The Atmel AT89S8252 microcontroller is a low-power, high-performance device featuring 8K bytes of Flash memory (CMOS PEROM), 2K bytes of EEPROM, and a Serial Peripheral Interface (SPI). The Flash and EEPROM memories may be reprogrammed in-system via the SPI. The EEPROM provides applications with re-writable, nonvolatile data storage. These features, and others, are described in the text which follows. Code samples are provided. Additional information on the AT89S8252 microcontroller may be found in the data sheet and relevant sections in the Atmel AT89- series Microcontroller Databook.