This paper presents a novel test-data volume-compression methodology called the embedded deterministic test (EDT), which reduces manufacturing test cost by providing one to two orders of magnitude reduction in scan test data volume and scan test time. The presented scheme is widely applicable and easy to deploy because it is based on the standard scan/ATPG methodology and adopts a very simple flow. It is nonintrusive as it does not require any modifications to the core logic such as the insertion of test points or logic bounding unknown states. The EDT scheme consists of logic embedded on a chip and a new deterministic test-pattern generation technique. The main contributions of the paper are test-stimuli compression schemes that allow us to deliver test data to the on-chip continuous-flow decompressor. In particular, it can be done by repeating certain patterns at the rates, which are adjusted to the requirements of the test cubes. Experimental results show that for industrial circuits with test cubes with very low fill rates, ranging from 3% to 0.2%, these schemes result in compression ratios of 30 to 500 times. A comprehensive analysis of the encoding efficiency of the proposed compression schemes is also provided.

Embedded deterministic test

VLSI Test Principles and Architectures: Design for Testability (Systems on Silicon)

This paper introduces embedded deterministic test (EDT) technology, which reduces manufacturing test cost by providing one to two orders of magnitude reduction in scan test data volume and scan test time. The EDT architecture, the compression algorithm, design flow, experimental results, and silicon implementation are presented.

Embedded deterministic test for low cost manufacturing test

This book is a comprehensive guide to new DFT methods that will show the readers how to design a testable and quality product, drive down test cost, improve product quality and yield, and speed up time-to-market and time-to-volume.

· Most up-to-date coverage of design for testability. 
· Coverage of industry practices commonly found in commercial DFT tools but not discussed in other books. 
· Numerous, practical examples in each chapter illustrating basic VLSI test principles and DFT architectures.
· Lecture slides and exercise solutions for all chapters are now available.
· Instructors are also eligible for downloading PPT slide files and MSWORD solutions files from the manual website.

Table of Contents

Chapter 1 - Introduction
Chapter 2 - Design for Testability
Chapter 3 - Logic and Fault Simulation 
Chapter 4 - Test Generation 
Chapter 5 - Logic Built-In Self-Test
Chapter 6 - Test Compression
Chapter 7 - Logic Diagnosis
Chapter 8 - Memory Testing and Built-In Self-Test
Chapter 9 - Memory Diagnosis and Built-In Self-Repair
Chapter 10 - Boundary Scan and Core-Based Testing
Chapter 11 - Analog and Mixed-Signal Testing
Chapter 12 - Test Technology Trends in the Nanometer Age

VLSI Test Principles and Architectures: Design for Testability

Power consumption of digital systems may increase significantly during testing. In this paper, systems equipped with a scan-based built-in self-test like the STUMPS architecture are analyzed, the modules and modes with the highest power consumption are identified, and design modifications to reduce power consumption are proposed. The design modifications include some gating logic for masking the scan path activity during shifting, and the synthesis of additional logic for suppressing random patterns which do not contribute to increase the fault coverage. These design changes reduce power consumption during BIST by several orders of magnitude, at very low cost in terms of area and performance.

https://www.iti.uni-stuttgart.de/fileadmin/rami/files/publications/2000/JETTA_GerstW2000.pdf

Minimized power consumption for scan-based BIST

We propose a new scheme for built-in test (BIT) that uses multiple-polynomial linear feedback shift registers (MP-LFSR's). The same MP-LFSR that generates random patterns to cover easy to test faults is loaded with seeds to generate deterministic vectors for difficult to test faults. The seeds are obtained by solving systems of linear equations involving the seed variables for the positions where the test cubes have specified values. We demonstrate that MP-LFSR's produce sequences with significantly reduced probability of linear dependence compared to single polynomial LFSR's. We present a general method to determine the probability of encoding as a function of the number of specified bits in the test cube, the length of the LFSR and the number of polynomials. Theoretical analysis and experiments show that the probability of encoding a test cube with s specified bits in an s-stage LFSR with 16 polynomials is 1-10/sup -6/. We then present the new BIT scheme that allows for an efficient encoding of the entire test set. Here the seeds are grouped according to the polynomial they use and an implicit polynomial identification reduces the number of extra bits per seed to one bit. The paper also shows methods of processing the entire test set consisting of test cubes with varied number of specified bits. Experimental results show the tradeoffs between test data storage and test application time while maintaining complete fault coverage. >

S. Venkataraman

Papers

Built-in test for circuits with scan based on reseeding of multiple-polynomial linear feedback shift registers