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

[Henrik Maier]

PragmaLab wrote:
  > 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?

Yes it does. The ISR must make sure that all pending interrupts are 
processed before leaving. That's why you find in the NIC driver's ISR a 
loop which checks the ISR for pending interrupts before exiting. The 
loop is only compiled in for edge triggered mode.


Henrik
http://www.proconx.com