On Sat, Nov 11, 2000 at 07:39:40AM -0800, Jason R Thorpe wrote:

> > I revise my previous statement, and it's good news.  The RTC *can* be used
> > for the jiffy (hz) clock!  I was just reading the code for arc/algor, and
> > the Algorithmics branch does exactly this.  I'm excited.  I was just reading
> > the specs sheet for our DS1287 rtc chip, and it provides a periodic clock
> > interrupt at rates from 500ms down to 122us.  Which makes it perfect for
> > our needs!  So again if the MCT ADR interval timer turns out to be
> > unusable on the Magnum, we have yet another option, and wouldn't have to
> > mess with the cpu timer code at all.  Awesome!
> 
> Indeed, it's the same clock chip the i386pc uses, so I would be surprised
> if we couldn't use that :-)

Afair the data sheets accessing registers on the DS1287 is very slow so you
want to avoid it whenever you can.  So I'd recommend the count / compare
interrupt.

  Ralf