DP83822I: phy address

Hello xuelin mo

Thank you for the query.

For the SMI to work, the clock power supply and the RESET is expected to be normal.

Is the clock locally generated ?

Kindly share the PDF schematic for me to verify.

Regards,

Sreenivasa

Power-on reset.

Hello xuelin mo

Thank you for he schematics. I will review and provide my inputs.

I assume the Reset is controlled by the PHY.

I also do not see any pull up on the MDIO. Can you please check.

You mentioned ->Power-on reset. Can you please elaborate.

Could you please check What is the AVD supply used ?

Regards,

Sreenivasa

RESET connect to MCU's reset ,the reset occured when my board power on

I'm sure the pins don't have any pull up.

My AVD is 24v

Hello xuelin mo

Thank you for the quick reply.

I assume you mean 2.4V AVD.

Did you say the MDIO does not have pullup. 

Please refer below datasheet recommendations. Could you please add a 2.2K and check.

Management Data I/O: Bidirectional management data signal that may be sourced by the management station or the PHY. This pin requires a 2.2-kΩ pullup resistor.

Regards,

Sreenivasa

I check my schematics, MDIO has a 2.2-kΩ pullup resistor

Hello xuelin mo

Thanks for confirming.

I will review the schematics. Can you please check the timing, reference section is as below 

Figure 7-3. Reset Timing

Regards,

Sreenivasa

It just reset at power up

Hello xuelin mo

Thank you for the reply.

The reset is expected to be released after the supply and clock is stabilized 

Can you try performing a reset after the system is up and accessing the registers.

Regards,

Sreenivasa

I have tried it before, and the phenomenon is the same

Hello xuelin mo

when I initialize dp83822 connected to PRU1(one dp83822's cols connect to ground,another not),two dp83822's address are 0 and 1.

But when I initialze dp83822 connect to PRU2(col not connect to fround), the address is 0x1F.According to datesheet, the address should be 1, I doubt that it's connect? 

How are you reading the address MII or MDIO ?

Regards,

Sreenivasa

I use ccs to read the regisiter.View-Regisiter-PRU2/PRU1(MDIOAlive regisiter)

Hello xuelin mo

Thank you for the reply. My question was are you reading the PHY address value using the serial MDIO interface or the MII interface.

Regards,

Sreenivasa

I use MII interface

I think this topic isn't important,I can use it when I set the PHY address 0x1F in my code.

In addation, I see that you have run ethercat master demo on AM5728, can you send it to me ?

Hello xuelin mo

Thank you. Some of the above debug was assuming you are using the MDIO.

Regards,

Sreenivasa

Hello xuelin mo

Thank you for the query. 

I will redirect the query internally. Please expect some delay.

Regards,

Sreenivasa