CHAPTER 8 INTC
Preliminary User’s Manual A14874EJ3V0UM
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Figure 8-1. Example of Non-Maskable Interrupt Request Acknowledgement Operation (2/2)
(b) NMI request generated during NMI servicing
NMI request generated during NMI servicing
NMI being
serviced
NMI0
NMI1
NMI2
NMI0
•
NMI0 request generated
during NMI0 servicing
Main routine
NMI0 request
NMI0 request
NMI0 servicing
(Held pending)
Servicing of
pending NMI0
•
NMI1 request generated
during NMI0 servicing
(NP = 1 retained before
NMI1 request)
Main routine
NMI0 request
NMI1 request
NMI0 servicing
(Held pending)
System reset
NMI1 servicing
•
NMI1 request generated
during NMI0 servicing (NP =
0 set after NMI1 request)
Main routine
NMI0
request
NMI1 request
NMI0 servicing
NMI1
servicing
System reset
NP = 0
•
NMI1 request generated
during NMI0 servicing (NP =
0 set before NMI1 request)
Main routine
NMI0
request
NMI1
request
NMI0 servicing
NMI1
servicing
System reset
NP = 0
(Held
pending)
•
NMI2 request generated
during NMI0 servicing
Main routine
NMI0 request
NMI2 request
NMI0 servicing
NMI2 servicing
System reset
NMI1
•
NMI0 request generated
during NMI1 servicing
Main routine
NMI1 request
NMI0 request
NMI1 servicing
(Invalid)
System reset
•
NMI1 request generated
during NMI1 servicing
Main routine
NMI1 request
NMI1 request
NMI1 servicing
(Invalid)
System reset
•
NMI2 request generated
during NMI1 servicing
Main routine
NMI1
request
NMI2 request
NMI1 servicing
NMI2
servicing
System reset
NMI2
•
NMI0 request generated
during NMI2 servicing
Main routine
NMI2 request
NMI0 request
NMI2 servicing
(Invalid)
System reset
•
NMI1 request generated
during NMI2 servicing
Main routine
NMI2 request
NMI1 request
NMI2 servicing
(Invalid)
System reset
•
NMI2 request generated
during NMI2 servicing
Main routine
NMI2 request
NMI2 request
NMI2 servicing
(Invalid)
System reset