Configuring GPIO as IRQs on Connect ME 9210

I am trying to configure two GPIO pins on my Connect ME 9210 as IRQ0 and IRQ1. Referring to the Hardware Reference manual, p40, implies that pins 12 and 18 can be configured for IRQs. In some other files I have found the routine naGpioSetInterrupt(function, level, edge). It implies I should be able to use this routine to configure these GPIO as interrupt, but nowhere does it suggest which ‘function’ I should use for pin 12 and which for pin 18.

Any clues how to do this would be greatly appreciated!

Many thanks,