This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
Replies: 2
Views: 285
Part Number: DP83867IR
Hi All,
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.
ADDR
DATA
Description
0x001F
0x8000
Hard Reset
0x0053
0x2054
Threshold for consecutive amount of Idle symbols for Viterbi Idle detector to assert Idle Mode set to 5
0x00EF
0x3840
CAGC DC Compensation Disable
0x0102
0x7477
Master Training Timers - increasing time in different training states
0x0103
0x7777
0x0104
0x4577
0x010C
Timing Loop Bandwidth
0x01C2
0x7FDE
0x0115
0x5555
Slave Timers - increasing time in different training states
0x0118
0x0771
0x011D
0x6DB2
0x011E
0x3FFB
0x01C3
0xFFC6
0x01C4
0x0FC2
0x01C5
0x0FF0
0x012C
0x0E81
FFE Fix
0x4000
Soft Reset
If you have further questions please start a new E2E thread and our Ethernet team can clarify these items further for you.
Thanks,
Cecilia
Hi Cecilia,
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.
In reply to seokyeon kim1:
Hello,
Thanks for reading! Let's discuss on a separate thread as this seems to be an issue we can debug further.