As one of the most promising candidates for nonvolatile memory, phase change memory (PCM) technology has shown great performance advantages in market applications. However, the conventional test methods have not kept pace with the development. In this article, focusing on specific PCM faults and others, an enhanced march test algorithm is proposed to achieve 100% fault coverage and diagnostic accuracy in bit-oriented PCM. The proposed algorithm is then converted for word-oriented PCM and equipped with capability to detect potential intraword impact. In addition, to reduce the dependence of memory test on the external devices, a novel storage scheme of fault information is devised. Through the modeling and simulation in C-language, this method is proven to improve the probability of finding the predefined fault-free regions in the tested memory. Finally, combining the enhanced test algorithm and the novel storage scheme, a built-in self-test (BIST) march test scheme is proposed, realizing the independent test of PCM without any external equipment. By comparison, the result of experiments, which are performed with C-language, proves that the proposed test scheme not only increases the fault coverage and diagnostic accuracy, but also reduces the additional area overhead.

中文翻译：

---

具有增强测试方案和无故障区域查找算法的基于 BIST 的 PCM 故障诊断

作为非易失性存储器最有前途的候选者之一，相变存储器（PCM）技术在市场应用中显示出巨大的性能优势。然而，传统的测试方法并没有跟上发展的步伐。在本文中，针对特定 PCM 故障等，提出了一种增强的行进测试算法，以实现面向比特的 PCM 中 100% 的故障覆盖率和诊断准确性。然后将所提出的算法转换为面向词的 PCM，并具备检测潜在词内影响的能力。此外，为了减少内存测试对外部设备的依赖性，设计了一种新颖的故障信息存储方案。通过C语言建模和仿真，证明该方法提高了在测试内存中找到预定义无故障区域的概率。最后，结合增强的测试算法和新颖的存储方案，提出了一种内置自测试（BIST）行进测试方案，实现了PCM的独立测试，无需任何外部设备。通过比较，用C语言进行的实验结果证明，所提出的测试方案不仅提高了故障覆盖率和诊断精度，而且减少了额外的面积开销。