First, an overview of the basics of the I²C standard and the need for such a standard. The I²C bus and I²C devices are used in a wide range of applications. The reason for this is that these devices are very simple to use and quick to implement in designs. Generally, I²C products are intended for housekeeping functions such as control, status check and update, and maintenance functions. The figure shown in this slide highlights typical applications such as temperature sensing, battery status checks, and LED control. I²C devices can also be used to enhance a feature set of an application, such as adding camera control or keypad control to cell phone applications. The I²C standard has been adopted by all industry segments and is used in many system applications and in a variety of functions. The I²C interface is a well known standard that has been around for more than twenty years. It consists of a 2-wire communications bus which supports bidirectional transfer of data between a master and several slave devices on the bus. The master, or processor, controls the bus, in particular the SCL, or serial clock line. The data then is transferred between the master and slave through a serial data line known as an SDA line. This data can be transferred in three speeds, of which the most common are the standard mode and fast mode speeds.