A mechanism for assigning unique addresses to identical devices attached to a serial bus is presented. Each device has at least one output and is provided with a storage device to provide a configurable portion of a bus address having a fixed portion and a configurable portion. The device is further provided with circuitry, coupled to the storage device and the output, to determine a state of the output and use the state to configure the configurable portion. Once the configurable portion is configured, the bus address uniquely identifies the device. Such configuration allows more than one such device to be coupled to the same serial bus, e.g., an I2C bus.