Editing Programmable logic device (section)

{{Short description|Reconfigurable digital circuit element}}
{{Use American English|date = April 2019}}
{{lead too short|date=January 2013}}

[[File:Programmable Logic Device.svg|300px|thumb|A simplified PAL device. The programmable elements (shown as a fuse) connect both the true and complemented inputs to the AND gates. These AND gates, also known as product terms, are ORed together to form a sum-of-products logic array.]]

A '''programmable logic device''' ('''PLD''') is an [[electronics|electronic]] component used to build [[Reconfigurable computing|reconfigurable]] [[digital circuits]]. Unlike digital logic constructed using discrete [[logic gate]]s with fixed functions, the function of a PLD is undefined at the time of manufacture. Before the PLD can be used in a circuit it must be programmed to implement the desired function.<ref name="HorowitzHillArts2015">{{Cite book|title=Horowitz P., Hill W. - The Art of Electronics|year=2015|isbn=978-0-521-80926-9|location=New York|pages=764|last1=Horowitz|first1=Paul|last2=Hill|first2=Winfield}}</ref> Compared to fixed logic devices, programmable logic devices simplify the design of complex logic and may offer superior performance.<ref>{{cite book|title=Digital Logic Design|last1=Holdsworth|first1=B.|last2=Woods|first2=R. C.|date=2003|edition=4th|url=https://www.sciencedirect.com/book/9780750645829/digital-logic-design|publisher=Elsevier|isbn=978-0-7506-4582-9}}</ref> Unlike for [[microprocessors]], programming a PLD changes the connections made between the gates in the device.

PLDs can broadly be categorised into, in increasing order of complexity, [[Simple programmable logic device|simple programmable logic devices (SPLDs)]], comprising [[programmable array logic]], [[programmable logic array]] and [[generic array logic]]; [[Complex programmable logic device|complex programmable logic devices (CPLDs)]]; and [[Field-Programmable Gate Array|field-programmable gate arrays (FPGAs)]].