When power (from 0 V) is applied to V_CCP, an internal power-on reset holds the TCA6424A in a reset condition until V_CCP has reached V_POR. At that time, the reset condition is released, and the TCA6424A registers and I²C/SMBus state machine initializes to their default states. After that, V_CCP must be lowered to below 0.2 V and back up to the operating voltage for a power-reset cycle.