Built-In Self Test (BIST). 1. Introduction 2. Pattern Generation 3. Signature Analysis 4. BIST...

Built-In Self Test (BIST)

Built-In Self Test (BIST)

1. Introduction

2. Pattern Generation

3. Signature Analysis

4. BIST Architectures

5. Summary

Outline

Built-In Self Test (BIST)

1. Introduction

2. Pattern Generation

3. Signature Analysis

4. BIST Architectures

5. Summary

Built-In Self Test (BIST)

1. Introduction

Built-In Self Test (BIST)

1. Introduction

General Structure

Built-In Self Test (BIST)

General Structure

UnitUnder

Test

DataCompressor

DataGenerator

Comparator

Display

Reference

BIST ControllerStart/Stop Ready

Electronic System

1. Introduction

Built-In Self Test (BIST)

1. Introduction

Built-In Self Test (BIST)

1. Introduction

Built-In Self Test (BIST)

1. Introduction

Built-In Self Test (BIST)

1. Introduction

2. Pattern Generation

3. Signature Analysis

4. BIST Architectures

5. Summary

Built-In Self Test (BIST)

2. Pattern Generation

Built-In Self Test (BIST)

2. Pattern Generation

Built-In Self Test (BIST)

2. Pattern Generation

Built-In Self Test (BIST)

2. Pattern Generation

Built-In Self Test (BIST)

2. Pattern Generation

A fixed set of “optimal” test patterns, usually derived from fault simulation, is used.

Built-In Self Test (BIST)

2. Pattern Generation

Built-In Self Test (BIST)

2. Pattern Generation

Built-In Self Test (BIST)

2. Pattern Generation

Built-In Self Test (BIST)

2. Pattern Generation

Built-In Self Test (BIST)

Pseudo-Random Generation using LFSR

2. Pattern Generation

Built-In Self Test (BIST)

Example of a 4-bit LFSR as a Pattern Generator.

Pseudorandom states generated by the LFSR.

Pseudo-Random Generation using LFSR

2. Pattern Generation

Built-In Self Test (BIST)

1. Introduction

2. Pattern Generation

3. Signature Analysis

4. BIST Architectures

5. Summary

3. Signature Analysis

Built-In Self Test (BIST)

3. Signature Analysis

Built-In Self Test (BIST)

Methods for Response Evaluation

Steps for Response Evaluation:

1

23

r-Bit (Internal XOR) Signature Generator.

The content of the LFSR is the remainder of the division operation.

3. Signature Analysis

Serial

Built-In Self Test (BIST)

Built-In Self Test (BIST)

r-Bit (External XOR) Signature Generator. The content of the LFSR is not the remainder of the division operation.

Serial

3. Signature Analysis

Serial

Example of a 4-bit (External) Signature Generator.

Built-In Self Test (BIST)

3. Signature Analysis

r-Bit (Internal XOR)

Parallel Signature Generator.

r-Bit (External XOR)

Parallel Signature Generator.

Parallel

Built-In Self Test (BIST)

3. Signature Analysis

Problem: Problem: When compacting results, there is a probability of fault maskingfault masking !

Probability of failing to detect an error in the response sequence:Probability of failing to detect an error in the response sequence:

Serial input Parallel input

Where: K: length of the sequence (# of bits)r: length of the LFRS (# of bits)

2mL- r

– 1

2mL

– 1

2k-r

– 1

2k – 1

Where: L: length of the sequence (# of test vectors)m: length of a vector (# of bits) r: length of the LFRS (# of bits)

Built-In Self Test (BIST)

3. Signature Analysis

Built-In Self Test (BIST)

3. Signature Analysis

Modular LFSR Serial Compacter Example

Built-In Self Test (BIST)

3. Signature Analysis

Modular LFSR Parallel Compacter Example

Built-In Self Test (BIST)

1. Introduction

2. Pattern Generation

3. Signature Analysis

4. BIST Architectures

5. Summary

Built-In Self Test (BIST)

4. BIST Architectures

Built-In Logic Block Observer (BILBO)

4. BIST Architectures

Built-In Self Test (BIST)

Modular Bus-Oriented Design with “BILBO”.

Built-In Self Test (BIST)

4. BIST Architectures

Built-In Logic Block Observer (BILBO)

4. BIST Architectures

Built-In Self Test (BIST)

Built-In Self Test (BIST)

4. BIST Architectures

General Form of a BILBO

B1 = 1, B2 = 1: S.A.B1 = 1, B2 = 0: Normal Op.B1 = 0, B2 = 0: ScanB1 = 0, B2 = 1: P.G.

MUX:B2 = 1: Out = Q1.B2 = 0: Out = Sin.

Example: 8-bit-Length Datapath

Built-In Self Test (BIST)

4. BIST Architectures

B1 = 1, B2 = 0: S.A.B1 = 1, B2 = 1: Normal Op.B1 = 0, B2 = 0: ScanB1 = 0, B2 = 1: Not Ap.

MUX:B1 = 1: Out = Q1.B1 = 0: Out = Sin.

Built-In Self Test (BIST)

Example: 8-bit-Length Datapath

4. BIST Architectures

Built-In Self Test (BIST)

Example: 8-bit-Length Datapath

4. BIST Architectures

Built-In Self Test (BIST)

1. Introduction

2. Pattern Generation

3. Signature Analysis

4. BIST Architectures

5. Summary

Built-In Self Test (BIST)