How to polarize unused input pins?

It states in the datasheet of the micro that I'm using for a project that all unused inputs for port 0 must be polarized to VDD or VSS to avoid parasitic current consumption. What exactly does this mean and how do I do it? And yes, I am a newbie

Re: Polarized Input Pins

I don't know what IC you will use...

But in some circuits i have used resistors of 10k and conect this to a ground(Vss) or Vdd(source)

Re: Polarized Input Pins

Input stages in microprocessors (and other digital IC's) consume more power when the input voltage is outside of definied digital levels which are close to Vss (ground) or Vdd (supply voltage).

For example, logical 0 may correspond to voltage in the range of 0..0.8V. Depending on the part you are using and type of input, logical levels may be also expressed in parts of the supply voltage, like, low level: Vin=0..0,2Vdd, high level: Vin=0,8..1Vdd. Signal in 0,2..0,8Vdd range is then unspecified (neither logical 0, nor 1). Input stages are optimized to work with defined logical levels. In the 'undefined' range internal switching transistors on both high side and low side conduct some current thus forming a path from Vdd to ground which leads to increased power consumption.

To avoid this, all unused inputs should be connected to ground or Vdd through a resistor (ussualy of the order of 10-100kOhms).

Re: Polarized Input Pins

Thanx, now I understand.