PHY Compliance Measurement Using Characterized Ethernet Test Fixtures
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Solution Overview
Problem
Current communication standards impose strict and impractical requirements on test fixtures for measuring physical layer parameter compliance, particularly for high-speed and multi-lane communication devices, making it difficult to design and manufacture suitable test fixtures.
Innovation Solution
A method and system that determine physical layer parameter compliance by embedding measured test fixture parameters into a reference model specified by the communication standard, allowing for relaxed test fixture requirements and flexible placement of I/O contacts, using a measurement system with processors to calculate reference values and assess compliance based on measured values at a test fixture point corresponding to an IC package contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If strict test fixture requirements are imposed to ensure accurate PHY parameter compliance measurement, then measurement precision is improved, but device complexity and manufacturing difficulty increase significantly
Solution Approach 1:
The patent introduces a test fixture as an intermediary component between the DUT and measurement equipment. The test fixture includes a channel with characterized parameters (loss, delay, impedance) that mediates the signal transmission. By measuring and compensating for the test fixture's parameters, accurate DUT compliance measurement is achieved without requiring the test fixture itself to meet strict specifications.
Solution Approach 2:
The patent changes the approach from requiring fixed test fixture parameters to measuring actual test fixture parameters (loss, delay, impedance) and using these measured values for compliance determination. This parameter measurement and compensation approach allows flexible test fixture design while maintaining measurement accuracy.
2Measurement precision
If strict test fixture loss requirements are specified to ensure compliance measurement accuracy, then measurement precision is improved, but ease of manufacture deteriorates
Solution Approach 1:
The test fixture performs self-characterization by including measurement capabilities to determine its own parameters (loss, delay, impedance). The test fixture measures its channel characteristics and uses this self-obtained information to enable accurate DUT compliance measurement, eliminating the need for external characterization and strict manufacturing specifications.
Solution Approach 2:
The patent transitions from fixed parameter specifications to measured parameter usage. Instead of requiring the test fixture to have predetermined loss values within tight tolerances, the actual measured loss of the test fixture channel is used for compliance determination, greatly simplifying manufacturing.
3Measurement precision
If test fixtures are designed with strict parameter specifications to reflect I/O contact compliance, then measurement precision is improved, but productivity decreases due to difficult design and manufacture
Solution Approach 1:
The patent performs preliminary measurement and characterization of the test fixture channel parameters before DUT compliance measurement. By pre-measuring and storing the test fixture's loss, delay, and impedance parameters, the system prepares compensation data in advance, enabling efficient compliance determination without requiring complex real-time calculations during actual testing.
4Measurement precision
If narrow range requirements are imposed on test fixture parameters, then measurement precision is improved, but adaptability decreases
Solution Approach 1:
The patent fundamentally changes from fixed parameter specifications to measured parameter usage. The test fixture channel's actual measured parameters (loss, delay, impedance) are used instead of predetermined specifications. This allows the same test fixture to be used for different compliance measurements by simply measuring and inputting the actual channel parameters, greatly enhancing adaptability.
Data Source
AI summary
An integrated circuit (IC) is manufactured and is mounted in an IC package. A processor of a measurement system determines a reference value of a physical layer (PHY) parameter at a second test point on a test fixture based on one or more model values, specified by an Ethernet communication standard, corresponding to a first test point on the test fixture corresponding to a contact on the IC package and one or more measured test fixture parameters characterizing a channel connecting the first test point to the second test point on the test fixture. The processor then determines whether the PHY parameter at the first test point on the IC package complies with the Ethernet communication standard based on i) the reference value of the PHY parameter and ii) a measured value of the PHY parameter obtained from a measurement of the PHY parameter at the second test point.