Strange bug on EP9302-based custom board

Jay Monkman jtm at
Thu Dec 15 16:42:33 UTC 2005

Fabien CASAS wrote:
> Ok, I've restored a version of my BSP with which the ticker test works,
> and then I've added, one by one, my board specific drivers.
> All worked fine !
> Then I wanted to lower the tick value (I'm not using the
> CONFIGURE_MICROSECONDS_PER_TICKS for now). The ticker test works fine
> when I set the tick value to 50ms. But when I set the tick to 10ms, the
> ticker test crashes with an Undefined exception.

That's odd. You should be able to do 10ms.

> Do you think that this crash is due to my clock ISR, which takes too
> long (it does nothing special, though) ?

I don't think so. Although, if you're ISR takes so long to run that another
interrupt comes along while the ISR is still running you might have some
problems. I thing you'd really have to screw up your interrupt handling for that
to happen, though.

> My EP9302 is running at 40MHz, and I need a tick at about 10µs, which is
> okay regarding the counter I'm using.

You want a timer tick every 10uS?!? At 40 MHz that's theoretically 400
instructions, but in reality probably less. The interrupt handling code is
probably longer than that, not to mention everything that runs as a result of

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