Part Number: DP83867IR
If you are encountering an issue with packet loss or CRC errors while using the DP83867, please consider some of these items for debug when using short cables.
Short cables at 1m or less in length for your device may experience signal quality issues. One reason could be that the digital signal processing internally may take too long to converge or may even converge incorrectly at shorter lengths which could result to a bad SNR - Signal to Noise Ratio. This then creates link dropping or potential packet losses which may require you to reset your device before beginning packet transfer again.
We have a script below that will be updated in the next revision of the DP83867 datasheet that should help eliminate any packet loss errors due to short cabling. This scripts allows for a change in the timing bandwidths to ensure the DSP converges correctly.
Threshold for consecutive amount of Idle symbols for Viterbi Idle detector to assert Idle Mode set to 5
CAGC DC Compensation Disable
Master Training Timers - increasing time in different training states
Timing Loop Bandwidth
Slave Timers - increasing time in different training states
If you have further questions please start a new E2E thread and our Ethernet team can clarify these items further for you.
I am the engineer who raised the above issue.
Thank you for organizing the above issues in a credible form.
I have an additional question, is the SNR issue for 1m applied equally to all communication frequency bands?
Or could the length vary depending on the frequency?
I ask a question because the wave length will vary depending on the frequency and it seems to be related to the part where the SNR becomes weak.
We are glad that we were able to resolve this issue, and will now proceed to close this thread.
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In reply to seokyeon kim1:
Thanks for reading! Let's discuss on a separate thread as this seems to be an issue we can debug further.
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