DP83TC813R-Q1: PHY ID problem.

xiaocan wu

The DP83TC813 operates in RMII master mode, and all readings from the MDIO bus are 0xfff. According to another post, this is likely a PHY ID issue. However, I have tried many PHY IDs without any change. What could be the possible PHY ID?

2 months ago

0 Drew Miller1 2 months ago

TI__Mastermind 39903 points

Hi Xiaocan,

It is likely the case that the PHY is either sleeping, or you have the incorrect PHY address.

1. If you have doubts on the PHY address, you can try sweeping through addresses 0-31.

2. You can confirm that PHY is not sleeping by monitoring INH pin. INH pin is high-z in TC10 sleep and is active high for all other states.

Thanks,

Drew

0 xiaocan wu 2 months ago in reply to Drew Miller1

Prodigy 10 points

Hi Drew,

Thank you for your help.

After changing phy-id to 10 ,we read the register success.

But the value of strap register 0x45d is 0x0C.

I want the master mode of RMII in my phy work. Is there any problem with this value？

+1 Drew Miller1 2 months ago in reply to xiaocan wu

TI__Mastermind 39903 points

Hi Xiaocan,

xiaocan wu said:
But the value of strap register 0x45d is 0x0C.

This value indicates that the PHY is not strapped into RMII master mode.

I would recommend using our schematic checklist tool to identify appropriate strap resistor settings.

https://www.ti.com/tool/download/DP83TC813-SCHEMATIC-REVIEW-CHECKLIST

Thanks,

Drew

0 xiaocan wu 2 months ago in reply to Drew Miller1

Prodigy 10 points

Hi Drew,

It works. thank you very much

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DP83TC813R-Q1: PHY ID problem.