SLVUCR7 September 2024 TPS26750
The PD Controller provides one I2C target. The I2Ct target is meant to be connected to an Embedded Controller (EC).
The Host Interface defines how the registers are accessed from I2C target port and target addresses. Target Address #1 is selected by the customer using the ADCIN1 and ADCIN2 pins on the PD controller. See also Section 6.2 for more details about the target addresses.
The Host Interface provides general status information to the controller of these I2C interfaces about the PD Controller, ability to control the PD Controller, status of USB Type-C® Port and communications to/from a connected device (Port Partner) and/or cable plug through USB PD messages. All Host Interface communication that uses the Unique I2C address is referred to as Unique Address Interface.
The PD Controller supports a register-based Unique Address Interface. Chapter 4 lists the Unique Address Interface registers and provides detailed Unique Address Interface register descriptions.
The key to the protocol diagrams is in the SMBus Specification, version 2.0 and is repeated here in part in Figure 1-1.