Figure 3.7 Port Mode Register Setting And Interrupt Request Flag Clearing Procedure - Renesas H8/3847R Series Hardware Manual

An alternative method is to avoid the setting of interrupt request flags when pin functions are
switched by keeping the pins at the high level so that the conditions in table 3.5 do not occur.
CCR I bit←1
Set port mode register bit
Execute NOP instruction
Clear interrupt request flag to 0
CCR I bit←0
Figure 3.7 Port Mode Register Setting and Interrupt Request Flag
Interrupts masked. (Another possibility
is to disable the relevant interrupt in
interrupt enable register 1.)
After setting the port mode register bit,
first execute at least one instruction
(e.g., NOP), then clear the interrupt
request flag to 0
Interrupt mask cleared
Clearing Procedure
Rev. 6.00 Aug 04, 2006 page 117 of 680
Section 3 Exception Handling
REJ09B0145-0600