# RTC_GetAlarmStatusAsync

## C Specification

  `#include <nitro/rtc.h>`

      RTCResult RTC_GetAlarmStatusAsync(
      RTCAlarmChan        chan,
      RTCAlarmStatus*	status,
      RTCCallback		callback,
      void*		arg );

## Arguments

chan | Uses `RTCAlarmChan` to specify the alarm channel.
status | Pointer to `RTCAlarmStatus` data structure.
callback | Pointer to the callback function. This callback is called from within the interrupt handler.
arg | Argument to pass to the callback function.

## Return Values

If the request succeeds, it returns 0. If the request fails, it returns some numeric value other than 0.

## Description

This function asynchronously reads alarm interrupt permission status from the real-time clock. It queries ARM7 for the values of the alarm permission status and returns the results without waiting for a response from the processor. To get the result from the processor, you must use the `result` argument. If this function fails, no operation is performed and no user callback function is called.

## Caution

Values are written to the variable specified by the `status` argument asynchronously with respect to the function. Do not use this variable for anything else until a user callback function confirms the completion of this asynchronous operation.

## See Also

`RTC_GetAlarmStatus, RTC_SetAlarmStatus, RTC_SetAlarmStatusAsync, RTCResult, RTCAlarmChan, RTCAlarmStatus, RTCCallback`

## Revision History

06/27/2005 Added statement about callback being called from the interrupt handler.
03/08/2005 Standardized the use of the term 'interrupt' in Japanese.
05/18/2004 Initial version