We are having trouble integrating the Verdin MP onto our custom carrier. The issue might be an impedance mismatch between the RGMII traces on our carrier and the impedance on the module.
We are seeing bad reflections when the module is installed. Can you tell us the designed impedance on the module?
I can send pics from the scope if needed.
Hi @frank.borkowski,
Please, check section 2.3 Ethernet of the Verdin Carrier Board Design Guide.
Can you please check if your custom carrier board schematics follow the schematics proposed in the design guide?
Best Regards,
Hiago.
Sorry. One of my team-mates found documentation that you designed the module for 55 Ohms on single traces (which applies to the RGMII signals). And I am an idiot, failing to realize that I am looking in the middle of a transmission line with source termination, not the ball of the iMX8. So I should expect a partial transition on the incident wave and the full swing on the reflected wave. This is in fact what I am seeing.
Once I did some hardware things to delay the clock by 2 ns (into the eye of the data), we were able to receive the packet without errors.
This issue is resolved.
Hi @frank.borkowski,
I’m glad it’s solved now. Feel free to reach us if you have any further questions.
Best Regards,
Hiago.
