Display Subsystem Concurrent Online Testing via Checksum Comparison

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Solution Overview

Problem

Current display subsystems in applications like automotive advanced driver assistance systems (ADAS) and flight control systems lack effective concurrent online testing methods, which can lead to operational faults such as blank screens, frozen frames, or incorrect data display, compromising safety by introducing errors during image processing.

Innovation Solution

Implementing a concurrent online testing methodology within the display subsystem that performs built-in self-tests during normal operation, using a test pattern and checksum comparison to detect faults in hardware units, allowing for continuous monitoring and fault detection without entering a dedicated test mode.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dedicated test mode is used for display subsystem testing, then testing thoroughness is improved, but system operational time is reduced and productivity deteriorates

Engineering Contradiction:
Improvetesting thoroughnessVSAvoidsystem operational time
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements continuous testing of the display subsystem during normal operation by injecting test patterns into the image processing pipeline and comparing output checksums. This allows fault detection to occur continuously without interrupting the display function, maintaining both reliability and productivity. The testing process runs concurrently with normal display operations, eliminating the need to switch to dedicated test modes.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent performs preliminary fault detection by continuously monitoring the display subsystem during normal operation. Test patterns are injected and checksums are calculated in advance before actual faults manifest as visible display errors. This preliminary detection mechanism allows for early fault identification without requiring dedicated test time, resolving the contradiction between thorough testing and operational continuity.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If concurrent online testing is implemented, then fault detection capability is improved, but device complexity increases

Engineering Contradiction:
Improvefault detection capabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent reuses existing display subsystem components for dual purposes: the image processing pipeline processes both normal display content and test patterns, while the checksum calculation unit serves both error detection and testing functions. This multi-functionality approach enables fault detection capability without adding significant device complexity, as existing hardware is utilized for testing purposes.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The display subsystem performs self-testing by automatically injecting test patterns into its own processing pipeline and comparing output checksums against expected values. The system monitors itself without requiring external testing equipment or additional complex test infrastructure, thereby improving fault detection capability while minimizing increases in device complexity.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If test patterns are injected into image processing pipeline, then fault detection accuracy is improved, but processing time increases

Engineering Contradiction:
Improvefault detection accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements periodic injection of test patterns at specific intervals (e.g., at frame boundaries or during vertical blanking periods) rather than continuous injection. This periodic approach maintains fault detection accuracy by regularly testing the display subsystem while minimizing interference with normal image processing, thereby reducing additional processing time requirements.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies partial testing by selectively injecting test patterns into specific regions or channels of the image processing pipeline rather than processing entire frames with test patterns. This partial action approach maintains adequate fault detection accuracy for critical display functions while reducing the overall processing time penalty compared to full-frame test pattern injection.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3353769B1Apparatus and method for testing of display subsystems
Publication Date: 2022.09.14 QUALCOMM INC
  • EP3353769B1 patent drawingFigure 1
  • EP3353769B1 patent drawingFigure 2
  • EP3353769B1 patent drawingFigure 3A~3F

AI summary

A display processor of a display system may receive an image that includes a test pattern. An input checksum may be associated with the test pattern. Hardware units of the display processor may process the image. The display system may generate an output checksum based at least in part on the test pattern after processing of the image. The display system may detect a fault in the hardware units of the display processor based on determining a difference between the input checksum and the output checksum.