The EZ-USB's I²C controller serves two purposes. First, it manages the serial EEPROM interface that operates automatically at power-on to determine the enumeration method. Second, once the CPU is up and running, firmware can access the I²C controller for general-purpose use. This makes a wide range of standard I²C peripherals available to an EZ-USB-based system. Other I²C devices can be attached to the SCL and SDA lines as long as there is no address conflict with the serial EEPROM.