When power (from 0 V) is applied to V_CC, an internal power-on reset holds the TCA9548A-Q1 in a reset condition until V_CC has reached V_POR. At that point, the reset condition is released and the TCA9548A-Q1 registers and I²C state machine initialize to their default states. After that, V_CC must be lowered to below V_POR and then back up to the operating voltage for a power-reset cycle.