The key to the default states is whether the part is above the POR threshold.
On power-up, the GPIO states are indeterminate until the Power On Reset is complete at about 1V or so – the chip will be in reset at this time and enable the default bit settings. On power-down, the LVD setting will generate a reset which will make the GPIO high impedance. At the falling POR threshold the GPIO can go back to indeterminate states. The region between POR and LVD thresholds will generate a reset and make the GPIO high impedance.
- John S
