UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 564

• Manufacturer Part Number: UPD784026
• Description: 16/8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

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Figure 20-13 Examples of Processing When Another Interrupt Request is Generated During Interrupt Processing (2/3)
Interrupt Request k
Interrupt Request n
Interrupt Request i
(Level 1)
(Level 2)
(Level 2)
Main routine
EI
Interrupt
Request l
(Level 3)
Request m
(Level 1)
Interrupt
Interrupt
Request o
(Level 3)
Interrupt
Request p
(Level 1)
Macro Service
Request j
(Level 2)
CHAPTER 20 INTERRUPT FUNCTIONS
EI
i Processing
n Processing
p Processing
o Processing
k Processing
l Processing
j Macro Service
m Processing
The macro service request is
processed irrespective of interrupt
enabling/disabling and priority.
The interrupt request is held
peding since it has a lower
priority than interrupt request k.
Interrupt request m generated
after interrupt request l has a
higher priority, and is therefore
acknowledged first.
Since processing of interrupt
request n performed in the
interrupt disabled state,
interrupt requests o and p
are held pending.
After interrupt request n
processing, the pending interrupt
requests are acknowledged.
Although interrupt request o
was generated first, interrupt
request p has a higher priority
and is therefore acknowledged
first.