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DP83822IF: PHY Auto negotiation failes + Link not established

Part Number: DP83822IF

Tool/software:

hello, 

we are having problem with what we belive is the auto negotiation process / Link not established.

we are using your PHY DP83822IFRHBR in our Servodrive in order to communicate via EtherCAT - we have two PHYs in our drive -Phy0 is IN and Phy1 is Out.

on some units we are having this issue almost every power-cycle of the drive and on other drives we are having it once in a while. 

setup:

port type: EtherCAT

Autonegotiation on

speed 100M

Full duplex

Auto-MDIX

MII (for interface)

Usually reseting the PHY via Serial command solves the issue.

This scenario is the most common:

here is a printout of the registers and there values when its NOT working
SWDrive reset Done

0>>>>phystatus 0

Register 0 : 0x00003100
Register 1 : 0x00007849
Register 4 : 0x00000181
Register 5 : 0x00000000
Register 6 : 0x00000005
Register 9 : 0x00000000
Register 10 : 0x00000100
Register 11 : 0x00001000
Register 16 : 0x00000002
Register 17 : 0x00000108
Register 24 : 0x00000400
Register 25 : 0x00008020
Register 37 : 0x00000240
Register 0x467 : 0x000003C3
Register 0x468 : 0x00000000
Register 0x4D1 : 0x0000018B

0>>>>phystatus 1

Register 0 : 0x00003100
Register 1 : 0x00007849
Register 4 : 0x00000181
Register 5 : 0x00000000
Register 6 : 0x00000004
Register 9 : 0x00000000
Register 10 : 0x00000100
Register 11 : 0x00001000
Register 16 : 0x00004002
Register 17 : 0x00000108
Register 24 : 0x00000400
Register 25 : 0x00008021
Register 37 : 0x00000040
Register 0x467 : 0x00000FC3
Register 0x468 : 0x00000000
Register 0x4D1 : 0x0000018B

and here is a print out when it is working:

phystatus 0

Register 0 : 0x00003100
Register 1 : 0x0000786D
Register 4 : 0x00000181
Register 5 : 0x0000C181
Register 6 : 0x0000000D
Register 9 : 0x00000000
Register 10 : 0x00000100
Register 11 : 0x00001000
Register 16 : 0x00005E15
Register 17 : 0x00000108
Register 24 : 0x00000400
Register 25 : 0x00008C20
Register 37 : 0x00000240
Register 0x467 : 0x000003C3
Register 0x468 : 0x00000000
Register 0x4D1 : 0x0000018B

phystatus 1

Register 0 : 0x00003100
Register 1 : 0x0000786D
Register 4 : 0x00000181
Register 5 : 0x0000C181
Register 6 : 0x0000000D
Register 9 : 0x00000000
Register 10 : 0x00000100
Register 11 : 0x00001000
Register 16 : 0x00000E15
Register 17 : 0x00000108
Register 24 : 0x00000400
Register 25 : 0x00008C21
Register 37 : 0x00000040
Register 0x467 : 0x00000FC3
Register 0x468 : 0x00000000
Register 0x4D1 : 0x0000018B

This scenario is less common:

0>>>>phystatus 0
Register 0 : 0x00003000
Register 1 : 0x00007849
Register 4 : 0x00000181
Register 5 : 0x0000C181
Register 6 : 0x0000000F
Register 9 : 0x00000000
Register 10 : 0x00000000
Register 11 : 0x00001000
Register 16 : 0x00005002
Register 17 : 0x00000008
Register 24 : 0x00000400
Register 25 : 0x00008020
Register 37 : 0x00000240
Register 1123 : 0x00000001
0>>>>PhyReset 0
(after reseting the phy the Link was established)
0>>>>phystatus 0
Register 0 : 0x00003100
Register 1 : 0x0000786D
Register 4 : 0x000001E1
Register 5 : 0x0000C1E1
Register 6 : 0x0000000F
Register 9 : 0x00000000
Register 10 : 0x00000100
Register 11 : 0x00001000
Register 16 : 0x00000215
Register 17 : 0x00000108
Register 24 : 0x00000400
Register 25 : 0x00008C20
Register 37 : 0x00000200
Register 1123 : 0x00000000
0>>>>
Thanks for your help, please answer asap
  • Hello,

    Allow me to look at this and please expect response by my EoD.

    Sincerely,

    Gerome

  • Hello,

    How are you reset PHY? Via which registers?

    What is link partner, cable type and length used?

    Is there anything triggering this linkdown, or is it link down at powerup?

    Can you please go through this document and try out the steps listed here to establish baseline debugging status and understanding of the system?

    Sincerely,

    Gerome

  • Hello Gerome, thanks for your reply, i will go through this document and let you know. 

    i am resetting the PHY using register 0  - first i am setting bit 11 to '1' and then bits 9 and 15.

    the device can be connected using two types of cables  (both length of 1m)

    1, one is M8 to M8 - so Phy to Phy (OUT from one drive and IN to another) 

    2, also can be connected via M8 to RJ45 -  (usually will be connected to a motion controller / Master) 

    when link down its 99% of the times at powerup, however we also noticed that while motor running that the phy losses its link and is not communicative while motor is running - this is a safety issue as well - big concern but harder to reproduce

  • Hello,

    For now, I would like to focus on the controllable issue; link down at powerup.

    You are stating that PHY is unable to linkup at startup, but issuing a register/software reset would fix the issue. So PHY is able to linkup in the first place, but there a timing aspect that is going on. 

    Some questions:

    - If no reset is given, will PHY forever not link up?

    - Can you please confirm power-on requirements have been met per datasheet?

    - What is the link partner for both PHYs? Could you try if the in and out ports are connected to each other as spotcheck if issue does not lie on DUT but on link partner?

    Sincerely,

    Gerome

  • Hi Gerome, 

    unfortunately I was sick with Covid the last few days and did not have a change to work on a solution -

    * i will test today and see if the PHY will resume connection on its own - without reset command.

    * i will ask my HW guy about the Power-up requirements - But i believe it was met

     the phys are connected to each other i have two drive (each has two phys which we set as Phy0(IN) and Phy1(OUT) in our setup the link partner are one drive's Phy0 and one drive's Phy1 

    We have noticed that in register 0x04D1 Energy Efficient Ethernet Configuration Register #2  bit0 is strap register but in our schematic it is set to 0 but we read 1, therefor i would like to send you our HW design schematics - do you have a private email i can sent it over to you?

    Thanks

  • Hello,

    Please reach out to your field representative for further email communication.
    Sincerely,

    Gerome

  • PHy will not resume connection on its own - once link was not established at startup - waited 5 minutes ( i believe its enough) and not link up (just for the test after the waited time, i reset via command and link was established)

    our Reset signal time is 1ms, according to the data sheet we need at least 10us - so i believe we are ok

  • Hello,

    What about the other PHY specs? Is the ramp time good? What about clock stabilization?

    Without link partner, if you scope the MDI using a diff probe with 100 Ohm termination differentially, do you see the FLP?

    Can you also look to compare the power sequence against our EVM?

    Sincerely,

    Gerome