Subject: [AT91SAM] level vs. edge
triggered interrupts
Hallo everybody,
In what cases should one use
level and in what cases edge triggered interrupts for the internal
sources?
Regards,
Roman
Reply by Charles Manning●February 21, 20062006-02-21
On Tuesday 21 February 2006 18:27, romanua1 wrote:
> Hallo everybody,
>
> In what cases should one use level and in what cases edge triggered
> interrupts for the internal sources?
>
This is not always an easy thing to answer, but the rule of thumb I use is
this:
* Does the interrupt get cleared after you process it?
If yes, then use a level interrupt, if no then use an edge interrupt.
and a revalidation:
* If you screw up the processing slightly, will the edges stop coming?
If so, you should not use an edge sensitive interrupt.
For example, a UART interrupt is high when there is something to process and
low when there is not. If you miss some processing, it will stay high. This
should be processed with a level sensitive interrupt. If you used edge
sensitive interrupts then any missed processing will mean you don't get any
more edges and the interrupt servicing will no longer trigger.
Reply by romanua1●February 21, 20062006-02-21
Hallo everybody,
In what cases should one use level and in what cases edge triggered
interrupts for the internal sources?
Regards,
Roman