Design and test for timing uncertainty in VLSI circuits.

由於特徵尺寸不斷縮小,集成電路在生產過程中的工藝偏差在運行環境中溫度和電壓等參數的波動以及在使用過程中的老化等效應越來越嚴重,導致芯片的時序行為出現很大的不確定性。多數情況下,芯片的關鍵路徑會不時出現時序錯誤。加入更多的時序餘量不是一種很好的解決方案,因為這種保守的設計方法會抵消工藝進步帶來的性能上的好處。這就為設計一個時序可靠的系統提出了極大的挑戰,其中的一些關鍵問題包括:(一)如何有效地分配有限的功率預算去優化那些正爆炸式增加的關鍵路徑的時序性能;(二)如何產生能夠捕捉準確的最壞情況時延的高品質測試向量;(三)為了能夠取得更好的功耗和性能上的平衡,我們將不得不允許芯片在使用過程中出現一些頻率很低的時序錯誤。隨之而來的問題是如何做到在線的檢錯和糾錯。 / 為了解決上述問題,我們首先發明了一種新的技術用於識別所謂的虛假路徑,該方法使我們能夠發現比傳統方法更多的虛假路徑。當將所提取的虛假路徑集成到靜態時序分析工具里以後,我們可以得到更為準確的時序分析結果,同時也能節省本來用於優化這些路徑的成本。接著,考慮到現有的延時自動向量生成(ATPG) 方法會產生功能模式下無法出現的測試向量,這種向量可能會造成測試過程中在被激活的路徑周圍出現過多(或過少)的電源噪聲(PSN) ,從而導致測試過度或者測試不足情況。為此,我們提出了一種新的偽功能ATPG工具。通過同時考慮功能約束以及電路的物理佈局信息,我們使用類似ATPG 的算法產生狀態跳變使其能最大化已激活的路徑周圍的PSN影響。最後,基於近似電路的原理,我們提出了一種新的在線原位校正技術,即InTimeFix,用於糾正時序錯誤。由於實現近似電路的綜合僅需要簡單的電路結構分析,因此該技術能夠很容易的擴展到大型電路設計上去。 / With technology scaling, integrated circuits (ICs) suffer from increasing process, voltage, and temperature (PVT) variations and aging effects. In most cases, these reliability threats manifest themselves as timing errors on speed-paths (i.e., critical or near-critical paths) of the circuit. Embedding a large design guard band to prevent timing errors to occur is not an attractive solution, since this conservative design methodology diminishes the benefit of technology scaling. This creates several challenges on build a reliable systems, and the key problems include (i) how to optimize circuit’s timing performance with limited power budget for explosively increased potential speed-paths; (ii) how to generate high quality delay test pattern to capture ICs’ accurate worst-case delay; (iii) to have better power and performance tradeoff, we have to accept some infrequent timing errors in circuit’s the usage phase. Therefore, the question is how to achieve online timing error resilience. / To address the above issues, we first develop a novel technique to identify so-called false paths, which facilitate us to find much more false paths than conventional methods. By integrating our identified false paths into static timing analysis tool, we are able to achieve more accurate timing information and also save the cost used to optimize false paths. Then, due to the fact that existing delay automated test pattern generation (ATPG) methods may generate test patterns that are functionally-unreachable, and such patterns may incur excessive (or limited) power supply noise (PSN) on sensitized paths in test mode, thus leading to over-testing or under-testing of the circuits, we propose a novel pseudo-functional ATPG tool. By taking both circuit layout information and functional constrains into account, we use ATPG like algorithm to justify transitions that pose the maximized functional PSN effects on sensitized critical paths. Finally, we propose a novel in-situ correction technique to mask timing errors, namely InTimeFix, by introducing redundant approximation circuit with more timing slack for speed-paths into the design. The synthesis of the approximation circuit relies on simple structural analysis of the original circuit, which is easily scalable to large IC designs. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Yuan, Feng. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 88-100). / Abstract also in Chinese. / Abstract --- p.i / Acknowledgement --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Challenges to Solve Timing Uncertainty Problem --- p.2 / Chapter 1.2 --- Contributions and Thesis Outline --- p.5 / Chapter 2 --- Background --- p.7 / Chapter 2.1 --- Sources of Timing Uncertainty --- p.7 / Chapter 2.1.1 --- Process Variation --- p.7 / Chapter 2.1.2 --- Runtime Environment Fluctuation --- p.9 / Chapter 2.1.3 --- Aging Effect --- p.10 / Chapter 2.2 --- Technical Flow to Solve Timing Uncertainty Problem --- p.10 / Chapter 2.3 --- False Path --- p.12 / Chapter 2.3.1 --- Path Sensitization Criteria --- p.12 / Chapter 2.3.2 --- False Path Aware Timing Analysis --- p.13 / Chapter 2.4 --- Manufacturing Testing --- p.14 / Chapter 2.4.1 --- Functional Testing vs. Structural Testing --- p.14 / Chapter 2.4.2 --- Scan-Based DfT --- p.15 / Chapter 2.4.3 --- Pseudo-Functional Testing --- p.17 / Chapter 2.5 --- Timing Error Tolerance --- p.19 / Chapter 2.5.1 --- Timing Error Detection --- p.19 / Chapter 2.5.2 --- Timing Error Recover --- p.20 / Chapter 3 --- Timing-Independent False Path Identification --- p.23 / Chapter 3.1 --- Introduction --- p.23 / Chapter 3.2 --- Preliminaries and Motivation --- p.26 / Chapter 3.2.1 --- Motivation --- p.27 / Chapter 3.3 --- False Path Examination Considering Illegal States --- p.28 / Chapter 3.3.1 --- Path Sensitization Criterion --- p.28 / Chapter 3.3.2 --- Path-Aware Illegal State Identification --- p.30 / Chapter 3.3.3 --- Proposed Examination Procedure --- p.31 / Chapter 3.4 --- False Path Identification --- p.32 / Chapter 3.4.1 --- Overall Flow --- p.34 / Chapter 3.4.2 --- Static Implication Learning --- p.35 / Chapter 3.4.3 --- Suspicious Node Extraction --- p.36 / Chapter 3.4.4 --- S-Frontier Propagation --- p.37 / Chapter 3.5 --- Experimental Results --- p.38 / Chapter 3.6 --- Conclusion and Future Work --- p.42 / Chapter 4 --- PSN Aware Pseudo-Functional Delay Testing --- p.43 / Chapter 4.1 --- Introduction --- p.43 / Chapter 4.2 --- Preliminaries and Motivation --- p.45 / Chapter 4.2.1 --- Motivation --- p.46 / Chapter 4.3 --- Proposed Methodology --- p.48 / Chapter 4.4 --- Maximizing PSN Effects under Functional Constraints --- p.50 / Chapter 4.4.1 --- Pseudo-Functional Relevant Transitions Generation --- p.51 / Chapter 4.5 --- Experimental Results --- p.59 / Chapter 4.5.1 --- Experimental Setup --- p.59 / Chapter 4.5.2 --- Results and Discussion --- p.60 / Chapter 4.6 --- Conclusion --- p.64 / Chapter 5 --- In-Situ Timing Error Masking in Logic Circuits --- p.65 / Chapter 5.1 --- Introduction --- p.65 / Chapter 5.2 --- Prior Work and Motivation --- p.67 / Chapter 5.3 --- In-Situ Timing Error Masking with Approximate Logic --- p.69 / Chapter 5.3.1 --- Equivalent Circuit Construction with Approximate Logic --- p.70 / Chapter 5.3.2 --- Timing Error Masking with Approximate Logic --- p.72 / Chapter 5.4 --- Cost-Efficient Synthesis for InTimeFix --- p.75 / Chapter 5.4.1 --- Overall Flow --- p.76 / Chapter 5.4.2 --- Prime Critical Segment Extraction --- p.77 / Chapter 5.4.3 --- Prime Critical Segment Merging --- p.79 / Chapter 5.5 --- Experimental Results --- p.81 / Chapter 5.5.1 --- Experimental Setup --- p.81 / Chapter 5.5.2 --- Results and Discussion --- p.82 / Chapter 5.6 --- Conclusion --- p.85 / Chapter 6 --- Conclusion and Future Work --- p.86 / Bibliography --- p.100

Identiferoai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_328778
Date January 2012
ContributorsYuan, Feng, Chinese University of Hong Kong Graduate School. Division of Computer Science and Engineering.
Source SetsThe Chinese University of Hong Kong
LanguageEnglish, Chinese
Detected LanguageEnglish
TypeText, bibliography
Formatelectronic resource, electronic resource, remote, 1 online resource (xi, 100 leaves) : ill. (some col.)
RightsUse of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

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