Optimal Test Access Mechanism (TAM) for Reducing Test Application Time of Core-Based SOCs

[[abstract]]In this paper, we propose an algorithm based on a framework of reconfigurable multiple scan chains for system-on-chip to minimize test application time. The control signal combination causes the computing time increasing exponentially, and the algorithm we proposed introduces a heuristic control signal selecting method to solve this serious problem. We also minimize the test application time by using the balancing method to assign registers into multiple scan chains. The results show that it could significantly reduces both the test application time and the computation time.[[notice]]補正完畢[[incitationindex]]EI[[booktype]]紙

An Efficient Algorithm to Selectively Gate Scan Cells for Capture Power Reduction

[[abstract]]Recently, power dissipation in full-scan testing has brought a great challenge for test engineers. In addition to shift power reduction, excessive switching activity during capture operation may lead to circuit malfunction and yield loss. In this paper, a new algorithm is proposed with using clock gating technique on a part of the scan cells to prevent the internal circuit from unnecessary transitions. These scan cells are divided into several exclusive scan groups. For each test vector, only a portion of the scan groups are activated to store the test response per capture cycle. The proposed method can reduce the capture power dissipation without any influence on fault coverage or testing time. Experimental results for ISCAS'89 benchmark circuits show that the capture power reduction in test sequence can up to 55%.[[notice]]補正完畢[[incitationindex]]EI[[booktype]]紙

A Novel Reseeding Mechanism for Improving Pseudo-Random Testing of VLSI Circuits

[[abstract]]During built-in self-test (BIST), the set of patterns generated by a pseudo-random pattern generator may not provide sufficiently high fault coverage and many patterns can't detect fault (called useless patterns). In order to reduce the test time, we can remove useless patterns or change them to useful patterns (fault dropping). In fact, a random test set includes many useless patterns. Therefore we present a technology, including both reseeding and bit modifying (a.k.a. pattern mapping) to remove useless patterns or change them to useful patterns. When patterns changed, we pick out number of different fewer bits, leading to very short test length. Then we use an additional bit counter to improve test length and achieve high fault coverage. The technique we present is applicable for single-stuck-at faults. Experimental results indicate that complete fault coverage-100% can be obtained with less test time.[[notice]]補正完畢[[journaltype]]國際[[incitationindex]]EI[[ispeerreviewed]]Y[[booktype]]紙本[[countrycodes]]TW

A broadcast-based test scheme for reducing test size and application time

[[abstract]]We present efficient method for reducing test application time by broadcasting test configuration. We compare our method based on single, multiple, 1-1 in-order mapping, even distribution, nearest signal probability matching, and in-order pseudo-exhaustive method. The results of our experiments indicate that our method reducing the test pattern number and the test application time by running the ATPG tool provided by SIS.[[conferencedate]]20060521~20060524[[conferencelocation]]Island of Kos, Greec

A novel reseeding mechanism for pseudo-random testing of VLSI circuits

[[abstract]]During built-in self-test (BIST), the set of patterns generated by a pseudo-random pattern generator may not provide sufficiently high fault coverage and many patterns were undetected fault (useless patterns). In order to reduce the test time, we can remove useless patterns or change them to useful patterns (fault dropping). In this paper, we reseed, modify the pseudo-random, and use an additional bit counter to improve test length and achieve high fault coverage. The fact is that a random test set contains useless patterns, so we present a technique, including both reseeding and bit modifying to remove useless patterns or change them to useful patterns, and when the patterns change, we pick out the numbers with less bits, leading to very short test length. The technique we present is applicable for single-stuck-at faults. The seeds we use are deterministic so 100% fault coverage can be achieve.[[conferencetype]]國際[[conferencedate]]20050523~20050526[[booktype]]紙本[[conferencelocation]]Kobe, Japa

Reconfigurable multiple scan-chains for reducing test application time of SOCs

[[abstract]]We propose an algorithm, based on a framework of reconfigurable multiple scan-chains for a system-on-chip, to minimize test application time. For the framework, the control signal combination causes the computing time to increase exponentially. The algorithm we propose introduces a heuristic control signal selection method to solve this problem. We also minimize the test application time by using the balancing method to assign registers into multiple scan-chains. It could show significant reductions in test application times and computing times.[[conferencetype]]國際[[conferencedate]]20050523~20050526[[conferencelocation]]Kobe, Japa

Design of Dynamically Assignmentable TAM Width for Testing Core-Based SOCs

[[abstract]]Test access mechanism (TAM) and testing schedule for system-on-chip (SOC) are challenging problems. Testing schedule must be effective to minimize testing time, under the constraint of test resources. This paper presents a new method based on generalized rectangle packing, as two-dimensional packing. A core cuts into many pieces and utilizes the design of reconfigurable core wrappers, and is dynamic to change the width of the TAM executing the core test. Therefore, a core can utilize different TAM width to complete test[[conferencetype]]國際[[conferencedate]]20061204~20061207[[iscallforpapers]]Y[[conferencelocation]]Singapor

Thermal-Aware Test Schedule and TAM Co-Optimization for Three-Dimensional IC

[[abstract]]Testing is regarded as one of the most difficult challenges for three-dimensional integrated circuits (3D ICs). In this paper, we want to optimize the cost of TAM (test access mechanism) and the test time for 3D IC. We used both greedy and simulated annealing algorithms to solve this optimization problem. We compare the results of two assumptions: soft-die mode and hard-die mode. The former assumes that the DfT of dies cannot be changed, while the latter assumes that the DfT of dies can be adjusted. The results show that thermal-aware cooptimization is essential to decide the optimal TAM and test schedule. Blindly adding TAM cannot reduce the total test cost due to temperature constraints. Another conclusion is that soft-die mode is more effective than hard-die mode to reduce the total test cost for 3D IC.[[notice]]補正完畢[[booktype]]電子

Power-aware compression scheme for multiple scan-chain

[[abstract]]As test data continues to grow quickly, test cost also increases. For the sake of decreasing the test cost, this article presents a new data dependency compression scheme for large circuit which is based on multiple scan chains. We propose new compression architecture with fixed length for running tests. In results, when the complexity of a VLSI circuit is growing, the number of input pins for testing is very low. Since test data in power aware is not changed frequently, we use a selector to filter the unnecessary status and buffers to hold the back data. We also propose a new algorithm to assign multiple scan chains and an improved linear dependency compute method to find the hidden dependency between scan chains. Experimental results show that the proposed method can reduce both test data volume and shift-in power.[[incitationindex]]SCI[[booktype]]紙本[[booktype]]電子

Power-aware multi-chains encoding scheme for system-on-a-chip in low-cost environment

[[abstract]]As the test data continues to grow quickly, test cost also increased. For the sake of decreasing the test cost, this study presents a new compression for large circuit, which is based on multiple scan-chains and unknown structure. The proposed method is targeted at intellectual property cores and system-on-a-chip. The authors consider the shift-in power and compression ratio in low-cost automatic test equipment (ATE) environment. A new compression architecture with fixed length for running ones is proposed. For the proposed method, the ATE has no repeated function and synchronisation signal. In the results, when the complexity of very large-scale integrated circuit is growing up, the number of input pins for testing is very low. The average compression ratio of our method is 63% for MinTest and TetraMAX on ISCAS'89 benchmarks. The average of peak/weight transition count shift-in turns to 3x/6.6x for MinTest and 2.3x/5.6x for TetraMAX, after comparing selective scan slice and the proposed method. The average of hardware overhead is 6% for MinTest and 6.5% for TetraMAX.[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]紙