• Stands for Read-Only Memory
  • Stores data and Instruction that are non-volatile and permanent like firmware and BIOS


  • Stands for Electrically Erasable Programmable Read-Only Memory
  • A type of ROM that allows individual bytes of data to be erased and reprogrammed

Comes with Lifespan

We can only write to each Memory Address of the EEPROM a certain number of times before it starts to fail and become unreliable. Most has a lifespan of 100,000 write/erase cycles, so be careful with placing EEPROM read / writes in loops!

We can counter this by Wear Leveling where we keep track of the the number of times we have written to an memory address. When it reaches the limit, we change to a fresh address. This will greatly increase the life expectancy of the EEPROM

Arduino Uno

Comes with 1kB of EEPROM storage which can be accessed using the Arduino EEPROM Library