I2C(also IIC; the "2" is superscripted) Inter-Integrated Circuit Bus -- A moderate-speed serial communications bus originally invented by Philips in the early 1980s for consumer-electronics applications, such as inter-chip communication in a television set or high-end stereo. The I2C bus has recently appeared on PCs in video capture boards and similar devices, as well as (surprisingly) SDRAM DIMMs (for the on-board serial EEPROM). The ACCESS.bus is a derivative of the I2C bus which forms the physical layer of the Universal Serial Bus. Similary, the SMBus (System Management Bus) also uses I2C as its physical layer. 01h - Reserved - Start Byte