Hello,
I'm investigating an issue where two DP83867IS PHYs are connected through a backplane and every once in a while transmission errors occur directly after the link is up.
For testing I wrote a small program that transmits a few UDP packets that get looped back/echoed on the other device, power down the PHY, wait a moment, power it back up, wait for the link to come up and repeat. Most of the time this works as expected with no problems at all. But every once in a while a few packets get lost.
With a second program I monitor the PHYs register (polling every 10ms and writing the values to a file if something changed).
I've observed to things when the error occured:
- The value of the STS2 register changes. From 0x0002 to 0x0003, 0x0005 and 0x0007.
- The value in the RECR register increases.
These bits 5:0 in the STS2 register are documented as reserved. Can anyone provide additional information on these?
And does anyone have some experience on what might cause the RECR value to increase?
In a previous iteration of my test program I didn't power the PHY down but set it into standby mode and the error did not occur. Could this indicate a problem with the power supplies?
Thanks for any advice!
Regards
Ferdinand
