PRE NMI Flag
This is a flag indicating whether or not a PRE NMI has been received. The following bits are set to 1 by the scheduler.
NU_SC_PRENMI_YET All bits are 0 when no PRE NMI event has occurred.
NU_SC_PRENMI_GET When a PRE NMI event has been received
NU_SC_BEFORE_RESET This bit is set 2 frames before the end of a 0.5 second interval after a PRE NMI event has been received. Once this bit has been set, graphics tasks and audio tasks can no longer be executed.