CINXE.COM

<!DOCTYPE html> <html class="client-nojs vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-sticky-header-enabled vector-toc-available" lang="en" dir="ltr"> <head> <meta charset="UTF-8"> <title>SGPIO - Wikipedia</title> <script>(function(){var className="client-js vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-sticky-header-enabled vector-toc-available";var cookie=document.cookie.match(/(?:^|; )enwikimwclientpreferences=([^;]+)/);if(cookie){cookie[1].split('%2C').forEach(function(pref){className=className.replace(new RegExp('(^| )'+pref.replace(/-clientpref-\w+$|[^\w-]+/g,'')+'-clientpref-\\w+( |$)'),'$1'+pref+'$2');});}document.documentElement.className=className;}());RLCONF={"wgBreakFrames":false,"wgSeparatorTransformTable":["",""],"wgDigitTransformTable":["",""],"wgDefaultDateFormat":"dmy", "wgMonthNames":["","January","February","March","April","May","June","July","August","September","October","November","December"],"wgRequestId":"3035f41e-02b2-4f1c-8fdc-ba6e7a6455f8","wgCanonicalNamespace":"","wgCanonicalSpecialPageName":false,"wgNamespaceNumber":0,"wgPageName":"SGPIO","wgTitle":"SGPIO","wgCurRevisionId":1225361557,"wgRevisionId":1225361557,"wgArticleId":5475830,"wgIsArticle":true,"wgIsRedirect":false,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["Wikipedia articles needing reorganization from May 2013","All articles with unsourced statements","Articles with unsourced statements from June 2011","Wikipedia articles needing clarification from April 2017","Articles with unsourced statements from November 2010","Serial buses","Communications protocols","SCSI"],"wgPageViewLanguage":"en","wgPageContentLanguage":"en","wgPageContentModel":"wikitext","wgRelevantPageName":"SGPIO","wgRelevantArticleId":5475830,"wgIsProbablyEditable":true, "wgRelevantPageIsProbablyEditable":true,"wgRestrictionEdit":[],"wgRestrictionMove":[],"wgNoticeProject":"wikipedia","wgCiteReferencePreviewsActive":false,"wgFlaggedRevsParams":{"tags":{"status":{"levels":1}}},"wgMediaViewerOnClick":true,"wgMediaViewerEnabledByDefault":true,"wgPopupsFlags":0,"wgVisualEditor":{"pageLanguageCode":"en","pageLanguageDir":"ltr","pageVariantFallbacks":"en"},"wgMFDisplayWikibaseDescriptions":{"search":true,"watchlist":true,"tagline":false,"nearby":true},"wgWMESchemaEditAttemptStepOversample":false,"wgWMEPageLength":9000,"wgEditSubmitButtonLabelPublish":true,"wgULSPosition":"interlanguage","wgULSisCompactLinksEnabled":false,"wgVector2022LanguageInHeader":true,"wgULSisLanguageSelectorEmpty":false,"wgWikibaseItemId":"Q17152376","wgCheckUserClientHintsHeadersJsApi":["brands","architecture","bitness","fullVersionList","mobile","model","platform","platformVersion"],"GEHomepageSuggestedEditsEnableTopics":true,"wgGETopicsMatchModeEnabled":false, "wgGEStructuredTaskRejectionReasonTextInputEnabled":false,"wgGELevelingUpEnabledForUser":false};RLSTATE={"ext.globalCssJs.user.styles":"ready","site.styles":"ready","user.styles":"ready","ext.globalCssJs.user":"ready","user":"ready","user.options":"loading","skins.vector.search.codex.styles":"ready","skins.vector.styles":"ready","skins.vector.icons":"ready","ext.wikimediamessages.styles":"ready","ext.visualEditor.desktopArticleTarget.noscript":"ready","ext.uls.interlanguage":"ready","wikibase.client.init":"ready","ext.wikimediaBadges":"ready"};RLPAGEMODULES=["mediawiki.page.media","site","mediawiki.page.ready","mediawiki.toc","skins.vector.js","ext.centralNotice.geoIP","ext.centralNotice.startUp","ext.gadget.ReferenceTooltips","ext.gadget.switcher","ext.urlShortener.toolbar","ext.centralauth.centralautologin","mmv.bootstrap","ext.popups","ext.visualEditor.desktopArticleTarget.init","ext.visualEditor.targetLoader","ext.echo.centralauth","ext.eventLogging","ext.wikimediaEvents", "ext.navigationTiming","ext.uls.interface","ext.cx.eventlogging.campaigns","ext.cx.uls.quick.actions","wikibase.client.vector-2022","ext.checkUser.clientHints","ext.growthExperiments.SuggestedEditSession"];</script> <script>(RLQ=window.RLQ||[]).push(function(){mw.loader.impl(function(){return["user.options@12s5i",function($,jQuery,require,module){mw.user.tokens.set({"patrolToken":"+\\","watchToken":"+\\","csrfToken":"+\\"}); }];});});</script> <link rel="stylesheet" href="/w/load.php?lang=en&modules=ext.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.wikimediaBadges%7Cext.wikimediamessages.styles%7Cskins.vector.icons%2Cstyles%7Cskins.vector.search.codex.styles%7Cwikibase.client.init&only=styles&skin=vector-2022"> <script async="" src="/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=vector-2022"></script> <meta name="ResourceLoaderDynamicStyles" content=""> <link rel="stylesheet" href="/w/load.php?lang=en&modules=site.styles&only=styles&skin=vector-2022"> <meta name="generator" content="MediaWiki 1.44.0-wmf.15"> <meta name="referrer" content="origin"> <meta name="referrer" content="origin-when-cross-origin"> <meta name="robots" content="max-image-preview:standard"> <meta name="format-detection" content="telephone=no"> <meta name="viewport" content="width=1120"> <meta property="og:title" content="SGPIO - Wikipedia"> <meta property="og:type" content="website"> <link rel="preconnect" href="//upload.wikimedia.org"> <link rel="alternate" media="only screen and (max-width: 640px)" href="//en.m.wikipedia.org/wiki/SGPIO"> <link rel="alternate" type="application/x-wiki" title="Edit this page" href="/w/index.php?title=SGPIO&action=edit"> <link rel="apple-touch-icon" href="/static/apple-touch/wikipedia.png"> <link rel="icon" href="/static/favicon/wikipedia.ico"> <link rel="search" type="application/opensearchdescription+xml" href="/w/rest.php/v1/search" title="Wikipedia (en)"> <link rel="EditURI" type="application/rsd+xml" href="//en.wikipedia.org/w/api.php?action=rsd"> <link rel="canonical" href="https://en.wikipedia.org/wiki/SGPIO"> <link rel="license" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en"> <link rel="alternate" type="application/atom+xml" title="Wikipedia Atom feed" href="/w/index.php?title=Special:RecentChanges&feed=atom"> <link rel="dns-prefetch" href="//meta.wikimedia.org" /> <link rel="dns-prefetch" href="login.wikimedia.org"> </head> <body class="skin--responsive skin-vector skin-vector-search-vue mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject mw-editable page-SGPIO rootpage-SGPIO skin-vector-2022 action-view"><a class="mw-jump-link" href="#bodyContent">Jump to content</a> <div class="vector-header-container"> <header class="vector-header mw-header"> <div class="vector-header-start"> <nav class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-dropdown" class="vector-dropdown vector-main-menu-dropdown vector-button-flush-left vector-button-flush-right" title="Main menu" > <input type="checkbox" id="vector-main-menu-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-main-menu-dropdown" class="vector-dropdown-checkbox " aria-label="Main menu" > <label id="vector-main-menu-dropdown-label" for="vector-main-menu-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-menu mw-ui-icon-wikimedia-menu"></span> <span class="vector-dropdown-label-text">Main menu</span> </label> <div class="vector-dropdown-content"> <div id="vector-main-menu-unpinned-container" class="vector-unpinned-container"> <div id="vector-main-menu" class="vector-main-menu vector-pinnable-element"> <div class="vector-pinnable-header vector-main-menu-pinnable-header vector-pinnable-header-unpinned" data-feature-name="main-menu-pinned" data-pinnable-element-id="vector-main-menu" data-pinned-container-id="vector-main-menu-pinned-container" data-unpinned-container-id="vector-main-menu-unpinned-container" > <div class="vector-pinnable-header-label">Main menu</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-main-menu.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-main-menu.unpin">hide</button> </div> <div id="p-navigation" class="vector-menu mw-portlet mw-portlet-navigation" > <div class="vector-menu-heading"> Navigation </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-mainpage-description" class="mw-list-item"><a href="/wiki/Main_Page" title="Visit the main page [z]" accesskey="z"><span>Main page</span></a></li><li id="n-contents" class="mw-list-item"><a href="/wiki/Wikipedia:Contents" title="Guides to browsing Wikipedia"><span>Contents</span></a></li><li id="n-currentevents" class="mw-list-item"><a href="/wiki/Portal:Current_events" title="Articles related to current events"><span>Current events</span></a></li><li id="n-randompage" class="mw-list-item"><a href="/wiki/Special:Random" title="Visit a randomly selected article [x]" accesskey="x"><span>Random article</span></a></li><li id="n-aboutsite" class="mw-list-item"><a href="/wiki/Wikipedia:About" title="Learn about Wikipedia and how it works"><span>About Wikipedia</span></a></li><li id="n-contactpage" class="mw-list-item"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us" title="How to contact Wikipedia"><span>Contact us</span></a></li> </ul> </div> </div> <div id="p-interaction" class="vector-menu mw-portlet mw-portlet-interaction" > <div class="vector-menu-heading"> Contribute </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-help" class="mw-list-item"><a href="/wiki/Help:Contents" title="Guidance on how to use and edit Wikipedia"><span>Help</span></a></li><li id="n-introduction" class="mw-list-item"><a href="/wiki/Help:Introduction" title="Learn how to edit Wikipedia"><span>Learn to edit</span></a></li><li id="n-portal" class="mw-list-item"><a href="/wiki/Wikipedia:Community_portal" title="The hub for editors"><span>Community portal</span></a></li><li id="n-recentchanges" class="mw-list-item"><a href="/wiki/Special:RecentChanges" title="A list of recent changes to Wikipedia [r]" accesskey="r"><span>Recent changes</span></a></li><li id="n-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_upload_wizard" title="Add images or other media for use on Wikipedia"><span>Upload file</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> <a href="/wiki/Main_Page" class="mw-logo"> <img class="mw-logo-icon" src="/static/images/icons/wikipedia.png" alt="" aria-hidden="true" height="50" width="50"> <span class="mw-logo-container skin-invert"> <img class="mw-logo-wordmark" alt="Wikipedia" src="/static/images/mobile/copyright/wikipedia-wordmark-en.svg" style="width: 7.5em; height: 1.125em;"> <img class="mw-logo-tagline" alt="The Free Encyclopedia" src="/static/images/mobile/copyright/wikipedia-tagline-en.svg" width="117" height="13" style="width: 7.3125em; height: 0.8125em;"> </span> </a> </div> <div class="vector-header-end"> <div id="p-search" role="search" class="vector-search-box-vue vector-search-box-collapses vector-search-box-show-thumbnail vector-search-box-auto-expand-width vector-search-box"> <a href="/wiki/Special:Search" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only search-toggle" title="Search Wikipedia [f]" accesskey="f"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>Search</span> </a> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail cdx-typeahead-search--auto-expand-width"> <form action="/w/index.php" id="searchform" class="cdx-search-input cdx-search-input--has-end-button"> <div id="simpleSearch" class="cdx-search-input__input-wrapper" data-search-loc="header-moved"> <div class="cdx-text-input cdx-text-input--has-start-icon"> <input class="cdx-text-input__input" type="search" name="search" placeholder="Search Wikipedia" aria-label="Search Wikipedia" autocapitalize="sentences" title="Search Wikipedia [f]" accesskey="f" id="searchInput" > <span class="cdx-text-input__icon cdx-text-input__start-icon"></span> </div> <input type="hidden" name="title" value="Special:Search"> </div> <button class="cdx-button cdx-search-input__end-button">Search</button> </form> </div> </div> </div> <nav class="vector-user-links vector-user-links-wide" aria-label="Personal tools"> <div class="vector-user-links-main"> <div id="p-vector-user-menu-preferences" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-userpage" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-dropdown" class="vector-dropdown " title="Change the appearance of the page's font size, width, and color" > <input type="checkbox" id="vector-appearance-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-appearance-dropdown" class="vector-dropdown-checkbox " aria-label="Appearance" > <label id="vector-appearance-dropdown-label" for="vector-appearance-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-appearance mw-ui-icon-wikimedia-appearance"></span> <span class="vector-dropdown-label-text">Appearance</span> </label> <div class="vector-dropdown-content"> <div id="vector-appearance-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div id="p-vector-user-menu-notifications" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-overflow" class="vector-menu mw-portlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en" class=""><span>Donate</span></a> </li> <li id="pt-createaccount-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:CreateAccount&returnto=SGPIO" title="You are encouraged to create an account and log in; however, it is not mandatory" class=""><span>Create account</span></a> </li> <li id="pt-login-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:UserLogin&returnto=SGPIO" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o" class=""><span>Log in</span></a> </li> </ul> </div> </div> </div> <div id="vector-user-links-dropdown" class="vector-dropdown vector-user-menu vector-button-flush-right vector-user-menu-logged-out" title="Log in and more options" > <input type="checkbox" id="vector-user-links-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-user-links-dropdown" class="vector-dropdown-checkbox " aria-label="Personal tools" > <label id="vector-user-links-dropdown-label" for="vector-user-links-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-ellipsis mw-ui-icon-wikimedia-ellipsis"></span> <span class="vector-dropdown-label-text">Personal tools</span> </label> <div class="vector-dropdown-content"> <div id="p-personal" class="vector-menu mw-portlet mw-portlet-personal user-links-collapsible-item" title="User menu" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport" class="user-links-collapsible-item mw-list-item"><a href="https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en"><span>Donate</span></a></li><li id="pt-createaccount" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:CreateAccount&returnto=SGPIO" title="You are encouraged to create an account and log in; however, it is not mandatory"><span class="vector-icon mw-ui-icon-userAdd mw-ui-icon-wikimedia-userAdd"></span> <span>Create account</span></a></li><li id="pt-login" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:UserLogin&returnto=SGPIO" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o"><span class="vector-icon mw-ui-icon-logIn mw-ui-icon-wikimedia-logIn"></span> <span>Log in</span></a></li> </ul> </div> </div> <div id="p-user-menu-anon-editor" class="vector-menu mw-portlet mw-portlet-user-menu-anon-editor" > <div class="vector-menu-heading"> Pages for logged out editors <a href="/wiki/Help:Introduction" aria-label="Learn more about editing"><span>learn more</span></a> </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-anoncontribs" class="mw-list-item"><a href="/wiki/Special:MyContributions" title="A list of edits made from this IP address [y]" accesskey="y"><span>Contributions</span></a></li><li id="pt-anontalk" class="mw-list-item"><a href="/wiki/Special:MyTalk" title="Discussion about edits from this IP address [n]" accesskey="n"><span>Talk</span></a></li> </ul> </div> </div> </div> </div> </nav> </div> </header> </div> <div class="mw-page-container"> <div class="mw-page-container-inner"> <div class="vector-sitenotice-container"> <div id="siteNotice"></div> </div> <div class="vector-column-start"> <div class="vector-main-menu-container"> <div id="mw-navigation"> <nav id="mw-panel" class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-pinned-container" class="vector-pinned-container"> </div> </nav> </div> </div> <div class="vector-sticky-pinned-container"> <nav id="mw-panel-toc" aria-label="Contents" data-event-name="ui.sidebar-toc" class="mw-table-of-contents-container vector-toc-landmark"> <div id="vector-toc-pinned-container" class="vector-pinned-container"> <div id="vector-toc" class="vector-toc vector-pinnable-element"> <div class="vector-pinnable-header vector-toc-pinnable-header vector-pinnable-header-pinned" data-feature-name="toc-pinned" data-pinnable-element-id="vector-toc" > <h2 class="vector-pinnable-header-label">Contents</h2> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-toc.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-toc.unpin">hide</button> </div> <ul class="vector-toc-contents" id="mw-panel-toc-list"> <li id="toc-mw-content-text" class="vector-toc-list-item vector-toc-level-1"> <a href="#" class="vector-toc-link"> <div class="vector-toc-text">(Top)</div> </a> </li> <li id="toc-History" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#History"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>History</span> </div> </a> <ul id="toc-History-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Host_bus_adapters" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Host_bus_adapters"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Host bus adapters</span> </div> </a> <ul id="toc-Host_bus_adapters-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Backplanes_with_SGPIO_bus_interface" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Backplanes_with_SGPIO_bus_interface"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Backplanes with SGPIO bus interface</span> </div> </a> <ul id="toc-Backplanes_with_SGPIO_bus_interface-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-SGPIO_interpretation_and_LED_blinking_patterns" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#SGPIO_interpretation_and_LED_blinking_patterns"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>SGPIO interpretation and LED blinking patterns</span> </div> </a> <ul id="toc-SGPIO_interpretation_and_LED_blinking_patterns-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Electrical_characteristics_of_the_SGPIO_bus" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Electrical_characteristics_of_the_SGPIO_bus"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Electrical characteristics of the SGPIO bus</span> </div> </a> <ul id="toc-Electrical_characteristics_of_the_SGPIO_bus-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Signal_lines_of_the_SGPIO_bus" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Signal_lines_of_the_SGPIO_bus"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Signal lines of the SGPIO bus</span> </div> </a> <button aria-controls="toc-Signal_lines_of_the_SGPIO_bus-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Signal lines of the SGPIO bus subsection</span> </button> <ul id="toc-Signal_lines_of_the_SGPIO_bus-sublist" class="vector-toc-list"> <li id="toc-SClock" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#SClock"> <div class="vector-toc-text"> <span class="vector-toc-numb">6.1</span> <span>SClock</span> </div> </a> <ul id="toc-SClock-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-SLoad" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#SLoad"> <div class="vector-toc-text"> <span class="vector-toc-numb">6.2</span> <span>SLoad</span> </div> </a> <ul id="toc-SLoad-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-SDataOut" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#SDataOut"> <div class="vector-toc-text"> <span class="vector-toc-numb">6.3</span> <span>SDataOut</span> </div> </a> <ul id="toc-SDataOut-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-SDataIn" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#SDataIn"> <div class="vector-toc-text"> <span class="vector-toc-numb">6.4</span> <span>SDataIn</span> </div> </a> <ul id="toc-SDataIn-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-SGPIO_implementation" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#SGPIO_implementation"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>SGPIO implementation</span> </div> </a> <ul id="toc-SGPIO_implementation-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Adoption_of_the_SGPIO_specification" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Adoption_of_the_SGPIO_specification"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>Adoption of the SGPIO specification</span> </div> </a> <ul id="toc-Adoption_of_the_SGPIO_specification-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-SGPIO_timeout_conditions" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#SGPIO_timeout_conditions"> <div class="vector-toc-text"> <span class="vector-toc-numb">9</span> <span>SGPIO timeout conditions</span> </div> </a> <ul id="toc-SGPIO_timeout_conditions-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Backplane_Implementations_of_the_SGPIO_bus" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Backplane_Implementations_of_the_SGPIO_bus"> <div class="vector-toc-text"> <span class="vector-toc-numb">10</span> <span>Backplane Implementations of the SGPIO bus</span> </div> </a> <ul id="toc-Backplane_Implementations_of_the_SGPIO_bus-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">11</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" title="Table of Contents" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">SGPIO</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 2 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-2" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">2 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/GPIO" title="GPIO – Finnish" lang="fi" hreflang="fi" data-title="GPIO" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/GPIO" title="GPIO – Chinese" lang="zh" hreflang="zh" data-title="GPIO" data-language-autonym="中文" data-language-local-name="Chinese" class="interlanguage-link-target"><span>中文</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q17152376#sitelinks-wikipedia" title="Edit interlanguage links" class="wbc-editpage">Edit links</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav aria-label="Namespaces"> <div id="p-associated-pages" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-associated-pages" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-nstab-main" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/SGPIO" title="View the content page [c]" accesskey="c"><span>Article</span></a></li><li id="ca-talk" class="vector-tab-noicon mw-list-item"><a href="/wiki/Talk:SGPIO" rel="discussion" title="Discuss improvements to the content page [t]" accesskey="t"><span>Talk</span></a></li> </ul> </div> </div> <div id="vector-variants-dropdown" class="vector-dropdown emptyPortlet" > <input type="checkbox" id="vector-variants-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-variants-dropdown" class="vector-dropdown-checkbox " aria-label="Change language variant" > <label id="vector-variants-dropdown-label" for="vector-variants-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">English</span> </label> <div class="vector-dropdown-content"> <div id="p-variants" class="vector-menu mw-portlet mw-portlet-variants emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> </div> </div> </nav> </div> <div id="right-navigation" class="vector-collapsible"> <nav aria-label="Views"> <div id="p-views" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-views" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-view" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/SGPIO"><span>Read</span></a></li><li id="ca-edit" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=SGPIO&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-history" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=SGPIO&action=history" title="Past revisions of this page [h]" accesskey="h"><span>View history</span></a></li> </ul> </div> </div> </nav> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-dropdown" class="vector-dropdown vector-page-tools-dropdown" > <input type="checkbox" id="vector-page-tools-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-tools-dropdown" class="vector-dropdown-checkbox " aria-label="Tools" > <label id="vector-page-tools-dropdown-label" for="vector-page-tools-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">Tools</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-tools-unpinned-container" class="vector-unpinned-container"> <div id="vector-page-tools" class="vector-page-tools vector-pinnable-element"> <div class="vector-pinnable-header vector-page-tools-pinnable-header vector-pinnable-header-unpinned" data-feature-name="page-tools-pinned" data-pinnable-element-id="vector-page-tools" data-pinned-container-id="vector-page-tools-pinned-container" data-unpinned-container-id="vector-page-tools-unpinned-container" > <div class="vector-pinnable-header-label">Tools</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-page-tools.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-page-tools.unpin">hide</button> </div> <div id="p-cactions" class="vector-menu mw-portlet mw-portlet-cactions emptyPortlet vector-has-collapsible-items" title="More options" > <div class="vector-menu-heading"> Actions </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-more-view" class="selected vector-more-collapsible-item mw-list-item"><a href="/wiki/SGPIO"><span>Read</span></a></li><li id="ca-more-edit" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=SGPIO&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-more-history" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=SGPIO&action=history"><span>View history</span></a></li> </ul> </div> </div> <div id="p-tb" class="vector-menu mw-portlet mw-portlet-tb" > <div class="vector-menu-heading"> General </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-whatlinkshere" class="mw-list-item"><a href="/wiki/Special:WhatLinksHere/SGPIO" title="List of all English Wikipedia pages containing links to this page [j]" accesskey="j"><span>What links here</span></a></li><li id="t-recentchangeslinked" class="mw-list-item"><a href="/wiki/Special:RecentChangesLinked/SGPIO" rel="nofollow" title="Recent changes in pages linked from this page [k]" accesskey="k"><span>Related changes</span></a></li><li id="t-upload" class="mw-list-item"><a href="//en.wikipedia.org/wiki/Wikipedia:File_Upload_Wizard" title="Upload files [u]" accesskey="u"><span>Upload file</span></a></li><li id="t-specialpages" class="mw-list-item"><a href="/wiki/Special:SpecialPages" title="A list of all special pages [q]" accesskey="q"><span>Special pages</span></a></li><li id="t-permalink" class="mw-list-item"><a href="/w/index.php?title=SGPIO&oldid=1225361557" title="Permanent link to this revision of this page"><span>Permanent link</span></a></li><li id="t-info" class="mw-list-item"><a href="/w/index.php?title=SGPIO&action=info" title="More information about this page"><span>Page information</span></a></li><li id="t-cite" class="mw-list-item"><a href="/w/index.php?title=Special:CiteThisPage&page=SGPIO&id=1225361557&wpFormIdentifier=titleform" title="Information on how to cite this page"><span>Cite this page</span></a></li><li id="t-urlshortener" class="mw-list-item"><a href="/w/index.php?title=Special:UrlShortener&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FSGPIO"><span>Get shortened URL</span></a></li><li id="t-urlshortener-qrcode" class="mw-list-item"><a href="/w/index.php?title=Special:QrCode&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FSGPIO"><span>Download QR code</span></a></li> </ul> </div> </div> <div id="p-coll-print_export" class="vector-menu mw-portlet mw-portlet-coll-print_export" > <div class="vector-menu-heading"> Print/export </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="coll-download-as-rl" class="mw-list-item"><a href="/w/index.php?title=Special:DownloadAsPdf&page=SGPIO&action=show-download-screen" title="Download this page as a PDF file"><span>Download as PDF</span></a></li><li id="t-print" class="mw-list-item"><a href="/w/index.php?title=SGPIO&printable=yes" title="Printable version of this page [p]" accesskey="p"><span>Printable version</span></a></li> </ul> </div> </div> <div id="p-wikibase-otherprojects" class="vector-menu mw-portlet mw-portlet-wikibase-otherprojects" > <div class="vector-menu-heading"> In other projects </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-wikibase" class="wb-otherproject-link wb-otherproject-wikibase-dataitem mw-list-item"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q17152376" title="Structured data on this page hosted by Wikidata [g]" accesskey="g"><span>Wikidata item</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> </div> </div> </div> <div class="vector-column-end"> <div class="vector-sticky-pinned-container"> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-pinned-container" class="vector-pinned-container"> </div> </nav> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-pinned-container" class="vector-pinned-container"> <div id="vector-appearance" class="vector-appearance vector-pinnable-element"> <div class="vector-pinnable-header vector-appearance-pinnable-header vector-pinnable-header-pinned" data-feature-name="appearance-pinned" data-pinnable-element-id="vector-appearance" data-pinned-container-id="vector-appearance-pinned-container" data-unpinned-container-id="vector-appearance-unpinned-container" > <div class="vector-pinnable-header-label">Appearance</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-appearance.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-appearance.unpin">hide</button> </div> </div> </div> </nav> </div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><style data-mw-deduplicate="TemplateStyles:r1251242444">.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 0;overflow:hidden;width:238px;border-collapse:collapse;font-size:88%;line-height:1.25em}.mw-parser-output .ambox-speedy{border-left:10px solid #b32424;background-color:#fee7e6}.mw-parser-output .ambox-delete{border-left:10px solid #b32424}.mw-parser-output .ambox-content{border-left:10px solid #f28500}.mw-parser-output .ambox-style{border-left:10px solid #fc3}.mw-parser-output .ambox-move{border-left:10px solid #9932cc}.mw-parser-output .ambox-protection{border-left:10px solid #a2a9b1}.mw-parser-output .ambox .mbox-text{border:none;padding:0.25em 0.5em;width:100%}.mw-parser-output .ambox .mbox-image{border:none;padding:2px 0 2px 0.5em;text-align:center}.mw-parser-output .ambox .mbox-imageright{border:none;padding:2px 0.5em 2px 0;text-align:center}.mw-parser-output .ambox .mbox-empty-cell{border:none;padding:0;width:1px}.mw-parser-output .ambox .mbox-image-div{width:52px}@media(min-width:720px){.mw-parser-output .ambox{margin:0 10%}}@media print{body.ns-0 .mw-parser-output .ambox{display:none!important}}</style><table class="box-Cleanup_reorganize plainlinks metadata ambox ambox-style" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><span><img src="//upload.wikimedia.org/wikipedia/commons/thumb/1/1c/Ambox_rewrite.svg/40px-Ambox_rewrite.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/1c/Ambox_rewrite.svg/60px-Ambox_rewrite.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/1c/Ambox_rewrite.svg/80px-Ambox_rewrite.svg.png 2x" data-file-width="620" data-file-height="620" /></span></span></div></td><td class="mbox-text"><div class="mbox-text-span">This article <b>may be in need of reorganization to comply with Wikipedia's <a href="/wiki/Wikipedia:Manual_of_Style/Layout" title="Wikipedia:Manual of Style/Layout">layout guidelines</a></b>.<span class="hide-when-compact"> Please help by <a class="external text" href="https://en.wikipedia.org/w/index.php?title=SGPIO&action=edit">editing the article</a> to make improvements to the overall structure.</span> <span class="date-container"><i>(<span class="date">May 2013</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <p><br /> <b>Serial general-purpose input/output</b> (SGPIO) is a four-signal (or four-wire) bus used between a <a href="/wiki/Host_bus_adapter" class="mw-redirect" title="Host bus adapter">host bus adapter</a> (HBA) and a <a href="/wiki/Backplane" title="Backplane">backplane</a>. Of the four signals, three are driven by the HBA and one by the backplane. Typically, the HBA is a storage controller located inside a server, desktop, rack or workstation computer that interfaces with <a href="/wiki/Hard_disk_drive" title="Hard disk drive">hard disk drives</a> or <a href="/wiki/Solid-state_drive" title="Solid-state drive">solid-state drives</a> to store and retrieve data. It is considered an extension of the <a href="/wiki/General-purpose_input/output" title="General-purpose input/output">general-purpose input/output</a> (GPIO) concept. – The SGPIO specification is maintained by the <a href="/wiki/Small_Form_Factor_Committee" title="Small Form Factor Committee">Small Form Factor Committee</a> in the <a href="/wiki/International_Blinking_Pattern_Interpretation" title="International Blinking Pattern Interpretation">SFF-8485</a> standard. The <a href="/wiki/International_Blinking_Pattern_Interpretation" title="International Blinking Pattern Interpretation">International Blinking Pattern Interpretation</a> indicates how SGPIO signals are interpreted into blinking <a href="/wiki/Light-emitting_diode" title="Light-emitting diode">light-emitting diodes</a> (LEDs) on <a href="/wiki/Disk_array" title="Disk array">disk arrays</a> and storage back-planes. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="History">History</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SGPIO&action=edit&section=1" title="Edit section: History"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>SGPIO was developed as an engineering collaboration between American Megatrends Inc, at the time makers of back-planes, and LSI-Logic in 2004. SGPIO was later published by the SFF committee as specification <a rel="nofollow" class="external text" href="https://doc.xdevs.com/doc/Seagate/SFF-8485.PDF">SFF-8485</a>. </p> <div class="mw-heading mw-heading2"><h2 id="Host_bus_adapters">Host bus adapters</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SGPIO&action=edit&section=2" title="Edit section: Host bus adapters"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <table style="float: right;"> <tbody><tr> <td><figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:TypHBAipassconn1.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/en/thumb/3/3a/TypHBAipassconn1.jpg/220px-TypHBAipassconn1.jpg" decoding="async" width="220" height="135" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/3/3a/TypHBAipassconn1.jpg/330px-TypHBAipassconn1.jpg 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/3/3a/TypHBAipassconn1.jpg/440px-TypHBAipassconn1.jpg 2x" data-file-width="473" data-file-height="291" /></a><figcaption>Typical host bus adapter with two 4× iPass connectors</figcaption></figure> </td> <td> </td></tr></tbody></table> <p>The SGPIO signal consists of 4 electrical signals; it typically originates from a <a href="/wiki/Host_bus_adapter" class="mw-redirect" title="Host bus adapter">host bus adapter</a> (HBA). iPass connectors (Usually SFF-8087 or SFF-8484) carry both SAS/SATA electrical connections between the HBA and the hard drives as well as the 4 SGPIO signals. </p> <div style="clear:both;" class=""></div> <div class="mw-heading mw-heading2"><h2 id="Backplanes_with_SGPIO_bus_interface">Backplanes with SGPIO bus interface</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SGPIO&action=edit&section=3" title="Edit section: Backplanes with SGPIO bus interface"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:AMI_958A_02.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/f/f3/AMI_958A_02.jpg/220px-AMI_958A_02.jpg" decoding="async" width="220" height="248" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/f3/AMI_958A_02.jpg/330px-AMI_958A_02.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/f3/AMI_958A_02.jpg/440px-AMI_958A_02.jpg 2x" data-file-width="521" data-file-height="587" /></a><figcaption>Backplane</figcaption></figure> <p>A <a href="/wiki/Backplane" title="Backplane">backplane</a> is a circuit board with connectors and power circuitry into which hard drives are attached; they can have multiple slots, each of which can be populated with a hard drive. Typically the back-plane is equipped with <a href="/wiki/Light-emitting_diode" title="Light-emitting diode">LEDs</a> which by their color and activity, indicate the slot's status; typically, a slot's LED will emit a particular color or blink pattern to indicate its current status. </p> <div class="mw-heading mw-heading2"><h2 id="SGPIO_interpretation_and_LED_blinking_patterns">SGPIO interpretation and LED blinking patterns</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SGPIO&action=edit&section=4" title="Edit section: SGPIO interpretation and LED blinking patterns"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Although many hardware vendors define their own proprietary LED blinking pattern, the common standard for SGPIO interpretation and LED blinking pattern can be found in the <a href="/wiki/IBPI" class="mw-redirect" title="IBPI">IBPI</a> specification. </p><p>On back-planes, vendors use typically 2 or 3 LEDs per slot – in both implementations a green LED indicates presence and/or activity – for back-planes with 2 LEDs per slot, the second LED indicates <i>Status</i> whereas in back-planes with 3 LEDs the second and third indicate <i>Locate</i> and <i>Fail</i>. </p> <div class="mw-heading mw-heading2"><h2 id="Electrical_characteristics_of_the_SGPIO_bus">Electrical characteristics of the SGPIO bus</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SGPIO&action=edit&section=5" title="Edit section: Electrical characteristics of the SGPIO bus"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The SGPIO bus consists of 4 signal lines and originates at the HBA, referred to as the <i>initiator</i> and ends at a <a href="/wiki/Backplane" title="Backplane">back-plane</a>, referred to as the <i>target</i>. If a back-plane (or <i>target</i>) is not present the HBA may still drive the bus without any harm to the system; if one does exist, it can communicate back to the HBA using the 4th wire. </p><p>The SGPIO bus is an <a href="/wiki/Open_collector" title="Open collector">open collector</a> bus with 2.0 kΩ pull-up resistors located at the HBA and the back-plane – as on any open collector bus information is transferred by devices on the bus pulling the lines to <a href="/wiki/Ground_(electricity)" title="Ground (electricity)">ground</a> (GND) using an open collector transistor or open drain <a href="/wiki/Field-effect_transistor" title="Field-effect transistor">FET</a>. </p> <div class="mw-heading mw-heading2"><h2 id="Signal_lines_of_the_SGPIO_bus">Signal lines of the SGPIO bus</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SGPIO&action=edit&section=6" title="Edit section: Signal lines of the SGPIO bus"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="SClock">SClock</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SGPIO&action=edit&section=7" title="Edit section: SClock"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The SGPIO bus has a dedicated clock line driven by the initiator (its maximum clock rate is 100 kHz), although many implementations use slower ones (typically 48 kHz). </p> <div class="mw-heading mw-heading3"><h3 id="SLoad">SLoad</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SGPIO&action=edit&section=8" title="Edit section: SLoad"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>This line is synchronous to the clock and is used to indicate the start of a new frame of data; a new SGPIO frame is indicated by SLoad being high at a rising edge of a clock after having been low for at least 5 clock cycles. The following 4 falling clock edges after a start condition is used to carry a <a href="/wiki/4-bit_computing" title="4-bit computing">4-bit</a> value from the HBA to the back-plane; the definition of this value is proprietary and varies between system vendors. </p> <div class="mw-heading mw-heading3"><h3 id="SDataOut">SDataOut</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SGPIO&action=edit&section=9" title="Edit section: SDataOut"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>This line carries 3 bits of data from the HBA to the backplane: the first bit typically carries <i>activity</i>; the second bit carries <i>locate</i>; and the third bit carries <i>fail</i>. A low value for the first bit indicates <i>no activity</i> and a high value indicates <i>activity</i>. </p> <div class="mw-heading mw-heading3"><h3 id="SDataIn">SDataIn</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SGPIO&action=edit&section=10" title="Edit section: SDataIn"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>This line is used by the back-plane and indicates some condition on the back-plane back to the HBA. The first bit being high commonly indicates the presence of a drive. The two following bits are typically unused, and driven low. Because this line would be high for all 3 bits when no backplane is connected, an HBA can detect the presence of a back-plane by the second or third bit of the SDataIn being driven low. </p><p>The SDataIn and SdataOut then repeats with 3 clocks per drive until the last drive is reached, and the cycle starts over again. </p> <div class="mw-heading mw-heading2"><h2 id="SGPIO_implementation">SGPIO implementation</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SGPIO&action=edit&section=11" title="Edit section: SGPIO implementation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>There are varieties in how the SGPIO bus is implemented between vendors of HBAs and storage controllers - some vendors will send a continuous stream of data which is advantageous to quickly update the LEDs on a backplane after cables are removed and re-inserted, while others send data only when there is a need to update the LED pattern. </p> <div class="mw-heading mw-heading2"><h2 id="Adoption_of_the_SGPIO_specification">Adoption of the SGPIO specification</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SGPIO&action=edit&section=12" title="Edit section: Adoption of the SGPIO specification"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>SGPIO and the SGPIO spec. is generally adopted and implemented in products from most major HBA and storage controller vendors such as <a href="/wiki/LSI_Corporation" title="LSI Corporation">LSI</a>, <a href="/wiki/Intel_Corporation" class="mw-redirect" title="Intel Corporation">Intel</a>, <a href="/wiki/Adaptec" title="Adaptec">Adaptec</a>, <a href="/wiki/Nvidia" title="Nvidia">Nvidia</a>, <a href="/wiki/Broadcom" title="Broadcom">Broadcom</a>, <a href="/wiki/Marvell_Technology_Group" class="mw-redirect" title="Marvell Technology Group">Marvell Technology Group</a> and <a href="/wiki/PMC-Sierra" title="PMC-Sierra">PMC-Sierra</a>. Most products shipping with support for <a href="/wiki/Serial_Attached_SCSI" title="Serial Attached SCSI">SAS</a> and <a href="/wiki/Serial_ATA" class="mw-redirect" title="Serial ATA">SATA</a> drives support this standard. </p> <div class="mw-heading mw-heading2"><h2 id="SGPIO_timeout_conditions">SGPIO timeout conditions</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SGPIO&action=edit&section=13" title="Edit section: SGPIO timeout conditions"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The SGPIO spec calls for the target to turn off all indicators when SClock, SLoad and SDataOut have been high for 64 ms; in practice this is not consistently followed by all vendors. Also, in some vendors' implementations the clock may be halted sporadically or stopped during or between cycles. Another – rather impractical – variation between vendors is the state in which the clock is left after a cycle. </p> <div class="mw-heading mw-heading2"><h2 id="Backplane_Implementations_of_the_SGPIO_bus">Backplane Implementations of the SGPIO bus</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SGPIO&action=edit&section=14" title="Edit section: Backplane Implementations of the SGPIO bus"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The idea behind this specification was to be able to use low cost <a href="/wiki/Complex_programmable_logic_device" title="Complex programmable logic device">CPLDs</a> or <a href="/wiki/Microcontroller" title="Microcontroller">microcontrollers</a> on a back-plane to drive LEDs; in practice, it has been found that there are variations in timing and interpretations of the bits between vendors, thus a simple CPLD would only work for a specific implementation thoroughly tested with one product from one vendor.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (June 2011)">citation needed</span></a></i>]</sup> A microcontroller is more applicable for this purpose, although the 4-bit SGPIO interface custom bus is not implemented on them<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (June 2011)">citation needed</span></a></i>]</sup> – sampling of the 4-bit lines using <a href="/wiki/General-purpose_input/output" title="General-purpose input/output">GPIOs</a> 100 kHz bit operations is too slow<sup class="noprint Inline-Template" style="margin-left:0.1em; white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Please_clarify" title="Wikipedia:Please clarify"><span title="The text near this tag may need clarification or removal of jargon. (April 2017)">clarification needed</span></a></i>]</sup> for many low-cost microcontrollers to handle whilst handling LED and other functions simultaneously. The length of the bit stream varies between HBA or storage controller; some vendors will stop the bit-stream when reaching the desired drive, while others will clock it all the way through. Some SAS-expander's bit streams may be as long as 108 (36×3) bits. </p><p>The safest implementation which ensures compatibility between all HBA and storage controller vendors is to use an <a href="/wiki/Application-specific_integrated_circuit" title="Application-specific integrated circuit">ASIC</a>, specifically, a combination of a microcontroller core with a hardware SGPIO interface; this concept was patented<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (November 2010)">citation needed</span></a></i>]</sup> in 2006 by <a href="/wiki/American_Megatrends" title="American Megatrends">AMI</a> and implemented in a series of backplane controller chips named the <a href="/w/index.php?title=MG9071&action=edit&redlink=1" class="new" title="MG9071 (page does not exist)">MG9071</a>, <a href="/w/index.php?title=MG9072&action=edit&redlink=1" class="new" title="MG9072 (page does not exist)">MG9072</a>, <a href="/w/index.php?title=MG9077&action=edit&redlink=1" class="new" title="MG9077 (page does not exist)">MG9077</a>, and <a href="/w/index.php?title=MG9082&action=edit&redlink=1" class="new" title="MG9082 (page does not exist)">MG9082</a>. </p><p>These chips will receive 1 or 2 SGPIO streams and drive LEDs accordingly; the latest chip from AMI, the <a href="/w/index.php?title=MG9077&action=edit&redlink=1" class="new" title="MG9077 (page does not exist)">MG9077</a>, can be configured by pull-up and pull-down resistors to adopt to 16 different configurations of SGPIO buses and drive the LEDs accordingly. Since the availability of these chips from AMI, major <a href="/wiki/Original_equipment_manufacturer" title="Original equipment manufacturer">OEMs</a> including <a href="/wiki/NEC" title="NEC">NEC</a>, <a href="/wiki/Hitachi,_Ltd." class="mw-redirect" title="Hitachi, Ltd.">Hitachi</a>, <a href="/wiki/Supermicro" title="Supermicro">Supermicro</a>, <a href="/wiki/IBM" title="IBM">IBM</a>, <a href="/wiki/Sun_Microsystems" title="Sun Microsystems">Sun Microsystems</a>, and others are using them on their back-planes to receive the SGPIO streams from a variety of HBA vendors and on-board controller chips to consistently drive LEDs with a pre-determined blinking pattern. </p> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=SGPIO&action=edit&section=15" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="https://members.snia.org/document/dl/25923">SFF-8485</a> Specification for Serial GPIO (SGPIO) Bus</li> <li><a rel="nofollow" class="external text" href="https://www.snia.org/sff/specifications">SFF Documents</a> (Documents & Specifications)</li></ul>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?useformat=desktop&type=1x1&usesul3=0" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=SGPIO&oldid=1225361557">https://en.wikipedia.org/w/index.php?title=SGPIO&oldid=1225361557</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Categories</a>: <ul><li><a href="/wiki/Category:Serial_buses" title="Category:Serial buses">Serial buses</a></li><li><a href="/wiki/Category:Communications_protocols" title="Category:Communications protocols">Communications protocols</a></li><li><a href="/wiki/Category:SCSI" title="Category:SCSI">SCSI</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden categories: <ul><li><a href="/wiki/Category:Wikipedia_articles_needing_reorganization_from_May_2013" title="Category:Wikipedia articles needing reorganization from May 2013">Wikipedia articles needing reorganization from May 2013</a></li><li><a href="/wiki/Category:All_articles_with_unsourced_statements" title="Category:All articles with unsourced statements">All articles with unsourced statements</a></li><li><a href="/wiki/Category:Articles_with_unsourced_statements_from_June_2011" title="Category:Articles with unsourced statements from June 2011">Articles with unsourced statements from June 2011</a></li><li><a href="/wiki/Category:Wikipedia_articles_needing_clarification_from_April_2017" title="Category:Wikipedia articles needing clarification from April 2017">Wikipedia articles needing clarification from April 2017</a></li><li><a href="/wiki/Category:Articles_with_unsourced_statements_from_November_2010" title="Category:Articles with unsourced statements from November 2010">Articles with unsourced statements from November 2010</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> This page was last edited on 23 May 2024, at 23:33<span class="anonymous-show"> (UTC)</span>.</li> <li id="footer-info-copyright">Text is available under the <a href="/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License" title="Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License">Creative Commons Attribution-ShareAlike 4.0 License</a>; additional terms may apply. By using this site, you agree to the <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Terms_of_Use" class="extiw" title="foundation:Special:MyLanguage/Policy:Terms of Use">Terms of Use</a> and <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy" class="extiw" title="foundation:Special:MyLanguage/Policy:Privacy policy">Privacy Policy</a>. Wikipedia® is a registered trademark of the <a rel="nofollow" class="external text" href="https://wikimediafoundation.org/">Wikimedia Foundation, Inc.</a>, a non-profit organization.</li> </ul> <ul id="footer-places"> <li id="footer-places-privacy"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy">Privacy policy</a></li> <li id="footer-places-about"><a href="/wiki/Wikipedia:About">About Wikipedia</a></li> <li id="footer-places-disclaimers"><a href="/wiki/Wikipedia:General_disclaimer">Disclaimers</a></li> <li id="footer-places-contact"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us">Contact Wikipedia</a></li> <li id="footer-places-wm-codeofconduct"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Universal_Code_of_Conduct">Code of Conduct</a></li> <li id="footer-places-developers"><a href="https://developer.wikimedia.org">Developers</a></li> <li id="footer-places-statslink"><a href="https://stats.wikimedia.org/#/en.wikipedia.org">Statistics</a></li> <li id="footer-places-cookiestatement"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Cookie_statement">Cookie statement</a></li> <li id="footer-places-mobileview"><a href="//en.m.wikipedia.org/w/index.php?title=SGPIO&mobileaction=toggle_view_mobile" class="noprint stopMobileRedirectToggle">Mobile view</a></li> </ul> <ul id="footer-icons" class="noprint"> <li id="footer-copyrightico"><a href="https://wikimediafoundation.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/static/images/footer/wikimedia-button.svg" width="84" height="29" alt="Wikimedia Foundation" lang="en" loading="lazy"></a></li> <li id="footer-poweredbyico"><a href="https://www.mediawiki.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/w/resources/assets/poweredby_mediawiki.svg" alt="Powered by MediaWiki" width="88" height="31" loading="lazy"></a></li> </ul> </footer> </div> </div> </div> <div class="vector-header-container vector-sticky-header-container"> <div id="vector-sticky-header" class="vector-sticky-header"> <div class="vector-sticky-header-start"> <div class="vector-sticky-header-icon-start vector-button-flush-left vector-button-flush-right" aria-hidden="true"> <button class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-sticky-header-search-toggle" tabindex="-1" data-event-name="ui.vector-sticky-search-form.icon"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>Search</span> </button> </div> <div role="search" class="vector-search-box-vue vector-search-box-show-thumbnail vector-search-box"> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail"> <form action="/w/index.php" id="vector-sticky-search-form" class="cdx-search-input cdx-search-input--has-end-button"> <div class="cdx-search-input__input-wrapper" data-search-loc="header-moved"> <div class="cdx-text-input cdx-text-input--has-start-icon"> <input class="cdx-text-input__input" type="search" name="search" placeholder="Search Wikipedia"> <span class="cdx-text-input__icon cdx-text-input__start-icon"></span> </div> <input type="hidden" name="title" value="Special:Search"> </div> <button class="cdx-button cdx-search-input__end-button">Search</button> </form> </div> </div> </div> <div class="vector-sticky-header-context-bar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-sticky-header-toc" class="vector-dropdown mw-portlet mw-portlet-sticky-header-toc vector-sticky-header-toc vector-button-flush-left" > <input type="checkbox" id="vector-sticky-header-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-sticky-header-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-sticky-header-toc-label" for="vector-sticky-header-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-sticky-header-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div class="vector-sticky-header-context-bar-primary" aria-hidden="true" ><span class="mw-page-title-main">SGPIO</span></div> </div> </div> <div class="vector-sticky-header-end" aria-hidden="true"> <div class="vector-sticky-header-icons"> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-talk-sticky-header" tabindex="-1" data-event-name="talk-sticky-header"><span class="vector-icon mw-ui-icon-speechBubbles mw-ui-icon-wikimedia-speechBubbles"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-subject-sticky-header" tabindex="-1" data-event-name="subject-sticky-header"><span class="vector-icon mw-ui-icon-article mw-ui-icon-wikimedia-article"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-history-sticky-header" tabindex="-1" data-event-name="history-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-history mw-ui-icon-wikimedia-wikimedia-history"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only mw-watchlink" id="ca-watchstar-sticky-header" tabindex="-1" data-event-name="watch-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-star mw-ui-icon-wikimedia-wikimedia-star"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-edit-sticky-header" tabindex="-1" data-event-name="wikitext-edit-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-wikiText mw-ui-icon-wikimedia-wikimedia-wikiText"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-ve-edit-sticky-header" tabindex="-1" data-event-name="ve-edit-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-edit mw-ui-icon-wikimedia-wikimedia-edit"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-viewsource-sticky-header" tabindex="-1" data-event-name="ve-edit-protected-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-editLock mw-ui-icon-wikimedia-wikimedia-editLock"></span> <span></span> </a> </div> <div class="vector-sticky-header-buttons"> <button class="cdx-button cdx-button--weight-quiet mw-interlanguage-selector" id="p-lang-btn-sticky-header" tabindex="-1" data-event-name="ui.dropdown-p-lang-btn-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-language mw-ui-icon-wikimedia-wikimedia-language"></span> <span>2 languages</span> </button> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive" id="ca-addsection-sticky-header" tabindex="-1" data-event-name="addsection-sticky-header"><span class="vector-icon mw-ui-icon-speechBubbleAdd-progressive mw-ui-icon-wikimedia-speechBubbleAdd-progressive"></span> <span>Add topic</span> </a> </div> <div class="vector-sticky-header-icon-end"> <div class="vector-user-links"> </div> </div> </div> </div> </div> <div class="vector-settings" id="p-dock-bottom"> <ul></ul> </div><script>(RLQ=window.RLQ||[]).push(function(){mw.config.set({"wgHostname":"mw-web.codfw.main-5d75d7759c-57c2x","wgBackendResponseTime":115,"wgPageParseReport":{"limitreport":{"cputime":"0.121","walltime":"0.162","ppvisitednodes":{"value":845,"limit":1000000},"postexpandincludesize":{"value":11903,"limit":2097152},"templateargumentsize":{"value":2098,"limit":2097152},"expansiondepth":{"value":12,"limit":100},"expensivefunctioncount":{"value":4,"limit":500},"unstrip-depth":{"value":0,"limit":20},"unstrip-size":{"value":1631,"limit":5000000},"entityaccesscount":{"value":0,"limit":400},"timingprofile":["100.00% 129.081 1 -total"," 49.63% 64.062 1 Template:Cleanup_reorganize"," 38.97% 50.298 1 Template:Ambox"," 36.59% 47.229 3 Template:Citation_needed"," 29.14% 37.620 3 Template:Fix"," 12.39% 15.992 8 Template:Category_handler"," 10.26% 13.238 4 Template:Delink"," 9.71% 12.532 1 Template:Clarify"," 7.89% 10.189 1 Template:Fix-span"," 4.33% 5.590 4 Template:Fix/category"]},"scribunto":{"limitreport-timeusage":{"value":"0.058","limit":"10.000"},"limitreport-memusage":{"value":2071336,"limit":52428800}},"cachereport":{"origin":"mw-web.codfw.main-84749c7844-nqst7","timestamp":"20250210045726","ttl":2592000,"transientcontent":false}}});});</script> <script type="application/ld+json">{"@context":"https:\/\/schema.org","@type":"Article","name":"SGPIO","url":"https:\/\/en.wikipedia.org\/wiki\/SGPIO","sameAs":"http:\/\/www.wikidata.org\/entity\/Q17152376","mainEntity":"http:\/\/www.wikidata.org\/entity\/Q17152376","author":{"@type":"Organization","name":"Contributors to Wikimedia projects"},"publisher":{"@type":"Organization","name":"Wikimedia Foundation, Inc.","logo":{"@type":"ImageObject","url":"https:\/\/www.wikimedia.org\/static\/images\/wmf-hor-googpub.png"}},"datePublished":"2006-06-08T08:37:19Z","dateModified":"2024-05-23T23:33:00Z","headline":"low-level computer bus used to communicate disk status information from a host controller to a backplane"}</script> </body> </html>