Overview

The MCUXpresso SDK provides a peripheral driver for the Real Time Clock (RTC) module of MCUXpresso SDK devices.

Typical use case

Example use of RTC API.

int main(void)
{
    /* Initialize board hardware. */
    BOARD_InitHardware();
    PRINTF("\r\nRTC second example.\r\n");
    RTC_Init(RTC);
    /* Set a start date time and start RT */
    g_RtcTime.year = 2014U;
    g_RtcTime.month = 12U;
    g_RtcTime.day = 25U;
    g_RtcTime.hour = 19U;
    g_RtcTime.minute = 0;
    g_RtcTime.second = 0;
    /* Set RTC time to default */
    RTC_SetDatetime(RTC, &g_RtcTime);
    /* Enable RTC second interrupt */
    RTC_EnableInterrupts(RTC, kRTC_SecondInterruptEnable);
    /* Enable at the NVIC */
    NVIC_EnableIRQ(RTC_SEC_IRQn);
    g_RtcSecondFlag = 0;
    while (1)
    {
        if (g_RtcSecondFlag)
        {
            g_RtcSecondFlag = 0;
            /* Get data */
            RTC_GetDatetime(RTC, &g_RtcTime);
            /* Show data */
            PRINTF("Current datetime: %04hd-%02hd-%02hd %02hd:%02hd:%02hd\r\n", g_RtcTime.year, g_RtcTime.month,
                   g_RtcTime.day, g_RtcTime.hour, g_RtcTime.minute, g_RtcTime.second);
        }
    }
}
void RTC_SEC_IRQHandler(void)
{
    if (RTC_GetStatusFlags(RTC) & kRTC_SecondInterruptFlag)
    {
        g_RtcSecondFlag = 1;
        /* Clear second interrupt flag */
        RTC_ClearStatusFlags(RTC, kRTC_SecondInterruptFlag);
    }
}

Data Structures
struct	rtc_datetime_t
	Structure is used to hold the date and time. More...

Enumerations
enum	rtc_calibration_direction_t { kRTC_ForwardCalibration = 0U, kRTC_BackwardCalibration }
	RTC calibration direction. More...

enum	_rtc_interrupt_enable
	RTC interrupt configuration structure.

enum	_rtc_status_flags
	RTC status flags.

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

Initialization and deinitialization
static void	RTC_Init (RTC_Type *base)
	Ungates the RTC clock. More...

static void	RTC_Deinit (RTC_Type *base)
	Gate the RTC clock. More...

Current Time
status_t	RTC_SetDatetime (RTC_Type base, const rtc_datetime_t datetime)
	Sets the RTC date and time according to the given time structure. More...

void	RTC_GetDatetime (RTC_Type base, rtc_datetime_t datetime)
	Gets the RTC time and stores it in the given time structure. More...

void	RTC_Calibration (RTC_Type *base, rtc_calibration_direction_t dir, uint16_t value)
	RTC calibration. More...

static uint32_t	RTC_GetSecond (RTC_Type *base)
	Get RTC's second value. More...

static uint32_t	RTC_GetCount (RTC_Type *base)
	Get RTC counter value. More...

RTC Free running
void	RTC_EnableFreeRunningReset (RTC_Type *base, bool enable)
	Enable/Disable free running reset. More...

void	RTC_SetFreeRunningInterruptThreshold (RTC_Type *base, uint32_t value)
	Set free running interrupt threshold. More...

static uint32_t	RTC_GetFreeRunningInterruptThreshold (RTC_Type *base)
	Get free running interrupt threshold. More...

void	RTC_SetFreeRunningResetThreshold (RTC_Type *base, uint32_t value)
	Set free running reset threshold. More...

static uint32_t	RTC_GetFreeRunningResetThreshold (RTC_Type *base)
	Get free running reset threshold. More...

static uint32_t	RTC_GetFreeRunningCount (RTC_Type *base)
	Get free running counter value. More...

void	RTC_FreeRunningEnable (RTC_Type *base, bool enable)
	Enable/Disable RTC free running. More...

Status
static uint32_t	RTC_GetStatusFlags (RTC_Type *base)
	Gets the RTC status flags. More...

void	RTC_ClearStatusFlags (RTC_Type *base, uint32_t mask)
	Clears status flags with the provided mask. More...

Interrupts
void	RTC_EnableInterrupts (RTC_Type *base, uint32_t mask)
	Enable RTC interrupts according to the provided mask. More...

void	RTC_DisableInterrupts (RTC_Type *base, uint32_t mask)
	Disable RTC interrupts according to the provided mask. More...

Data Structure Documentation

struct rtc_datetime_t

Data Fields
uint16_t	year
	Range from 1970 to 2099. More...

uint8_t	month
	Range from 1 to 12. More...

uint8_t	day
	Range from 1 to 31 (depending on month). More...

uint8_t	hour
	Range from 0 to 23. More...

uint8_t	minute
	Range from 0 to 59. More...

uint8_t	second
	Range from 0 to 59. More...

Field Documentation

uint16_t rtc_datetime_t::year

uint8_t rtc_datetime_t::month

uint8_t rtc_datetime_t::day

uint8_t rtc_datetime_t::hour

uint8_t rtc_datetime_t::minute

uint8_t rtc_datetime_t::second

Enumeration Type Documentation

enum rtc_calibration_direction_t

Enumerator
kRTC_ForwardCalibration	Forward calibration.
kRTC_BackwardCalibration	Backward calibration.

Function Documentation

static void RTC_Init ( RTC_Type * base )

inlinestatic

Parameters

base	RTC peripheral base address

static void RTC_Deinit ( RTC_Type * base )

inlinestatic

Parameters

base	RTC peripheral base address

status_t RTC_SetDatetime	(	RTC_Type *	base,
		const rtc_datetime_t *	datetime
	)

The RTC counter must be stopped prior to calling this function as writes to the RTC seconds register will fail if the RTC counter is running.

Parameters

base	RTC peripheral base address
datetime	Pointer to structure where the date and time details to set are stored

Returns: kStatus_Success: Success in setting the time and starting the RTC kStatus_InvalidArgument: Error because the datetime format is incorrect

void RTC_GetDatetime	(	RTC_Type *	base,
		rtc_datetime_t *	datetime
	)

Parameters

base	RTC peripheral base address.
datetime	Pointer to structure where the date and time details are stored.

void RTC_Calibration	(	RTC_Type *	base,
		rtc_calibration_direction_t	dir,
		uint16_t	value
	)

Parameters

base	RTC peripheral base address.
dir	Forward or backward calibration.
value	calibration value.

static uint32_t RTC_GetSecond ( RTC_Type * base )

inlinestatic

Parameters

base	RTC peripheral base address.

Returns: RTC's second value

static uint32_t RTC_GetCount ( RTC_Type * base )

inlinestatic

Parameters

base	RTC peripheral base address.

Returns: RTC counter value

void RTC_EnableFreeRunningReset	(	RTC_Type *	base,
		bool	enable
	)

Parameters

base	RTC peripheral base address.
enable	true to enable the reset, false to disable.

void RTC_SetFreeRunningInterruptThreshold	(	RTC_Type *	base,
		uint32_t	value
	)

Parameters

base	RTC peripheral base address.
value	Free running interrupt threshold value.

static uint32_t RTC_GetFreeRunningInterruptThreshold ( RTC_Type * base )

inlinestatic

Parameters

base	RTC peripheral base address.

Returns: Free running interrupt threshold value.

void RTC_SetFreeRunningResetThreshold	(	RTC_Type *	base,
		uint32_t	value
	)

Parameters

base	RTC peripheral base address.
value	Free running reset threshold value.

static uint32_t RTC_GetFreeRunningResetThreshold ( RTC_Type * base )

inlinestatic

Parameters

base	RTC peripheral base address.

Returns: Free running reset threshold value.

static uint32_t RTC_GetFreeRunningCount ( RTC_Type * base )

inlinestatic

Parameters

base	RTC peripheral base address.

Returns: Free running counter value

void RTC_FreeRunningEnable	(	RTC_Type *	base,
		bool	enable
	)

Parameters

base	RTC peripheral base address.
enable	true to enable free running, false to disable.

static uint32_t RTC_GetStatusFlags ( RTC_Type * base )

inlinestatic

This function get all RTC status flags, the flags are returned as the logical OR value of the enumerators _rtc_status_flags.

Parameters

base	RTC peripheral base address.

Returns: RTC status flags which are ORed by the enumerators in the _rtc_status_flags.

void RTC_ClearStatusFlags	(	RTC_Type *	base,
		uint32_t	mask
	)

This function clears RTC status flags with a provided mask.

Parameters

base	RTC peripheral base address.
mask	The status flags to be cleared, it is logical OR value of _rtc_status_flags.

void RTC_EnableInterrupts	(	RTC_Type *	base,
		uint32_t	mask
	)

This function enables the RTC interrupts according to the provided mask. The mask is a logical OR of enumeration members. See _rtc_interrupt_enable

Parameters

base	RTC peripheral base address.
mask	The interrupts to enable. Logical OR of _rtc_interrupt_enable.

void RTC_DisableInterrupts	(	RTC_Type *	base,
		uint32_t	mask
	)

This function disables the RTC interrupts according to the provided mask. The mask is a logical OR of enumeration members. See _rtc_interrupt_enable

Parameters

base	RTC peripheral base address.
mask	The interrupts to disable. Logical OR of _rtc_interrupt_enable.

Overview

Typical use case

Data Structures

Enumerations

Driver version

Initialization and deinitialization

Current Time

RTC Free running

Status

Interrupts

Data Structure Documentation

Data Fields

Field Documentation

Enumeration Type Documentation

Function Documentation