What the MXD1210ESA does on the board
The MXD1210ESA is a Nonvolatile RAM controller from Analog Devices — it manages the transition between a standard SRAM and a backup battery so that data survives a power loss without a dedicated nonvolatile memory array.
Note that the part is marked RoHS non-compliant. If your BOM requires RoHS exemption or a fully compliant alternative, verify the date-code and any applicable exemption before committing the line.