History of the I2C Bus

The I2C bus was developed in the early 1980's by Philips Semiconductors. Its original purpose was to provide an easy way to connect a CPU to peripheral chips in a TV-set.

Peripheral devices in embedded systems are often connected to the MCU as memory-mapped I/O devices, using the microcontroller's parallel address and data bus. This results in lots of wiring on the PCB's to route the address and data lines, not to mention a number of address decoders and glue logic to connect everything. In mass production items such as TV-sets, VCR's and audio equipment, this is not acceptable. In these appliances, every component that can be saved means increased profitability for the manufacturer and more affordable products for the end customer. Furthermore, lots of control lines implies that the systems is more susceptible to disturbances by Electromagnetic Interference (EMI) and Electrostatic Discharge (ESD).

The research done by Philips Labs in Eindhoven (The Netherlands) to overcome these problems resulted in a 2-wire communication bus called the I2C bus. I2C is an acronym for Inter-IC bus. Its name literally explains its purpose: to provide a communication link between Integrated Circuits.

Today, the I2C bus is used in many other application fields than just audio and video equipment. The bus is generally accepted in the industry as a de-facto standard. The I2C bus has been adopted by several leading chip manufacturers like Xicor, ST Microelectronics, Infineon Technologies, Intel, Texas Instruments, Maxim, Atmel, Analog Devices and others.