基于BIST的编译码器IP核测试

介绍了用于IP核测试的内建自测试方法（BIST）和面向测试的IP核设计方法,指出基于IP核的系统芯片（SOC）的测试、验证以及相关性测试具有较大难度,传统的测试和验证方法均难以满足。以编译码器IP核为例,说明了基于BIST的编译码器IP核测试的基本实现原理和具体实现过程,通过加入测试外壳实现了对IP核的访问、隔离和控制,提高了IP核的可测性。     

一种改进的层次化SOCs并行测试封装扫描单元

 测试封装是实现SOC内部IP核可测性和可控性的关键,而扫描单元是测试封装最重要的组成部分.然而传统的测试封装扫描单元在应用于层次化SOCs测试时存在很多缺点,无法保证内部IP核的完全并行测试,并且在测试的安全性,功耗等方面表现出很大问题.本文提出一种改进的层次化SOCs测试封装扫描单元结构,能够有效解决上述问题,该结构的主要思想是对现有的扫描单元进行改进,实现并行测试的同时,通过在适当的位置增加一个传输门,阻止无序的数据在非测试时段进入IP核,使得IP核处于休眠状态,保证了测试的安全性,实现了测试时的低功耗.最后将这种方法应用在一个工业上的层次化SOCs,实验分析表明,改进的测试封装扫描单元比现有扫描单元在增加较小硬件开销的前提下,在并行测试、低功耗、测试安全性和测试覆盖率方面有着明显的优势.     

SOC基于LFSR的混合模式测试

随着集成电路深亚微米制造技术和设计技术迅速发展,系统芯片(SOC)作为一种解决方案得到了越来越广泛的应用。SOC的测试中,内建自测试(Built.In Self-Test,BIST)成为人们研究的热点。文中对SOC的设计特点及其BIST中的混合模式测试进行了探讨。     

基于安全控制边界单元的IP核测试封装方法

为了解决测试信息传递的问题,IEEE组织推出了IEEE1500 IP(Intellectual Property)核测试封装标准以标准化口核测试接口.然而该标准给出的典型测试封装存在由测试数据扫描移人造成的不安全隐患.本文提出了一种基于安全控制边界单元的IP核测试封装方法.这种方法的核心思想是在典型的测试封装边界单元的...     

Deterministic Built-in Pattern Generation for Sequential Circuits

We present a new pattern generation approach for deterministic built-in self testing (BIST) of sequential circuits. Our approach is based on precomputed test sequences, and is especially suited to sequential circuits that contain a large number of flip-flops but relatively few controllable primary inputs. Such circuits, often encountered as embedded cores and as filters for digital signal processing, are difficult to test and require long test sequences. We show that statistical encoding of precomputed test sequences can be combined with low-cost pattern decoding to provide deterministic BIST with practical levels of overhead. Optimal Huffman codes and near-optimal Comma codes are especially useful for test set encoding. This approach exploits recent advances in automatic test pattern generation for sequential circuits and, unlike other BIST schemes, does not require access to a gate-level model of the circuit under test. It can be easily automated and integrated with design automation tools. Experimental results for the ISCAS 89 benchmark circuits show that the proposed method provides higher fault coverage than pseudorandom testing with shorter test application time and low to moderate hardware overhead.     

Test-access mechanism optimization for core-based three-dimensional SOCs

Embedded cores in a core-based system-on-chip (SOC) are not easily accessible via chip I/O pins. Test-access mechanisms (TAMs) and test wrappers (e.g., the IEEE Standard 1500 wrapper) have been proposed for the testing of embedded cores in a core-based SOC in a modular fashion. We show that such a modular testing approach can also be used for emerging three-dimensional integrated circuits based on through-silicon vias (TSVs). Core-based SOCs based on 3D IC technology are being advocated as a means to continue technology scaling and overcome interconnect-related bottlenecks. We present an optimization technique for minimizing the post-bond test time for 3D core-based SOCs under constraints on the number of TSVs, the TAM bitwidth, and thermal limits. The proposed optimization method is based on a combination of integer linear programming, LP-relaxation, and randomized rounding. It considers the Test Bus and TestRail architectures, and incorporates wire-length constraints in test-access optimization. Simulation results are presented for the ITC 02 SOC Test Benchmarks and the test times are compared to that obtained when methods developed earlier for two-dimensional ICs are applied to 3D ICs. The test time dependence on various 3D parameters (e.g. 3D placement, the number of layers, thermal constraints, and the number of TSVs) is also studied.     

Test Wrapper and Test Access Mechanism Co-Optimization for System-on-Chip

Test access mechanisms (TAMs) and test wrappers are integral parts of a system-on-chip (SOC) test architecture. Prior research has concentrated on only one aspect of the TAM/wrapper design problem at a time, i.e., either optimizing the TAMs for a set of pre-designed wrappers, or optimizing the wrapper for a given TAM width. In this paper, we address a more general problem, that of carrying out TAM design and wrapper optimization in conjunction. We present an efficient algorithm to construct wrappers that reduce the testing time for cores. Our wrapper design algorithm improves on earlier approaches by also reducing the TAM width required to achieve these lower testing times. We present new mathematical models for TAM optimization that use the core testing time values calculated by our wrapper design algorithm. We further present a new enumerative method for TAM optimization that reduces execution time significantly when the number of TAMs being designed is small. Experimental results are presented for an academic SOC as well as an industrial SOC.     

面向SOC设计的可变规模的LCD驱动lP核的设计

文章介绍了一个面向SOC设计的可变规模的LeD驱动IP核,该IP包括四个独立的LeD驱动单元（DU）。不仅可以通过配置该IP使四个独立的Du分别驱动不同规模的LCD,而且能够实现四个Du级联来面对更复杂的应用场合。此外,设计了一个与wishbone总线相兼容的接口模块wrapper,并将该IP结合wrapper模块嵌入到0R1200平台来进行系统级的仿真验证。仿真结果表明该IP达到了设计要求,且通过修改wrapper模块可使该IP核适用于不同的SOC设计平台。     

Optimization of Test Wrapper for TSV Based 3D SOCs

Manufacturing of core based three-dimensional (3D) integrated circuit (IC) is an emerging field of semiconductor industry that promises greater number of devices on chip, increased performance and reduced power consumption. But due to scaling in technology features these chips are more complex. Hence testing of these 3D ICs is a challenging task and designing the test wrapper of core is also an important issue in this respect. This paper follows a IEEE 1500-style wrapper design for 3D ICs using Through Silicon Vias (TSVs) for testing purpose. It is assumed that the core elements are distributed over several layers of the ICs. As the number of available TSVs are limited due to small chip area, this work is intended to design balanced wrapper chains using minimum number of TSVs so that testing time of a core is reduced. In this work we have proposed a polynomial time algorithm of O(N) to design the test wrapper. The results are presented based on the ITC’02 SOC test benchmarks and compared with prior works. Obtained results show that our algorithm provides better utilization of TSVs compared to the work presented in Noia et al. (2011).     

BIST test pattern generator for delay testing

To detect delay faults in a digital circuit requires a test sequence applied at the nominal frequency of the circuit. Built-in self-test (BIST) is a technique that provides such testing possibilities at speed, without expensive test equipments. A BIST test pattern generator (TPG) design, targeting the detection of delay faults is proposed     

SOC的可测试性设计策略

介绍了几种主要的VLSI可测性设计技术,如内部扫描法、内建自测试法和边界扫描法等,论述如何综合利用这些方法解决SOC内数字逻辑模块、微处理器、存储器、模拟模块、第三方IP核等的测试问题,并对SOC的可测性设计策略进行了探讨.     

基于March C＋算法的SRAMBIST设计

为了增加存储器测试的可控性和可观测性,减少存储器测试的时间和成本开销,在此针对LEON处理器中的32位宽的SRAM进行BIST设计。采用MarchC＋算法,讨论了SRAM的故障模型及BIST的实现。设计的BIST电路可以与系统很好的相连,并且仅增加很少的输入／输出端口。仿真结果证明,BIST的电路的加入在不影响面积开销的同时,能够达到很好的故障覆盖率。     

Reusing existing resources for testing a multi-processor system-on-chip

In this article, we propose a test strategy for a multi-processor system-on-chip and model the test time for distributed Intellectual Property (IP) cores. The proposed test methodology uses the existing on-chip resources, IP cores and network elements in network-on-chip. The use of embedded IP cores as a built- in self-test (BIST) module completes the test much faster than an external test and provides flexibility in the test program. Moreover, the reuse of the existing network resources as a test media eliminates additional test access mechanism (TAM) wires in the design and increases test parallelism, reducing the area and test time. Based on the proposed test methodology, we evaluate the test time for distributed IP cores. First, we define the model for a distributed IP core with four parameters in the context of test purposes. Next, the required test time is driven. Finally, we show the characteristics of IP cores for a parallel testing that provides useful information for the test scheduling.     

A Built-in Self-Test Scheme with Diagnostics Support for Embedded SRAM

In this paper we propose a novel built-in self-test (BIST) design for embedded SRAM cores. Our contribution includes a compact and efficient BIST circuit with diagnosis support and an automatic diagnostic system. The diagnosis module of our BIST circuit can capture the error syndromes as well as fault locations for the purposes of repair and fault/failure analysis. In addition, our design provides programmability for custom March algorithms with lower hardware cost. The combination of the on-line programming mode and diagnostic system dramatically reduces the effort in design debugging and yield enhancement. We have designed and implemented test chips with our BIST design. Experimental results show that the area overhead of the proposed BIST design is only 2.4% for a 128 KB SRAM, and 0.65% for a 2 MB one.     

多核共享存储控制器中AMBA-AHB总线接口的设计

在基于IP复用的SOC设计中,片上总线作为SOC系统集成的互连结构,负责各种移植IP之间的正常通信.片上总线作为各设计模块通信的桥梁,成为了SOC设计中的关键问题.基于AMBA Rev2.0 AHB-Lite 总线协议,通过在存储控制器与AHB总线之间设计AMBA接口,实现系统专用网络据数处理引擎PE与嵌入式通用处理器...     

A Test Time Reduction Algorithm for Test Architecture Design for Core-Based System Chips

This paper deals with the design of SOC test architectures which are efficient with respect to required ATE vector memory depth and test application time. We advocate the usage of a TestRail Architecture, as this architecture, unlike others, allows not only for efficient core-internal testing, but also for efficient testing of the circuitry external to the cores. We present a novel heuristic algorithm that effectively optimizes the TestRail Architecture for a given SOC by efficiently determining the number of TestRails and their widths, the assignment of cores to the TestRails, and the wrapper design per core. Experimental results for four benchmark SOCs show that, compared to previously published algorithms, we obtain comparable or better test times at negligible compute time.     

A Cost-efficient Input Vector Monitoring Concurrent On-line BIST Scheme Based on Multilevel Decoding Logic

Input vector monitoring concurrent on-line BIST based on multilevel decoding logic is an attractive approach to reduce hardware overhead. In this paper, a novel optimization scheme is proposed for further reducing the hardware overhead of the decoding structure, which refers to improved decoding, input reduction, and simulated annealing inputs swapping approaches. Furthermore, utilizing similar multilevel decoding logic as the responses verifier, a novel cost-efficient input vector monitoring concurrent on-line BIST scheme is presented. The proposed scheme is applicable to the concurrent on-line testing for the CUT, the detail of which can not be obtained, such as hard IP cores. Experimental results indicate that the proposed optimization approaches can significantly reduce the hardware overhead of the decoding structure, and the proposed scheme costs lower hardware than other existing schemes.     

Low-Area Wrapper Cell Design for Hierarchical SoC Testing

System-on-chip (SoC) integrated circuits are designed and fabricated with multiple levels of hierarchy. However, most previous works on wrapper design, test access mechanism optimization and test scheduling did not take care of the hierarchy properly, thus the corresponding test schedules were often invalid for SoCs with hierarchical cores. We propose a low-area wrapper cell design which can treat SoCs with hierarchy properly and allows simultaneous testing of parent and child cores. The proposed cell uses 13%∼23% less area than a recently proposed cell design in equivalent gate count. As a result we achieve up to 21% area reduction for hierarchical ITC ’02 SoCs compared to the most recently proposed designs.     

一款雷达信号处理SOC芯片的存储器内建自测试设计

内建自测试(BIST)为嵌入式存储器提供了一种有效的测试方法.详细介绍了存储器故障类型及内建自测试常用的March算法和ROM算法.在一款雷达信号处理SOC芯片中BIST被采用作为芯片内嵌RAM和ROM的可测试性设计的解决方案.利用BIST原理成功地为芯片内部5块RAM和2块ROM设计了自测试电路,并在芯片的实际测试过程中成功完成对存储器的测试并证明内嵌存储器不存在故障.     

SOC设计中的IP挑战

IC设计正逐渐转向系统级芯片(SOC)设计,IP核是其中的重要核心部分.本文介绍了IP核的概念及交付形式,讨论了IP核相关标准、IP验证、IP的质量评估,以及知识产权的保护,并从上述几个方面分析了IP核所面临的挑战.