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USB-2-MDIO: USB-2-MDIO

Part Number: USB-2-MDIO

Hi,

I am using the USB-2-MDIO interface to write to the registers in my Ethernet switch from Marvell. Initially when I read the regsiter I get

Register 0001 is: FFFF

This happens with any register.

Later I try to write the data to the register . suppose i try to write FFFE into the register 0001, it says :

Register 0001 is: FFFE

and when i read it back its FFFF again.

Register 0001 is: FFFF

I am not able to write to the registers to configure it. could you please help me in this regard?

Thanks,

Ramya

  • Hi Ramya,

    I have designed the firmware to only work with TI extended register access.
    You need to change 'Extended Register' to NO.

    This will give you access to the base 32 registers. If you need to access registers beyond 0x1Fh, you will have to do it manually since the Extended Register tab will only use TI vendor specific MMD = 1F.

    Kind regards,
    Ross
  • Dear Ross,

    Thank you very much for your reply. This really helped.

    Thanks,

    Ramya

  • Hi Ross,

    I am using single chip addressing and according to the switch datasheet for single chip we set the PHY adress to 00000. So theoritically now all the 32(0 to 31) PHY IDs must be available when I try to find PHYs. But I only see it that PHY IDs : 16, 17, 18, 19, 20, 21,22 and 27, 28, 29 are available. Its not available for the other PHY IDs. Do you have an idea as to why this is so?

    Thanks,
    Ramya
  • Hi Ramya,

    I am not sure which mode you are trying to use the switch in. What switch are you using? Is the datasheet available so I can look at it?

    Thanks,
  • Hi Rob,

    Thanks for the reply. Single chip addressing mode is the mode in which all the devices respond to all 32 available SMI device addresses. Unfortunately, the datasheet is still confidential and cannot be forwarded. I now understand that the ports of the switch pick up these SMI device addresses internally and this is being read by the USB2MDIO application as available PHY IDs. But I see more number  of PHY IDs available, than the number ports available on the switch (although at most 1 device per port is connected).

    Thanks,

    Ramya

  • Hi Ramya,

    It is going to be extremely difficult for us to help you if we cannot see the specifics of how the single chip addressing mode is working. Our USB-2-MDIO device was designed to be used with a single or dual external TI PHY and any use outside of that cannot be guaranteed.

    I can tell you that our find PHY ID function simply queries all 32 PHY addresses sequentially from 0 to 31, and reports when it gets a response. If the Marvell switch's special mode makes its internal devices respond to all addresses, and I can't look at the mode in detail, I can't give you much more information than what the USB-2-MDIO tool does.

    Best Regards,