DP83869HM: connecting different PHYs at single MDC/MDIO lines of the processor code / dts reference

mahesh gohil

Part Number: DP83869HM
Other Parts Discussed in Thread: DP83869, DP83TC811

Hello Ti team,

We have connected DP83869 and another PHY at single MDC-MDIO lines of the processor.

Can you pls suggest if there is any reference or guide available to attach different PHYs at single MDC/MDIO lines of processor ? Any DTS file reference / anything will be helpful.

Mahesh

over 3 years ago

0 Justin Lazaruk over 3 years ago

TI__Expert 7040 points

Hi Mahesh,

We don't have any reference documentation specifically for connecting multiple PHYs to a single MDC/MDIO line. Multiple PHYs can be connected to the same MDC/MDIO lines from the processor, you can take a look at the DP83TC811 EVM which has two PHYs connected over one MDC-MDIO line for USB2MDIO communication. I recommend a pull-up resistor on the MDIO line close to each PHY.

www.ti.com/.../snlu231.pdf

Regards,
Justin

0 mahesh gohil over 3 years ago in reply to Justin Lazaruk

Prodigy 190 points

Thank You Justin for the reply.

Can you pls share the code reference to handle two phys at single MDIO bus ? Could you please suggest what is the change / where do we need to change in BSP ?

We appreciate any help here.

0 Justin Lazaruk over 3 years ago in reply to mahesh gohil

TI__Expert 7040 points

Hi Mahesh,

I am not sure what you are asking for. The only hardware changes needed are to ensure that the PHY_ID of each PHY is unique so that register writes can be addressed to each PHY.

Regards,
Justin

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DP83869HM: connecting different PHYs at single MDC/MDIO lines of the processor code / dts reference