6.6 User Row
In addition to the EEPROM, the ATtiny3216/3217 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 be written by the UPDI when the part is locked. USERROW is not affected by a chip erase.