2.1.4 Start Condition

The I²C Specification defines a Start condition as a transition of SDA, from a High to a Low state, while the SCL line is high. A Start condition is always generated by the master and signifies the transition of the bus from an Idle to an Active state. Figure 2-2 shows wave forms for Start and Stop conditions.

A bus collision can occur on a Start condition if the module samples the SDA line low, before asserting it low. This does not conform to the I²C Specification that states no bus collision can occur on a Start.