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CPU LS1043A RGMII interface

Question asked by Julien Cavallo on Jun 11, 2020
Latest reply on Jun 12, 2020 by Julien Cavallo

Dear Sir,

 

I developp a custom board with the LS1043A CPU.

 

I have some questions about the RGMII interface of the CPU.

 

In my custom board, the RGMII interface of the CPU (EC1) is connected to a stacked connector to use it with a daughter board for debug only.

 

In most time, the daughter board is not connected, so the RGMII signals are left open.

 

I think, it is good to add pull-down resistors on all RGMII RX pins on the CPU board to avoid noise input when the debug daughter board is not connected.

 

So, could you confirm me  if it is necessary to add pull-down resistors on all RX RGMII signals (EC1_RXD0 to EC1_RXD3, EC1_RX_DV, EC1_RX_CLK and EC1_GTX_CLK125) to avoid RX RGMII bus open.

 

Thank you in advance for your reply.

 

Best regards 

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