Cyg_Alarm::Cyg_Alarm
(
  Cyg_Counter  *counter, /* Attached to this counter */
  cyg_alarm_fn *alarm,   /* Call-back function       */
  CYG_ADDRWORD data      /* Call-back data           */
)

The callback is of the form: void cyg_alarm_fn(Cyg_Alarm *alarm, CYG_ADDRWORD data).

Cyg_Alarm::~Cyg_Alarm
(
  void
)

void Cyg_Alarm::initialize
(
  cyg_tick_count trigger,   /* Absolute trigger time       */
  cyg_tick_count interval=0 /* Relative retrigger interval */
)

The alarm will be enabled automatically after this call

void Cyg_Alarm::enable
(
  void
)

A periodic alarm that has been disabled and later re-enabled will fire at the same intervals it did previously. For example, a periodic alarm that fired every 10 seconds at time T0, T10, T20, T30... etc that was disabled for 15 seconds at time T31 and then renabled would then start firing again at T50, T60, T70 etc.

If this behavior is not desired, use Cyg_Alarm::initialize to reset the intervals.

void Cyg_Alarm::disable
(
  void
)

Cyg_Alarm::initialize or Cyg_Alarm::enable can be used to re-enable the alarm once it's been disabled.

void Cyg_Alarm::get_times
(
  cyg_tick_count *trigger, /* pointer to the next trigger time */
  cyg_tick_count *interval /* pointer to the current interval  */
)

It is legal to pass NULL as the "trigger" and "interval" pointers if those values are not needed.