• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 34 subscribers
  • Views 716 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

DS110DF410: DS110DF410 show high bit error rate while unplug the SFP+ cable and plug the SFP+ cable again.

Peter Chen(ICP_FAE)
Intellectual 2480 points
Part Number: DS110DF410

the board with DS110DF410 supporting 10Gbps application. customer report high bit error rate while unplug the SFP+ cable and plug the SFP+ cable again.

issue descriptions (step by step):

1) plug the SFP+ and power up the system, 10Gbps communication function well(no bit error)

2) remove the SFP+ cable then plug the SFP+ cable back again(bit error happen)===> issue

3) if in step 2) then reboot the system again, there is no bit error problem.

I capture the register map in with and without bit error condition. I found it might due to CDR unlock.

questions:

1) Does the DS110DF410 need load its configuration again while SFP+ cable been remove and plug it back?

2) Can you review the register map and support your thoughts?

  • 0
    Prodigy 10 points
    When the SFP+ port comes up again, do we need to load its (DS110DF410) configuration again or just reset CDR when port goes down and release the reset when port comes up?
  • 0 in reply to Yuchia Chen
    TI__Intellectual 870 points

    Hi Yuchia,

     

    There is no need to re-configure the retimer.

     

    The register dump value seems strange to me. For the RX, Channel register Reg_0x02=0x04 means CDR does not lock. This means for both good and bad cases, CDR are not able to lock.

     

    Before knowing more details(register settings, application block diagram, trace length, cable type, full channel register dump for TX and RX), I would suggest trying adapt mode 0 for the retimer at the RX direction(receive signal from optical module) to see this is solving the problem. I am posting the below adapt mode 0 recipe for the RX direction to see if this is helping.

     

     

     

    Address

    Value

    Description

    1

    Shared Register

    0xFF

    0x0C

    Select all the channels to set the same settings(Ch0,Ch1,Ch2,Ch3)

    Please select the right channel to configure accordingly

    2

    Channel

    0x2F

    0x04

    Select to support 10.3125Gbps and 1.25Gbps

    3

    Channel

    0x36

    0x31

    Select Ref-mode3(this  0x31 is the default value of register 0x36)

    4

    Channel

    0x31

    0x00

    Set adapt mode 0

    5

    Channel

    0x3A

    0x00

    EQ=0x00

    6

    Channel

    0x40

    0x00

    EQ=0x00

    7

    Channel

    0x03

    0x00

    EQ=0x00

    8

    Channel

    0x2D

    0x80

    Configure the VOD, default is 600mV

    9

    Channel

    0x15

    0x10

    Configure the DEM, default is 0db

    10

    Channel

    0xA

    0x1c

    Reset CDR

    11

    Channel

    0xA

    0x10

    Release CDR Reset

    Note:  Register 0x3A, Register 0x40 and register 0x03’s value need to be the same. Here the CTLE string value is 0x00. Customer can set other CTLE values that defined in table 14 on the datasheet

    Regards

    Liang