29.8.3 Non-Maskable Interrupt Flag Status and Clear

Important: For SAM L11 Non-Secure accesses, read and write accesses (RW*) are allowed only if the NMI interrupt is set as Non-Secure in the NONSEC register (NONSEC.NMI bit).
Name: NMIFLAG
Offset: 0x2
Reset: 0x00
Property: Mix-Secure

Bit 76543210 
        NMI 
Access RW/RW*/RW 
Reset 0 

Bit 0 – NMI Non-Maskable Interrupt

This flag is cleared by writing a '1' to it.

This flag is set when the NMI pin matches the NMI sense configuration, and will generate an interrupt request.

Writing a '0' to this bit has no effect.