How to count EEPROM wear cycles when flipping an address back and forth?
See also 100k EEPROM writes &quot;per bit&quot; or as a whole?

The polarity is the other way up for most chips: "erase" sets a byte or group of bytes to all 1s. So you need to be a little careful. Because writing the byte to 0x00 incurs an erase and a write, and then setting it to e.g. 0x01 incurs another erase (to 0xFF) then a write.