eolas/Hardware/Logic_Gates/Not_gate.md

tags
Logic Electronics Hardware logic-gates

NOT gate

This gate corresponds to the NOT Boolean or negation logical connective. It is really simple and derived from the trivial logical fact that true is true and false is false also known as logical identity.

Natural language

The negation operator (¬ or ~ ) switches the value of a proposition from true to false. When we put ~ before true it becomes false and when we put ~ before false it becomes true .

Truth table

This corresponds to a simple on-off switch.

In terms of logic gates we would create this by using a single NAND gate. Although it can take a total of two inputs, it would be controlled by a single switch, so both inputs would be set to 1 1 or 0 0 when the switch is activated and deactivated. This would remove the AND aspect of NAND and reduce it to NOT .

A NAND gate simulating NOT logic

TO DO: Come back to this with new book and explain better how a NAND can be reduced to NOT.

Symbol for NOT gate

NOT has its own electrical symbol to distinguish it from a NAND: