RTC - Real Time Counter

Description

Real Time Counter (RTC) Peripheral API.

This module contains functions to control the RTC peripheral of Silicon Labs 32-bit MCUs and SoCs. The RTC ensures timekeeping in low energy modes.

Data Structures

struct RTC_Init_TypeDef
RTC initialization structure.

Functions

uint32_t RTC_CompareGet (unsigned int comp)
Get the RTC compare register value.
void RTC_CompareSet (unsigned int comp, uint32_t value)
Set the RTC compare register value.
uint32_t RTC_CounterGet (void)
Get RTC counter value.
void RTC_CounterReset (void)
Restart the RTC counter from zero.
void RTC_Enable (bool enable)
Enable/disable RTC.
void RTC_FreezeEnable (bool enable)
RTC register synchronization freeze control.
void RTC_Init (const RTC_Init_TypeDef *init)
Initialize RTC.
void RTC_IntClear (uint32_t flags)
Clear one or more pending RTC interrupts.
void RTC_IntDisable (uint32_t flags)
Disable one or more RTC interrupts.
void RTC_IntEnable (uint32_t flags)
Enable one or more RTC interrupts.
uint32_t RTC_IntGet (void)
Get pending RTC interrupt flags.
uint32_t RTC_IntGetEnabled (void)
Get enabled and pending RTC interrupt flags.
void RTC_IntSet (uint32_t flags)
Set one or more pending RTC interrupts from SW.
void RTC_Reset (void)
Restore RTC to reset state.

Macros

#define NUM_RTC_CHANNELS 2U
The RTC peripheral on series 0 devices support 2 compare channels while the RTC peripheral on series 1 devices support 6 compare channels.
#define RTC_INIT_DEFAULT
Suggested default configuration for RTC initialization structure.

Function Documentation

◆ RTC_CompareGet()

uint32_t RTC_CompareGet ( unsigned int comp )

Get the RTC compare register value.

Parameters
[in] comp A compare register to get. This value must be less than NUM_RTC_CHANNELS .
Returns
A compare register value, 0 if invalid register selected.

◆ RTC_CompareSet()

void RTC_CompareSet ( unsigned int comp,
uint32_t value
)

Set the RTC compare register value.

Note
The setting of a compare register requires synchronization into the low-frequency domain. If the same register is modified before a previous update has completed, this function will stall until the previous synchronization has completed. This only applies to the Gecko Family. See comments in the regSync() internal function call.
Parameters
[in] comp A compare register to set. This value must be less than NUM_RTC_CHANNELS .
[in] value An initialization value (<= 0x00ffffff).

◆ RTC_CounterGet()

uint32_t RTC_CounterGet ( void )
inline

Get RTC counter value.

Returns
Current RTC counter value.

◆ RTC_CounterReset()

void RTC_CounterReset ( void )

Restart the RTC counter from zero.

◆ RTC_Enable()

void RTC_Enable ( bool enable )

Enable/disable RTC.

Note
The enabling/disabling of RTC modifies the RTC CTRL register which requires synchronization into the low-frequency domain. If this register is modified before a previous update to the same register has completed, this function will stall until the previous synchronization has completed. This only applies to the Gecko Family. See comments in the regSync() internal function call.
Parameters
[in] enable True to enable counting, false to disable.

◆ RTC_FreezeEnable()

void RTC_FreezeEnable ( bool enable )

RTC register synchronization freeze control.

Some RTC registers require synchronization into the low-frequency (LF) domain. The freeze feature allows for several registers to be modified before passing them to the LF domain simultaneously (which takes place when the freeze mode is disabled).

Note
When enabling freeze mode, this function will wait for all current ongoing RTC synchronization to LF domain to complete (normally synchronization will not be in progress.) However, for this reason, when using freeze mode, modifications of registers requiring LF synchronization should be done within one freeze enable/disable block to avoid unnecessary stalling. This only applies to the Gecko Family. See the reference manual chapter about Access to Low Energy Peripherals (Asynchronos Registers) for details.
Parameters
[in] enable
  • True - enable freeze, modified registers are not propagated to the LF domain
  • False - disables freeze, modified registers are propagated to LF domain

◆ RTC_Init()

void RTC_Init ( const RTC_Init_TypeDef * init )

Initialize RTC.

Note that the compare values must be set separately with RTC_CompareSet() prior to the use of this function if configuring the RTC to start when initialization is completed.

Note
The initialization of the RTC modifies the RTC CTRL register which requires synchronization into the low-frequency domain. If this register is modified before a previous update to the same register has completed, this function will stall until the previous synchronization has completed. This only applies to the Gecko Family. See comments in the regSync() internal function call.
Parameters
[in] init A pointer to the RTC initialization structure.

◆ RTC_IntClear()

void RTC_IntClear ( uint32_t flags )
inline

Clear one or more pending RTC interrupts.

Parameters
[in] flags RTC interrupt sources to clear. Use a set of interrupt flags OR-ed together to clear multiple interrupt sources for the RTC module (RTC_IFS_nnn).

◆ RTC_IntDisable()

void RTC_IntDisable ( uint32_t flags )
inline

Disable one or more RTC interrupts.

Parameters
[in] flags RTC interrupt sources to disable. Use a set of interrupt flags OR-ed together to disable multiple interrupt sources for the RTC module (RTC_IFS_nnn).

◆ RTC_IntEnable()

void RTC_IntEnable ( uint32_t flags )
inline

Enable one or more RTC interrupts.

Note
Depending on the use, a pending interrupt may already be set prior to enabling the interrupt. To ignore a pending interrupt, consider using RTC_IntClear() prior to enabling the interrupt.
Parameters
[in] flags RTC interrupt sources to enable. Use a set of interrupt flags OR-ed together to set multiple interrupt sources for the RTC module (RTC_IFS_nnn).

◆ RTC_IntGet()

uint32_t RTC_IntGet ( void )
inline

Get pending RTC interrupt flags.

Note
Event bits are not cleared by using this function.
Returns
Pending RTC interrupt sources. Returns a set of interrupt flags OR-ed together for multiple interrupt sources in the RTC module (RTC_IFS_nnn).

◆ RTC_IntGetEnabled()

uint32_t RTC_IntGetEnabled ( void )
inline

Get enabled and pending RTC interrupt flags.

Useful for handling more interrupt sources in the same interrupt handler.

Note
Interrupt flags are not cleared by using this function.
Returns
Pending and enabled RTC interrupt sources. The return value is the bitwise AND of
  • the enabled interrupt sources in RTC_IEN and
  • the pending interrupt flags RTC_IF.

◆ RTC_IntSet()

void RTC_IntSet ( uint32_t flags )
inline

Set one or more pending RTC interrupts from SW.

Parameters
[in] flags RTC interrupt sources to set to pending. Use a set of interrupt flags OR-ed together to set multiple interrupt sources for the RTC module (RTC_IFS_nnn).

◆ RTC_Reset()

void RTC_Reset ( void )

Restore RTC to reset state.

Macro Definition Documentation

◆ NUM_RTC_CHANNELS

#define NUM_RTC_CHANNELS   2U

The RTC peripheral on series 0 devices support 2 compare channels while the RTC peripheral on series 1 devices support 6 compare channels.

◆ RTC_INIT_DEFAULT

#define RTC_INIT_DEFAULT
Value:
{ \
true, /* Start counting when initialization is done. */ \
false, /* Disable updating during debug halt. */ \
true /* Restart counting from 0 when reaching COMP0. */ \
}

Suggested default configuration for RTC initialization structure.