AMI306R is identical to AMI306 with the exception of the pin layout. 

The AMI306R is an intelligent electronic compass that integrates various MI sensors for detecting 3-axis magnetic fields and the IC necessary to control those sensors in one miniaturized package.

The IC used to control the AMI306R contains specialized circuits to detect magnetic signals from 3 MI sensors, an amplifier to calibrate each sensor's starting point and sensitivity to the proper figures, a temperature sensor that measures ambient temperature, a 12bitAD converter, an I2C serial output circuit, a fixed voltage circuit, and logic circuits to control each circuit.