Description
If your dedicated input or IO pins are left floating, then the input transistors might fall outside of the saturation or cut-off region. As a result, the device could draw additional current and increase the device's power consumption.
Additionally, if left floating, these pins are apt to switch (they behave similar to antennas) which can inject noise into the device.
As such, Altera recommends connecting these dedicated pins to the appropriate logic level defined by the Altera® software pin file (typically either VCC or GND).