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RE: Fast responce (Interrupts)



How exact timing do you need? 5 +/- 1 ms or 5 +/- 1 us? 
 
>The solution I have been thinking of is using an external hardware generating a pulse on the NMI pin available on the Etrax. Do you think this is the >best way to do this or do you have any other ideas?
 
If you need very exact timing this is the only way I think (because other interrupts are disabled sometimes).
 
>Are there any documentation or sample code available for the use of NMI (or the solution that you proposes)?
Look at the watchdog code (CONFIG_ETRAX_WATCHDOG). The watchdog in the ETRAX gives an NMI
when it is starving. 
 
In arch/cris/kernel/entry.S you will find the NMI handler (IRQ1_interrupt). Otherwise you are pretty much
on your own since we don't have any code to register NMI handler etc. 
 
/Mikael

-----Original Message-----
From: owner-dev-etrax@xxxxxxx.com]On">mailto:owner-dev-etrax@xxxxxxx.com]On Behalf Of Peter Fredriksson
Sent: Friday, December 13, 2002 10:26 AM
To: dev-etrax
Subject: Fast responce (Interrupts)


Hi all,

I am working on a project where we are in need to periodically (~5ms) run a piece of code to handle external signals. This code is required to run every 5 ms or there will be problems.

The solution I have been thinking of is using an external hardware generating a pulse on the NMI pin available on the Etrax. Do you think this is the best way to do this or do you have any other ideas?

Are there any documentation or sample code available for the use of NMI (or the solution that you proposes)?

Thanks,
Peter







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