DP83822IF: MDIO is fix to high after reset

Hello,

Thank you for using the TI forum, we will get back to you as soon as we can.

Hi ACGUY,

On the schematics, there are 10k pull down resistors on MDIO and MDC. Can you try removing those and trying again?

-Regards,
Aniruddha

Hi Aniruddha,

I tried it already. The situation did not change.

Regards,
ACGUY

Hello ACGUY,

If I understand the application correct, the FPGA can communicate with the PHY properly after power up but after applying a reset the PHY does not respond to MDIO operation, right?

Can you verify that the PHY comes out of reset by checking the Reset pin of the PHY?
Can you check if the FPGA has internal pull resistors, especially on pins connected to COL, RX_D0, RX_D1, RX_D2, and RX_D3 pins of DP83822? If it does have internal pulls then the PHY might be getting strapped to a different address after applying Reset. You can also try scanning for PHY Address 0x00-0x1F (0-31 decimal) and see if you get the correct register read out.

-Regards,
Aniruddha

Hello Aniruddha,

Thank you for advice.
I tried read out that address incrementing from 0x00 to 0x1F. Readed data were all high.
I trying to change the PHY from TI to other brand.

Thanks,
ACGUY