7.6 User Row (USERROW)
In addition to the EEPROM, the ATmega4808/4809 has one extra page of EEPROM memory that can be used for firmware settings, the User Row (USERROW). This memory supports single-byte read and write as the normal EEPROM. The CPU can write and read this memory as normal EEPROM, and the UPDI can write and read it as a normal EEPROM memory if the part is unlocked. The User Row can also be written by the UPDI when the part is locked. USERROW is not affected by a chip erase. The USERROW can be used for the final configuration without having programming or debugging capabilities enabled.