Allowed system calls in ISRs

[Joel Sherrill <joel@OARcorp.com>]

Ingolf Steinbach wrote:
> On Friday 27 May 2005 15:23, Joel Sherrill <joel at OARcorp.com> wrote:
> 
>>That should be OK.  It doesn't allocate memory or block.  Those
>>are the two biggest factors.
> 
> 
> So, the write operation for the setting of the new vector is
> atomic or protected against parallel access? Is an ISR allowed
> to change the vector for "its own" interrupt?

Although the API is consistent, the actual routine which
installs the ISR and returns the old one is CPU dependent.
The entire critical section you are referring to is
thus CPU dependent so you would have to check the port.

If it isn't, it would be easy to fix.


> Kind regards
>     Ingolf


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