Leaving an interrupt pin unconnected.

[alphacat]

Hello,

In my MCU, in order to define a certain pin as an interrupt source, i need to define a whole nibble (4 pins) as an interrupt source, even that i want to use only one pin as an interrupt source.

My question is, if I leave this 3 other pins N/C, could i have a problem of receiving interrupts due to noise?

I should add that i can configure these other 3 pins as pulled-up or pulled-down, which i assume might prevent from external noise to cause an interrupt, but i'm not sure.
(For example, configuring the pin as pulled-up, and have an interrupt caused when the pin's voltage drops to 0V).

What do you think?

Thanks.

 

[Nigel Goodwin]

Ues pull-down resistors on each unused input.