R01UH0822EJ0100 Rev.1.00
Page 224 of 1041
Jul 31, 2019
RX13T Group
14. Interrupt Controller (ICUb)
14.4.1.2
Operation of Status Flags for Level-Detected Interrupts
shows the operation of the interrupt status flag (IR flag) in IRn (n = interrupt vector number) in the case of
level detection of an interrupt from a peripheral module or an external pin.
The IR flag in IRn remains set to 1 as long as the interrupt signal is asserted. To clear the IRn.IR flag to 0, clear the
interrupt request in the source generating the interrupt. Confirm that the interrupt request flag in the source generating the
interrupt has been cleared to 0 and that the IRn.IR flag has been cleared to 0, and then complete the interrupt handling.
Figure 14.5
IRn.IR Flag Operation for Level Detection Interrupts
shows the procedure for handling level detection interrupts.
Figure 14.6
Procedure for Handling Level Detection Interrupts
System clock
Interrupt signal
IRn.IR flag
Confirm IRn.IR flag
Start interrupt handling
Interrupt has been generated
Interrupt has not been generated
End of interrupt handling
Clear interrupt request source
Perform interrupt request source processing
IRn.IR = 1
IRn.IR = 0
Confirm interrupt
request source