User's Manual

Table Of Contents
R01UH0823EJ0110 Rev.1.10 Page 304 of 1852
Nov 30, 2020
RX23W Group 15. Interrupt Controller (ICUb)
15.4.1.2 Operation of Status Flags for Level-Detected Interrupts
Figure 15.6 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 15.6 IRn.IR Flag Operation for Level Detection Interrupts
Figure 15.7 shows the procedure for handling level detection interrupts.
Figure 15.7 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