Np Flag; Noise Eliminator Of Nmi Pin - NEC Renesas V850/SC1 User Manual

7.2.3 NP flag

The NP flag is a status flag that indicates that non-maskable interrupt (NMI) servicing is under execution. This
flag is set when an NMI interrupt request has been acknowledged, and masks all interrupt requests to prohibit
multiple interrupts from being acknowledged.
After reset: 00000020H
Symbol 31
PSW
NP
0 No NMI interrupt servicing
1 NMI interrupt currently being serviced

7.2.4 Noise eliminator of NMI pin

NMI pin noise is eliminated by a noise eliminator using analog delay. Therefore, a signal input to the NMI pin is
not detected as an edge, unless it maintains its input level for a certain period. The edge is detected only after a
certain period has elapsed.
The NMI pin is used for canceling the software stop mode. In the software stop mode, noise elimination using the
system clock does not occur because the internal system clock is stopped.
CHAPTER 7 INTERRUPT/EXCEPTION PROCESSING FUNCTION
Figure 7-4. NP Flag (NP)
0
NMI servicing state
User's Manual U15109EJ3V0UD
8 7 6 5 4 3 2
NP EP ID SAT CY OV
1 0
S Z
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