Hi,
your description leads me to idea of setup feature of some bits.
Write: Once in normal, anytime in special mode
If we change value of such a bit in debug mode more than once then nothing happens and the MCU will perform function on the basis of the bit current bit setup. However, if we are in normal mode then the only first setup of the bit is accepted and al other changes are ignored.
We have met a lot of times that user uses some general setup functions or some project wizard and then you decide to set some registers yourself. Project wizard sets its own values and your ones are then ignored or vice versa.
Next thing you should check is interrupt flag clearing. Some bit is not cleared and the MCU is always in some interrupt with higher priority. Usually, flags are cleared by writing 1 to corresponding bit.
However, following approach is incorrect.
register_bit6 = 1;
Also incorrect is
register |= 0x40;
Correct approach is register = 0x40; // =0B01000000
More info in https://www.nxp.com/docs/en/application-note/AN2554.pdf
But, I always suggest to check approach for correct clearing of given bit because some interrupt flags can be placed inside standard register which contains also setup bits. In this case the approach is to work directly with given bit to do not influence other bits.
Best regards,
Ladislav
