Microchip has launched a new family of serial EEPROM devices that feature a unique, pre-programmed 32-bit serial number for customers requiring unique IDs in their applications. The 32-bit ID can be extended to 48-bit, 64-bit, 96-bit, 128-bit and other lengths by increasing the number of bytes read from memory. Because the 32-bit ID is unique within these devices, any longer bit sequence is also unique. These 2 Kb serial EEPROM devices are available in standard busses, such as I²C, SPI and Microwire, and integrate up to 1.5 Kb of memory that can be used as a standard EEPROM.
In addition, Microchip has released a 256 Kb I²C unique-ID device, which also contains the IEEE EUI-48 and IEEE EUI-64 MAC addresses. These IDs are in a write-protected area of the memory, giving users up to 224 Kb of EEPROM to use in their applications.
Even more devices with pre-programmed IEEE EUI-64 MAC addresses, available with I²C,SPI or UNI/O busses, provide easy and inexpensive access to MAC addresses, and feature up to 1.5 Kb of EEPROM which can be used for storing configuration settings, or as a scratch-pad area for buffering small amounts of data. The built-in MAC addresses enable designers to buy addresses only when needed, and also eliminate the need for serialization and programming.