493CHAPTER 21 INTERRUPT AND TEST FUNCTIONSFigure 21-12. Non-Maskable Interrupt Request Acknowledge Operation(a) If a new non-maskable interrupt request is generated duringnon-maskable interrupt servicing program execution(b) If two non-maskable interrupt requests are generated duringnon-maskable interrupt servicing program executionMain RoutineNMI Request <1> NMI Request <1> executed.NMI Request <2> held.1 Instruction ExecutionHeld NMI Request <2> processed.NMI Request <2>NMI Request <3> is not received.Even if more than 2 NMI requests are generated,they can only be received 1 time.Main RoutineNMI Request <1> NMI Request <1> executed.NMI Request <2> heldNMI Request <3> held.1 Instruction ExecutionHeld NMI Request <2> processed.NMI Request <2>NMI Request <3>
