The multiple interface options of the ATSHA204 make it that much easier for embedded systems developers. The chip can be accessed at speeds up to 1MBit per second with the I²C interface and can drop into any system using a standard serial EEPROM. The alternate one-wire interface uses just a single GPIO pin on the processor and can be driven by a standard UART. With the ATSHA204, multiple chips can share the same bus, which saves processor GPIO requirements and supports system implementations that require the use of multiple authentication devices. The reduced number of pins required for both the system micro and the connector can be a significant benefit in cost-sensitive applications.