[En-Nut-Discussion] interrupt sense control for RTL8019AS

[PragmaLab]

Hello Henrik

>For a standard Ethernut hardware the classic level triggered mode should be
used. 
>This mode is also backwards compatible to the Atmega103 MCU which does 
>not support edge triggered interrupts.

Thanks for your explanation on this matter. I feel comfortable now using the
level triggered interrupt as is. 

Just out of curiosity: I always remembered that a level triggered interrupt
keeps triggering an interrupt as long as the level is active. So the moment
the ISR is finished and re-enables the interrupt, it's there again. While an
edge triggered interrupt will only fire once... Does that make sense to you?


The datasheet tells us:
"if enabled, a level triggered interrupt will generate an interrupt request
as long as the pin is held low". 

If this is the case, replacing a level triggered interrupt by an
edge-triggered interrupt may result different behaviour: level triggered
forces SW to keep executing the ISR, e.g to read data from a device, while
edge triggered will only let the ISR be executed once.

Appearantly, that doesn't make a difference when it comes to handling the
RTL8019AS?


Best regards,

Rob