multitasking question

Aaron J. Grier aaron at frye.com
Tue Feb 12 23:20:16 UTC 2002


On Mon, Feb 11, 2002 at 04:19:54PM -0700, "Michael P. Collins" on korat wrote:

>   To provide some real-world info, I have been using the following
> parameters on a 25MHz MC68331 board over the past few days:
> 
>       #define CONFIGURE_MICROSECONDS_PER_TICK   122

is this just hardcoded to match what the clock driver is programmed for?
or are people writing support in their clock drivers for (compile-time)
configurable µs/tick?

I'm currently using 10ms ticks out of default more than anything else,
and even then they're not 10ms exactly (actually 10 * 1/1024 ticks) so I
end up having some hacks in my timer ISR to handle "leap sub-ticks."
with my hacks the RTEMS clock is still off a few seconds a month, which
can be dealt with, but I wonder if there's a better way.

-- 
  Aaron J. Grier  |   Frye Electronics, Tigard, OR   |  aaron at frye.com
     "In a few thousand years people will be scratching their heads
       wondering how on earth the first computer was invented and
          bootstrapped without a prior computer to do it with."
                    --  Chris Malcolm, on comp.arch



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