Overview

This section describes the programming interface of the LPTMR Peripheral driver. The LPTMR driver configures the LPTMR.

LPTMR Initialization

To initialize the LPTMR module, call the LPTMR_DRV_Init() function and pass in the user configuration data structure. This function automatically enables the LPTMR module and clock .
After the LPTMR_DRV_Init() function is called, call the LPTRM_DRV_Start to start the LPTMR.
To stop the LPTMR counter, call the LPTMR_DRV_Stop.

This is example code to configure the driver:

// Defines the LPTM user configuration structure . //
const lptmr_user_config_t config =
{
    .timerMode = kLptmrTimerModeTimerCounter, // timer counter is selected//
    .freeRunningEnable = false, // free running is disabled //
    .intEnable = true, // interrupt is enabled //
    .compareValue = 1024, // compare value is 1024 //
    .prescalerEnable = true, // prescaler is enabled //
    .prescalerClockSource = kLptmrPrescalerClockSourceLpo, // prescaler clock is LPO //
    .prescalerValue = kLptmrPrescalerDivede2, // prelscaler divide is 2 //
};
// Initializes the LPTMR 0. //
LPTMR_DRV_Init(0,&config);
// Starts the LPTMR 0. //
LPTMR_DRV_Start(0);
// Stops LPTMR 0. //
LPTMR_DRV_Stop(0);
// Deinitializes LPTMR 0. //
LPTMR_DRV_Deinit(0);

LPTMR Interrupt

Enable the LPTMR interrupt. The LPTMR interrupt is enabled in the user configuration structure with the lptmr_user_config_t.intEnable=true.
Define the LPTMR IRQ function.

void LPTimer_IRQHandler()
{
    if(true == LPTMR_DRV_IsIntPending(0))
    {
        LPTMR_DRV_ClearIntFlag(0);
    }
    lptmrIsrAssertCount++;
}

Data Structures
struct	lptmr_user_config_t
	Data structure to initialize the LPTMR. More...

struct	lptmr_state_t
	Internal driver state information. More...

Typedefs
typedef void(*	lptmr_callback_t )(void)
	Defines a type of the user-defined callback function.

Variables
LPTMR_Type *const	g_lptmrBase []
	Table of base addresses for LPTMR instances. More...

const IRQn_Type	g_lptmrIrqId [LPTMR_INSTANCE_COUNT]
	Table to save LPTMR IRQ enumeration numbers defined in the CMSIS header file. More...

lptmr_state_t *	g_lptmrStatePtr [LPTMR_INSTANCE_COUNT]
	Table to save pointers to context data. More...

LPTMR Driver
lptmr_status_t	LPTMR_DRV_Init (uint32_t instance, lptmr_state_t userStatePtr, const lptmr_user_config_t userConfigPtr)
	Initializes the LPTMR driver. More...

lptmr_status_t	LPTMR_DRV_Deinit (uint32_t instance)
	Deinitializes the LPTMR driver. More...

lptmr_status_t	LPTMR_DRV_Start (uint32_t instance)
	Starts the LPTMR counter. More...

lptmr_status_t	LPTMR_DRV_Stop (uint32_t instance)
	Stops the LPTMR counter. More...

lptmr_status_t	LPTMR_DRV_SetTimerPeriodUs (uint32_t instance, uint32_t us)
	Configures the LPTMR timer period in microseconds. More...

uint32_t	LPTMR_DRV_GetCurrentTimeUs (uint32_t instance)
	Gets the current LPTMR time in microseconds. More...

lptmr_status_t	LPTMR_DRV_SetPulsePeriodCount (uint32_t instance, uint32_t pulsePeriodCount)
	Sets the pulse period value. More...

uint32_t	LPTMR_DRV_GetCurrentPulseCount (uint32_t instance)
	Gets the current pulse count. More...

lptmr_status_t	LPTMR_DRV_InstallCallback (uint32_t instance, lptmr_callback_t userCallback)
	Installs the user-defined callback in the LPTMR module. More...

void	LPTMR_DRV_IRQHandler (uint32_t instance)
	Driver-defined ISR in the LPTMR module. More...

Data Structure Documentation

struct lptmr_user_config_t

This structure is used when initializing the LPTMR during the LPTMR_DRV_Init function call.

Data Fields
lptmr_timer_mode_t	timerMode
	Timer counter mode or pulse counter mode.

lptmr_pin_select_t	pinSelect
	LPTMR pulse input pin select.

lptmr_pin_polarity_t	pinPolarity
	LPTMR pulse input pin polarity.

bool	freeRunningEnable
	Free running configure. More...

bool	prescalerEnable
	Prescaler enable configure. More...

clock_lptmr_src_t	prescalerClockSource
	LPTMR clock source.

lptmr_prescaler_value_t	prescalerValue
	Prescaler value.

bool	isInterruptEnabled
	Timer interrupt 0-disable/1-enable.

Field Documentation

bool lptmr_user_config_t::freeRunningEnable

True means enable free running

bool lptmr_user_config_t::prescalerEnable

True means enable prescaler

struct lptmr_state_t

The contents of this structure are internal to the driver and should not be modified by users. Contents of the structure are subject to change in future releases.

Data Fields
lptmr_callback_t	userCallbackFunc
	Callback function that is executed in ISR. More...

Field Documentation

lptmr_callback_t lptmr_state_t::userCallbackFunc

Function Documentation

lptmr_status_t LPTMR_DRV_Init	(	uint32_t	instance,
		lptmr_state_t *	userStatePtr,
		const lptmr_user_config_t *	userConfigPtr
	)

This function initializes the LPTMR. The LPTMR can be initialized as a time counter or pulse counter, which is determined by the timerMode in the lptmr_user_config_t. pinSelect and pinPolarity do not need to be configured while working as a time counter.

Parameters

instance	The LPTMR peripheral instance number.
userStatePtr	The pointer to the structure of the context memory, see lptmr_state_t.
userConfigPtr	The pointer to the LPTMR user configure structure, see lptmr_user_config_t.

Returns: kStatus_LPTMR_Success means succeed, otherwise means failed.

lptmr_status_t LPTMR_DRV_Deinit ( uint32_t instance )

This function deinitializes the LPTMR. It disables the interrupt and turns off the LPTMR clock.

Parameters

instance The LPTMR peripheral instance number.

Returns: kStatus_LPTMR_Success means succeed, otherwise means failed.

lptmr_status_t LPTMR_DRV_Start ( uint32_t instance )

This function starts the LPTMR counter. Ensure that all necessary configurations are set before calling this function.

Parameters

instance The LPTMR peripheral instance number.

Returns: kStatus_LPTMR_Success means success. Otherwise, means failure.

lptmr_status_t LPTMR_DRV_Stop ( uint32_t instance )

This function stops the LPTMR counter.

Parameters

instance The LPTMR peripheral instance number.

Returns: kStatus_LPTMR_Success means success. Otherwise, means failure.

lptmr_status_t LPTMR_DRV_SetTimerPeriodUs	(	uint32_t	instance,
		uint32_t	us
	)

This function configures the LPTMR time period while the LPTMR is working as a time counter. After the time period in microseconds, the callback function is called. This function cannot be called while the LPTMR is working as a pulse counter. The value in microseconds (us) should be integer multiple of the clock source time slice. If the clock source is 1 kHz, then both 2000 µs and 3000 µs are valid while 2500 µs gets the same result as the 2000 µs, because 2500 µs cannot be generated in 1 kHz clock source.

Parameters

instance	The LPTMR peripheral instance number.
us	time period in microseconds.

Returns: kStatus_LPTMR_Success means success. Otherwise, means failure.

uint32_t LPTMR_DRV_GetCurrentTimeUs ( uint32_t instance )

This function gets the current time while operating as a time counter. This function cannot be called while operating as a pulse counter.

Parameters

instance The LPTMR peripheral instance number.

Returns: current time in microsecond unit.

lptmr_status_t LPTMR_DRV_SetPulsePeriodCount	(	uint32_t	instance,
		uint32_t	pulsePeriodCount
	)

This function configures the pulse period of the LPTMR while working as a pulse counter. After the count of pulsePeriodValue pulse is captured, the callback function is called. This function cannot be called while operating as a time counter.

Parameters

instance	The LPTMR peripheral instance number.
pulsePeriodCount	pulse period value.

Returns: kStatus_LPTMR_Success means success. Otherwise, means failure.

uint32_t LPTMR_DRV_GetCurrentPulseCount ( uint32_t instance )

This function gets the current pulse count captured on the pulse input pin. This function cannot be called while operating as a time counter.

Parameters

instance The LPTMR peripheral instance number.

Returns: pulse count captured on the pulse input pin.

lptmr_status_t LPTMR_DRV_InstallCallback	(	uint32_t	instance,
		lptmr_callback_t	userCallback
	)

This function installs the user-defined callback in the LPTMR module. When an LPTMR interrupt request is served, the callback is executed inside the ISR.

Parameters

instance	LPTMR instance ID.
userCallback	User-defined callback function.

Returns: kStatus_LPTMR_Success means success. Otherwise, means failure.

void LPTMR_DRV_IRQHandler ( uint32_t instance )

This function is the driver-defined ISR in the LPTMR module. It includes the process for interrupt mode defined by the driver. Currently, it is called inside the system-defined ISR.

Parameters

instance LPTMR instance ID.

Variable Documentation

LPTMR_Type* const g_lptmrBase[]

const IRQn_Type g_lptmrIrqId[LPTMR_INSTANCE_COUNT]

lptmr_state_t* g_lptmrStatePtr[LPTMR_INSTANCE_COUNT]

Overview

LPTMR Initialization

LPTMR Interrupt

Data Structures

Typedefs

Variables

LPTMR Driver

Data Structure Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Function Documentation

Variable Documentation