Tool/software:
Hi,
I have found a strange problem that I can't totally explain. The PHY does not answer on the MDIO interface.
Everything seemed to be correct (power, bootstrap, power-up, signal integrity and so on), however pin "LED_1/GPIO1" and "LED_0" are both connected with a 22k resistor to LEDs. The LEDs could of course not light up due to the low current(high resistor value).
For pin "LED_1/GPIO1" this also contributed to the main problem. When removing the LED (D68) connected on this pin or lowering the resistor to a more reasonable value(~500Ohm), the chip starts to respond on the MDIO interface.
For pin LED_0, regardless of the connection, the chip worked(except for the LED).
Can you find some kind of explanation for this? I'm guessing that the ~30uA flowing through the LED on pin "LED1" is somehow disturbing the chip. This pin must also be more sensitive since the same configuration on LED_0 does not have the any affect on the chip.
Looking forward into getting more clarity to the root cause here.
Br
Anders
