The Microchip AT21CS11 is a 1 Kb Serial EEPROM utilizing the Single-Wire bus. Only two pins are needed to access the device: SI/O and GND. The SI/O signal is a combination data and power line, providing power to the device with a parasitic power scheme. The device is organized as one block of 128 x 8 and is optimized for use in consumer and industrial applications where reliable and dependable nonvolatile memory storage is essential. The EEPROM is available in a variety of space-saving packaging options. The AT21CS11 features a 256-bit Security register which includes a 64-bit serial number. The device also features manufacturer ID support in which the device responds with a unique value for density and revision information.