More...

Read and Write the timer period
static void	PIT_SetTimerPeriod (PIT_Type *base, pit_chnl_t channel, uint32_t count)
	Sets the timer period in units of count. More...

static uint32_t	PIT_GetCurrentTimerCount (PIT_Type *base, pit_chnl_t channel)
	Reads the current timer counting value. More...

Timer Start and Stop
static void	PIT_StartTimer (PIT_Type *base, pit_chnl_t channel)
	Starts the timer counting. More...

static void	PIT_StopTimer (PIT_Type *base, pit_chnl_t channel)
	Stops the timer counting. More...

Data Structure Documentation

struct pit_config_t

This structure holds the configuration settings for the PIT peripheral. To initialize this structure to reasonable defaults, call the PIT_GetDefaultConfig() function and pass a pointer to your config structure instance.

The config struct can be made const so it resides in flash

Data Fields
bool	enableRunInDebug
	true: Timers run in debug mode; false: Timers stop in debug mode

Enumeration Type Documentation

enum pit_chnl_t

Note: Actual number of available channels is SoC dependent

Enumerator
kPIT_Chnl_0	PIT channel number 0.
kPIT_Chnl_1	PIT channel number 1.
kPIT_Chnl_2	PIT channel number 2.
kPIT_Chnl_3	PIT channel number 3.

enum pit_interrupt_enable_t

Enumerator
kPIT_TimerInterruptEnable	Timer interrupt enable.

enum pit_status_flags_t

Enumerator
kPIT_TimerFlag	Timer flag.

Function Documentation

void PIT_Init	(	PIT_Type *	base,
		const pit_config_t *	config
	)

Note: This API should be called at the beginning of the application using the PIT driver.

Parameters

base	PIT peripheral base address
config	Pointer to user's PIT config structure

void PIT_Deinit ( PIT_Type * base )

Parameters

base	PIT peripheral base address

static void PIT_GetDefaultConfig ( pit_config_t * config )

inlinestatic

The default values are:

config->enableRunInDebug = false;

Parameters

config Pointer to user's PIT config structure.

static void PIT_EnableInterrupts	(	PIT_Type *	base,
		pit_chnl_t	channel,
		uint32_t	mask
	)

inlinestatic

Parameters

base	PIT peripheral base address
channel	Timer channel number
mask	The interrupts to enable. This is a logical OR of members of the enumeration pit_interrupt_enable_t

static void PIT_DisableInterrupts	(	PIT_Type *	base,
		pit_chnl_t	channel,
		uint32_t	mask
	)

inlinestatic

Parameters

base	PIT peripheral base address
channel	Timer channel number
mask	The interrupts to disable. This is a logical OR of members of the enumeration pit_interrupt_enable_t

static uint32_t PIT_GetEnabledInterrupts	(	PIT_Type *	base,
		pit_chnl_t	channel
	)

inlinestatic

Parameters

base	PIT peripheral base address
channel	Timer channel number

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

static uint32_t PIT_GetStatusFlags	(	PIT_Type *	base,
		pit_chnl_t	channel
	)

inlinestatic

Parameters

base	PIT peripheral base address
channel	Timer channel number

Returns: The status flags. This is the logical OR of members of the enumeration pit_status_flags_t

static void PIT_ClearStatusFlags	(	PIT_Type *	base,
		pit_chnl_t	channel,
		uint32_t	mask
	)

inlinestatic

Parameters

base	PIT peripheral base address
channel	Timer channel number
mask	The status flags to clear. This is a logical OR of members of the enumeration pit_status_flags_t

static void PIT_SetTimerPeriod	(	PIT_Type *	base,
		pit_chnl_t	channel,
		uint32_t	count
	)

inlinestatic

Timers begin counting from the value set by this function until it reaches 0, then it will generate an interrupt and load this regiter value again. Writing a new value to this register will not restart the timer; instead the value will be loaded after the timer expires.

Note: User can call the utility macros provided in fsl_common.h to convert to ticks

Parameters

base	PIT peripheral base address
channel	Timer channel number
count	Timer period in units of ticks

static uint32_t PIT_GetCurrentTimerCount	(	PIT_Type *	base,
		pit_chnl_t	channel
	)

inlinestatic

This function returns the real-time timer counting value, in a range from 0 to a timer period.

Note: User can call the utility macros provided in fsl_common.h to convert ticks to usec or msec

Parameters

base	PIT peripheral base address
channel	Timer channel number

Returns: Current timer counting value in ticks

static void PIT_StartTimer	(	PIT_Type *	base,
		pit_chnl_t	channel
	)

inlinestatic

After calling this function, timers load period value, count down to 0 and then load the respective start value again. Each time a timer reaches 0, it generates a trigger pulse and sets the timeout interrupt flag.

Parameters

base	PIT peripheral base address
channel	Timer channel number.

static void PIT_StopTimer	(	PIT_Type *	base,
		pit_chnl_t	channel
	)

inlinestatic

This function stops every timer counting. Timers reload their periods respectively after the next time they call the PIT_DRV_StartTimer.

Parameters

base	PIT peripheral base address
channel	Timer channel number.

Overview

Files

Data Structures

Enumerations

Driver version

Initialization and deinitialization

Interrupt Interface

Status Interface

Read and Write the timer period

Timer Start and Stop

Data Structure Documentation

Data Fields

Enumeration Type Documentation

Function Documentation