In summary, the pre-programmed MAC address chips are both EUI-48™ and EUI-64™ compatible. The plug-and-play devices are available in standard pin-outs and contain up to 1.5Kb of serial EEPROM allowing the use of scratch-pad memory to store settings or to buffer data. They are also designed to work on standard serial busses like the SPI, I²C and the new single I/O  UNI/O® bus.