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PHY - DP83848C not responding through RMII (MDIO line)

Question asked by bachabharat on Jan 5, 2017
Latest reply on Jan 30, 2017 by bachabharat

I am using EZKit Blackfin 609 with standalone debug agent.  I am writing the device drivers for ethernet and configuring the PHY chip (DP83848C). I followed the programming sequence mentioned in the datasheet and the PHY doesn't respond to the read of the registers through MDIO (RMII Interface). I am using PHY address = 0x01 and still now responding. I have provided you the snippets of the code i been using to communicate with PHY. 


I have tested the MDC and MDIO using logic analyzer and I can see the clock(2.016 MHZ) and correct data(Startbit + OpCode + PHY add + REG add + TurnAround bit)  from EMAC Core but the  PHY isn't putting any data on the MDIO line.

At times seeing 16 bit zeros after the MDIO was held by the PHY.


Can I know If i am heading in the wrong direction.


I am using private RTOS and LWIP Stack and confused with the descriptor list in EMAC DMA and System  DMA. Also It would be great if you can provide any programming examples for EMAC DMA and SCB.