RX610 Group
10. ICU
R01UH0032EJ0120 Rev.1.20
Page 244 of 1006
Feb 20, 2013
Once the IR flag in IRi has been set to 1, even if the interrupt is disabled at its source, that is, if output of the interrupt is
disabled by the interrupt enable bit of the corresponding peripheral module or detection of an external interrupt on pin
IRQn is disabled by the IRQEN bit in IRQERn, the IR flag in IRi is not affected and retains its value. Figure 10.4 shows
operation when the interrupt is disabled at its source.
Interrupt signal
IR flag in IRi
Disabling does not lead to clearing
of the IR flag in IRi
.
Enabling/disabling the
interrupt request.
Enabled
Disabled
Figure 10.4 Relation between the IR Flag in IRi and Disabling of the Interrupt Sources
10.4.2.2
Interrupt Status Flag in Level Detection
Operation is individually described for the cases of level detection of peripheral module interrupts and external interrupts.
Figure 10.5 shows how the IR flag in IRi operates in the case of level detection of an interrupt from a peripheral function.
When the IR flag in IRi for an interrupt from a peripheral module has been set to 1, this setting is maintained while
generation of the interrupt signal by the source continues. To clear the IR flag in IRi, software should clear the status flag
at the source of the interrupt or change the interrupt enable bit at the source of the interrupt to disable interrupt generation.
Also, after clearing the source of the interrupt, confirm that the IR flag in IRi has actually been cleared before executing
further instructions.
Interrupt signal
IR flag in IRi
Clearing the request source of the interrupt
The IR flag in IRi is cleared.
Figure 10.5 Operation of the IR Flag in IRi in the Case of Level Detection of a Peripheral Module Interrupt