Hey,
When the Uc's IO input pin is to receive interrupts from an external IC, would it be correct to say that you'd want the Uc's IO input pin to be set to Pull-up/down mode, and not to Tristate mode, as the external IC might shut down at some stage, and you wouldn't want it to trigger an interrupt?
However, what if the VDD of the Uc is different than the VDD of the extermal IC, wouldn't it be better to set the Uc's IO input pin to Tristate in order to save on power consumption of the system?
Thanks.