# rtc\_if.h - [Overview](#section468934416165628) - [Summary](#section1696974119165628) - [Data Structures](#nested-classes) - [Typedefs](#typedef-members) - [Enumerations](#enum-members) - [Functions](#func-members) ## **Overview** **Related Modules:** [RTC](RTC.md) **Description:** Declares the standard RTC APIs. **Since:** 1.0 ## **Summary** ## Data Structures

Data Structure Name	Description
RtcTime	Defines the RTC information.

## Typedefs

Typedef Name	Description
RtcAlarmCallback) (enum RtcAlarmIndex)	typedef int32_t(* Defines a callback that will be invoked when an alarm is generated at the specified time.

Typedef Name

Description

RtcAlarmCallback) (enum RtcAlarmIndex)

typedef int32_t(*

Defines a callback that will be invoked when an alarm is generated at the specified time.

## Enumerations

Enumeration Name	Description
RtcAlarmIndex { RTC_ALARM_INDEX_A = 0, RTC_ALARM_INDEX_B = 1 }	Enumerates alarm indexes.

## Functions

Function	Description
RtcOpen (void)	DevHandle Opens the RTC device to obtain its handle.
RtcClose (DevHandle handle)	void Releases a specified handle of the RTC device.
RtcReadTime (DevHandle handle, struct RtcTime *time)	int32_t Reads time from the RTC driver.
RtcWriteTime (DevHandle handle, const struct RtcTime *time)	int32_t Writes format-compliant time to the RTC driver.
RtcReadAlarm (DevHandle handle, enum RtcAlarmIndex alarmIndex, struct RtcTime *time)	int32_t Reads the RTC alarm time that was set last time.
RtcWriteAlarm (DevHandle handle, enum RtcAlarmIndex alarmIndex, const struct RtcTime *time)	int32_t Writes the RTC alarm time based on the alarm index.
RtcRegisterAlarmCallback (DevHandle handle, enum RtcAlarmIndex alarmIndex, RtcAlarmCallback cb)	int32_t Registers RtcAlarmCallback that will be invoked when an alarm is generated at the specified time.
RtcAlarmInterruptEnable (DevHandle handle, enum RtcAlarmIndex alarmIndex, uint8_t enable)	int32_t Enables or disables alarm interrupts.
RtcGetFreq (DevHandle handle, uint32_t *freq)	int32_t Reads the RTC external frequency.
RtcSetFreq (DevHandle handle, uint32_t freq)	int32_t Sets the frequency of the external crystal oscillator connected to the RTC driver.
RtcReset (DevHandle handle)	int32_t Resets the RTC driver.
RtcReadReg (DevHandle handle, uint8_t usrDefIndex, uint8_t *value)	int32_t Reads the configuration of a custom RTC register based on the register index.
RtcWriteReg (DevHandle handle, uint8_t usrDefIndex, uint8_t value)	int32_t Writes the configuration of a custom RTC register based on the register index.