• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 62 subscribers
  • Views 191 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.

DCP021212D: Trying avoid external sync circuit

Dan Ringger
Intellectual 1790 points
Part Number: DCP021212D
Other Parts Discussed in Thread: DP83826I

Hello - In looking at the DCP021212D data sheet, it states you can sync up to 8 devices together.  I would like to avoid using an external sync circuit so can I use 4 stand alone devices?  Thank you

  • 0
    TI__Expert 8130 points

    Hello Dan,

    I'm not understanding what you would like to do. Are you trying to leave them all floating or tie them together?

    Either way should be fine without an external clock.

    Regards,
    Alejandro

  • 0 in reply to iAlejandro
    TI__Intellectual 1790 points

    Thanks for writing back. We've resigned ourselves to wedging some strap resistors into the PCB layout, particularly three, to set the MAC Mode and the PHY address as with your help it has become clear that those few strap resistors are unavoidable and must be included in the already packed PCB layout.

    It's just an isolated question for the DP83826I. I want to make sure that when a SMI bit has "R/W,STRAP" in the "Type" column, that means I can overwrite the strap value via SMI.

    In the specific case, the bit I am looking at is in register BMCR (register address 0), specifically bit 8 Duplex Mode.

    • After the strap values latch, can I override this strap value via the SMI, that is, via MDC + MDIO?
    • If you could confirm overriding the strap value via SMI is also possible for bits 12 (Auto-Negotiation Enable) and 13 (Speed Selection) in this same register BMCR (address 0) I would appreciate it as well.

    The internal pull-down resistor would default this to "Auto Negotiation Disable" "Speed 10M" "Half-Duplex" mode, which is not what I want, so I would have to overwrite via SMI after the strap values latch. Please advise if I can override these strap values via the SMI.

  • 0 in reply to Dan Ringger
    TI__Expert 8130 points

    Unfortunately, I am not aware of that device. That is not part of our coverage of parts. Please open up a new thread with that part number so you can get the proper support. They will get back to you accordingly.

    Thanks,
    Alejandro

  • 0 in reply to iAlejandro
    TI__Intellectual 1790 points

    Sorry posted wrong E2E thread before.  For the DCP and your initial question, just want to make sure that you can connect up to eight DCP-02's together  via syncpin without an external clock

  • 0 in reply to Dan Ringger
    TI__Expert 8130 points

    Dan,

    I want to make sure I am understanding your question correctly. Your first question was in regards to four DCP02's.
    You just stated eight..? Can you please clarify your application/question?

    Thanks,
    Alejandro