The functionality and differences in the functionality of the ROMON bit inthe HC711E9 and HC711E20 microcontrollers (MCU) are discussed inthis engineering bulletin. Although all 68HC11 Family parts are designedwith full code compatibility in mind, bits may vary slightly due tocustomer-specific requirements in the CONFIG register. As a rule ofthumb, however, the configuration bits should be similar from series toseries within the family, having only slight differences.