Conference Paper

Hierarchy-aware and area-efficient test infrastructure design for core-based system chips.

DOI: 10.1145/1131561 Conference: Proceedings of the Conference on Design, Automation and Test in Europe, DATE 2006, Munich, Germany, March 6-10, 2006
Source: DBLP


Multiple levels of design hierarchy are common in current- generation system-on-chip (SOC) integrated circuits. However, most prior work on test access mechanism (TAM) optimization and test scheduling is based on a flattened design hierarchy. We investigate hierarchy-aware test infrastructure design, wherein wrapper/TAM optimization and test scheduling are carried out for hierarchical SOCs for two practical design scenarios. In the first scenario, the wrapper and TAM implementation for the em- bedded child cores in hierarchical (parent) cores are delivered in a hard form by the core provider. In the second scenario, the wrapper and TAM architecture of the child cores embedded in the parent cores are implemented by the system integrator. Ex- perimental results are presented for the ITC'02 SOC test bench- marks. test schedules designed for non-hierarchical SOCs are typically not valid for SOCs with hierarchical cores. The hierarchy im- poses a number of constraints on the manner in which tests must be applied to parent cores and their embedded child cores (8); hierarchy-oblivious methods make no attempt to satisfy these constraints. In this paper, we describe a test infrastructure design approach for hierarchical SOCs; our approach is based on hierarchy-aware wrapper design for parent cores, TAM optimization techniques for the SOC and the parent cores, and chip-level test scheduling. We consider two different test infrastructure design scenarios. In Scenario 1, we assume that the wrappers and TAM architectures for the child cores are given and fixed (hard), while the wrappers and TAM architectures for the parent cores are to be determined by our approach (soft). In Scenario 2, the wrapper and TAM for both parent and child cores are assumed to be soft. The sequel of this paper is organized as follows. In Section 2, we review the limitations of prior work. In Section 3, we discuss various DfT techniques that can be used to reduce test length. Section 4 describes our approach for Scenario 1, while Section 5 addresses Scenario 2. We derive lower bounds on the test time in Section 6. In Section 7, we present test application times and lower bounds for the ITC'02 SOC test benchmarks (5). Finally, Section 8 concludes the paper.

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Available from: Erik Jan Marinissen
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    • "In our test data volume formulations in modular SOC testing, we also include the hierarchical cores; the reader may refer to [6] and [24] for details regarding the test of hierarchical cores. When a parent core is being tested, its wrapper is configured in InTest mode while the wrapper of the child cores are all configured into ExTest mode. "
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    ABSTRACT: Modular SOC testing offers numerous benefits that include test power reduction, ease of timing closure, and test re-use among many others. While all these benefits have been emphasized by researchers, the test time and data volume comparisons has been mostly constrained within the context of modular SOC testing only, by comparing the impact of various different modular SOC testing techniques to each other. In this paper, we provide a theoretical test data volume analysis that compares the monolithic test of a flattened design with the same design tested in a modular manner; we present numerous experiments that gauge the magnitude of this benefit. We show that the test data volume reduction delivered by modular SOC testing directly hinges on the test pattern count variation across different modules, and that this reduction can exceed 99% in the SOC benchmarks that we have experimented with.
    Full-text · Conference Paper · Apr 2008
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    ABSTRACT: This paper presents a new modular SOC test architecture that uses an improved single TAM daisy-chain for scan test access to embedded modules. The architecture by definition guarantees that the total SOC test time is close to the lower bound. To make third party IP cores to fit the architecture, IP with test infrastructure 'on-demand' is introduced. An area-efficient bypass implementation for our IEEE std. 1500 compliant test wrapper is presented and results from a single TAM daisy-chain on silicon are shown
    No preview · Conference Paper · Dec 2005
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