Almost 20 years ago the I2C bus was designed by Philips to allow easy communication between c omponents which reside on the same circuit board. Philips Semiconductors migrated to NXP in 2006.
The name I2C translates into "Inter IC". The original communication speed was defined with a maximum of 100 kbit per second and many applications don't require faster transmissions. For those that do there is a 400 kbit and - since 1998 - a high speed 3.4 Mbit option available.
Meanwhile I2C is not only used on single boards, but also to connect components which are linked via cable. Simplicity and flexibility are key characteristics that make this bus especially attractive for consumer and automotive electronics.
to know more about I2C Bus---
http://www.esacademy.com/faq/i2c/
The I2C-Bus and how to use it is a well-known document from Philips discussing the use of this bus in applications.
