OS_SetPeriodicAlarm


C Specification

#include <nitro/os.h>

void OS_SetPeriodicAlarm(
                OSAlarm*        alarm , 
                OSTick          start , 
                OSTick          period , 
                OSAlarmHandler  handler , 
                void*           arg );

Description

Sets a periodic alarm

The alarm handler, handler, is first called when the tick value equals start. handler is then subsequently called after each tick period count. handler is a OSAlarmHandler type function defined by :

typedef void (*OSAlarmHandler)( void*);

When handler is called, it takes arg as an argument.

One tick count unit is 1/64 of the hardware system clock.

If alarm specifies the pointer to the OSAlarm structure which the alarm has set, OS_Panic stops the alarm.

OS_CancelAlarm() is used to stop the alarm.

Arguments

alarm Pointer to the alarm structure that sets the alarm
start Tick count for first actuation of the alarm (calling the handler) (This is not a relative value from the current time, but an absolute value.)
period Interval at which the alarm will be activated
handler Alarm handler
arg Argument used when the alarm handler is called

Return Values

None

See Also

OS_InitAlarm, OS_CreateAlarm, OS_SetAlarm, OS_CancelAlarm, OS_*SecondsToTick

Revision History

08/30/2004 Added the description that the alarm structure that has been set is not usable.
02/25/2004 Changed systemClock to tick
02/04/2004 Initial Version