The Unique Address Interface allows for complex interactions between an I2C controller and a single PD Controller. The I2C target unique address is used to receive or respond to Host Interface protocol commands. Figure 1-2 and Figure 1-3 show the write and read protocols, respectively. The Byte Count used during a register write may be longer than the number of bytes actually written. In other words the, controller may issue the stop bit without writing N bytes. Similarly, during a register read, the controller may issue the stop bit before reading all N bytes.

Figure 1-2 I2C Unique Address Write Register Protocol

Figure 1-3 I2C Unique Address Read Register Protocol