• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 33 subscribers
  • Views 368 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.

DP83TG720S-Q1: Usage of the PHY without microcontroller for configuration.

Bernstein
Prodigy 10 points
Part Number: DP83TG720S-Q1


Dear technical team,

we are using the DP83TG720 PHY on one of our electronics and want to connect it to an external SPE to 1000Base-T converter also designed by ourselves in a space constrained scenario. We have observed severe performance issues (1MB/s max datarate) if the PHY registers are not configured by the Linux driver for both master and slave side. If the registers are set, the datarate is much better in a range of 85MB/s which is sufficient for our applications.

1. is it mandatory to configure the PHY so that it is most robust in a slave and master scenario?

2. Is there a revision planned that inherits the driver register settings without need of direct register access or is there a kind of workaround?

Thanks a lot and have a nice day,

Bernd

  • 0
    TI__Mastermind 40375 points

    Hi Bernd,

    The PHY will work out of the box, but if there is some initial configurations for your specific use case then there will be programming required. However, I would advise checking different link partners to see if the speed rate is an issue of the DUT or the link partner. We do have a 1G media converter that uses DP83TG720 and DP83867 available for purchase.

    Sincerely,

    Gerome

  • 0 in reply to Gerome Cacho
    Prodigy 10 points

    Hi Gerome,

    we have used the 1G media converter board of TI for checking if this is an hardware related issue or not, but we observed the same behaviour. Now we have the scenario that we have a "dumb" receiver of the data without a uC. We have checked some boards and the behaviour is pretty much the same.

    Some measurement results done with different boards

    Master - Slave
    Custom hardware - TI Eval Board
    unconfigured - unconfigured D 1MB/s U 1MB/s
    unconfigured - configured D 82MB/s U 3MB/s
    configured - unconfigured D 1MB/s U 1MB/s
    configured - configured D 82MB/s U 45MB/s

    Slave - Master
    Custom hardware - TI Eval Board
    unconfigured - unconfigured D 1MB/s U 1MB/s
    unconfigured - configured D 85MB/s U 1MB/s
    configured - unconfigured D 55MB/s U 51MB/s
    configured - configured D 85MB/s U 51MB/s

    Is the only solution to add always a uC to the PHY for the additional configuration or will there be a revision or new IC which inherits these registers out of the box?

    Thanks,

    Bernd

  • +1 in reply to Bernstein
    TI__Mastermind 40375 points

    Hi Bernd,

    For you application, there will need to have SMI programmability available for the PHY.

    Sincerely,

    Gerome