10.3.2.3.5 EEPROM Erase/Write Mode
The EEPROM Erase/Write (EEERWR) mode enables the EEPROM array for the erase operation, which is then directly followed by a write operation. Several erase/writes can be done while the EEERWR mode is enabled in the CTRLA register. When the EEERWR mode is enabled, writes with the ST* instructions are performed one byte at a time.
When writing/erasing the EEPROM, the CPU will continue executing the application.
The CPU will halt if a new load or store instruction starts before the erase/write has been completed.