• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 33 subscribers
  • Views 646 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.

DP83640: DP83640 forced mode

yoann le jeune
Prodigy 30 points
Part Number: DP83640

Hi

Currently, we are using the DP83640 PHYTER to link 2 of our equipments. Until this day we linked them at 100M in FullDuplex with auto-negociation. Our customer is asking us to speed up the boot. So now, we are trying to link our PHYTERs in forced mode to avoid extra timing due to auto-negociation.

But we are not able to link PHYTERs by this way. If the BMCR register is loaded with AUTONEG bit set to 0 and with link information (100M/FD), the link status in BSMR register is never set to 1 (as in the PHYSTS register too).

Please let us know suggestions to implement this solution.

  • 0
    TI__Mastermind 23675 points
    Hi Yoann,

    Can you confirm a few things:
    1. Is your link partner capable of parallel detection?
    2. Is your link partner capable of supporting 100Mbps speeds?
    3. Are you using forced or auto-mdix? How about your link partner? What type of cable are you using (i.e. cross or straight)?
    4. When you force to 100Mbps do you see MLT3 signaling on the MDI? Please send me a scope shot
    5. You can also enable 100Mbps Forced through bootstraps, have you tried this as well to rule our a software issue with your drive?

    Kind regards,
    Ross
  • 0 in reply to Ross Pimentel
    Prodigy 30 points

    Hi Ross

    1.    In our both devices, the same PHYTER is used. Parallel detection is used when a device that is capable of autonegotiation is connected to one that is not, isn’t it? But in our system, PHYTERs are configured with same values to avoid Auto-Negociation. In the following diagram I summarize our system architecture.
    2.    Yes. When auto-negociation is enabled both device are able to communicate at 100M in FULL DUPLEX mode.
    3.    AUTO-MDIX is enabled but we are using a straight cable to link our devices. What we want is to configure our devices with the same speed and duplex mode to avoid the autoneg process.
    4.    I’ll send you a shot as soon as the hardware enginner will be available.
    5.    Yes we did. We have forced duplex mode and speed via bootstrap. When we RESET the PHY (by setting the bit#15 in BMCR register), following metrics are set by defaut :
            - duplex mode is set to FULL.
            - speed is set to 100M.
            - autoneg is disable.

    Regards,

    Yoann

  • 0 in reply to yoann le jeune
    TI__Mastermind 23675 points

    Hi Yoann,

    Can you send me the register dump for 0x0 to 0x1F registers?

    This will help me better understand what the PHY is doing.

    Please send when you have bootstraps for 100Mbps FD enabled and when you have it for Auto-Negotiation.

    Kind regards,

    Ross

  • 0 in reply to Ross Pimentel
    Prodigy 30 points

    Hi Ross

    Finally we have successfully connected our devices by using the force mode. The problem was that the straight cable wasn’t suit for this configuration.

    By using a cross cable, the link is established quicker than with autonegociation.

    I suppose that without autonegociation the MDIX_EN bit in PHYCR register is irrelevant.

    Thanks for your support.

    Regards,
    Yoann.

  • 0 in reply to yoann le jeune
    TI__Mastermind 23675 points

    Hi Yoann,


    Glad that it is now working.

    Please note that even with Auto-Negotiation disabled, Auto-MDIX can still be used.

    Kind regards,

    Ross