RTC - Real Time Counter#

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.

Modules#

RTC_Init_TypeDef

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

Get RTC counter value.

void
RTC_CounterSet(uint32_t value)

Set the RTC counter value.

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

Get pending RTC interrupt flags.

uint32_t

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

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

#define

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.


Definition at line 111 of file platform/emlib/src/em_rtc.c

RTC_CompareSet#

void RTC_CompareSet (unsigned int comp, uint32_t value)

Set the RTC compare register value.

Parameters
[in]comp

A compare register to set. This value must be less than NUM_RTC_CHANNELS.

[in]value

An initialization value (<= 0x00ffffff).

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.


Definition at line 157 of file platform/emlib/src/em_rtc.c

RTC_CounterGet#

uint32_t RTC_CounterGet (void)

Get RTC counter value.

Parameters
N/A

Returns

  • Current RTC counter value.


Definition at line 93 of file platform/emlib/inc/em_rtc.h

RTC_CounterSet#

void RTC_CounterSet (uint32_t value)

Set the RTC counter value.

Parameters
[in]value

The new RTC counter value.


Definition at line 106 of file platform/emlib/inc/em_rtc.h

RTC_CounterReset#

void RTC_CounterReset (void)

Restart the RTC counter from zero.

Parameters
N/A

Definition at line 369 of file platform/emlib/src/em_rtc.c

RTC_Enable#

void RTC_Enable (bool enable)

Enable/disable RTC.

Parameters
[in]enable

True to enable counting, false to disable.

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.


Definition at line 220 of file platform/emlib/src/em_rtc.c

RTC_FreezeEnable#

void RTC_FreezeEnable (bool enable)

RTC register synchronization freeze control.

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

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.


Definition at line 264 of file platform/emlib/src/em_rtc.c

RTC_Init#

void RTC_Init (const RTC_Init_TypeDef *init)

Initialize RTC.

Parameters
[in]init

A pointer to the RTC initialization structure.

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.


Definition at line 305 of file platform/emlib/src/em_rtc.c

RTC_IntClear#

void RTC_IntClear (uint32_t flags)

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).


Definition at line 128 of file platform/emlib/inc/em_rtc.h

RTC_IntDisable#

void RTC_IntDisable (uint32_t flags)

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).


Definition at line 142 of file platform/emlib/inc/em_rtc.h

RTC_IntEnable#

void RTC_IntEnable (uint32_t flags)

Enable one or more RTC interrupts.

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).

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.


Definition at line 161 of file platform/emlib/inc/em_rtc.h

RTC_IntGet#

uint32_t RTC_IntGet (void)

Get pending RTC interrupt flags.

Parameters
N/A

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).


Definition at line 177 of file platform/emlib/inc/em_rtc.h

RTC_IntGetEnabled#

uint32_t RTC_IntGetEnabled (void)

Get enabled and pending RTC interrupt flags.

Parameters
N/A

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.


Definition at line 196 of file platform/emlib/inc/em_rtc.h

RTC_IntSet#

void RTC_IntSet (uint32_t flags)

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).


Definition at line 213 of file platform/emlib/inc/em_rtc.h

RTC_Reset#

void RTC_Reset (void)

Restore RTC to reset state.

Parameters
N/A

Definition at line 339 of file platform/emlib/src/em_rtc.c

Macro Definition Documentation#

NUM_RTC_CHANNELS#

#define NUM_RTC_CHANNELS
Value:
2U

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


Definition at line 55 of file platform/emlib/inc/em_rtc.h

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.


Definition at line 72 of file platform/emlib/inc/em_rtc.h