BIST Signature Adjustment Code for ROM Self-Verification

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In integrated circuits with Built-In Self-Test (BIST) circuits, changing the code or data stored in ROM requires updating the predetermined signature pattern, leading to additional mask costs and testing expenses, especially for electronic products that need to execute BIST every time they turn on.

Innovation Solution

An integrated circuit design that includes a BIST circuit, a ROM storing information and a BIST signature adjustment code irrelevant to functional data, allowing the generation of a signature pattern identical to previous versions by using a BIST signature adjustment code to match the signature pattern of the previous chip, thus avoiding changes to the predetermined signature pattern and reducing mask redesign and testing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the code or data stored in ROM is changed, then the functionality of the electronic product is improved or updated, but the predetermined signature pattern must be updated, leading to additional mask costs and testing expenses

Engineering Contradiction:

ImproveROM content update capabilityVSAvoidmask cost and testing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent introduces a BIST signature adjustment code as an intermediary element stored in the ROM. This adjustment code acts as a mediator between the functional data and the BIST verification process. When ROM content needs to be updated, only the adjustment code changes while the predetermined signature pattern remains constant, thus avoiding mask redesign costs

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the ROM content into two distinct parts: functional data and BIST signature adjustment code. This segmentation allows independent management of each part - functional data can be updated without affecting the BIST verification mechanism, while the adjustment code handles the signature pattern adaptation, thereby reducing manufacturing costs

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If the predetermined signature pattern is updated to match new ROM content, then the BIST verification accuracy is maintained, but the design complexity and testing requirements increase

Engineering Contradiction:

ImproveBIST verification accuracyVSAvoiddesign complexity and testing requirements

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The BIST circuit performs self-verification by automatically generating a signature pattern from the ROM content and comparing it with the predetermined signature pattern. The BIST signature adjustment code enables this self-service mechanism to work correctly without requiring external intervention to update the predetermined pattern, thus maintaining verification accuracy while reducing design complexity

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent changes the parameter that needs to be updated from the predetermined signature pattern to the BIST signature adjustment code stored in ROM. This parameter change strategy maintains BIST verification accuracy because the comparison mechanism remains the same, while significantly reducing design complexity since the adjustment code can be freely modified without affecting the fixed predetermined pattern

Inventive Principle:

Principle #35Parameter changes

3Productivity

If the BIST circuit uses a fixed predetermined signature pattern, then the verification process is simple and fast, but any ROM updates require costly mask redesign

Engineering Contradiction:

Improveverification speed and simplicityVSAvoidROM update flexibility

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent segments ROM content into functional data and BIST signature adjustment code, allowing the verification process to remain simple and fast using the fixed predetermined signature pattern, while simultaneously enabling ROM update flexibility through modification of the adjustment code portion

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The BIST signature adjustment code serves as an intermediary that enables ROM updates without requiring changes to the predetermined signature pattern. This intermediary maintains the simplicity and speed of the verification process while providing the flexibility to update ROM content

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9885754B2Integrated circuit with self-verification function, verification method and method for generating a BIST signature adjustment code

Publication Date: 2018.02.06 REALTEK SEMICON CORP

AI summary

An integrated circuit includes a Built-In Self-Test (BIST) circuit, a predetermined signature pattern and a Read Only Memory (ROM), wherein the predetermined signature pattern is stored in the integrated circuit. The ROM stores at least effective information and a BIST signature adjustment code, the BIST signature adjustment code is irrelevant to any functional information stored in the ROM; wherein the BIST circuit is used to test content stored in the ROM to generate a signature pattern, and compare the signature pattern with the predetermined signature pattern to judge if the content stored in the ROM has error.