Hallo everybody, In what cases should one use level and in what cases edge triggered interrupts for the internal sources? Regards, Roman
level vs. edge triggered interrupts
Started by ●February 21, 2006
Reply by ●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 ●February 21, 20062006-02-21
romanua,
Here is a link that you might find
helpful:
http://www.at91.com/www/phpBB2_mirror/viewtopic.php4?t29
----- Original Message -----From: romanua1To: A...@yahoogroups.comSent: Monday, February 20, 2006 9:27 PMSubject: [AT91SAM] level vs. edge triggered interruptsHallo everybody,
In what cases should one use level and in what cases edge triggered
interrupts for the internal sources?
Regards,
Roman
