* bit0 - CF - Carry Flag
|| Flags are affected by most operations.
The When Decimal Mode is on, the ADC and SBC instructions don't modify update NF, VF and ZF if Decimal Mode is based onthe binary result before the decimal correction is applied. Only CF is set updated correctly.
DF is unchanged following an interrupt of any kind. This can cause unexpected bugs in the interrupt handler if Decimal Mode is on when an interrupt occurs.