[En-Nut-Discussion] Interrupt disable time

Harald Kipp harald.kipp at egnite.de
Fri Dec 13 21:24:13 CET 2002


Dave,


>First, between the hardware assertion and my ISR activation, I see a
>consistent 13 uSec delay. I believe this is the preamble and setup for the
>driver (the top piece of which is below and has some overhead).

The overhead will even grow in the near future to support
SNMP.

Right now the only thing you can do is to comment out the
part in irqreg, that is handling your interrupt, and provide
a native interrupt routine in your application code.


>Second, and more importantly, is that occasionally (too frequently for my
>system), the ISR appears to be blocked, probably by another interrupt, and
>since I'm using Ethernet, I'm guessing that might be one of the culprits.

Typically the Ethernet interrupts are very short. Except,
when packet overflows occur. May be a solution would be
to enable interrupts in this case, but disable Ethernet
interrupts to avoid nested Ethernet interrupts.

Harald

P.S. I'm forced to stop here, sorry.





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