NEC uPD78P078 User Manual
Page 515
515
CHAPTER 22 INTERRUPT FUNCTIONS
Figure 22-12. Non-Maskable Interrupt Request Acknowledge Operation
(a)
If a new non-maskable interrupt request is generated during
non-maskable interrupt servicing program execution
(b)
If two non-maskable interrupt requests are generated during
non-maskable interrupt servicing program execution
NMI Request <2>
NMI Request <1>
1 Instruction Execution
Main Routine
NMI Request <1> Execute
NMI Request <2> Reserve
Reserved NMI Request <2> Processing
NMI Request <3>
NMI Request <2>
NMI Request <1>
1 Instruction Execution
Main Routine
NMI Request <1> Execute
NMI Request <2> Reserve
NMI Request <3> Reserve
Reserved NMI Request <2> Processing
NMI Request <3> Not Acknowledged
(Only 1 NMI request is acknowledged even if
two or more NMI requests are generated.)