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Interrupt Controller (INTC)
Chapter 5
Preliminary User’s Manual U17566EE1V2UM00
Caution
The values of the EIPC and EIPSW registers must be saved before executing
multiple interrupts. When returning from multiple interrupt servicing, restore the
values of EIPC and EIPSW after executing the DI instruction.
Note
1.
Lower default priority
2.
Higher default priority
Figure 5-9
Example of processing interrupt requests simultaneously generated
Caution
The values of the EIPC and EIPSW registers must be saved before executing
multiple interrupts. When returning from multiple interrupt servicing, restore the
values of EIPC and EIPSW after executing the DI instruction.
Remark
<a> to <c> in the figure are the temporary names of interrupt requests shown
for the sake of explanation.
Default priority
a > b > c
Main routine
EI
Interrupt request a (level 2)
Interrupt request b (level 1)
Interrupt request c (level 1)
Processing of interrupt request b
.
.
Processing of interrupt request c
Processing of interrupt request a
Interrupt request b and c are
acknowledged first according to
their priorities.
Because the priorities of b and c are
the same, b is acknowledged first
according to the default priority.
NMI request
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