SherbyNet - /page/wikibook/entry.mu

Micron Document

<!DOCTYPE html>

<title>Clock generator</title>

</head>

<span id="openzim-page-title" class="mw-page-title-main"><span class="mw-page-title-main">Clock generator</span></span>

</h1>

</header>

/* start https://en.wikipedia.org/ */

.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}}

/* end https://en.wikipedia.org/ */

</style>

<p>A <b>clock generator</b> is an <a href="Electronic_oscillator" title="Electronic oscillator">electronic oscillator</a> that produces a <a href="Clock_signal" title="Clock signal">clock signal</a> for use in synchronizing a circuit's operation. The output <a href="Clock_signal" title="Clock signal">clock signal</a> can range from a simple symmetrical <a href="Square_wave_(waveform)" title="Square wave (waveform)">square wave</a> to more complex arrangements. The basic parts that all clock generators share are a resonant circuit and an amplifier.

</p><p>The resonant circuit is usually a <a href="Quartz" title="Quartz">quartz</a> <a href="Piezoelectricity" title="Piezoelectricity">piezo-electric</a> <a href="Crystal_oscillator" title="Crystal oscillator">oscillator</a>, although simpler <a href="Tank_circuit" class="mw-redirect" title="Tank circuit">tank circuits</a> and even <a href="RC_circuit" title="RC circuit">RC circuits</a> may be used.

</p><p>The <a href="Amplifier" title="Amplifier">amplifier</a> circuit usually inverts the signal from the oscillator and feeds a portion back into the oscillator to maintain oscillation.

</p><p>The generator may have additional sections to modify the basic signal. The <a href="Intel_8088" title="Intel 8088">8088</a> for example, used a 2/3 <a href="Duty_cycle" title="Duty cycle">duty cycle</a> clock, which required the clock generator to incorporate logic to convert the 50/50 duty cycle which is typical of raw oscillators.

</p><p>Other such optional sections include <a href="Frequency_divider" title="Frequency divider">frequency divider</a> or <a href="Clock_multiplier" class="mw-redirect" title="Clock multiplier">clock multiplier</a> sections. Programmable clock generators allow the number used in the divider or multiplier to be changed, allowing any of a wide variety of output frequencies to be selected without modifying the hardware.

</p><p>The clock generator in a <a href="Motherboard" title="Motherboard">motherboard</a> is often changed by computer enthusiasts to control the speed of a <a href="Central_processing_unit" title="Central processing unit">CPU</a>, <a href="Front-side_bus" title="Front-side bus">FSB</a>, <a href="Graphics_processing_unit" title="Graphics processing unit">GPU</a> or <a href="Random-access_memory" title="Random-access memory">RAM</a>. Typically the programmable clock generator is set by the <a href="BIOS" title="BIOS">BIOS</a> at boot time to the selected value; although some systems have <a href="Dynamic_frequency_scaling" title="Dynamic frequency scaling">dynamic frequency scaling</a>, which frequently re-programs the clock generator.

</p>

<div class="mw-heading mw-heading2"><h2 id="Timing-signal_generators_(TSGs)">Timing-signal generators (TSGs)</h2></div>

<p>TSGs are <a href="Clock" title="Clock">clocks</a> that are used throughout service-provider networks, frequently as the building integrated timing supply (BITS) for a central office.

</p><p><a href="Digital_switching_system" class="mw-redirect" title="Digital switching system">Digital switching systems</a> and some transmission systems (e.g., SONET, RREX, LUBI) depend on reliable, high-quality synchronization (or timing) to prevent impairments. To provide this, most service providers use interoffice synchronization distribution networks based on the stratum hierarchy and implement the BITS concept to meet intraoffice synchronization needs.

</p><p>A TSG is clock equipment that accepts input timing reference signals and generates output timing reference signals. The input reference signals can be either DS1 or composite-clock (CC) signals, and the output signals can also be DS1 or CC signals (or both). A TSG is made up of the six components listed below:

</p>

<ol><li>An input timing interface that accepts DS1 or CC input signals</li>

<li>A timing-generation component that creates the timing signals used by the output timing-distribution component</li>

<li>An output timing distribution component that utilizes the timing signals from the timing-generation component to create multiple DS1 and CC output signals</li>

<li>A performance-monitoring (PM) component that monitors the timing characteristics of the input signals</li>

<li>An alarm interface that connects to the central-office (CO) alarm-monitoring system</li>

<li>An operations interface for local crafts person use and communications with remote operations systems</li></ol>

<ul><li><a href="Pulse_generator" title="Pulse generator">Pulse generator</a> – Electronic circuit or test equipment</li></ul>

<div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2></div>

<ul><li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20120112062334/http://www.nuvoton.com/hq/enu/ProductAndSales/ProductLines/ComputerIC/Pages/default.aspx">Datasheets of clock generators from Nuvoton / Winbond</a></li>

<li><a rel="nofollow" class="external text" href="http://www.idt.com/?catID=18691971">Datasheets of clock generators from IDT</a></li>

<li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20111124032556/http://www.realtek.com/products/productsView.aspx?Langid=1&PNid=8&PFid=16&Level=3&Conn=2">Datasheets of clock generators from Realtek</a></li>

<li><a rel="nofollow" class="external text" href="http://www.pericom.com/products/clock-and-timing-ics/clock-generators/">Datasheets of clock generators from Pericom Semiconductor</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20160719072218/https://www.pericom.com/products/clock-and-timing-ics/clock-generators/">Archived</a> 2016-07-19 at the <a href="Wayback_Machine" title="Wayback Machine">Wayback Machine</a></li></ul></div><div><div class="zim-footer">

This article is issued from <a class="external text" title="Last edited on 2025-03-06" href="https://en.wikipedia.org/wiki/?title=Clock_generator&oldid=1279161666">Wikipedia</a>. The text is available under <a class="external text" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en">Creative Commons Attribution-Share Alike 4.0</a> unless otherwise noted. Additional terms may apply for the media files.

</div>

</div></div>

</div>

</main>

</div>

</body></html>