Putting wasted clock cycles to use: Enhancing fortuitous cell-aware fault detection with scan shift capture
Putting wasted clock cycles to use: Enhancing fortuitous cell-aware fault detection with scan shift capture
复制标题
利用浪费的时钟周期：通过扫描移位捕获增强偶然单元感知故障检测
DOI：
10.1109/test.2016.7805828
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
Jennifer Dworak
中科院分区：
文献类型：
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作者：
Fanchen Zhang;D. Hwong;Yi Sun;Allison Garcia;Soha Alhelaly;G. Shofner;L. Winemberg;Jennifer Dworak
概率的方法可以检测未靶向的缺陷，例如N-DECT和标准LBIST（逻辑内置测试），通常需要使用很长的测试集以实现良好的覆盖范围。但是，试图明确建模新型缺陷类型（例如细胞感知故障），以便可以确定性地检测到的更多针对性的方法也可能导致不可接受的长期测试集。通常，当将测试应用于包含扫描链的电路时，仅一旦整个模式被移入并应用了所需的确定性模式，才会捕获测试结果。介入循环仅作为开销。之所以这样做，是因为在扫描移动过程中捕获电路扫描触发器中的数据会破坏所转移的模式。但是，如果将数据捕获在MISR中的阴影拖上捕获，则可以使用这些移位周期来获得额外的故障覆盖范围。在本文中，我们研究了仅使用生成的测试模式来检测卡住的故障的测试模式。我们还调查减少所需的影子拖鞋的数量。我们的结果表明，即使仅应用了卡住的测试集，也可以实现高细胞感知的覆盖范围 - 在某些情况下，与专用的细胞感知测试集获得的覆盖率相当。
Probabilistic approaches to the detection of untargeted defects, such as n-detect and standard LBIST (logic built-in-self-test), generally suffer from the need to apply very long test sets to achieve good coverage. However, more targeted approaches that attempt to explicitly model new types of defects, such as cell-aware faults, so that they can be deterministically detected may also lead to unacceptably long test sets. Generally, when tests are applied to circuits that contain scan chains, test results are only captured once the entire pattern has been shifted in and the desired deterministic pattern has been applied. Intervening shift cycles serve only as overhead. This is done because capturing data in the circuit's scan flip-flops during scan shift would destroy the pattern being shifted in. However, if data is captured in shadow flops in a MISR instead, those shift cycles could be used to obtain additional fault coverage. In this paper, we investigate the ability of the intervening shift cycles to achieve high static cell-aware fault coverage using only the test patterns generated to detect stuck-at faults. We also investigate reducing the number of shadow flops required. Our results show that high cell-aware coverage is achievable even when only a stuck-at test set is applied - in some cases equal to the coverage obtained by a dedicated cell-aware test set.