Re: time and timers in FreeMWare

[Ramon van Handel]

"Timothy J. Massey" wrote:
> 
> On Fri, 20 Aug 1999 01:12:03 +0200, Ramon van Handel wrote:
> 
> >> So if we wanted highly accurate timing, we need a mechanism for
> >> interrupting us in the middle.  Fortunately, the built-in
> >> APIC on the Pentium has a timer based on CPU clock speed which
> >> can do this.  It can be programmed to either periodic or one-shot
> >> mode.  (thanks to one of the developers for suggesting use of
> >> this timer facility)
> >
> >The problem is that we still don't know whether this timer
> >is present on AMD.  I fear that it may not be.
> 
> I could be wrong (it wouldn't be the first time), but isn't the APIC part of
> the chipset?  If so, the AMD would have the same facilities as the Pentium:
> they use the same chipsets...

On pentium, the LOCAL APIC is part of the processor.
On 486, it is a separate chip.
The I/O APIC is always in the chipset, but it's the local
APIC that has the timers.

Ramon