NAME

       rtapi_clock_set_period - set the basic time interval for realtime tasks

SYNTAX

               rtapi_clock_set_period(long int nsec)

ARGUMENTS

       nsec   The desired basic time interval for realtime tasks.

DESCRIPTION

       rtapi_clock_set_period  sets  the  basic  time  interval for realtime tasks.  All periodic
       tasks  will  run  at  an  integer  multiple  of  this   period.    The   first   call   to
       rtapi_clock_set_period with nsec greater than zero will start the clock, using nsec as the
       clock period in nano-seconds.  Due to hardware and RTOS limitations, the actual period may
       not  be exactly what was requested.  On success, the function will return the actual clock
       period if it is available, otherwise it returns the requested period.   If  the  requested
       period  is outside the limits imposed by the hardware or RTOS, it returns -EINVAL and does
       not start the clock.  Once the clock is  started,  subsequent  calls  with  non-zero  nsec
       return  -EINVAL  and have no effect.  Calling rtapi_clock_set_period with nsec set to zero
       queries the clock, returning the current clock period, or zero if the clock  has  not  yet
       been started.

REALTIME CONSIDERATIONS

       Call  only  from  within init/cleanup code, not from realtime tasks.  This function is not
       available from user (non-realtime) code.

RETURN VALUE

       The actual period provided by the RTOS, which may be different than the requested  period,
       or a RTAPI status code.