Modeling, verification and pattern generation for reconfigurable scan networks
Modeling, verification and pattern generation for reconfigurable scan networks
复制标题
可重构扫描网络的建模、验证和模式生成
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
H. Wunderlich
中科院分区：
文献类型：
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作者：
R. Baranowski;M. Kochte;H. Wunderlich
可重新配置的扫描架构允许灵活集成和有效访问SoC中的基础设施，例如用于测试、诊断、修复或调试。这种扫描网络通常是分层的，并且具有复杂的结构和功能依赖性。例如，IEEE P1687提案（称为IJTAG）允许将多路复用扫描网络与任意内部控制信号集成。基于静态结构分析和功能仿真的扫描验证的常见方法不足以确保这些类型的架构的正确操作。层次结构和灵活性可能导致访问单个元素的配置要求复杂甚至矛盾。因此，顺序逻辑调整是强制性的，既要验证扫描网络的有效性，又要生成所需的访问序列。这项工作提出了一种形式化的方法，用于验证可重构扫描架构，以及图案重定向，即所需的扫描数据的生成。该方法是基于结构和功能依赖的形式化模型。网络验证和模式重定向被映射到一个布尔可满足性问题，这使得使用高效的SAT求解器来彻底探索有效扫描配置的搜索空间。
Reconfigurable scan architectures allow flexible integration and efficient access to infrastructure in SoCs, e.g. for test, diagnosis, repair or debug. Such scan networks are often hierarchical and have complex structural and functional dependencies. For instance, the IEEE P1687 proposal, known as IJTAG, allows integration of multiplexed scan networks with arbitrary internal control signals. Common approaches for scan verification based on static structural analysis and functional simulation are not sufficient to ensure correct operation of these types of architectures. Hierarchy and flexibility may result in complex or even contradicting configuration requirements to access single elements. Sequential logic justification is therefore mandatory both to verify the validity of a scan network, and to generate the required access sequences. This work presents a formal method for verification of reconfigurable scan architectures, as well as pattern retargeting, i.e. generation of required scan-in data. The method is based on a formal model of structural and functional dependencies. Network verification and pattern retargeting is mapped to a Boolean satisfiability problem, which enables the use of efficient SAT solvers to exhaustively explore the search space of valid scan configurations.