Hi,
We are working with the DP83826I ethernet Phy on our project. Currently it is in the testing phase.
We are getting the below error when we try to ping to an IP address which is locally configured between our PC and the custom board.
Error: ARP Retry count exceeded; starting again, ping failed; host xxx.xxx.x.x is not alive.
We have read the Phy register Addresses using MDIO/MDC. The same is attached with the case.
Kindly help us out to fix this issue.
Thanks in advance,
Melbin
Hi Hillman,
Let me clarify regarding the register 0x10. We are observing a value 0X4017 at 0x10 and expecting a value 0x4715/0x0715 (DP83826 trouble shooting guide)
We are connecting two Phy DP83826 with a processor though a single MDC/MDIO lines. The Phys are in slave mode.
The hardware strapping provided for the Phys are attached below.
When we connect RJ45 cable from an external PC with our custom board, both the link and activity status LEDs are blinking on the RJ45 connector.
Also, the Phy is getting detected in the processor boot and the Phy registers are accessible.
The registers value read and expected register values from the DP83826E Troubleshooting Guide is recorded in the excel sheet attached.
The Green highlighted columns indicate that the observed register value is same are expected.
The Red Font color indicate that the observed register value is different from the expected register value.
3463.TI DP83826 Register Values.xlsx
Another observation is, when we try to ping from external PC to our board, we are getting a data transfer in the Phy RX line. But no toggling in the TX line or refclk line.
When we try to ping from our board to external PC, the below error is coming.
Error: ARP Retry count exceeded; starting again, ping failed; host xxx.xxx.x.x is not alive.
Thank you for the quick response Lin. Please find the response below
If possible, could you let me know your test setup? A block diagram would be helpful.
From the register dump you share with me, I see that you have two value on 0x0010: 0x4715/0x0715. May I ask why there are two values? Is the PHY constantly swapping between MDI/MDIX when you are reading the register 0x0010?
We are only getting one value, the two values are references from the application note. Hope you get a clarity from Melbin's reply. 
If so, could you write 0x0019 bit[15] = 0 and see if that help with your link up?
Hi Theevan,
Thank you for the clarification.
For further debug, I would like to see if you are able to receive packets back to RZN1D when we enable a digital loopback so that we can isolate the problem from RMII interface.
If possible, could you program the following script and see if you are able to generate an receive back the packets on RZN1D?
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Thank you,
Hillman Lin
Hi Hillman,
We probed the RX_CLK/50MHz_RMII pin of the Phy.
We are not observing any clock in the pin.
As per the current connection, RX_CLK pin is directly connected to Processor only.
Do we need to connect an external 50MHz clock source to this line as below diagram?
Thanks,
Melbin
Hi Melbin,
May I ask what mode is your DP83826PHY want to operate in? RMII master mode or RMII slave mode? Reading register 0x0467 would help you to determine which mode your PHY is operate in.
Based on your block diagram, it seems like your connection of RMII interface might be bit off. Please refer to the following diagram to for RMII connection. (Make sure clock signal is input to XI pin instead of RX_CLK pin)
When DP83826 is RMII master:
When DP83826 is RMII slave:
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Regards,
Hillman Lin
