tick timing

[mcollins at hawkeye.sps.mot.com]

Joel wrote:

> You don't have to circumvent the macros if this is simply an application
> configuration.  Set the CONFIGURATION_MICROSECONDS_PER_TICK to whatever
> you want.  The problem is the construction of the clock tick driver.
> THe powerpc decrementer based clock tick driver does it better.  See
> c/src/lib/libcpu/powerpc/mpc6xx/clock/c_clock.c and notice that it
> takes a BSP supplied value for an arbitrary clock tick.   Basically
> you just have to program the tick source based on the value configured.

  This is the info I needed.  I changed the tick driver to do nothing
more than increment Clock_driver_ticks and call rtems_clock_tick(),
and now things work as expected.

  I'm currently experimenting with an algorithm which should improve
the average accuracy of the time-of-day functions despite the wierd
tick rate offered by the 68331 with a 32.768kHz oscillator.  If my
concept proves to be sound, I'll post an update.

  Thanks for the help.

					-- MC --
--
mcollins at wdc.sps.mot.com