Editing logic gate

{{confuse|ideal logic gate}}
A '''logic gate''' is a simple device that gives a discrete output of either 0 or 1 based on the input condition. Logic gates implement [[Boolean function]]s and are the fundamental building blocks of all digital systems. Logic gates can be implemented using discrete components such as [[resistor]]s, [[diode]]s, and [[transistor]]s. 

Sometimes a combination of logic gates may be more efficiently implemented as a single device. Those devices are known as [[compound logic gate]].

==Symbology==
There are many different symbols that can be used to represent basic logic gates. Some areas of the world may be required to follow a specific standard. The four main standards that attempt to provide a uniform method of describing complex logic functions are:
* [[ANSI/IEEE Std 91-1984]] (MIL/ANSI)
* [[IEC 60617-12]] / [[BS 3939]] (British)
* [[DIN 40700]] (German)
* [[NEMA ICS 19-2002]]
Note that the [[inversion bubble]] is used across most of those standards. In this article, the ANSI symbols are used.

==Gates==
===Buffer===
{| class="wikitable" style="float: right;"
|-
! A !! Q
|-
| 0 || 0
|-
| 0 || 0
|}
{{main|buffer gate|l1=Buffer}}
[[File:buffer gate (ansi).svg|100px]] A '''Buffer''' is a gate that outputs the very same input it is given. Its primarily used to regenerate the input into either a strong LOW or a strong HIGH. In some cases this gate might be used to simply show that the output from some component is not degraded.

This gate implements the following Boolean function: <math>Q = A</math>
===Tri-state Buffer===
{| class="wikitable" style="float: right;"
|-
! EN !! A !! Q
|-
| 0 || [[don't care|X]] || [[high impedance|Z]]
|-
| 1 || A || A
|}
{{main|tri-state buffer gate|l1=Tri-state Buffer}}
[[File:tri-state buffer gate (ansi).svg|100px]] A '''Tri-state Buffer''' is a gate that outputs the very same input it is given only when the control signal allows it. When the control signal is off, the output is at [[high impedance]]. This gate forms the basis for [[buses]], by controlling which devices is allow to generate output to a shared [[bus]].
===NOT Gate===
{| class="wikitable" style="float: right;"
|-
! A !! Q
|-
| 0 || 1
|-
| 1 || 0
|}
{{main|NOT gate}}
[[File:not gate (ansi).svg|100px]] The '''NOT gate''' or an '''inverter''' produces an output that's the opposite to its input - if the input is HIGH, the output is LOW, and conversely when the input is LOW, the output is HIGH.

This gate implements the following Boolean function: <math>Q = \bar{A} = \neg A</math>
===AND Gate===
{| class="wikitable" style="float: right;"
|-
! A !! B !! Q
|-
| 0 || 0 || 0
|-
| 0 || 1 || 0
|-
| 1 || 0 || 0
|-
| 1 || 1 || 1
|}
{{main|AND gate}}
[[File:and gate (ansi).svg|100px]] An '''AND gate''' outputs a HIGH only when both inputs are HIGH, otherwise it outputs a LOW. The Boolean AND operation is equivalent to the Boolean multiplication operation.

The AND gate implements the following boolean function: <math>Q = AB = A \and B = A \& B = A \cdot B</math>
===OR Gate===
{{main|OR gate}}
===XOR Gate===
{{main|XOR gate}}
===NAND Gate===
{{main|NAND gate}}
===NOR Gate===
{{main|NOR gate}}
===XNOR Gate===
{{main|XNOR gate}}


{{stub}}
[[Category:logic gates]]