CHAPTER 7 INTERRUPT/EXCEPTION PROCESSING FUNCTION
167
User’s Manual U14492EJ3V0UD
7.2
Non-Maskable Interrupt
A non-maskable interrupt request is acknowledged unconditionally, even when interrupts are in the interrupt
disabled (DI) status. An NMI is not subject to priority control and takes precedence over all the other interrupts.
A non-maskable interrupt request is input from the NMI pin. When the valid edge specified by bit 0 (ESN0) of the
external interrupt mode register 0 (INTM0) is detected on the NMI pin, the interrupt occurs.
While the service program of the non-maskable interrupt is being executed (PSW.NP = 1), the acknowledgement
of another non-maskable interrupt request is held pending. The pending NMI is acknowledged after the original
service program of the non-maskable interrupt under execution has been terminated (by the RETI instruction). Note
that if two or more NMI requests are input during the execution of the service program for an NMI, the number of
NMIs that will be acknowledged after PSW.NP is cleared to 0 is only one.
Remark
PSW.NP: NP bit of the PSW register
Содержание V850E/IA1 mPD703116
Страница 2: ...2 User s Manual U14492EJ3V0UD MEMO...