OS_SetPeriodicAlarm

Syntax

#include <nitro/os.h>
void OS_SetPeriodicAlarm(
                OSAlarm*       alarm,
                OSTick          start ,
                OSTick          period ,
                OSAlarmHandler handler,
                void*           arg );

Arguments

alarm Pointer to an alarm structure that is initialized for this 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.

Description

Sets a periodic alarm.

The alarm handler handler is first called when the tick value equals start . The V-Count alarm handler handler is an OSVAlarmHandler function defined by the following:

typedef void (*OSAlarmHandler)( void* );

When the handler is called, it takes arg as an argument. The handler argument is passed from the OS timer interrupt handler. Therefore, interrupts are prohibited.

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.

See Also

OS_InitAlarm, OS_CreateAlarm, OS_SetAlarm, OS_CancelAlarm
OS_*SecondsToTick

Revision History

2005/03/08 Standardized the use of the term interrupt in Japanese.
2004/12/22 Added a statement about the alarm handler's being called from the timer interrupt handler.
2004/08/30 Added a statement about not being able to use the set alarm structure.
2004/02/25 Changed systemClock to tick.
2004/02/04 Initial version.

CONFIDENTIAL