23.5.5 Interrupts
There are several interrupt request lines, some (the number depends on the product variant) for the external interrupts (EXTINT) and one for Non-Maskable Interrupt (NMI).
Each EXTINT interrupt request line is connected to the interrupt controller. Using the EIC interrupt requires the interrupt controller to be configured first.
The NMI interrupt request line is connected to the interrupt controller, but does not require the interrupt to be configured.