UPD70F3212 Datasheet, PDF (598/861 Pages) NEC – 32-Bit Single-Chip Microcontrollers

CHAPTER 20 INTERRUPT/EXCEPTION PROCESSING FUNCTION
20.2.3 NP flag
The NP flag is a status flag that indicates that non-maskable interrupt servicing is in progress. This flag is set when
a non-maskable interrupt request has been acknowledged, and masks all non-maskable requests to prevent multiple
interrupts.
After reset: 00000020H
PSW
0
NP EP ID SAT CY OV S Z
NP
NMI servicing status
0
No non-maskable interrupt servicing
1
Non-maskable interrupt serving in progress
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User’s Manual U16890EJ1V0UD