When power is applied to the VCC pin, an internal power-on reset holds the TCA9548A-Q1 in a reset condition until V_CC has reached V_PORR. At this point, the reset condition is released, and the TCA9548A-Q1 registers and I²C state machine are initialized to their default states, all zeroes, causing all the channels to be deselected. Thereafter, V_CC must be lowered below V_PORF to reset the device.