CINXE.COM

<!DOCTYPE html> <html lang="en"> <head> <title>microprocessor from FOLDOC</title> <meta http-equiv="Content-Security-Policy" content="default-src 'unsafe-inline' http: https:"> <meta name="verify-v1" content="siAI0ZOMn41hao0E/T76D1I2L3MtFjzE48P3ctCjRNU="> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <meta name="msapplication-TileColor" content="#da532c"> <meta name="theme-color" content="#ffffff"> <meta name="google-translate-customization" content="828219db36930e1e-c51d915bf2ea717c-g9b503f9a85d5b5a7-a">  <script src="https://www.googletagmanager.com/gtag/js?id=UA-9715943-1"></script> <script> window.dataLayer = window.dataLayer || []; function gtag(){dataLayer.push(arguments);} gtag('js', new Date()); gtag('config', 'UA-9715943-1'); </script>  <link href="//fonts.googleapis.com/css?family=Duru+Sans%7CBelgrano%7CInconsolata%7CAlef%7CArmata" rel="stylesheet" type="text/css"> <link rel="stylesheet" type="text/css" href="/css/layout.css?2">  <link rel="apple-touch-icon" sizes="152x152" href="/im/apple-touch-icon.png"> <link rel="icon" type="image/png" sizes="32x32" href="/im/favicon-32x32.png"> <link rel="icon" type="image/png" sizes="16x16" href="/im/favicon-16x16.png"> <link rel="manifest" href="/im/site.webmanifest"> <link rel="mask-icon" href="/im/safari-pinned-tab.svg" color="#5bbad5"> <link rel="canonical" href="https://foldoc.org/microprocessor"> <link rel="alternate" type="application/rss+xml" title="FOLDOC" href="/rss.xml"> <link rel="search" title="FOLDOC" type="application/opensearchdescription+xml" href="//foldoc.org/search.xml">  <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-5521724329338202" crossorigin="anonymous"></script>  </head> <body> <div id="fb-root"></div> <script> (function (d, s, id) { var js, fjs = d.getElementsByTagName(s)[0]; if (d.getElementById(id)) return; js = d.createElement(s); js.id = id; js.src = "//connect.facebook.net/en_GB/all.js#xfbml=1"; fjs.parentNode.insertBefore(js, fjs); }(document, 'script', 'facebook-jssdk')); </script> <div id="container"> <div id="left"> <a href="/"> <img src="/foldoc.gif" width="300" height="98" alt="Free On-line Dictionary of Computing" class="logo"> </a> <div id="nav"> <a href="/contents.html" class="button">Contents</a> <a href="/help.html" class="button">Help</a> <a href="/random-entry" class="button">Random</a> </div> <form action="/"> <input type="text" name="query" id="query" autofocus="autofocus"> <input type="submit" name="action" value="Search" class="button"> </form> <div id="content"> <h2>microprocessor</h2> <p></p> <p><<i><a href="contents/architecture.html">architecture</a></i>></p> <p> (Or "micro") A computer whose entire <a href="/CPU">CPU</a> is contained on one (or a small number of) <a href="/integrated+circuits">integrated circuits</a>. <p></p> The important characteristics of a microprocessor are the widths of its internal and external <a href="/address+bus">address bus</a> and <a href="/data+bus">data bus</a> (and instruction), its <a href="/clock+rate">clock rate</a> and its <a href="/instruction+set">instruction set</a>. Processors are also often classified as either <a href="/RISC">RISC</a> or <a href="/CISC">CISC</a>. <p></p> The first commercial microprocessor was the <a href="/Intel+4004">Intel 4004</a> which appeared in 1971. This was the CPU member of a set of four <a href="/LSI">LSI</a> <a href="/integrated+circuits">integrated circuits</a> called the MCS-4, which was originally designed for use in a calculator but was marketed as "programmable controller for logic replacement". The 4004 is referred to as a 4-bit microprocessor since it processed only 4 bits of data at a time. This very short word size is due mainly to the limitations imposed by the maximum integrated circuit density then achievable. <p></p> As integrated circuit densities increased with the rapid development of integrated circuit manufacturing technology, the power and performance of the microprocessors also increased. This is reflected in the increase in the CPU word size to 4, 8, 16, and by mid-1980s, 32 bits. The smaller microprocessors have relatively simple <a href="/instruction+sets">instruction sets</a>, e.g., no <a href="/floating+point">floating point</a> instructions, but they are nevertheless suitable as controllers for a very wide range of applications such as car engines and microwave ovens. <p></p> The <a href="/Intel+4004">Intel 4004</a> was followed with, among others the <a href="/4040">4040</a>, <a href="/8008">8008</a>, <a href="/8080">8080</a>, <a href="/8086">8086</a>, <a href="/80186">80186</a>, <a href="/80286">80286</a>, <a href="/80386">80386</a>, <a href="/486">486</a> and <a href="/Pentium">Pentium</a>. Other families include the <a href="/Motorola">Motorola</a> <a href="/6800">6800</a> and <a href="/680x0">680x0</a> families, <a href="/National+Semiconductor+16000">National Semiconductor 16000</a> and <a href="/National+Semiconductor+32000">National Semiconductor 32000</a>, <a href="/SPARC">SPARC</a>, <a href="/ARM">ARM</a>, <a href="/MIPS">MIPS</a>, <a href="/Zilog+Z8000">Zilog Z8000</a>, <a href="/PowerPC">PowerPC</a> and the <a href="/Inmos">Inmos</a> <a href="/Transputer">Transputer</a> family. <p></p> The larger, more recent microprocessors families have gradually acquired most of the features of large computers. As the microprocessor industry has matured, several families of microprocessors have evolved into de facto industrial standards with multiple manufacturers and numerous "support" chips including <a href="/RAM">RAM</a>, <a href="/ROM">ROM</a>, <a href="/I/O+controllers">I/O controllers</a> etc. <p></p> A single chip microprocessor may include other components such as memory (<a href="/RAM">RAM</a>, <a href="/ROM">ROM</a>, <a href="/PROM">PROM</a>), <a href="/memory+management">memory management</a>, <a href="/caches">caches</a>, <a href="/floating-point+unit">floating-point unit</a>, input/output ports and timers. Such devices are also known as <a href="/microcontrollers">microcontrollers</a>. <p></p> The one-chip microcomputer is in many respects, a landmark development in computer technology because it reduces the computer to a small, inexpensive, and easily replaceable design component. <p></p> Microcomputers have given rise to a new class of general-purpose machines called <a href="/personal+computers">personal computers</a>. These are small low cost computers that are designed to sit on an ordinary office desk or to be portable and fuelled the computer boom of the late 1980s. The most widespread example is the also <a href="/IBM+PC">IBM PC</a>, based on microprocessors from <a href="/Intel+Corporation">Intel Corporation</a>. <a href="/Apple+Computers,+Inc.">Apple Computers, Inc.</a> have also produced a range of personal computers, as have several other companies. <p></p> See also <a href="/killer+micro">killer micro</a>, <a href="/minicomputer">minicomputer</a>, <a href="/CPU+Info+Center">CPU Info Center</a>. <p></p> <p class="updated">Last updated: <a href="/new.html">2002-07-16</a></p> <p></p> <p class="vertical-space"></p><h3>Nearby terms:</h3> <p class="neighbours"> <b><a href="/microprocessor">microprocessor</a></b> &diams; <a href="/Microprocessor+without+Interlocked+Pipeline+Stages">Microprocessor without Interlocked Pipeline Stages</a> </p> <p> Try this search on <a href="https://www.wikipedia.org/wiki/Special:Search?search=microprocessor">Wikipedia</a>, <a href="https://www.wiktionary.org/wiki/microprocessor">Wiktionary</a>, <a href="https://www.google.com/search?q=define:microprocessor">Google</a>, <a href="https://www.onelook.com/?w=microprocessor">OneLook</a>. </p> <p class="vertical-space"></p> <hr> <div></div> <hr>  <div id="HCB_comment_box">Loading</div> <link rel="stylesheet" type="text/css" href="//www.htmlcommentbox.com/static/skins/bootstrap/twitter-bootstrap.css?v=0"> <script language="javascript" id="hcb"> hcb_user = { PAGE: 'https://foldoc.org/microprocessor', comments_header: ' ', no_comments_msg: ' ', err_comment_empty: 'Your comment was not posted because it was empty!', rss: '', }; var s = document.createElement("script"); s.setAttribute("type", "text/javascript"); s.setAttribute("src", "//www.htmlcommentbox.com/jread?page=" + escape(hcb_user.PAGE).replace(/\+/g, "%2B") + "&mod=%241%24wq1rdBcg%24.0y2uzvjA2bsnhzpXVq9F." + "&opts=17374&num=10"); // No e-mail field: 16846 if (typeof s != "undefined") document.getElementsByTagName("head")[0].appendChild(s); </script> <script> setTimeout(function () { document.getElementById('hcb_form_content').rows = 1 }, 1000); </script> <hr>  </div>  </div>  <div id="right"> <div id="google_translate_element"> <script> function googleTranslateElementInit() { new google.translate.TranslateElement({ pageLanguage: 'en' }, 'google_translate_element'); } </script> <script src="https://translate.google.com/translate_a/element.js?cb=googleTranslateElementInit"></script> </div> <p><br></p> <hr> <div id="social"> <div class="fb-like" data-href="http://foldoc.org/" data-layout="button_count" data-action="like" data-show-faces="false" data-share="true"> </div> <a href="https://twitter.com/share" class="twitter-share-button" data-via="foldoc"> Tweet </a> <script> if (!document.getElementById('twitter-wjs')) { var fjs = document.getElementsByTagName('script')[0], js = document.createElement('script'); js.id = 'twitter-wjs'; js.src = 'https://platform.twitter.com/widgets.js'; fjs.parentNode.insertBefore(js, fjs); } </script> </div> <hr> <div> <p></p> </div> <p> <a href="/rss.xml"> <img src="/orangerss.gif" width="14" height="14" alt="RSS feed of new items"> </a>   <a href="/new.html">Recent Updates</a>     |     <a href="/missing.html">Missing Terms</a> </p> <p>Updated: Sun, 06 Oct 2024 20:18:24 GMT</p> <p>15274 entries</p> <p><em><a href="/Free+On-line+Dictionary">Copyright Denis Howe 1985</a></em></p> </div>  </div>   <script type="text/javascript"> window._qevents = window._qevents || []; (function() { var elem = document.createElement('script'); elem.src = 'https://secure.quantserve.com/quant.js'; elem.async = true; elem.type = 'text/javascript'; var scpt = document.getElementsByTagName('script')[0]; scpt.parentNode.insertBefore(elem, scpt); })(); window._qevents.push({ qacct: 'p-48Rosdvs3EiOc', uid: '__INSERT_EMAIL_HERE__' }); </script> <noscript> <div style="display:none;"> <img src="https//pixel.quantserve.com/pixel/p-48Rosdvs3EiOc.gif" border="0" height="1" width="1" alt="Quantcast"/> </div> </noscript>  </body> </html>