How Can I Create MDIO Master Signals to Exercise and Test an MDIO Port?

Question from the Customer:

I have been using the Beagle I2C/SPI Protocol Analyzer as an MDIO analyzer.  Today, I need to exercise a CFP2 MDIO port, reading at 2.5 MHz, or 4 MHz MDC rates at 2.5V. I have  the Aardvark I2C/SPI Host Adapter and the Cheetah SPI Host Adapter – could either do the job?

Response from Technical Support:

Thanks for your question! The Aardvark and Cheetah adapters do not support MDIO.  However, we do have a recommendation. For emulating signals over the SPI lines, we suggest using the Promira Serial Platform with and the appropriate Active Level Software, such as SPI Active - Level 1 Application.

Why Use the Promira Serial Platform

The Promira platform has many built-in features, including level shifting. Here is a summary:

  • Level Shifting: 0.9 – 5.0V. For your setup, this feature saves you from integrating another component, the Level Shifter Board, in your setup.
  • High-speed USB connectivity
  • Ethernet connectivity

Additional features are available per Active Level application. The table below summarizes shows the features per application.

I2C SPI device features

Emulating MDIO Signals

The Promira API allows you to develop the script to control two GPIO lines, making it possible to use the Promira platform as a MDIO master.

  • One line operates as the MDIO clock (management data clock, similar to SPI clock)
  • One line operates as the bidirectional MDIO data

The Promira API supports several operating systems and programming languages.  In addition, functional examples are provided that can be used as-is or modified for your setup requirements. For more information, please refer to the API Documentation section of the  Promira I2C/SPI Active User Manual

Please note, as the clock is software-driven, the duration of the clock periods cannot be controlled, only the clock edges.

We hope this answers your questions. Additional resources that you may find helpful include the following:

If you want more information, feel free to contact us with your questions, or request a demo that applies to your application.

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