hi precision timing

[Gregory.D.Menke.1 at gsfc.nasa.gov]

We're using a mcp750, and would like to get at some of the timers
available in the chipset.  After wading thru the openpic code, I found
a few functions that look nice for that purpose.

- does RTEMS use any of the Raven timers?  If so, are any free for
  use?

- Our application needs an incrementing counter for timing at a
  resolution of 50 to 100us, and we would prefer to poll it rather
  than have an interrupt.  Is there an RTEMS kernel feature that would
  expedite setting up this kind of thing?  A fast isr that increments
  an int somewhere would be fine- I'm mostly wondering if this
  approach is reasonable.

- Does RTEMS prefer PCI work be done via some internal API, or is
  direct access down on the bare metal OK?

Thanks,

Greg