This driver for Atmel® | SMART ARM®-based microcontrollers provides an interface for the configuration and management of the device's Real Time Clock functionality in Count operating mode, for the configuration and retrieval of the current RTC counter value.

The following driver API modes are covered by this manual:

Polled APIs

The following peripheral is used by this module:

RTC (Real Time Clock)

The following devices can use this module:

Atmel | SMART SAM D20/D21
Atmel | SMART SAM R21
Atmel | SMART SAM D09/D10/D11
Atmel | SMART SAM L21/L22
Atmel | SMART SAM DA1
Atmel | SMART SAM C20/C21
Atmel | SMART SAM HA1
Atmel | SMART SAM R30
Atmel | SMART SAM R34
Atmel | SMART SAM R35

The outline of this documentation is as follows:

Prerequisites

There are no prerequisites for this module.

Module Overview

The RTC module in the SAM devices is a 32-bit counter, with a 10-bit programmable prescaler. Typically, the RTC clock is run continuously, including in the device's low-power sleep modes, to track the current time and date information. The RTC can be used as a source to wake up the system at a scheduled time or periodically using the alarm functions.

In this driver, the RTC is operated in Count mode. This allows for an easy integration of an asynchronous counter into a user application, which is capable of operating while the device is in sleep mode.

Whilst operating in Count mode, the RTC features:

16-bit counter mode
- Selectable counter period
- Up to six configurable compare values
32-bit counter mode
- Clear counter value on match
- Up to four configurable compare values

Driver Feature Macro Definition

Driver Feature Macro	Supported devices
FEATURE_RTC_PERIODIC_INT	SAM L21/L22/C20/C21/R30
FEATURE_RTC_PRESCALER_OFF	SAM L21/L22/C20/C21/R30
FEATURE_RTC_CLOCK_SELECTION	SAM L21/L22/C20/C21/R30
FEATURE_RTC_GENERAL_PURPOSE_REG	SAM L21/L22/R30
FEATURE_RTC_CONTINUOUSLY_UPDATED	SAM D20, SAM D21, SAM R21, SAM D10, SAM D11, SAM DA1, SAM HA1
FEATURE_RTC_TAMPER_DETECTION	SAM L22

Note: The specific features are only available in the driver when the selected device supports those features.

Compare and Overflow

The RTC can be used with up to 4/6 compare values (depending on selected operation mode). These compare values will trigger on match with the current RTC counter value, and can be set up to trigger an interrupt, event, or both. The RTC can also be configured to clear the counter value on compare match in 32-bit mode, resetting the count value back to zero.

If the RTC is operated without the Clear on Match option enabled, or in 16-bit mode, the RTC counter value will instead be cleared on overflow once the maximum count value has been reached:

\[ COUNT_{MAX} = 2^{32}-1 \]

for 32-bit counter mode, and

\[ COUNT_{MAX} = 2^{16}-1 \]

for 16-bit counter mode.

When running in 16-bit mode, the overflow value is selectable with a period value. The counter overflow will then occur when the counter value reaches the specified period value.

Periodic Events

The RTC can generate events at periodic intervals, allowing for direct peripheral actions without CPU intervention. The periodic events can be generated on the upper eight bits of the RTC prescaler, and will be generated on the rising edge transition of the specified bit. The resulting periodic frequency can be calculated by the following formula:

\[ f_{PERIODIC}=\frac{f_{ASY}}{2^{n+3}} \]

Where \(f_{ASY}\) refers to the asynchronous clock is set up in the RTC module configuration. The n parameter is the event source generator index of the RTC module. If the asynchronous clock is operated at the recommended frequency of 1KHz, the formula results in the values shown in the table below.

RTC Event Frequencies for Each Prescaler Bit Using a 1KHz Clock
n	Periodic event
7	1Hz
6	2Hz
5	4Hz
4	8Hz
3	16Hz
2	32Hz
1	64Hz
0	128Hz

Note: The connection of events between modules requires the use of the SAM Event System (EVENTS) Driver to route output event of one module to the the input event of another. For more information on event routing, refer to the event driver documentation.

Digital Frequency Correction

The RTC module contains Digital Frequency Correction logic to compensate for inaccurate source clock frequencies which would otherwise result in skewed time measurements. The correction scheme requires that at least two bits in the RTC module prescaler are reserved by the correction logic. As a result of this implementation, frequency correction is only available when the RTC is running from a 1Hz reference clock.

The correction procedure is implemented by subtracting or adding a single cycle from the RTC prescaler every 1024 RTC GCLK cycles. The adjustment is applied the specified number of time (maximum 127) over 976 of these periods. The corresponding correction in PPM will be given by:

\[ Correction(PPM) = \frac{VALUE}{999424}10^6 \]

The RTC clock will tick faster if provided with a positive correction value, and slower when given a negative correction value.

RTC Tamper Detect

see RTC Tamper Detect

Special Considerations

Clock Setup

SAM D20/D21/R21/D10/D11/DA1/HA1 Clock Setup

The RTC is typically clocked by a specialized GCLK generator that has a smaller prescaler than the others. By default the RTC clock is on, selected to use the internal 32KHz RC-oscillator with a prescaler of 32, giving a resulting clock frequency of 1KHz to the RTC. When the internal RTC prescaler is set to 1024, this yields an end-frequency of 1Hz.

The implementer also has the option to set other end-frequencies. The table below lists the available RTC frequencies for each possible GCLK and RTC input prescaler options.

RTC Output Frequencies from Allowable Input Clocks
End-frequency	GCLK prescaler	RTC prescaler
32KHz	1	1
1KHz	32	1
1Hz	32	1024

The overall RTC module clocking scheme is shown in the figure below.

SAM L21/C20/C21/R30 Clock Setup

The RTC clock can be selected from OSC32K, XOSC32K, or OSCULP32K, and a 32KHz or 1KHz oscillator clock frequency is required. This clock must be configured and enabled in the 32KHz oscillator controller before using the RTC.

The table below lists the available RTC clock asfdoc_sam0_rtc_count_rtc_clk.

RTC Clocks Source
RTC clock frequency	Clock source	Description
1.024KHz	ULP1K	1.024KHz from 32KHz internal ULP oscillator
32.768KHz	ULP32K	32.768KHz from 32KHz internal ULP oscillator
1.024KHz	OSC1K	1.024KHz from 32KHz internal oscillator
32.768KHz	OSC32K	32.768KHz from 32KHz internal oscillator
1.024KHz	XOSC1K	1.024KHz from 32KHz internal oscillator
32.768KHz	XOSC32K	32.768KHz from 32KHz external crystal oscillator

Extra Information

For extra information, see Extra Information for RTC COUNT Driver. This includes:

Examples

For a list of examples related to this driver, see Examples for RTC (COUNT) Driver.

API Overview

Data Structures
struct	rtc_count_config
	RTC Count configuration structure. More...

struct	rtc_count_events
	RTC Count event enable/disable structure. More...

Enumerations
enum	rtc_count_callback { RTC_COUNT_CALLBACK_COMPARE_0 = 0, RTC_COUNT_CALLBACK_COMPARE_1, RTC_COUNT_CALLBACK_COMPARE_2, RTC_COUNT_CALLBACK_COMPARE_3, RTC_COUNT_CALLBACK_COMPARE_4, RTC_COUNT_CALLBACK_COMPARE_5, RTC_COUNT_CALLBACK_OVERFLOW }
	Callback types. More...

enum	rtc_count_compare { RTC_COUNT_COMPARE_0 = 0, RTC_COUNT_COMPARE_1 = 1, RTC_COUNT_COMPARE_2 = 2, RTC_COUNT_COMPARE_3 = 3, RTC_COUNT_COMPARE_4 = 4, RTC_COUNT_COMPARE_5 = 5 }
	Available compare channels. More...

enum	rtc_count_mode { RTC_COUNT_MODE_16BIT = 0, RTC_COUNT_MODE_32BIT = 1 }
	Available operation modes for the RTC. More...

enum	rtc_count_prescaler { RTC_COUNT_PRESCALER_DIV_1 = RTC_MODE0_CTRL_PRESCALER_DIV1, RTC_COUNT_PRESCALER_DIV_2 = RTC_MODE0_CTRL_PRESCALER_DIV2, RTC_COUNT_PRESCALER_DIV_4 = RTC_MODE0_CTRL_PRESCALER_DIV4, RTC_COUNT_PRESCALER_DIV_8 = RTC_MODE0_CTRL_PRESCALER_DIV8, RTC_COUNT_PRESCALER_DIV_16 = RTC_MODE0_CTRL_PRESCALER_DIV16, RTC_COUNT_PRESCALER_DIV_32 = RTC_MODE0_CTRL_PRESCALER_DIV32, RTC_COUNT_PRESCALER_DIV_64 = RTC_MODE0_CTRL_PRESCALER_DIV64, RTC_COUNT_PRESCALER_DIV_128 = RTC_MODE0_CTRL_PRESCALER_DIV128, RTC_COUNT_PRESCALER_DIV_256 = RTC_MODE0_CTRL_PRESCALER_DIV256, RTC_COUNT_PRESCALER_DIV_512 = RTC_MODE0_CTRL_PRESCALER_DIV512, RTC_COUNT_PRESCALER_DIV_1024 = RTC_MODE0_CTRL_PRESCALER_DIV1024 }
	RTC input clock prescaler settings. More...

Driver Feature Definition
Define port features set according to different device family.
#define	FEATURE_RTC_CONTINUOUSLY_UPDATED
	RTC continuously updated. More...

Configuration and Initialization
static void	rtc_count_get_config_defaults (struct rtc_count_config *const config)
	Gets the RTC default configurations. More...

void	rtc_count_reset (struct rtc_module *const module)
	Resets the RTC module. More...

void	rtc_count_enable (struct rtc_module *const module)
	Enables the RTC module. More...

void	rtc_count_disable (struct rtc_module *const module)
	Disables the RTC module. More...

enum status_code	rtc_count_init (struct rtc_module const module, Rtc const hw, const struct rtc_count_config *const config)
	Initializes the RTC module with given configurations. More...

enum status_code	rtc_count_frequency_correction (struct rtc_module *const module, const int8_t value)
	Calibrate for too-slow or too-fast oscillator. More...

Count and Compare Value Management
enum status_code	rtc_count_set_count (struct rtc_module *const module, const uint32_t count_value)
	Set the current count value to desired value. More...

uint32_t	rtc_count_get_count (struct rtc_module *const module)
	Get the current count value. More...

enum status_code	rtc_count_set_compare (struct rtc_module *const module, const uint32_t comp_value, const enum rtc_count_compare comp_index)
	Set the compare value for the specified compare. More...

enum status_code	rtc_count_get_compare (struct rtc_module const module, uint32_t const comp_value, const enum rtc_count_compare comp_index)
	Get the current compare value of specified compare. More...

enum status_code	rtc_count_set_period (struct rtc_module *const module, uint16_t period_value)
	Set the given value to the period. More...

enum status_code	rtc_count_get_period (struct rtc_module const module, uint16_t const period_value)
	Retrieves the value of period. More...

Status Management
static bool	rtc_count_is_overflow (struct rtc_module *const module)
	Check if an RTC overflow has occurred. More...

static void	rtc_count_clear_overflow (struct rtc_module *const module)
	Clears the RTC overflow flag. More...

bool	rtc_count_is_compare_match (struct rtc_module *const module, const enum rtc_count_compare comp_index)
	Check if RTC compare match has occurred. More...

enum status_code	rtc_count_clear_compare_match (struct rtc_module *const module, const enum rtc_count_compare comp_index)
	Clears RTC compare match flag. More...

Event Management
static void	rtc_count_enable_events (struct rtc_module const module, struct rtc_count_events const events)
	Enables an RTC event output. More...

static void	rtc_count_disable_events (struct rtc_module const module, struct rtc_count_events const events)
	Disables an RTC event output. More...

Callbacks
enum status_code	rtc_count_register_callback (struct rtc_module *const module, rtc_count_callback_t callback, enum rtc_count_callback callback_type)
	Registers callback for the specified callback type. More...

enum status_code	rtc_count_unregister_callback (struct rtc_module *const module, enum rtc_count_callback callback_type)
	Unregisters callback for the specified callback type. More...

void	rtc_count_enable_callback (struct rtc_module *const module, enum rtc_count_callback callback_type)
	Enables callback. More...

void	rtc_count_disable_callback (struct rtc_module *const module, enum rtc_count_callback callback_type)
	Disables callback. More...

#define FEATURE_RTC_CONTINUOUSLY_UPDATED

RTC continuously updated.

enum rtc_count_callback

Callback types.

The available callback types for the RTC count module.

Enumerator
RTC_COUNT_CALLBACK_COMPARE_0	Callback for compare channel 0.
RTC_COUNT_CALLBACK_COMPARE_1	Callback for compare channel 1.
RTC_COUNT_CALLBACK_COMPARE_2	Callback for compare channel 2.
RTC_COUNT_CALLBACK_COMPARE_3	Callback for compare channel 3.
RTC_COUNT_CALLBACK_COMPARE_4	Callback for compare channel 4.
RTC_COUNT_CALLBACK_COMPARE_5	Callback for compare channel 5.
RTC_COUNT_CALLBACK_OVERFLOW	Callback for overflow.

enum rtc_count_compare

Available compare channels.

Note: Not all compare channels are available in all devices and modes.

Enumerator
RTC_COUNT_COMPARE_0	Compare channel 0.
RTC_COUNT_COMPARE_1	Compare channel 1.
RTC_COUNT_COMPARE_2	Compare channel 2.
RTC_COUNT_COMPARE_3	Compare channel 3.
RTC_COUNT_COMPARE_4	Compare channel 4.
RTC_COUNT_COMPARE_5	Compare channel 5.

enum rtc_count_mode

Available operation modes for the RTC.

RTC Count operating modes, to select the counting width and associated module operation.

Enumerator
RTC_COUNT_MODE_16BIT	RTC Count module operates in 16-bit mode.
RTC_COUNT_MODE_32BIT	RTC Count module operates in 32-bit mode.

enum rtc_count_prescaler

RTC input clock prescaler settings.

The available input clock prescaler values for the RTC count module.

Enumerator
RTC_COUNT_PRESCALER_DIV_1	RTC input clock frequency is prescaled by a factor of 1.
RTC_COUNT_PRESCALER_DIV_2	RTC input clock frequency is prescaled by a factor of 2.
RTC_COUNT_PRESCALER_DIV_4	RTC input clock frequency is prescaled by a factor of 4.
RTC_COUNT_PRESCALER_DIV_8	RTC input clock frequency is prescaled by a factor of 8.
RTC_COUNT_PRESCALER_DIV_16	RTC input clock frequency is prescaled by a factor of 16.
RTC_COUNT_PRESCALER_DIV_32	RTC input clock frequency is prescaled by a factor of 32.
RTC_COUNT_PRESCALER_DIV_64	RTC input clock frequency is prescaled by a factor of 64.
RTC_COUNT_PRESCALER_DIV_128	RTC input clock frequency is prescaled by a factor of 128.
RTC_COUNT_PRESCALER_DIV_256	RTC input clock frequency is prescaled by a factor of 256.
RTC_COUNT_PRESCALER_DIV_512	RTC input clock frequency is prescaled by a factor of 512.
RTC_COUNT_PRESCALER_DIV_1024	RTC input clock frequency is prescaled by a factor of 1024.

enum status_code rtc_count_clear_compare_match	(	struct rtc_module *const	module,
		const enum rtc_count_compare	comp_index
	)

Clears RTC compare match flag.

Clears the compare flag. The compare flag is set when there is a compare match between the counter and the compare.

Note: Compare 4 and 5 are only available in 16-bit mode.

Parameters

[in,out]	module	Pointer to the software instance struct
[in]	comp_index	Index of compare to check current flag

Returns: Status indicating if flag was successfully cleared.

Return values

STATUS_OK	If flag was successfully cleared
STATUS_ERR_INVALID_ARG	If invalid argument(s) were provided
STATUS_ERR_BAD_FORMAT	If the module was not initialized in a mode

References Assert, RTC_COUNT_MODE_16BIT, RTC_COUNT_MODE_32BIT, STATUS_ERR_BAD_FORMAT, STATUS_ERR_INVALID_ARG, and STATUS_OK.

static void rtc_count_clear_overflow ( struct rtc_module *const module )

inlinestatic

Clears the RTC overflow flag.

Clears the RTC module counter overflow flag, so that new overflow conditions can be detected.

Parameters

[in,out] module RTC hardware module

References Assert.

void rtc_count_disable ( struct rtc_module *const module )

Disables the RTC module.

Parameters

[in,out] module RTC hardware module

References Assert, rtc_count_is_syncing(), system_interrupt_disable(), and SYSTEM_INTERRUPT_MODULE_RTC.

Referenced by rtc_count_reset().

void rtc_count_disable_callback	(	struct rtc_module *const	module,
		enum rtc_count_callback	callback_type
	)

Disables callback.

Disables the callback specified by the callback_type.

Parameters

[in,out]	module	Pointer to the software instance struct
[in]	callback_type	Callback type to disable

References Assert, and RTC_COUNT_CALLBACK_OVERFLOW.

static void rtc_count_disable_events	(	struct rtc_module *const	module,
		struct rtc_count_events *const	events
	)

inlinestatic

Disables an RTC event output.

Disabled one or more output events from the RTC module. See rtc_count_events for a list of events this module supports.

Note: Events cannot be altered while the module is enabled.

Parameters

[in,out]	module	RTC hardware module
[in]	events	Struct containing flags of events to disable

References Assert, rtc_count_events::generate_event_on_compare, rtc_count_events::generate_event_on_overflow, and rtc_count_events::generate_event_on_periodic.

void rtc_count_enable ( struct rtc_module *const module )

Enables the RTC module.

Enables the RTC module once it has been configured, ready for use. Most module configuration parameters cannot be altered while the module is enabled.

Parameters

[in,out] module RTC hardware module

References Assert, rtc_count_is_syncing(), system_interrupt_enable(), and SYSTEM_INTERRUPT_MODULE_RTC.

Referenced by configure_rtc_count().

void rtc_count_enable_callback	(	struct rtc_module *const	module,
		enum rtc_count_callback	callback_type
	)

Enables callback.

Enables the callback specified by the callback_type.

Parameters

[in,out]	module	Pointer to the software instance struct
[in]	callback_type	Callback type to enable

References Assert, and RTC_COUNT_CALLBACK_OVERFLOW.

Referenced by configure_rtc_callbacks().

static void rtc_count_enable_events	(	struct rtc_module *const	module,
		struct rtc_count_events *const	events
	)

inlinestatic

Enables an RTC event output.

Enables one or more output events from the RTC module. See rtc_count_events for a list of events this module supports.

Note: Events cannot be altered while the module is enabled.

Parameters

[in,out]	module	RTC hardware module
[in]	events	Struct containing flags of events to enable

References Assert, rtc_count_events::generate_event_on_compare, rtc_count_events::generate_event_on_overflow, and rtc_count_events::generate_event_on_periodic.

enum status_code rtc_count_frequency_correction	(	struct rtc_module *const	module,
		const int8_t	value
	)

Calibrate for too-slow or too-fast oscillator.

When used, the RTC will compensate for an inaccurate oscillator. The RTC module will add or subtract cycles from the RTC prescaler to adjust the frequency in approximately 1 PPM steps. The provided correction value should be between 0 and 127, allowing for a maximum 127 PPM correction.

If no correction is needed, set value to zero.

Note: Can only be used when the RTC is operated in 1Hz.

Parameters

[in,out]	module	Pointer to the software instance struct
[in]	value	Ranging from -127 to 127 used for the correction

Returns: Status of the calibration procedure.

Return values

STATUS_OK	If calibration was executed correctly
STATUS_ERR_INVALID_ARG	If invalid argument(s) were provided

References Assert, rtc_count_is_syncing(), STATUS_ERR_INVALID_ARG, and STATUS_OK.

enum status_code rtc_count_get_compare	(	struct rtc_module *const	module,
		uint32_t *const	comp_value,
		const enum rtc_count_compare	comp_index
	)

Get the current compare value of specified compare.

Retrieves the current value of the specified compare.

Note: Compare 4 and 5 are only available in 16-bit mode.

Parameters

[in,out]	module	Pointer to the software instance struct
[out]	comp_value	Pointer to 32-bit integer that will be populated with the current compare value
[in]	comp_index	Index of compare to check

Returns: Status of the reading procedure.

Return values

STATUS_OK	If the value was read correctly
STATUS_ERR_INVALID_ARG	If invalid argument(s) were provided
STATUS_ERR_BAD_FORMAT	If the module was not initialized in a mode

References Assert, RTC_COUNT_MODE_16BIT, RTC_COUNT_MODE_32BIT, STATUS_ERR_BAD_FORMAT, STATUS_ERR_INVALID_ARG, and STATUS_OK.

static void rtc_count_get_config_defaults ( struct rtc_count_config *const config )

inlinestatic

Gets the RTC default configurations.

Initializes the configuration structure to default values. This function should be called at the start of any RTC initialization.

The default configuration is:

Input clock divided by a factor of 1024
RTC in 32-bit mode
Clear on compare match off
Continuously sync count register off
No event source on
All compare values equal 0
Count read synchronization is enabled for SAM L22

Parameters

[out] config Configuration structure to be initialized to default values

References Assert, rtc_count_config::clear_on_match, rtc_count_config::compare_values, rtc_count_config::continuously_update, rtc_count_config::enable_read_sync, rtc_count_config::mode, rtc_count_config::prescaler, RTC_COUNT_MODE_32BIT, and RTC_COUNT_PRESCALER_DIV_1024.

Referenced by configure_rtc_count().

uint32_t rtc_count_get_count ( struct rtc_module *const module )

Get the current count value.

Parameters

[in,out] module Pointer to the software instance struct

Returns the current count value.

Returns: The current counter value as a 32-bit unsigned integer.

References Assert, rtc_count_is_syncing(), RTC_COUNT_MODE_16BIT, and RTC_COUNT_MODE_32BIT.

enum status_code rtc_count_get_period	(	struct rtc_module *const	module,
		uint16_t *const	period_value
	)

Retrieves the value of period.

Retrieves the value of the period for the 16-bit mode counter.

Note: Only available in 16-bit mode.

Parameters

[in,out]	module	Pointer to the software instance struct
[out]	period_value	Pointer to value for return argument

Returns: Status of getting the period value.

Return values

STATUS_OK	If the period value was read correctly
STATUS_ERR_UNSUPPORTED_DEV	If incorrect mode was set

References Assert, RTC_COUNT_MODE_16BIT, STATUS_ERR_UNSUPPORTED_DEV, and STATUS_OK.

enum status_code rtc_count_init	(	struct rtc_module *const	module,
		Rtc *const	hw,
		const struct rtc_count_config *const	config
	)

Initializes the RTC module with given configurations.

Initializes the module, setting up all given configurations to provide the desired functionality of the RTC.

Parameters

[out]	module	Pointer to the software instance struct
[in]	hw	Pointer to hardware instance
[in]	config	Pointer to the configuration structure

Returns: Status of the initialization procedure.

Return values

STATUS_OK	If the initialization was run stressfully
STATUS_ERR_INVALID_ARG	If invalid argument(s) were given

References _rtc_count_set_config(), _rtc_instance, Assert, rtc_count_config::continuously_update, GCLK_GENERATOR_2, rtc_count_config::mode, rtc_count_reset(), system_gclk_chan_config::source_generator, system_apb_clock_set_mask(), SYSTEM_CLOCK_APB_APBA, system_gclk_chan_enable(), system_gclk_chan_get_config_defaults(), and system_gclk_chan_set_config().

Referenced by configure_rtc_count().

bool rtc_count_is_compare_match	(	struct rtc_module *const	module,
		const enum rtc_count_compare	comp_index
	)

Check if RTC compare match has occurred.

Checks the compare flag to see if a match has occurred. The compare flag is set when there is a compare match between counter and the compare.

Note: Compare 4 and 5 are only available in 16-bit mode.

Parameters

[in,out]	module	Pointer to the software instance struct
[in]	comp_index	Index of compare to check current flag

References Assert, RTC_COUNT_MODE_16BIT, and RTC_COUNT_MODE_32BIT.

static bool rtc_count_is_overflow ( struct rtc_module *const module )

inlinestatic

Check if an RTC overflow has occurred.

Checks the overflow flag in the RTC. The flag is set when there is an overflow in the clock.

Parameters

[in,out] module RTC hardware module

Returns: Overflow state of the RTC module.

Return values

true	If the RTC count value has overflowed
false	If the RTC count value has not overflowed

References Assert.

enum status_code rtc_count_register_callback	(	struct rtc_module *const	module,
		rtc_count_callback_t	callback,
		enum rtc_count_callback	callback_type
	)

Registers callback for the specified callback type.

Associates the given callback function with the specified callback type. To enable the callback, the rtc_count_enable_callback function must be used.

Parameters

[in,out]	module	Pointer to the software instance struct
[in]	callback	Pointer to the function desired for the specified callback
[in]	callback_type	Callback type to register

Returns: Status of registering callback.

Return values

STATUS_OK	Registering was done successfully
STATUS_ERR_INVALID_ARG	If trying to register a callback not available

References RTC_COUNT_CALLBACK_OVERFLOW, RTC_COUNT_MODE_16BIT, RTC_COUNT_MODE_32BIT, STATUS_ERR_INVALID_ARG, and STATUS_OK.

Referenced by configure_rtc_callbacks().

void rtc_count_reset ( struct rtc_module *const module )

Resets the RTC module.

Resets the RTC to hardware defaults.

Parameters

[in,out] module Pointer to the software instance struct

References Assert, rtc_count_disable(), and rtc_count_is_syncing().

Referenced by rtc_count_init().

enum status_code rtc_count_set_compare	(	struct rtc_module *const	module,
		const uint32_t	comp_value,
		const enum rtc_count_compare	comp_index
	)

Set the compare value for the specified compare.

Sets the value specified by the implementer to the requested compare.

Note: Compare 4 and 5 are only available in 16-bit mode.

Parameters

[in,out]	module	Pointer to the software instance struct
[in]	comp_value	The value to be written to the compare
[in]	comp_index	Index of the compare to set

Returns: Status indicating if compare was successfully set.

Return values

STATUS_OK	If compare was successfully set
STATUS_ERR_INVALID_ARG	If invalid argument(s) were provided
STATUS_ERR_BAD_FORMAT	If the module was not initialized in a mode

References Assert, rtc_count_is_syncing(), RTC_COUNT_MODE_16BIT, RTC_COUNT_MODE_32BIT, STATUS_ERR_BAD_FORMAT, STATUS_ERR_INVALID_ARG, and STATUS_OK.

Referenced by _rtc_count_set_config().

enum status_code rtc_count_set_count	(	struct rtc_module *const	module,
		const uint32_t	count_value
	)

Set the current count value to desired value.

Sets the value of the counter to the specified value.

Parameters

[in,out]	module	Pointer to the software instance struct
[in]	count_value	The value to be set in count register

Returns: Status of setting the register.

Return values

STATUS_OK	If everything was executed correctly
STATUS_ERR_INVALID_ARG	If invalid argument(s) were provided

References Assert, rtc_count_is_syncing(), RTC_COUNT_MODE_16BIT, RTC_COUNT_MODE_32BIT, STATUS_ERR_INVALID_ARG, and STATUS_OK.

enum status_code rtc_count_set_period	(	struct rtc_module *const	module,
		const uint16_t	period_value
	)

Set the given value to the period.

Sets the given value to the period.

Note: Only available in 16-bit mode.

Parameters

[in,out]	module	Pointer to the software instance struct
[in]	period_value	The value to set to the period

Returns: Status of setting the period value.

Return values

STATUS_OK	If the period was set correctly
STATUS_ERR_UNSUPPORTED_DEV	If module is not operated in 16-bit mode

References Assert, rtc_count_is_syncing(), RTC_COUNT_MODE_16BIT, STATUS_ERR_UNSUPPORTED_DEV, and STATUS_OK.

Referenced by timer_init().

enum status_code rtc_count_unregister_callback	(	struct rtc_module *const	module,
		enum rtc_count_callback	callback_type
	)

Unregisters callback for the specified callback type.

When called, the currently registered callback for the given callback type will be removed.

Parameters

[in,out]	module	Pointer to the software instance struct
[in]	callback_type	Specifies the callback type to unregister

Returns: Status of unregistering callback.

Return values

STATUS_OK	Unregistering was done successfully
STATUS_ERR_INVALID_ARG	If trying to unregister a callback not available

References RTC_COUNT_CALLBACK_OVERFLOW, RTC_COUNT_MODE_16BIT, RTC_COUNT_MODE_32BIT, STATUS_ERR_INVALID_ARG, and STATUS_OK.

Microchip® Advanced Software Framework

Prerequisites

Module Overview

Driver Feature Macro Definition

Compare and Overflow

Periodic Events

Digital Frequency Correction

RTC Tamper Detect

Special Considerations

Clock Setup

SAM D20/D21/R21/D10/D11/DA1/HA1 Clock Setup

SAM L21/C20/C21/R30 Clock Setup

Extra Information

Examples

API Overview

Data Structures

Enumerations

Driver Feature Definition

Configuration and Initialization

Count and Compare Value Management

Status Management

Event Management

Callbacks