A BIST and boundary-scan economics framework

IC level built-in self-test and IEEE 1149.1 boundary-scan architecture offer potential benefits at all phases of a product's life cycle: development, manufacturing, and field deployment. During early model debugging, for example, boundary scan rapidly flushes out structural defects such as solder bridges or opens. During manufacturing test, BIST and boundary scan can improve coverage, reduce test and diagnosis time, and reduce test capital. In the field, embedded boundary-scan and BIST capabilities may facilitate accurate system diagnostics that isolate defects to individual field-replaceable units. Before investing in these design-for-testability features, however, a product development team should carefully consider their costs as well as their benefits. So far, tools for accurately evaluating these economic trade offs have not been available. At Lucent Technologies, therefore, we have developed a framework to guide a cost-benefit analysis of an investment in BIST and/or boundary scan. The framework is in its formative stages and will continue to evolve. BIST and boundary scan affect cost at all levels of product integration and during all phases of the product life cycle. This analysis framework helps developers decide if the benefits are worth the costs     

Synchronizing the IEEE 1149.1 test access port for chip leveltestability

IEEE STD 1149.9 is a widely accepted testability standard in the industry. Although its mandatory provisions focus narrowly on board level assembly verification testing, primarily via the boundary-scan register, its test access port (TAP) and many optional provisions make the standard usable for a much broader range of applications. Since its inception, numerous extensions and applications have been proposed that allow the standard's TAP to be used at the system level for general system-level test and maintenance tasks and at the chip level for accessing chip-level testability features. Chip-level applications thus far have used the port for accessing the chip's scan design or for simple triggering of on-chip built-in self-test features via the RUNBIST instruction. Applications requiring general access to chipwide testability features that operate at the full chip-clock rate have been rare, primarily because of one of the standard's basic tenets-namely, its dedicated test clock. This strategy enhances the test port to let it operate with two clocks. One is used while accessing IEEE 1149.1-compliant features, the other while accessing chip manufacturing test features     

Boundary scan with built-in self-test

The authors propose a way to merge boundary scan with the built-in self-test (BIST) of printed circuit boards. Their boundary-scan structure is based on Version 2.0 of the Joint Task Action Group's recommendations for boundary scan and incorporates BIST using a register based on cellular automata (CA) techniques. They examine test patterns generated from this register and the more conventional linear-feedback shift register. The advantages of the CA register, or CAR, are its modularity, which allows modification without major redesign, its higher stuck-at fault coverage, and its higher transition fault coverage     

A Wiring-Aware Approach to Minimizing Built-In Self-Test Overhead

This paper describes a built-in self-test (BIST) hardware overhead minimization technique used during a BIST synthesis process. The technique inserts a minimal amount of BIST resources into a digital system to make it fully testable. The BIST resource insertion is guided by the results of symbolic testability analysis. It takes into consideration both BIST register cost and wiring overhead in order to obtain the minimal area designs. A Simulated Annealing algorithm is used to solve the overhead minimization problem. Experiments show that considering wiring area during BIST synthesis results in smaller final designs as compared to the cases when the wiring impact is ignored.     

应用于逻辑核的BIST关键技术研究

随着集成电路工艺进入深亚微米阶段后,电路复杂度的不断提高,特别是片上系统的不断发展,主要包括验证测试和制造测试的芯片测试,正在面临着巨大的挑战,传统的使用自动测试设备的测试方法越来越不能满足测试需要。各种用于提高芯片可测试性的可测性设计方法被提出,其中逻辑内建自测试方法已经被证明为大规模集成电路（VLS1）和SOC测试的一项有效的可测试性设计方法。文章首先对Logic BIST的基本原理结构进行介绍,然后对其在实践应用中的一些难点问题进行详细分析,最后给出针对一款高性能通用处理器实验的结果。     

Automated BIST for sequential logic synthesis

An automated built-in self-test (BIST) technique for general sequential logic is described that can be used directly at all levels of testing from device testing through system diagnostics. The technique selectively replaces existing system memory elements with BIST flip-flop cells, which it then connects to form a circular chain. Data are compacted and test patterns are generated simultaneously. The approach has been incorporated in a system for behavioral model synthesis to implement BIST in VLSI devices based on standard cells and in circuit packs based on PLDs, automatically. Seven production VLSI devices have been implemented with this automated BIST approach. Area overhead was between 6% and 19% for a fault coverage of 90%+ with the BIST capability alone     

Scan BIST with biased scan test signals

The conventional test-per-scan built-in self-test （BIST） scheme needs a number of shift cycles followed by one capture cycle. Fault effects received by the scan flipflops are shifted out while shifting in the next test vector like scan testing. Unlike deterministic testing, it is unnecessary to apply a complete test vector to the scan chains. A new scan-based BIST scheme is proposed by properly controlling the test signals of the scan chains. Different biased random values are assigned to the test signals of scan flip-flops in separate scan chains. Capture cycles can be inserted at any clock cycle if necessary. A new testability estimation procedure according to the proposed testing scheme is presented. A greedy procedure is proposed to select a weight for each scan chain. Experimental results show that the proposed method can improve test effectiveness of scan-based BIST greatly, and most circuits can obtain complete fault coverage or very close to complete fault coverage.     

Built-In Self-Test Trends in Motorola Microprocessors

The first built-in self-test feature in a Motorola sidered a ?wart? until a RAM test application recast it as a ? feature.? Though the BIST approach?an idea conceived as a way to reduce production costs for the MC6805 family?did not meet its major design objective, the experience provided impetus for the development of BIST techniques for the MC6804P2, which met most of the objectives intended for the MC6805P2. The Motorola microprocessor family has come to incorporate a growing number of testability features; current devices typically employ a combination of BIST and other techniques. If present trends continue, transistor counts for microprocessor-related parts should approach 10 million within 10 years. The authors argue that structured design techniques offer the most promising prospects for solving the design and test problems resulting from this increase in complexity.     

基于BIST软件测试思想的单元测试框架

BIST是一种成熟的硬件可测性设计的方法,BIST软件测试思想则借用了该技术,它主要包括模板和自治测试部分两大基本结构。在该思想的指导下,整合测试用例、测试点、插装函数、测试报告等测试要素,提出了各个要素的存储或使用方式,以路径覆盖为测试目标,提出了一种BIST软件自测试的测试框架。实践证明,该测试框架有利于BIST软件测试思想的进一步研究和实现。     

Economics of built-in self-test

Using built-in self-test at the right level offers users significant cost savings, but determining which level, if any, is best for BIST can be complex. A detailed economic analysis can unravel heterogeneous costs and benefits so that designers and managers can make the right decision     

Low-cost testing of high-density logic components

The evolution of a testing method and architecture of a logic-device tester to be used for the next generation of IBM's high-density CMOS ASIC (application-specific integrated circuit) logic components is described. The tester's design is based on the architecture of an existing IBM memory tester rather than on a conventional logic-tester design. The testing strategy calls for boundary-scan in each component design, built-in self-test logic within embedded memory arrays, and the use of weighted random-pattern logic testing. The development of the tester hardware is discussed, and capital costs of the new tester are compared with those of other approaches     

The compiled logic simulator

A two-value, zero-delay simulator that computes signatures and analyzes fault coverage for circuits with built-in self-test (BIST) is described. The simulator, called the compiled logic simulator (CLS), is used with a monitor that simulates BIST control logic at a high level. The simulator's compiled code is well suited to the IBM 3090 pipeline and fault simulation using flat random patterns. The linear-feedback-shift-register simulation monitor is discussed. Performance results are presented. Fault simulation with one million random patterns on a 40000-gate circuit was done in 16 CPU minutes     

A tutorial on built-in self-test. I. Principles

An overview of built-in self-test (BIST) principles and practices is presented. The issues and economics underlying BIST are discussed, and the related hierarchical test structures are introduced. The fundamental BIST concepts of pattern generation and response analysis are explained. Linear feedback shift register theory is reviewed     

嵌入式只读存储器的内建自测试设计

随着存储器件日益向着高速、高集成方向发展,依靠外部设备对嵌入式存储器的测试变得越来越困难,内建自测试是解决这个问题的有效方法;文中详细分析了存储器的故障表现和诊断算法,给出了嵌入式只读存储器的内建自测试的一种设计实现,同时研究了将边界扫描技术与只读存储器的内建自测试相结合、形成层次化系统芯片SoC的设计策略.     

Built-in Self Testing of Embedded Memories

The authors present a built-in self-test (BIST) method for testing embedded memories. Two algorithms are proposed for self-testing of embedded bedded RAMs, both of which can detect a large variety of stuck-at and non-stuck-at faults. The hardware implementation of the methods requires a hardware test-pattern generator, which produces address, data, and read/write inputs. The output responses of the memory can be compressed by using a parallel input signature analyzer, or they can be compared with expected responses by an output comparator. The layout of memories has been considered in the design of additional BIST circuitry. The authors conclude by evaluating the two schemes on the basis of area overhead, performance degradation, fault coverage, test application time, and testing of self-test circuitry. The BIST overhead is very low and test time is quite short. Six devices, with one of the test schemes, have been manufactured and are in the field.     

ScanBist: a multifrequency scan-based BIST method

The authors present ScanBist, a low-overhead, scan-based built-in self-test method, along with its performance in several designs. A novel clock synchronization scheme allows at-speed testing of circuits. This design allows the testing of circuits operating at more than one frequency while retaining the combinational character of the circuit to be analyzed. We can therefore apply scan patterns that will exercise the circuit under test at the system speed, potentially providing a better coverage of delay faults when compared to other self-test methods. Modifications to an existing transition fault simulator account for cases where inputs originating from scan registers clocked at different frequencies drive a gate. We claim to detect transition faults only if the transition originates from the inputs driven by the highest frequency clock. ScanBist is useful at all levels of system packaging assuming that a standard TAP provides the control and boundary scan isolates the circuit from primary inputs and outputs during BIST mode     

C++类测试描述语言的设计和实现

根据一种软件可测性设计技术——软件内建自测试的实施方案，该文提出了一种针对C 类测试的测试描述语言TDL，以提高C 类测试数据的存储结构化，方便其共享和复用。重点讨论了TDL语言的核心对象和结构，并给出了一个TDL程序的实例。     

A tutorial on built-in self-test. 2. Applications

For pt.1 see ibid., vol.10, no.1, p.73-82 (1993). The hardware structures and tools used to implement built-in self-test (BIST) pattern generation and response analysis concepts are reviewed. The authors describe testing approaches for general and structured logic, including ROMs, RAMs, and PLAs. They illustrate BIST techniques with real-world examples     

基于FPGA的内建自测试的实现研究

内建自测试技术源于激励-响应-比较的测试机理,信号可以通过边界扫描传输到芯片引脚,因而即使BIST本身发生故障也可以通过边界扫描进行检测;为了解决大规模SOC芯片设计中BIST测试时间长和消耗面积大的问题,提出了一种用FPGA实现BIST电路的方法,对测试向量发生器、被测内核和特征分析器进行了研究;通过对被测内核注入故障,然后将正常电路和注入故障后的电路分别进行仿真,比较正常响应和实际响应的特征值,如果相等则认为没有故障,否则发生了特定的故障;利用ModelSim SE 6.1f软件仿真结果表明了该方法的正确有效性和快速性。     

Testing and built-in self-test – A survey

As the density of VLSI circuits increases it becomes attractive to integrate dedicated test logic on a chip. This built-in self-test (BIST) approach not only offers economic benefits but also interesting technical opportunities with respect to hierarchical testing and the reuse of test logic during the application of the circuit.Starting with an overview of test problems, test applications and terminology this survey reviews common test methods and analyzes the basic test procedure. The concept of BIST is introduced and discussed, BIST strategies for random logic as well as for structured logic are shown.