内建自测试的测试生成方法研究

内建自测试（BIST）方法是目前可测试性设计（DFT）中应用前景最好的一种方法,其中测试生成是关系BIST性能好坏的一个重要方面。测试生成的目的在于生成尽可能少的测试向量并用以获得足够高的故障覆盖率,同时使得用于测试的硬件电路面积开销尽可能低、测试时间尽可能短。内建自测试的测试生成方法有多种,文中即对这些方法进行了简单介绍和对比研究,分析了各自的优缺点,并在此基础上探讨了BIST面临的主要问题及发展方向。     

组合电路内建自测试技术的研究

随着集成电路技术的发展,可测性设计在电路设计中占有越来越重要的地位,内建自测试作为可测性设计的一种重要方法也越来越受到关注。文中首先介绍了内建自测试的实现原理,在此基础上以八位行波进位加法器为例,详细介绍了组合电路内建自测试的设计过程。采用自顶向下的设计方法对整个内建自测试电路进行模块划分,用VHDL语言对各个模块进行代码编写并在QuartusII软件环境下通过了综合仿真,结果表明此设计合理,对电路的测试快速有效。     

一种有效的ADC内建自测试方案

内建自测试是降低ADC电路测试成本的有效方法。通过最小二乘法和斜坡柱状图。我们得出了测试ADC电路的增益误差、失调误差、微分非线性和积分非线性的算法。根据这些测试算法。介绍了一种易于片上集成的内建自测试结构。实验结果表明，该内建自测试方案具有较高的测试精度。     

基于部分扫描的低功耗内建自测试

在分析全扫描内建自测试 (BIST)过高测试功耗原因的基础上 ,提出了一种选择部分寄存器成为扫描单元的部分扫描算法来实现低功耗 BIST。实验表明 ,提出的方法在保证测试覆盖率的条件下能同时降低 BIST的峰值功耗和平均功耗 ,降幅分别高达 46%和 69%。     

FIR数字滤波器的简化格型实现

格型滤波器在数值计算性能和结构的模块化等方面都优于直接型,但实现起来较复杂。本文提出一种实现PIR数字滤波器的简化格型结构,它所需的硬件设备量只有常规格型实现时的一半,与直接型实现时相当。文中给出了从直接型到简化格型的综合算法。并对线性相位FIR数字滤波器的格型综合算法作了简化。用实例演示了本文的主要结论。     

数字集成电路故障测试策略和技术的研究进展

IC制造工艺的发展，持续增加着VLSI电路的集成密度，亦日益加大了电路故障测试的复杂性和困难度。作者在承担相应研究课题的基础上，综述了常规通用测试方法和技术，并分析了其局限性。详细叙述了边界扫描测试(BST)标准、可测性设计(DFT)思想和内建自测试(BIST)策略。针对片上系统(SoC)和深亚微米(VDSM)技术给故障测试带来的新挑战，本文进行了初步的论述和探讨。     

面向低功耗BIST 的VLSI 可测性设计技术

随着手持设备的兴起和芯片对晶片测试越来越高的要求，内建自测试的功耗问题引起了越来越多人的关注，本文对目前内建自测试的可测性设计技术进行了分析并对低功耗的VLSI可测性设计技术的可行性和不足分别进行了探讨。在文章的最后简单介绍了笔者最近提出的一种低功耗的BIST结构。     

层次化设计方法在存储器内建自测试上的应用

本文简单介绍存储器内建自测试设计技术原理,针对具体的RTL实例,对自顶向下设计方法和层次化设计方法进行了比较。实例结果表明：层次化的设计方法在大型芯片的存储器内建自测试设计中,可以加速设计,减少设计迭代时间,大幅提高工作效率。     

存储器内建自测试的程序控制方法

文中提出了一种利用处理器的指令系统编写特定程序,通过程序运行来控制完成整个存储器内建自测试过程的方法.基于此方法的设计已经成功应用于一款处理器中,有效地提高了芯片的可测试性和应用系统的容错性.     

嵌入式存储器的内建自测试算法及测试验证

嵌入式存储器的广泛应用使得内建自测试(BIST,Built-In Self-Test)在当前SoC设计中具有重要的作用,本文着重分析比较了几种BIST测试算法,并对嵌入式BIST的体系结构进行了剖析,最后深入研究了MARCH C-算法的实际应用,使用UMC.18SRAM和2PRAM仿真模型对存储器的BIST测试进行了验证,并成功将其应用于一款USB音视频芯片。     

Built-In Self-Test of Field Programmable Analog Arrays based on Transient Response Analysis

In this work a strategy for testing analog networks, known as Transient Response Analysis Method, is applied to test the Configurable Analog Blocks (CABs) of Field Programmable Analog Arrays (FPAAs). In this method the Circuit Under Test (CUT) is programmed to implement first and second order blocks and the transient response of these blocks to known input stimuli is analyzed. Taking advantage of the inherent programmability of the FPAAs, a BIST-based scheme is used in order to obtain an error signal representing the difference between fault-free and faulty CABs. Two FPAAs from different manufacturers and distinct architectures are considered as CUT. For one of the devices there is no detailed information about its structural implementation. For this reason, a functional fault model based on high-level parameters of the transfer function of the programmed blocks is adopted, and then, the relationship between these parameters and CAB component deviations is investigated. The other considered device allows a structural programming in which the designer can directly modify the values of programmable components. This way, faults can be injected by modifying the values of these components in order to emulate a defective behavior. Therefore, it is possible to estimate the fault coverage and test application time of the proposed functional test method when applied to both considered devices.

一款百万门缀SOC芯片的可测性设到

本文介绍了一款基于65nm工艺的数字处理芯片的可测性设计,采用了边界扫描测试,存储器内建自测试和内部扫描测试技术。这些测试技术的使用为该芯片提供了方便可靠的测试方案,实验结果表明该设计的测试覆盖率符合工程应用要求。     

Design for Consecutive Testability of System-on-a-Chip with Built-In Self Testable Cores

This paper introduces a new concept of testability called consecutive testability and proposes a design-for-testability method for making a given SoC consecutively testable based on integer linear programming problem. For a consecutively testable SoC, testing can be performed as follows. Test patterns of a core are propagated to the core inputs from test pattern sources (implemented either off-chip or on-chip) consecutively at the speed of system clock. Similarly the test responses are propagated to test response sinks (implemented either off-chip or on-chip) from the core outputs consecutively at the speed of system clock. The propagation of test patterns and responses is achieved by using interconnects and consecutive transparency properties of surrounding cores. All interconnects can be tested in a similar fashion. Therefore, it is possible to test not only logic faults but also timing faults that require consecutive application of test patterns at the speed of system clock since the consecutively testable SoC can achieve consecutive application of any test sequence at the speed of system clock.     

Diagnostic Data Compression Techniques for Embedded Memories with Built-In Self-Test

A system-on-chip (SOC) usually consists of many memory cores with different sizes and functionality, and they typically represent a significant portion of the SOC and therefore dominate its yield. Diagnostics for yield enhancement of the memory cores thus is a very important issue. In this paper we present two data compression techniques that can be used to speed up the transmission of diagnostic data from the embedded RAM built-in self-test (BIST) circuit that has diagnostic support to the external tester. The proposed syndrome-accumulation approach compresses the faulty-cell address and March syndrome to about 28% of the original size on average under the March-17N diagnostic test algorithm. The key component of the compressor is a novel syndrome-accumulation circuit, which can be realized by a content-addressable memory. Experimental results show that the area overhead is about 0.9% for a 1Mb SRAM with 164 faults. A tree-based compression technique for word-oriented memories is also presented. By using a simplified Huffman coding scheme and partitioning each 256-bit Hamming syndrome into fixed-size symbols, the average compression ratio (size of original data to that of compressed data) is about 10, assuming 16-bit symbols. Also, the additional hardware to implement the tree-based compressor is very small. The proposed compression techniques effectively reduce the memory diagnosis time as well as the tester storage requirement.     

Innovative Built-In Self-Test Schemes for On-Chip Diagnosis, Compliant with the IEEE 1149.4 Mixed-Signal Test Bus Standard

This paper presents a testing scheme for analog and mixed-signal circuitry compatible with the IEEE 1149.4 mixed-signal test bus standard. A high-speed dynamic current sensor is described, as well as an innovative self-diagnostic method called VDDQ. The former is used to measure signature supply currents and to compare them with the footprint of a defect-free circuit. The latter senses the quiescent nodal voltages on several nodes of the circuit under test and compares them to their nominal values. A flag is raised if significant deviations are found. Simulation results are provided for the high-speed dynamic current sensor. Through simulations the VDDQ method has performed at one node test every half millisecond and has potential for much higher speed. It is faster than currently used methods in industry, which average to 5000 nodes per minute. This will potentially allow a defect-free IC to enter the market in significantly less time than with conventional testing methods.     

Integration of partial scan and built-in self-test

Partial-Scan based Built-In Self-Test (PSBIST) is a versatile Design for Testability (DFT) scheme, which employs pseudo-random BIST at all levels of test to achieve fault coverages greater than 98% on average, and supports deterministic partial scan at the IC level to achieve nearly 100% fault coverage. PSBIST builds its BIST capability on top a partial scan structure by adding a test pattern generator, an output data compactor, and a PSBIST controller in a way similar to that of deriving a full scan BIST from a full scan structure. However, to make the scheme effective, there is a minimum requirement regarding which flip-flops in the circuit should be replaced by scan flip-flops and/or initialization flip-flops. In addition, test arents are usually added to boost the fault coverage to the range of 95 to 100 percent. These test points are selected based on a novel probabilistic testability measure, which can be computed extremely fast for a special class of circuits. This ciass of circuits is precisely the type of circuits that we obtain after replacing some of the flip-flops.withscan and/or initilization flip-flops. The testability measure is also used for a very useful quick estimation of the fault coverage right after the selection of sean flip-flops, even before the circuit is modified to incorporate PSBIST capability. While PSBIST provides all the benefits of BIST, it incurs lower area overhead and performance degradation than full scan. The area overhead is further reduced when the boundary scan cells are reconfigured for BIST usage.     

Ring-like testing of digital circuits

Here we propose a new approach to the testing of digital devices, which can potentially save diagnostic hardware. An example is given for testing combinational devices. Estimates are given for reliability and hardware complexity, and an algorithm for designing operability tests is described.     

Generating a family of testable designs using the BILBO methodology

There are usually many different ways to make a digital circuit testable using the BILBO methodology. Each solution can have different values of test time and area overhead. A design system based on the BILBO methodology has been developed that can efficiently explore the testable design space to generate a family of designs ranging from the minimal test time design to the minimal area overhead design. A designer can select an appropriate design based on trade-offs between test time and area overhead. The branch and bound technique is employed during the exploring process to prune the design space. This significantly reduces the execution time of this process. To effectively bound the exploring process, a very efficient test scheduler has been developed. Unlike previous approaches, this new test scheduler can process a partially testable design as well as a complete testable design. A test schedule for a design is constructed incrementally. The test scheduling procedures are presented along with experimental results that show that this test scheduler usually outperforms existing schedulers. In many cases, it generates an optimal test schedule. Experiments have been performed on several circuits generated by MABAL, a CAD synthesis tool, to demonstrate the performance and practicality of this system.This work was supported by the Defense Advanced Research Projects Agency and monitored by the Federal Bureau of Investigation under Contract No. JFBI90092. The views and conclusions considered in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the Defense Advanced Research Projects Agency or the U.S. Government.     

一种改进的嵌入式SRAM内建自测试设计

对单端口SRAM常用的13N测试算法进行修改和扩展,提出了一种适用于双端口SRAM的测试算法。该测试算法的复杂度为O(n),具有很好的实用性。作为一个实际应用,通过将该算法和13N测试算法实现于测试算法控制单元,完成了对片内多块单端口SRAM和双端口SRAM的自测试设计。