This is the documentation for the latest (main) development branch of Zephyr. If you are looking for the documentation of previous releases, use the drop-down menu on the left and select the desired version.

X-NUCLEO-EEPRMA2 EEPROM memory expansion board


The ST X-NUCLEO-EEPRMA2 expansion board can be used to evaluate M24xx series I2C and M95xx series SPI EEPROM devices. The X-NUCLEO-EEPRMA2 expansion board is compatible with the Arduino UNO R3 connector pin assignment. Additionally the pins are routed to dedicated headers and ST morpho connectors can be mounted if required.

The I2C EEPROMs are compatible with the atmel,at24 driver and the SPI EEPROMs are compatible with the atmel,at25 driver.


More information about the board can be found at the X-NUCLEO-EEPRMA2 website.


This shield can only be used with a development board that provides a configuration for Arduino connectors and defines a node alias for the SPI or I2C interface (see Shields for more details).

The SPI EEPROM devices can write protect complete memory blocks by setting the corresponding block protect bits in the status register. As the driver does not change this status register, make sure this protections are disabled in case writes to the EEPROM should be supported.

For more information about interfacing the M24xx and M95xx series EEPROM devices and the X-NUCLEO-EEPRMA2 in particular, see these ST Microelectronics documents:


The EEPROM Sample can be used to demonstrate the expansion boards functionality. Per default the shield sets an eeprom-0 alias for the M24C02-FMC6TG EEPROM, which can be overwritten to use the other EEPROM deivces instead.


Set -DSHIELD=x_nucleo_eeprma2 when you invoke west build. For example:

# From the root of the zephyr repository
west build -b nucleo_g0b1re samples/drivers/eeprom/ -- -DSHIELD=x_nucleo_eeprma2