W1014 Logic Gates
A logic gate is an idealized or physical device implementing a Boolean function; that is, it performs a logical operation on one or more binary inputs and produces one or more binary outputs.
The table below provides the symbols that are used to represent common gates.
Additionally, a multiplexer is a device which selects from digital inputs and forwards the signal to a single output line. Given inputs, there are selector pins. Conversely, a demultiplexer forwards the signal from a single line to one of multiple outputs.
|Formal Name||Abbreviated Name||Symbol||Gate||Truth Table|
The Special Role of NAND and NOR Gates
Both NAND and NOR gates exhibit a property known as functional completeness. Any Boolean function can be implemented using one or more of either of these gates. This is a very powerful principal because it enables us, using only one type of logic gate, to implement systems of arbitrary complexity.
- NAND Gate (Wikipedia)
- Schocken, Simon and Nisan, Noam. The Elements of Computing Systems. MIT Press, 2005.