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)

Test data compression consists of test vector compression on the input side and response, compaction on the output side This vector compression has been an active area of research This article summarizes and categories these techniques The focus is on hardware-based test vector compression techniques for scan architectures Test vector compression schemes fall broadly into three categories: code-based schemes use data compression codes to encode test cubes; linear-decompression-based schemes decompress the data using only linear operations (that is LFSRs and XOR networks) and broadcast-scan-based schemes rely on broadcasting the same values to multiple scan chains

https://users.ece.utexas.edu/~touba/research/dt06.pdf

Survey of Test Vector Compression Techniques

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

We propose a new design for testability technique, Parallel Serial Full Scan (PSFS), for reducing the test application time for full scan embedded cores. Test application time reduction is achieved by dividing the scan chain into multiple partitions and shifting in the same vector to each scan chain through a single scan in input. The experimental results for the ISCAS890 circuits showed that PSFS technique significantly reduces both the test application time and the amount of test data for full scan embedded cores.

Reducing test application time for full scan embedded cores

Single scan chain architectures suffer from long test application time, while multiple scan chain architectures require large pin overhead and are not supported by boundary scan. We present a novel method to allow a single input line to support multiple scan chains. By appropriately connecting the inputs of all circuits under test during ATPG process such that the generated test patterns can be broadcast to all scan chains when actual testing is executed, we show that 177 and 280 test patterns are enough to detect all detectable faults in all 10 ISCAS'85 combinational circuits and 10 largest ISCAS'89 sequential circuits, respectively.

/pdf/using-a-single-input-to-support-multiple-scan-chains-32rof2v1jj.pdf

Using a single input to support multiple scan chains

Scan designs can alleviate test difficulties of sequential circuits by replacing the memory elements with scannable registers. However, scan operations usually result in long test application time. Most classical methods to solving this problem either perform test compaction to obtain fewer test vectors or use multiple scan chain design to reduce the scan time. For a large system, test vector compaction is a time-consuming process, while multiple scan chains either require extra pin overhead or need the sharing of normal I/O and scan I/O pins. In this paper, we present a novel test methodology that not only substantially reduces the total test pattern number for multiple circuits but also allows a single input data line to support multiple scan chains. Our main idea is to explore the "sharing" property of test patterns among all circuits under test (CUT's). By appropriately connecting the inputs of all CUT's during the automatic test-pattern generation process such that the generated test patterns can be broadcast to all scan chains when the actual testing operation is executed, the above-mentioned problems can be solved effectively. Our method also provides a low-cost and high-performance method to integrate the boundary scan and scan architectures. Experimental results show that 157 test patterns are enough to detect all detectable faults in the ten ISCAS'85 combinational circuits, while 280 are enough for the ten largest ISCAS'89 scan-based sequential circuits.

Broadcasting test patterns to multiple circuits

A test method for a plurality of circuits respectively having inputs for greatly reducing the required test time and the control circuit complexity is provided. The method includes steps of providing a set of test patterns for detecting a characteristic of the circuits, providing a common data line, and electrically connecting the circuit inputs to the common data line so that the test pattern can be broadcasted to the circuits through the common data line. The present invention also provides an architecture for implementing such method.

Cheng-Hua Huang

Papers

Using a single input to support multiple scan chains

Broadcasting test patterns to multiple circuits

Test method and architecture for circuits having inputs