• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 32 subscribers
  • Views 1690 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

DP83867IR: DP83867 TDR enable

billy
Prodigy 90 points
Part Number: DP83867IR
Other Parts Discussed in Thread: DP83867CR

Hello

I'm using dp83867 phy chip with custom board.

I'm in the process of developing a cable tester to measurement lenth etc using tdr function.

Can I know process to enable TDR and get result using dp83867?

I have checked document dp83867cr.pdf. TDR measurement is described as below.

8.4.6.1 TDR

-> TDR could be automatically activated when the link fails or is dropped by setting bit 7 of register 0x0009 (CFG1). 

dp83867 TDR function only active when link down? It's not support active link cable?

Thanks in advance.

billy

  • 0
    TI__Mastermind 23675 points
    Hi Billy,

    You can enable TDR with the auto run like you describe or manually execute it by setting bit[0] in register 0x1Eh.
    When running TDR, no active link is allowed.

    TDR completion is bit[1] within register 0x1Eh.
    TDR configuration is found in register 0x180h.
    TDR peak locations found in registers 0x190h - 0x199h.
    TDR amplitude found in registers 0x19Ah - 0x1A3h.
    TDR status found in register 0x1A4h.

    Please use the DP83822 TDR application note to understand how to use the register fields:
    www.ti.com/.../snla253.pdf

    Best regards,
    Ross
  • 0 in reply to Ross Pimentel
    Prodigy 90 points

    Thank you for your help, Ross!

    -> When running TDR, no active link is allowed. 

    When checking active link cable,

    first link down on purpose and then execute TDR? 

    Thanks in advance

    Billy

  • 0 in reply to billy
    TI__Mastermind 23675 points
    Hi Billy,

    You will need to only ensure that the link partner is silent to run TDR (i.e. either not awake, not connected, etc..).
    The purpose of TDR is to detect faults in the line when link is dropped or not established and also to check the quality of the channel when connected to a Link Partner.
    However, for the case when connected to a Link Partner, the Link Partner must be silent so that the injected pulses by the DUT are not influenced by the partner.

    Best regards,
    Ross