Fabric Bridge Controller In-Field Self-Testing for Processor Reliability

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Solution Overview

Problem

Integrated circuits (ICs) face challenges in meeting stringent low defect requirements, particularly in autonomous driving systems, due to high process defect density and 'walking dead units' that fail after initial testing, with current testing schemes being inadequate for in-field operation.

Innovation Solution

The implementation of a dynamic functional safety testing capability within ICs, utilizing a fabric bridge controller to periodically perform self-testing, generate test patterns, and report defects, allowing for the identification and correction of errors, including latent faults and environmental failures, without significant cost increases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If manufacturing-based testing is performed by manufacturer or platform manufacturer, then initial product quality can be ensured, but in-field failures cannot be detected and defect rate remains high

Engineering Contradiction:
Improvein-field reliabilityVSAvoidtesting system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The fabric interconnect performs self-testing through built-in test pattern generation and evaluation logic. The fabric bridge controller initiates tests and the fabric autonomously generates test patterns, routes them through interconnect paths, and evaluates results without requiring external testing equipment, enabling in-field defect detection

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Test patterns are generated and evaluation logic is built into the fabric structure during manufacturing. This preliminary preparation of testing capability within the fabric allows immediate in-field testing without requiring complex external test equipment when the product is deployed

Inventive Principle:
Principle #10Preliminary action

2Reliability

If stringent low defect requirements are implemented for autonomous driving systems, then functional safety is improved, but product cost increases substantially

Engineering Contradiction:
Improvefunctional safetyVSAvoidproduct cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The fabric interconnect performs self-testing through built-in test pattern generation and evaluation logic. The fabric bridge controller initiates tests and the fabric autonomously generates test patterns, routes them through interconnect paths, and evaluates results without requiring external testing equipment, enabling in-field defect detection

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The testing approach changes from external manufacturing-based testing to internal in-field self-testing. This parameter change in when and how testing occurs allows meeting functional safety requirements without substantial cost increase by using existing fabric resources for testing

Inventive Principle:
Principle #35Parameter changes

3Productivity

If high process defect density is present in process nodes of 14 nanometers and smaller, then manufacturing capability is maintained, but defect rate per million increases

Engineering Contradiction:
Improvemanufacturing capabilityVSAvoiddefect rate per million
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The fabric evaluation logic provides feedback about test pattern results to indicate potential defects. This feedback mechanism allows detection of defects that occur during manufacturing or in-field operation, enabling identification of issues despite high process defect density in advanced process nodes

Inventive Principle:
Principle #23Feedback

4Ease of manufacture

If walking dead units occur that pass initial testing but fail in field, then initial product testing is sufficient, but in-field reliability deteriorates

Engineering Contradiction:
Improveinitial testing sufficiencyVSAvoidin-field reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The fabric interconnect performs self-testing through built-in test pattern generation and evaluation logic. The fabric bridge controller initiates tests and the fabric autonomously generates test patterns, routes them through interconnect paths, and evaluates results without requiring external testing equipment, enabling in-field defect detection

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The fabric can perform self-testing periodically or on-demand during in-field operation. This periodic testing capability allows detection of defects that develop after initial manufacturing testing, such as walking dead units, without requiring continuous external monitoring

Inventive Principle:
Principle #19Periodic action

Data Source

PatentUS11686767B2System, apparatus and method for functional testing of one or more fabrics of a processor
Publication Date: 2023.06.27 INTEL CORP
  • US11686767B2 patent drawing
  • US11686767B2 patent drawing
  • US11686767B2 patent drawing

AI summary

In one embodiment, an apparatus includes at least one fabric to interface with a plurality of intellectual property (IP) blocks of the apparatus, the at least one fabric including at least one status storage, and a fabric bridge controller coupled to the at least one fabric. The fabric bridge controller may be configured to initiate a functional safety test of the at least one fabric in response to a fabric test signal received during functional operation of the apparatus, receive a result of the functional safety test via the at least one status storage, and send to a destination location a test report based on the result. Other embodiments are described and claimed.