RL78/G1H CHAPTER 19 INTERRUPT FUNCTIONS
R01UH0575EJ0120 Rev. 1.20 Page 727 of 920
Dec 22, 2016
Figure 19 - 14 Examples of Multiple Interrupt Servicing (2/2)
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 xxPR1x = 0, xxPR0x = 0 (higher priority level)
PR = 01: Specify level 1 with xxPR1x = 0, xxPR0x = 1
PR = 10: Specify level 2 with xxPR1x = 1, xxPR0x = 0
PR = 11: Specify level 3 with xxPR1x = 1, xxPR0x = 1 (lower priority level)
IE = 0: Interrupt request acknowledgment is disabled
IE = 1: Interrupt request acknowledgment is enabled.
EI
RETI
RETI
1 instruction execution
Main processing INTxx servicing INTyy servicing
INTxx
(PR = 11)
IE = 0
IE = 1
IE = 0
IE = 1
INTyy
(PR = 00)
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