The DP83TC813S-Q1 can be set to respond to any of 9 possible PHY addresses through bootstrap pins. The PHY address is latched into the device upon power-up or hardware reset. Each PHY on the serial management bus in the system must have a unique PHY address.

By default, DP83TC813S-Q1 will latch to a PHY address of 0 (<0b00000>). This address can be changed by adding pullup resistors to bootstrap pins found in Section 8.5.3.