Pixel-Accurate Test Method for High-Speed Serial Transmitters
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Solution Overview
Problem
Existing methods for testing high-speed pixel information, such as those used in DisplayPort, are costly and impractical due to long test times and difficulty in distinguishing failures in Automated Test Equipment (ATE) versus LCD panels, especially at speeds like 1.62 Gbps and 2.7 Gbps.
Innovation Solution
A low-cost, pixel-accurate test method and apparatus using a field programmable gate array (FPGA) to generate and compare test data patterns, identifying per-pixel errors and their locations, capable of real-time data streaming and supporting high-speed serial transfer rates up to 10.7 Gbps, adaptable for board-level and ATE testing, and compatible with LCD panels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ATE high-speed channel is used to measure eye pattern and capture thousands of cycles of data patterns, then measurement precision is improved, but device complexity and cost increase significantly
Solution Approach 1:
The patent creates a virtual reference model that generates expected pixel data patterns digitally, replacing the need for complex physical ATE equipment. The reference model replicates the pixel generation circuit behavior to produce reference data that can be compared against actual output, achieving measurement precision without expensive instrumentation
Solution Approach 2:
The patent replaces the mechanical/electrical ATE measurement system with a software-based virtual reference model. Instead of using physical high-speed channels and eye pattern analyzers, the solution uses digital signal processing and algorithmic pattern generation to achieve the same measurement objectives
2Measurement precision
If ATE is used for testing high-speed pixel information, then measurement capability is improved, but test time increases making it impractical
Solution Approach 1:
The virtual reference model pre-generates expected pixel data patterns based on known input sequences and the pixel generation circuit logic. By preparing reference data in advance through algorithmic generation rather than capturing thousands of cycles during testing, the system achieves rapid comparison and fault detection
Solution Approach 2:
The patent enables rapid testing by directly comparing actual pixel output against pre-computed reference patterns without the need to capture and analyze thousands of data cycles. This skipping of lengthy measurement processes allows fast fault identification while maintaining measurement precision
3Measurement precision
If ATE is used for testing, then measurement capability is improved, but difficulty in distinguishing failure location increases
Solution Approach 1:
The patent segments the pixel data stream into individual pixel units and compares each pixel's actual output against its corresponding reference pattern independently. This pixel-level segmentation allows precise identification of which specific pixel or group of pixels is faulty, rather than only detecting general data errors
Solution Approach 2:
The virtual reference model acts as an intermediary that generates expected output patterns for each pixel position. By introducing this reference layer between the input data and the actual pixel output, the system can pinpoint exactly where deviations occur in the data path, enabling precise failure location identification
4Measurement precision
If expensive commercial test instrumentation is used, then measurement precision is improved, but cost increases
Solution Approach 1:
The patent replaces expensive, complex commercial test instrumentation with a software-based virtual reference model that runs on standard computing hardware. The virtual reference model is a software construct rather than physical equipment, eliminating the need for costly specialized instruments while maintaining measurement precision
Solution Approach 2:
The virtual reference model can be configured to test different pixel generation circuit designs and configurations through software modification rather than requiring different physical test equipment. This universality allows a single low-cost platform to perform multiple testing functions that would otherwise require expensive specialized instrumentation
Data Source
AI summary
A method and system of testing pixels output from a pixel generation unit under test includes generating pixels from the pixel generation unit under test using a first test data pattern to generate pixel information. The method and system also generate a per pixel error value for a pixel from the unit under test that contains an error based on the pixel by pixel comparison with pixel information generated substantially concurrently with pixels by a different unit using the first test data pattern. If desired, corresponding pixel screen location information (e.g., x-y location) can also be determined for the pixel that has the error. The per pixel error and x-y location information can be displayed.