DP83848-EP: Can two DP83848 be connected each other with MII

Katsu Matsunaga

Part Number: DP83848-EP

Hello,

My customer would like to design an evaluation board by themselves. They plan to make below system configuration.

Is it OK to connect directly two DP83848s with MII?

LAN tester ---- RJ45 ---- Transformer ---- DP83848 ----(MII direct connection)---- DP83848 ---- Transformer ---- RJ45 ---- LAN tester

From LAN tester (MP1230A) to first PD83848 is responsible for packet transmit/receive. This is only for compliance test.

In addition, could you please give your advice?

Best regards, Katsu

0 Cecilia Reyes over 3 years ago

Hi Katsu,

You can not do MII back to back because the signals are not mirrors of each other (ie the line status signals and the TxRx signals)

If you would like to use RMII there is an application note on connecting two single PHYs back to back in RMII mode (www.ti.com/.../snla076).

Thanks,

Cecilia

0 Katsu Matsunaga over 3 years ago in reply to Cecilia Reyes

Hi Cevilia-san,

Thank you for your reply.

I understand MII doesn't work.

One question.

DP83848 EVM can use USB-MDIO to access to register. What HW tool can we use?

Best regards, Katsu

0 Cecilia Reyes over 3 years ago in reply to Katsu Matsunaga

Hi Katsu,

Yes you are able to use the USB2MDIO tool. Here is more details about it in another E2E question:

Thanks,

Cecilia

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