Memory sizing for metrology firmware
256 KB of Flash holds the metering algorithm stack, calibration coefficients, and communication protocol stacks (DLMS/COSEM or Modbus) with room to spare. The 16 KB RAM is the tighter resource — it limits the size of real-time data buffers and the number of active meter profiles you can keep in memory. If your application needs to log interval data for more than a few channels, plan for external serial RAM or a FRAM part on the SPI bus.
Active product status per the manufacturer.