A NOR gate (of English: not- or - or not, or of English nor - nor, nor Peirce function after Charles S. Peirce called ) is a basic logic circuit ( gate ) with two or more inputs x, y,. .. and an output Q, between which the logic operation NOR prevails, the Peirce ie the function realized: The output Q is only 1 if x is 0 and y is equal to 0.
For the NOR of the variables x and y, there are in the literature, the following notations:
The electronic is recognized, for example, with two (or correspondingly more ) parallel switches ( transistors) to ground (logic 0 ) define the output Q when one of them is turned on. If all fails, the ground connection is interrupted and the output Q is (logic 1) to plus potential.
Implementation of a NOR gate with CMOS technology
According to the following logical equivalence, a NOR operation but also alone be constructed from NAND gates:
Logical operations and their implementation using NOR gates:
With the Peirce - function alone all bivalent truth-functions are representable, ie any Boolean function is equivalent to a formula that contains only the NOR function. Because of this property of the functional integrity is called the Peirce - function a base of the two-digit logic functions (another base is the NAND function).