Overview of Interrupts
M30240 Group
Rev.1.00 Sep 24, 2003 Page 344 of 360
Figure 4.9: Multiple interrupts
Main routine
Reset
I = 0
IPL = 0
I = 1
Interrupt 1
I = 0
IPL = 3
I = 1
Interrupt 2
I = 0
IPL = 5
REIT
I = 1
IPL = 3
Interrupt 3
REIT
I = 1
IPL = 0
Interrupt 3
I = 0
IPL = 2
REIT
I = 1
IPL = 0
Interrupt 1
Interrupt priority level = 3
Interrupt 2
Interrupt 3
Interrupt priority level = 5
Interrupt priority level = 2
Not acknowledged because
of low interrupt priority
Interrupt request
generated
Nesting
Time
: Automatically executed.
: Be sure to set in software.
I : Interrupt enable flag
IPL : Processor interrupt priority level
Main routine instructions
are not executed.
Multiple interrupts