Pull-input: the potential of the input pulled high, such as pull VCC. A pull is to uncertain electric signal through a resistor embedded in the high level, while the resistance of the current limiting functions. Strength but different value of the pullup resistor, there is no strict distinction.
Input pull-down: the input point low, such as pull GND. The same principles and pull.
Floating Input: floating logic device input pin is connected to neither high nor low-level access. Since the internal configuration of the logic device, the input pin when it is floating, the high level corresponding to this pin. For normal use, it does not recommend floating, vulnerable to outside interference.
Analog Input: Analog input means inputs a conventional manner, a digital input PCM digital input signals, digital signals, and a binary 0 is converted into an analog signal by a digital to analog. By entering the pre-amplification power amplifier, or analog amplifier.
Open-drain output: output terminal corresponding to the collector of the transistor, to obtain a high level state required pull-up resistor for the job suitable for the current driving type, its ability to absorb a relatively strong current (typically less than 20ma).
Push-pull output: high and low output can be connected to a digital device. The push-pull configuration generally refers to two transistors are controlled by two complementary signals, it is always in a turned on when the other transistor is turned off.
Push-pull output multiplexing, the multiplexing open-drain output may be used as the second function, i.e., non-use general IO.