Hi all
we use the DP83848 for 100Base-Tx and 10Base-T communication and the QualiPHY test-suite of Teledyne Lecroy.
All 100Base-TX tests are passed. But the TP_IDL Load 2 with TPM of 10Base-T is still failing. The test report is attached as well as our MDI schematics.
We worked on all possible adjusting screws:
-Replaced the filtering resistor R203 with 0R.
-Moved R62/R63 termination closely to the tranformer.
-Removed optional filter MLCCs C114...C117
The differential pairs are routed on the top layer witrh 100 Ohm +- 15% differential impedance.
Our last idea would be to reduce the impedance tolerance of the PCB altough we are not sure if this fixes the issue.
The PHY is set-up for random data generation as follows:
| ./phyio -d eth0 -a 0x01 -r 0x00 -w 0x8000 |
| ./phyio -d eth0 -a 0x01 -r 0x01 -w 0x1000 |
| ./phyio -d eth0 -a 0x01 -r 0x1A -w 0x845 |
| ./phyio -d eth0 -a 0x01 -r 0x19 -w 0x8120 |
Thanks in advance.
BR Achim
Neues_PCBA_10Base-T.pdf
