Resetting option byte 8 ICUM


I have Renesas F1KM controller and I was able to change the option byte 8 - 12, now for my application I wanted to enable the option byte 8 and disable it in some cases, till now enable works fine with Renesas FCL lib, but disabling does not work, also FCL does not report any error, from option 9-12 everything just set to default which is intended, but option byte 8 (responsible for ICUM - on/off) always shows enable states.


Am I doing something wrong?

please help me with this issue.