Renesas RL78 Series User Manual page 707

RL78/G1D
Example 3. Multiple interrupt servicing does not occur because interrupts are not enabled
Interrupts are not enabled during servicing of interrupt INTxx (EI instruction is not issued), therefore, interrupt request
INTyy is not acknowledged and multiple interrupt servicing does not take place. The INTyy interrupt request is held
pending, and is acknowledged following execution of one main processing instruction.
PR = 00: Specify level 0 with ××PR1× = 0, ××PR0× = 0 (higher priority level)
PR = 01: Specify level 1 with ××PR1× = 0, ××PR0× = 1
PR = 10: Specify level 2 with ××PR1× = 1, ××PR0× = 0
PR = 11: Specify level 3 with ××PR1× = 1, ××PR0× = 1 (lower priority level)
IE = 0: Interrupt request acknowledgment is disabled
IE = 1: Interrupt request acknowledgment is enabled.
R01UH0515EJ0120 Rev.1.20
Dec 16, 2016
Figure 18-10. Examples of Multiple Interrupt Servicing (2/2)
Main processing
IE = 0
EI
INTxx
(PR = 11)
IE = 1
1 instruction execution
CHAPTER 18 INTERRUPT FUNCTIONS
INTxx servicing INTyy servicing
INTyy
(PR = 00)
RETI
IE = 0
RETI
IE = 1
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