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Ethernet Interface to Micrel KSZ9021 PHY.
Added by Raja Vankam over 11 years ago
Hi,
We are using MityARM SOM and MICREL KSZ9021RNI gigabit as PHY on it for Ethernet Interface.
We have configured ETH_RXD0, ETH_RXD1, ETH_RXD2, ETH_RXD3, ETH_RXCTL as pullup high on PHY reset to get mode[3 -0] to 0xF (RGMII Mode – advertise all capabilities (10/100/1000 speed half/full duplex).) and enable clock 125.
However we are not getting link up also we are not getting 125MHZ clk on CLK125_NDO Pin on the PHY.
The TX_CLK from controller to PHY is 2.5MHZ and RX_CLK is always low, not sure if this is reason why 125MHZ clock output not getting generated.
Let me know if I have missed anything in configuring PHY.
Appreciate your response.
Regards,
Raja.
Replies (1)
RE: Ethernet Interface to Micrel KSZ9021 PHY. - Added by Michael Williamson over 11 years ago
Hi Raja,
I don't think we've used this PHY with the MityARM-3359 here, but we have had problems strapping this device on other designs. The AM3359 has several pins pulled down (or up) after a power on reset. You should check Table 2-7 of the AM3359 specification to see what states the AM3359 pins come up in after a reset.
In the past, we have had to (using u-Boot or other software) either ensure that the pull-ups are disabled and then toggle a reset to the PHY after power up or use the SPI interface and re-write the configuration in order to ensure proper operation.
I suspect this may be your issue.
-Mike
