The inputs to the I/O peripherals are driven with default values when another source is not routed to either the MIO or the EMIO. If an input is routed to EMIO, but the PL is powered down, then the same default value is driven to the I/O peripheral (see This Figure.)
For MIO-only signals, the default signal input is driven when the MIO multiplexer does not route the signal to an MIO pin.
For MIO-EMIO signals, the default signal input is driven when the MIO multiplexer does not route the signal to an MIO pin (the signal defaults to the EMIO interface) and when the signal is programmed to be routed through the EMIO, but the PL either does not drive the signal (not configured) or is not able to drive it (powered down).
The default input signal logic levels are designed to be benign to the I/O peripheral. As a precaution, the related peripheral core should also be disabled when not in use. The logic levels are shown in the signal tables in each chapter for each I/O peripheral.
When PS_POR_B is asserted Low, the PS GPIO outputs connected to EMIO are forced and held High.