IBIS 模型在做類(lèi)似板級(jí)SI 仿真得到廣泛應(yīng)用。在做仿真的初級(jí)階段，經(jīng)常對(duì)于ibis 模型的描述有些疑問(wèn)，只知道把模型拿來(lái)轉(zhuǎn)換為軟件所支持的格式或者直接使用，而對(duì)于IBIS 模型里面的數(shù)據(jù)描述什么都不算很明白，因此下面的一些描述是整理出來(lái)的一點(diǎn)對(duì)于ibis 的基本理解。在此引用很多presention來(lái)描述ibis 內(nèi)容（有的照抄過(guò)來(lái)，阿彌陀佛，不要說(shuō)抄襲，只不過(guò)習(xí)慣信手拈來(lái)說(shuō)明一些問(wèn)題），僅此向如muranyi 等ibis 先驅(qū)者致敬。本文難免有些錯(cuò)誤或者考慮不周，隨時(shí)歡迎進(jìn)行討論并對(duì)其進(jìn)行修改！IBIS 模型的一些基本概念I(lǐng)BIS 這個(gè)詞是Input/Output buffer information specification 的縮寫(xiě)。本文是基于IBIS ver3.2 所撰寫(xiě)出來(lái)（www.eigroup.org/IBIS/可下載到各種版本spec）,ver4.2增加很多新特性，由于在目前設(shè)計(jì)中沒(méi)用到不予以討論。。。在業(yè)界經(jīng)常會(huì)把spice 模型描述為transistor model 是因?yàn)樗枋龊芏嚯娐芳?xì)節(jié)問(wèn)題。而把ibis 模型描述為behavioral model 是因?yàn)樗⒉幌髎pice 模型那樣描述電路的構(gòu)成，IBIS 模型描述的只不過(guò)是電路的一種外在表現(xiàn)，象個(gè)黑匣子一樣，輸入什么然后就得到輸出結(jié)果，而不需要了解里面驅(qū)動(dòng)或者接收的電路構(gòu)成。因此有所謂的garbage in, garbage out，ibis 模型的仿真精度依賴于模型的準(zhǔn)確度以及考慮的worse case，因此無(wú)論你的模型如何精確而考慮的worse case 不周全或者你考慮的worse case 如何周全而模型不精確，都是得不到較好的仿真精度。
上傳時(shí)間： 2013-10-16
上傳用戶：zhouli
16.6 版本出來(lái)將近半年了，一直想和大家分享一下OrCAD 在16.6 上面的表現(xiàn)。今天終于可以坐下來(lái)說(shuō)一下了。今天要討論的是Capture 非常有用的一個(gè)更新，原理圖與SI 分析的完美結(jié)合結(jié)合。
標(biāo)簽： OrCAD_Capture_CIS Cadence 16.6
上傳時(shí)間： 2013-11-14
上傳用戶：15070202241
PCB methodologies originated in the United States.Units of measurement are therefore typically in Imperial units, not SI/metric units.
標(biāo)簽： 布局技術(shù)
上傳時(shí)間： 2013-11-21
上傳用戶：Tracey
印刷電路板（PCB）設(shè)計(jì)解決方案市場(chǎng)和技術(shù)領(lǐng)軍企業(yè)Mentor Graphics（Mentor Graphics）宣布推出HyperLynx® PI（電源完整性）產(chǎn)品，滿足業(yè)內(nèi)高端設(shè)計(jì)者對(duì)于高性能電子產(chǎn)品的需求。HyperLynx PI產(chǎn)品不僅提供簡(jiǎn)單易學(xué)、操作便捷，又精確的分析，讓團(tuán)隊(duì)成員能夠設(shè)計(jì)可行的電源供應(yīng)系統(tǒng)；同時(shí)縮短設(shè)計(jì)周期，減少原型生成、重復(fù)制造，也相應(yīng)降低產(chǎn)品成本。隨著當(dāng)今各種高性能/高密度/高腳數(shù)集成電路的出現(xiàn)，傳輸系統(tǒng)的設(shè)計(jì)越來(lái)越需要工程師與布局設(shè)計(jì)人員的緊密合作，以確保能夠透過(guò)眾多PCB電源與接地結(jié)構(gòu)，為IC提供純凈、充足的電力。配合先前推出的HyperLynx信號(hào)完整性（SI）分析和確認(rèn)產(chǎn)品組件，Mentor Graphics目前為用戶提供的高性能電子產(chǎn)品設(shè)計(jì)堪稱業(yè)內(nèi)最全面最具實(shí)用性的解決方案。“我們擁有非常高端的用戶，受到高性能集成電路多重電壓等級(jí)和電源要求的驅(qū)使，需要在一個(gè)單一的PCB中設(shè)計(jì)30余套電力供應(yīng)結(jié)構(gòu)。”Mentor Graphics副總裁兼系統(tǒng)設(shè)計(jì)事業(yè)部總經(jīng)理Henry Potts表示。“上述結(jié)構(gòu)的設(shè)計(jì)需要快速而準(zhǔn) 確的直流壓降(DC Power Drop)和電源雜訊(Power Noise)分析。擁有了精確的分析信息，電源與接地層結(jié)構(gòu)和解藕電容數(shù)(de-coupling capacitor number)以及位置都可以決定，得以避免過(guò)于保守的設(shè)計(jì)和高昂的產(chǎn)品成本。”
上傳時(shí)間： 2013-10-31
上傳用戶：ljd123456
現(xiàn)代的電子設(shè)計(jì)和芯片制造技術(shù)正在飛速發(fā)展，電子產(chǎn)品的復(fù)雜度、時(shí)鐘和總線頻率等等都呈快速上升趨勢(shì)，但系統(tǒng)的電壓卻不斷在減小，所有的這一切加上產(chǎn)品投放市場(chǎng)的時(shí)間要求給設(shè)計(jì)師帶來(lái)了前所未有的巨大壓力。要想保證產(chǎn)品的一次性成功就必須能預(yù)見(jiàn)設(shè)計(jì)中可能出現(xiàn)的各種問(wèn)題，并及時(shí)給出合理的解決方案，對(duì)于高速的數(shù)字電路來(lái)說(shuō)，最令人頭大的莫過(guò)于如何確保瞬時(shí)跳變的數(shù)字信號(hào)通過(guò)較長(zhǎng)的一段傳輸線，還能完整地被接收，并保證良好的電磁兼容性，這就是目前頗受關(guān)注的信號(hào)完整性（SI）問(wèn)題。本章就是圍繞信號(hào)完整性的問(wèn)題，讓大家對(duì)高速電路有個(gè)基本的認(rèn)識(shí)，并介紹一些相關(guān)的基本概念。 第一章 高速數(shù)字電路概述.....................................................................................51.1 何為高速電路...............................................................................................51.2 高速帶來(lái)的問(wèn)題及設(shè)計(jì)流程剖析...............................................................61.3 相關(guān)的一些基本概念...................................................................................8第二章 傳輸線理論...............................................................................................122.1 分布式系統(tǒng)和集總電路.............................................................................122.2 傳輸線的RLCG 模型和電報(bào)方程...............................................................132.3 傳輸線的特征阻抗.....................................................................................142.3.1 特性阻抗的本質(zhì).................................................................................142.3.2 特征阻抗相關(guān)計(jì)算.............................................................................152.3.3 特性阻抗對(duì)信號(hào)完整性的影響.........................................................172.4 傳輸線電報(bào)方程及推導(dǎo).............................................................................182.5 趨膚效應(yīng)和集束效應(yīng).................................................................................232.6 信號(hào)的反射.................................................................................................252.6.1 反射機(jī)理和電報(bào)方程.........................................................................252.6.2 反射導(dǎo)致信號(hào)的失真問(wèn)題.................................................................302.6.2.1 過(guò)沖和下沖.....................................................................................302.6.2.2 振蕩：.............................................................................................312.6.3 反射的抑制和匹配.............................................................................342.6.3.1 串行匹配.........................................................................................352.6.3.1 并行匹配.........................................................................................362.6.3.3 差分線的匹配.................................................................................392.6.3.4 多負(fù)載的匹配.................................................................................41第三章 串?dāng)_的分析...............................................................................................423.1 串?dāng)_的基本概念.........................................................................................423.2 前向串?dāng)_和后向串?dāng)_.................................................................................433.3 后向串?dāng)_的反射.........................................................................................463.4 后向串?dāng)_的飽和.........................................................................................463.5 共模和差模電流對(duì)串?dāng)_的影響.................................................................483.6 連接器的串?dāng)_問(wèn)題.....................................................................................513.7 串?dāng)_的具體計(jì)算.........................................................................................543.8 避免串?dāng)_的措施.........................................................................................57第四章 EMI 抑制....................................................................................................604.1 EMI/EMC 的基本概念..................................................................................604.2 EMI 的產(chǎn)生..................................................................................................614.2.1 電壓瞬變.............................................................................................614.2.2 信號(hào)的回流.........................................................................................624.2.3 共模和差摸EMI ..................................................................................634.3 EMI 的控制..................................................................................................654.3.1 屏蔽.....................................................................................................654.3.1.1 電場(chǎng)屏蔽.........................................................................................654.3.1.2 磁場(chǎng)屏蔽.........................................................................................674.3.1.3 電磁場(chǎng)屏蔽.....................................................................................674.3.1.4 電磁屏蔽體和屏蔽效率.................................................................684.3.2 濾波.....................................................................................................714.3.2.1 去耦電容.........................................................................................714.3.2.3 磁性元件.........................................................................................734.3.3 接地.....................................................................................................744.4 PCB 設(shè)計(jì)中的EMI.......................................................................................754.4.1 傳輸線RLC 參數(shù)和EMI ........................................................................764.4.2 疊層設(shè)計(jì)抑制EMI ..............................................................................774.4.3 電容和接地過(guò)孔對(duì)回流的作用.........................................................784.4.4 布局和走線規(guī)則.................................................................................79第五章 電源完整性理論基礎(chǔ)...............................................................................825.1 電源噪聲的起因及危害.............................................................................825.2 電源阻抗設(shè)計(jì).............................................................................................855.3 同步開(kāi)關(guān)噪聲分析.....................................................................................875.3.1 芯片內(nèi)部開(kāi)關(guān)噪聲.............................................................................885.3.2 芯片外部開(kāi)關(guān)噪聲.............................................................................895.3.3 等效電感衡量SSN ..............................................................................905.4 旁路電容的特性和應(yīng)用.............................................................................925.4.1 電容的頻率特性.................................................................................935.4.3 電容的介質(zhì)和封裝影響.....................................................................955.4.3 電容并聯(lián)特性及反諧振.....................................................................955.4.4 如何選擇電容.....................................................................................975.4.5 電容的擺放及Layout ........................................................................99第六章 系統(tǒng)時(shí)序.................................................................................................1006.1 普通時(shí)序系統(tǒng)...........................................................................................1006.1.1 時(shí)序參數(shù)的確定...............................................................................1016.1.2 時(shí)序約束條件...................................................................................1066.2 源同步時(shí)序系統(tǒng).......................................................................................1086.2.1 源同步系統(tǒng)的基本結(jié)構(gòu)...................................................................1096.2.2 源同步時(shí)序要求...............................................................................110第七章 IBIS 模型................................................................................................1137.1 IBIS 模型的由來(lái)...................................................................................... 1137.2 IBIS 與SPICE 的比較.............................................................................. 1137.3 IBIS 模型的構(gòu)成...................................................................................... 1157.4 建立IBIS 模型......................................................................................... 1187.4 使用IBIS 模型......................................................................................... 1197.5 IBIS 相關(guān)工具及鏈接..............................................................................120第八章 高速設(shè)計(jì)理論在實(shí)際中的運(yùn)用.............................................................1228.1 疊層設(shè)計(jì)方案...........................................................................................1228.2 過(guò)孔對(duì)信號(hào)傳輸?shù)挠绊?..........................................................................1278.3 一般布局規(guī)則...........................................................................................1298.4 接地技術(shù)...................................................................................................1308.5 PCB 走線策略............................................................................................134
標(biāo)簽： 信號(hào)完整性
上傳時(shí)間： 2013-11-01
上傳用戶：xitai
第一部分 信號(hào)完整性知識(shí)基礎(chǔ).................................................................................5第一章 高速數(shù)字電路概述.....................................................................................51.1 何為高速電路...............................................................................................51.2 高速帶來(lái)的問(wèn)題及設(shè)計(jì)流程剖析...............................................................61.3 相關(guān)的一些基本概念...................................................................................8第二章 傳輸線理論...............................................................................................122.1 分布式系統(tǒng)和集總電路.............................................................................122.2 傳輸線的RLCG 模型和電報(bào)方程...............................................................132.3 傳輸線的特征阻抗.....................................................................................142.3.1 特性阻抗的本質(zhì).................................................................................142.3.2 特征阻抗相關(guān)計(jì)算.............................................................................152.3.3 特性阻抗對(duì)信號(hào)完整性的影響.........................................................172.4 傳輸線電報(bào)方程及推導(dǎo).............................................................................182.5 趨膚效應(yīng)和集束效應(yīng).................................................................................232.6 信號(hào)的反射.................................................................................................252.6.1 反射機(jī)理和電報(bào)方程.........................................................................252.6.2 反射導(dǎo)致信號(hào)的失真問(wèn)題.................................................................302.6.2.1 過(guò)沖和下沖.....................................................................................302.6.2.2 振蕩：.............................................................................................312.6.3 反射的抑制和匹配.............................................................................342.6.3.1 串行匹配.........................................................................................352.6.3.1 并行匹配.........................................................................................362.6.3.3 差分線的匹配.................................................................................392.6.3.4 多負(fù)載的匹配.................................................................................41第三章 串?dāng)_的分析...............................................................................................423.1 串?dāng)_的基本概念.........................................................................................423.2 前向串?dāng)_和后向串?dāng)_.................................................................................433.3 后向串?dāng)_的反射.........................................................................................463.4 后向串?dāng)_的飽和.........................................................................................463.5 共模和差模電流對(duì)串?dāng)_的影響.................................................................483.6 連接器的串?dāng)_問(wèn)題.....................................................................................513.7 串?dāng)_的具體計(jì)算.........................................................................................543.8 避免串?dāng)_的措施.........................................................................................57第四章 EMI 抑制....................................................................................................604.1 EMI/EMC 的基本概念..................................................................................604.2 EMI 的產(chǎn)生..................................................................................................614.2.1 電壓瞬變.............................................................................................614.2.2 信號(hào)的回流.........................................................................................624.2.3 共模和差摸EMI ..................................................................................634.3 EMI 的控制..................................................................................................654.3.1 屏蔽.....................................................................................................654.3.1.1 電場(chǎng)屏蔽.........................................................................................654.3.1.2 磁場(chǎng)屏蔽.........................................................................................674.3.1.3 電磁場(chǎng)屏蔽.....................................................................................674.3.1.4 電磁屏蔽體和屏蔽效率.................................................................684.3.2 濾波.....................................................................................................714.3.2.1 去耦電容.........................................................................................714.3.2.3 磁性元件.........................................................................................734.3.3 接地.....................................................................................................744.4 PCB 設(shè)計(jì)中的EMI.......................................................................................754.4.1 傳輸線RLC 參數(shù)和EMI ........................................................................764.4.2 疊層設(shè)計(jì)抑制EMI ..............................................................................774.4.3 電容和接地過(guò)孔對(duì)回流的作用.........................................................784.4.4 布局和走線規(guī)則.................................................................................79第五章 電源完整性理論基礎(chǔ)...............................................................................825.1 電源噪聲的起因及危害.............................................................................825.2 電源阻抗設(shè)計(jì).............................................................................................855.3 同步開(kāi)關(guān)噪聲分析.....................................................................................875.3.1 芯片內(nèi)部開(kāi)關(guān)噪聲.............................................................................885.3.2 芯片外部開(kāi)關(guān)噪聲.............................................................................895.3.3 等效電感衡量SSN ..............................................................................905.4 旁路電容的特性和應(yīng)用.............................................................................925.4.1 電容的頻率特性.................................................................................935.4.3 電容的介質(zhì)和封裝影響.....................................................................955.4.3 電容并聯(lián)特性及反諧振.....................................................................955.4.4 如何選擇電容.....................................................................................975.4.5 電容的擺放及Layout ........................................................................99第六章 系統(tǒng)時(shí)序.................................................................................................1006.1 普通時(shí)序系統(tǒng)...........................................................................................1006.1.1 時(shí)序參數(shù)的確定...............................................................................1016.1.2 時(shí)序約束條件...................................................................................1063.2 高速設(shè)計(jì)的問(wèn)題.......................................................................................2093.3 SPECCTRAQuest SI Expert 的組件.......................................................2103.3.1 SPECCTRAQuest Model Integrity .................................................2103.3.2 SPECCTRAQuest Floorplanner/Editor .........................................2153.3.3 Constraint Manager .......................................................................2163.3.4 SigXplorer Expert Topology Development Environment .......2233.3.5 SigNoise 仿真子系統(tǒng)......................................................................2253.3.6 EMControl .........................................................................................2303.3.7 SPECCTRA Expert 自動(dòng)布線器.......................................................2303.4 高速設(shè)計(jì)的大致流程...............................................................................2303.4.1 拓?fù)浣Y(jié)構(gòu)的探索...............................................................................2313.4.2 空間解決方案的探索.......................................................................2313.4.3 使用拓?fù)淠０弪?qū)動(dòng)設(shè)計(jì)...................................................................2313.4.4 時(shí)序驅(qū)動(dòng)布局...................................................................................2323.4.5 以約束條件驅(qū)動(dòng)設(shè)計(jì).......................................................................2323.4.6 設(shè)計(jì)后分析.......................................................................................233第四章 SPECCTRAQUEST SIGNAL EXPLORER 的進(jìn)階運(yùn)用..........................................2344.1 SPECCTRAQuest Signal Explorer 的功能包括：................................2344.2 圖形化的拓?fù)浣Y(jié)構(gòu)探索...........................................................................2344.3 全面的信號(hào)完整性(Signal Integrity)分析.......................................2344.4 完全兼容 IBIS 模型...............................................................................2344.5 PCB 設(shè)計(jì)前和設(shè)計(jì)的拓?fù)浣Y(jié)構(gòu)提取.......................................................2354.6 仿真設(shè)置顧問(wèn)...........................................................................................2354.7 改變?cè)O(shè)計(jì)的管理.......................................................................................2354.8 關(guān)鍵技術(shù)特點(diǎn)...........................................................................................2364.8.1 拓?fù)浣Y(jié)構(gòu)探索...................................................................................2364.8.2 SigWave 波形顯示器........................................................................2364.8.3 集成化的在線分析(Integration and In-process Analysis) .236第五章 部分特殊的運(yùn)用...............................................................................2375.1 Script 指令的使用..................................................................................2375.2 差分信號(hào)的仿真.......................................................................................2435.3 眼圖模式的使用.......................................................................................249第四部分：HYPERLYNX 仿真工具使用指南............................................................251第一章 使用LINESIM 進(jìn)行前仿真.......................................................................2511.1 用LineSim 進(jìn)行仿真工作的基本方法...................................................2511.2 處理信號(hào)完整性原理圖的具體問(wèn)題.......................................................2591.3 在LineSim 中如何對(duì)傳輸線進(jìn)行設(shè)置...................................................2601.4 在LineSim 中模擬IC 元件.....................................................................2631.5 在LineSim 中進(jìn)行串?dāng)_仿真...................................................................268第二章 使用BOARDSIM 進(jìn)行后仿真......................................................................2732.1 用BOARDSIM 進(jìn)行后仿真工作的基本方法...................................................2732.2 BoardSim 的進(jìn)一步介紹..........................................................................2922.3 BoardSim 中的串?dāng)_仿真..........................................................................309
標(biāo)簽： PCB 內(nèi)存 仿真技術(shù)
上傳時(shí)間： 2013-11-07
上傳用戶：aa7821634
基于量子流體動(dòng)力學(xué)模型，自主編制程序開(kāi)發(fā)了半導(dǎo)體器件仿真軟件。其中包括快速、準(zhǔn)確數(shù)值離散方法和準(zhǔn)確的物理模型。基于對(duì)同一個(gè)si雙極晶體管的模擬，與商用軟件有近似的仿真結(jié)果。表明量子流體動(dòng)力學(xué)模型具有可行性，同時(shí)也表明數(shù)值算法和物理模型的正確性。
標(biāo)簽： 量子 流體 動(dòng)力學(xué)模型 半導(dǎo)體器件
上傳時(shí)間： 2013-10-08
上傳用戶：fanxiaoqie
仿真1：首先把網(wǎng)絡(luò)溫度參數(shù)T固定在100，按工作規(guī)則共進(jìn)行1000次狀態(tài)更新,把這1000次狀態(tài)轉(zhuǎn)移中網(wǎng)絡(luò)中的各個(gè)狀態(tài)出現(xiàn)的次數(shù)Si（i＝1，2，…，16）記錄下來(lái) 按下式計(jì)算各個(gè)狀態(tài)出現(xiàn)的實(shí)際頻率： Pi=Si/∑i=1,NSi=Si/M 同時(shí)按照Bo1tzmann分布計(jì)算網(wǎng)絡(luò)各個(gè)狀態(tài)出現(xiàn)概率的理論值： Q（Ei）=（1/Z）exp（-Ei/T） 仿真2：實(shí)施降溫方案，重新計(jì)算 采用快速降溫方案：T（t）= T0/（1+t） T從1000降到0.01，按工作規(guī)則更新網(wǎng)絡(luò)狀態(tài) 當(dāng)T=0.01時(shí)結(jié)束降溫，再讓T保持在0.01進(jìn)行1000次狀態(tài)轉(zhuǎn)移，比較兩種概率
標(biāo)簽： 100 仿真 網(wǎng)絡(luò)溫度 參數(shù)
上傳時(shí)間： 2014-01-20
上傳用戶：獨(dú)孤求源
帶有SQL，如果沒(méi)有請(qǐng)安上，最初密碼可以在SQL代碼中找到，。既：用戶名和密碼都為：ming
標(biāo)簽： SQL
上傳時(shí)間： 2015-03-28
上傳用戶：Zxcvbnm
模擬退火算法 模擬退火算法(Simulated Annealing,簡(jiǎn)稱SA算法)是模擬加熱熔化的金屬的退火過(guò)程，來(lái)尋找全局最優(yōu)解的有效方法之一。 模擬退火的基本思想和步驟如下： 設(shè)S＝{s1,s2,…,sn}為所有可能的狀態(tài)所構(gòu)成的集合， f：S—R為非負(fù)代價(jià)函數(shù)，即優(yōu)化問(wèn)題抽象如下： 尋找s*∈S，使得f(s*)＝min f(si) 任意si∈S （1）給定一較高初始溫度T，隨機(jī)產(chǎn)生初始狀態(tài)S （2）按一定方式，對(duì)當(dāng)前狀態(tài)作隨機(jī)擾動(dòng)，產(chǎn)生一個(gè)新的狀態(tài)S’ S’＝S＋sign(η).δ 其中δ為給定的步長(zhǎng)， η為[－1,1]的隨機(jī)數(shù)
標(biāo)簽： Simulated Annealing 模擬退火算法 模擬
上傳時(shí)間： 2014-01-02
上傳用戶：gengxiaochao
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