Vacuity Analysis by Fault Simulation

A Manual Diagnosis Approach Using Targeted Fault Injection and Fault Simulation to Extend ATPG Diagnostic Resolution in Localizing Faults

ISTFA 2019: Conference Proceedings from the 45th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2019p0419 ◽

2019 ◽

Author(s):

Rommel Estores ◽

Karo Vander Gucht

Keyword(s):

Fault Injection ◽

Fault Simulation ◽

Fault Localization ◽

Pattern Generation ◽

Test Coverage ◽

Actual Case ◽

Electrical Failure ◽

Starting Point ◽

Diagnostic Resolution ◽

Diagnosis Approach

Abstract This paper discusses a creative manual diagnosis approach, a complementary technique that provides the possibility to extend Automatic Test Pattern Generation (ATPG) beyond its own limits. The authors will discuss this approach in detail using an actual case – a test coverage issue where user-generated ATPG patterns and the resulting ATPG diagnosis isolated the fault to a small part of the digital core. However, traditional fault localization techniques was unable to isolate the fault further. Using the defect candidates from ATPG diagnosis as a starting point, manual diagnosis through fault Injection and fault simulation was performed. Further fault localization was performed using the ‘not detected’ (ND) and/or ‘detected’ (DT) fault classes for each of the available patterns. The result has successfully deduced the defect candidates until the exact faulty net causing the electrical failure was identified. The ability of the FA lab to maximize the use of ATPG in combination with other tools/techniques to investigate failures in detail; is crucial in the fast root cause determination and, in case of a test coverage, aid in having effective test screen method implemented.

Download Full-text

Diagnostic Fault Simulation for the Failure Analyst

ISTFA 2004: Conference Proceedings from the 30th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2004p0181 ◽

2004 ◽

Author(s):

Dan Bodoh ◽

Anthony Blakely ◽

Terry Garyet

Keyword(s):

Fault Diagnosis ◽

Failure Analysis ◽

Complete Solution ◽

Fault Simulation ◽

Building Blocks ◽

Physical World ◽

Design For Test ◽

Fault Diagnosis System ◽

Diagnosis Algorithm ◽

Diagnosis Tool

Abstract Since failure analysis (FA) tools originated in the design-for-test (DFT) realm, most have abstractions that reflect a designer's viewpoint. These abstractions prevent easy application of diagnosis results in the physical world of the FA lab. This article presents a fault diagnosis system, DFS/FA, which bridges the DFT and FA worlds. First, it describes the motivation for building DFS/FA and how it is an improvement over off-the-shelf tools and explains the DFS/FA building blocks on which the diagnosis tool depends. The article then discusses the diagnosis algorithm in detail and provides an overview of some of the supporting tools that make DFS/FA a complete solution for FA. It also presents a FA example where DFS/FA has been applied. The example demonstrates how the consideration of physical proximity improves the accuracy without sacrificing precision.

Download Full-text