CHAPTER 7 INTERRUPT/EXCEPTION PROCESSING FUNCTION
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User’s Manual U14492EJ3V0UD
Figure 7-7. Example of Servicing Interrupt Requests Generated Simultaneously
Default priority
a > b > c
Main routine
EI
Interrupt request a (level 2)
Interrupt request b (level 1)
Interrupt request c (level 1)
Servicing of interrupt request b
.
.
Servicing of interrupt request c
Servicing of interrupt request a
Interrupt requests 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.
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.
Содержание V850E/IA1 mPD703116
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