A.T.E. Solutions, Inc. | Design for Testability and for Built-In Self Test

Design for Testability and for
Built-In Self Test

What you will learn:

In this course you will learn all aspects of Design for Testability, from what it is, why you might need it, why someone would object to it, and what it can and cannot accomplish. You will learn how today's technology has become elusive to certain failure modes and how important it is to expose them through more testable designs. First you will learn some simple techniques to enhance observability and controllability. You will learn how you can access literally hundreds of internal points with as few as four additional edge connector pins. You will learn specific guidelines for both digital and analog circuit testability. You will learn structured testability techniques, such as internal and boundary-scan. You will come away with a deep understanding of the IEEE 1149.1 (JTAG) standard's operation, use and even its limitations. You will also learn some new techniques in testability, including I_DDQ testing and I/O Mapping.

In the second part of the course, you will learn what built-in [self] test (BIST) is and how it can be specified. You will learn structures such as linear feedback shift registers (LFSRs), signature analyzers, and pseudo-random signal generators. With these building blocks you will be able to evaluate a number of BIST architectures. You will learn BIT Software techniques and consider the effect false alarms have on BIT. You will finally be able to specify BIT for your products and look at the possibilities of BIT taking over some of the ATE functions.

Abstract:

This is really two courses combined into one. The first part, Design for Testability provides the guidelines necessary to improve circuit design from a test perspective. It includes simple and easy-to-implement ad-hoc testability guidelines. Then the course looks at more sophisticated structured approaches to testability that can be placed into ICs and boards. Special emphasis will be given to boundary-scan, the (JTAG) IEEE-1149.1. This standard, which is often difficult to understand, will be made crystal clear. Analog circuit testability builds on the IEEE-1149.1 and is now the Mixed-Signal testability standard, designated as IEEE-1149.4. We examine this standard as well. A standard also exists to access board-level boundary-scan at the systems level. This is accomplished using the IEEE-1149.5, which we will also introduce.

The second part of the course will cover Built-In Test. Starting with classification of Built-In Test approaches, the course introduces the building blocks of built-in self test (BIST) architectures. The course then examines some of these architectures, including Random Test Socket (RTS), the Built-In Logic Block Observer (BILBO), the Cyclic Analysis Testing Systems (CATS), the Built-In Test Exerciser and Sensor (BITES), and others. BIT software is also covered and a discussion on BIT false alarms is included. Finally, a hierarchical approach to BIT is examined, which offers a reduction if not elimination of ATE in both a manufacturing and maintenance environment.

Who should Attend:

This is a design course, intended for designers and for those who motivate them for testability, namely test engineers. Managers concerned with testability issues will also find this course useful. Anyone interested in boundary-scan (JTAG/IEEE-1149.1) will agree with many of our graduates who called this the best course available on the subject. Since Built-In Test is becoming an issue of concern for top management as well as to marketing, this course - though a bit on the technical side - does examine applications for BIT in a product.

DESIGN FOR TESTABILITY

Part 1 - Introduction to Design for Testability

What is Design for Testability?

Quality As a Function of Yield and Test Coverage

Fault Models

Effect of Time-to-Market On Profits

Technical Goals of Testable Designs

Considerations for Testability

Approaches to Design for Testability

Ad Hoc Design for Testability
Structured Design for Testability
Extended Design for Testability Or Built-In Self Test (BIST)

Design for Testability Attributes

Controllability
Observability
Others

Basic Ad Hoc Design for Testability Rules

Controllability

Controlling Buses
Control of Large Fan-In
Control Long Counters and Shift Registers

Observability

I/O Amplification

Predictability

Partitioning to Functionally Independent Sub-Systems

Power Level Partitioning
System Level Partitioning
Mechanical Partitioning
Partitioning Using Degating Circuits

Methods for Breaking Feedback Loops

Breaking Long Counters and Shift Registers

Methods for Breaking Free Running Clocks

Part 2 - Application of Testability Guidelines

Programmable Logic Arrays (PLAs) Testability Guidelines

ASIC DFT Guidelines

Analog Testability

Low Frequency (Under 50 kHz)
High Frequency (50kHz - 100 MHz)
RF

LSI, VLSI, V²LSI, GSI, VHSIC Testability Guidelines

Mechanical Design for Testability

Guidelines for Surface Mount Devices

Schematic Drawings

Documentation for Testability

Testability Problems With Memories

Cross-Check

I/O Mapping

I_DDQ Testing

What is I_DDQ Testing?
External Current Sensor
Built-In Current Sensor
Effectiveness of I_DDQ , Scan & Functional Tests

Evaluating Designs for Testability

Dependency Models
Testability Checklists
Other Testability Analysis tools

Part 3 - Structured Design for Testability

Technical Goals of Testable Designs

General Structure of Scan

Scan Design Mode of Operation

Level Sensitive Scan Design
Scan/Set
Random Access Scan
Scan Features vs. Cost
Full Scan vs. Partial Scan

Boundary Scan Structure

The Boundary Scan Cell and JTAG/IEEE-1149.1

Construction Of The Test Access Port (TAP)

TAP Control Lines
TAP Controller States
Controller State Operation

Boundary-Scan Registers

Boundary-Scan Operational Modes

Non-Invasive Operational Modes
Pin Permission Operational Modes

Boundary-Scan Description Language (BSDL)

Boundary-Scan Tests

Test Access Port (TAP) Integrity Test
Wrong Component Test
Boundary-Scan In-Circuit Test
Virtual Interconnect Test
Virtual Component or Cluster Test
Boundary Functional Test

Mixed Signal Boundary Scan Using the IEEE-1149.4

AC EXTEST Using the IEEE-1149.6

Evaluating Designs for Testability

Built-In Self Test

Part 1 - Technical Approach to BIST

Forms Of Built-In Test

Continuous Monitoring (CM)
Initiated Bit (I-BIT)
Operational Readiness Test (ORT)

Elements of a BIST Architecture

Types of BIST

BIST Classification

BIT Using Error Detection Codes

Error-Correcting Codes

BIT Using Set/Scan Logic

Signature Analyzer
Pseudo-Random Signal Generator
Linear Feedback Shift Register from Scan Cells
Built-In Logic Block Observer (BILBO)

BIST Signal Generation tools

Test Generation Methods for BIST

BIST Response Collection tools

BIST Architectures

Random Test Socket (RTS)
Self-Testing Using MISR and Parallel SRSG (STUMPS)
Centralized and Separate Board-Level BIST
Built-In Evaluation & Self Test (BEST)
Concurrent BIST Architecture
Simultaneous Self Test (SST)
Cyclic Analysis Testing Systems (CATS)
Circular Self Test Path (CSTP)

BIT and BITE Architectures

Redundancy BIT
Wrap-around BIT
Voltage Summing BIT
Built-In Test Exerciser and Sensor (BITES)
Exercisers and Sensors (EASs)

General Structure Of Non-Concurrent Bit

Part 2 - BIT Software

Why use BIT Software?

BIT Software Considerations

Guidelines for Software BIT
Selecting a Software Language
Performance Monitoring Software

Failure Analysis Software

Fault Filtering
Heuristics in BIT

Evaluating BIT

Basic BIT and BITE Requirements

Self Checking BIST

BIT False Alarms

Concerns of False Alarm
BIT False Alarm Rate (BFAR)
Causes of BIT False Alarms
Overcoming False Alarms

BIT Specification

Manufacturing Test Strategies with Hierarchical BIT

Maintenance Test and Repair Strategies with Hierarchical BIT

What happens to ATE?

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