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R01UH0336EJ0102 Rev.1.02
Page 184 of 1538
Jul 17, 2014
V850E2/PG4-L
Section 4 Interrupt Functions
Table 4-4
Example of EIINT Interrupt Priority Level Settings and Priority Levels
During interrupt servicing, the interrupt controller also processes multiple
interrupts acknowledging other interrupts. When multiple EIINT interrupts are
requested at the same time, the interrupt to be acknowledged is determined
with the following procedure.
(1)
Comparison with the Priority Level as the Interrupt Currently Being
Serviced
Interrupts with the same or lower priority level as the interrupt currently being
serviced are held.
The priority level of the interrupt currently being serviced is held in the ISPR
register.
Interrupts with a higher priority level than the interrupt currently being serviced
go on to the next priority judgment stage.
(2)
Masking through Priority Mask Register (PMR)
Only interrupts enabled by the PMR register go on to the next priority judgment
stage.
(3)
Of the Requested Interrupt Sources, that with the Highest Priority Level
is Selected
In the case of simultaneous interrupt requests at the highest priority level from
multiple sources, that with the lowest interrupt channel number is selected.
(4)
Interrupt Hold by CPU
Interrupt acknowledgment is pended according to the state of the NP and ID
bits of the PSW register. At this time, priority judgment among EIINT interrupts,
and priority judgment among EIINT interrupts, FEINT interrupts, and FENMI
interrupts is performed even while interrupt acknowledgment is pended, and
the interrupt with the highest priority is selected upon realization of the
acknowledgment condition.
Example
When a priority level 5 EIINT interrupt has already been requested and interrupt
generation is pended because the value of the PSW.ID bit is "1", a subsequent priority
level 3 EIINT interrupt is requested. Then, if the PSW.ID bit is cleared (0), the priority level
3 EIINT interrupt is generated.
EIINT
P3xx to P0xx Setting
Priority Level During Operation
EIINT0
3
10
EIINT1
4
11
EIINT2
0
1
EIINT3
0
2
EIINT4
1
3
EIINT5
2
6
EIINT6
2
7
EIINT7
1
4
EIINT8
1
5
EIINT9
2
8
EIINT10
2
9