The purpose of receiver equalization is to compensate for channel insertion loss and the resulting inter-symbol interference in the system before the input or after the output of the TUSB564. The receiver overcomes these losses by attenuating the low frequency components of the signals with respect to the high frequency components. The proper gain setting should be selected to match the channel insertion loss. Two 4-level input pins enable up to 16 possible equalization settings. USB3.1 upstream path, USB3.1 downstream path, and DisplayPort each have their own two 4-level inputs. The TUSB564 also provides the flexibility of adjusting settings through I²C registers.