Hello,
I am using PIC32 processor to DP83848-EP in RMII mode. I'm unable to communicate thru MDIO. Oscilloscope shows that PIC32 send out the read command, but PHY doesn't respond. Default Phy Address is 0x1. All power pins look good, but I am not able to measure PHY Address 0 to be high. It reads as 0.012V. Even when I blue-wired the pull up resistor to force the address to be high, it sill measures low. Also, MII MODE measures low although it has a pull up resistor. I reflowed the PHY chip and all passive components around. It is still not working. Could you help me out to resolve this issue?
PFBOUT,PBFIN1,PFBIN2 = 1.74V
All VDD = 3.3V
X1 = 50MHz (CMOS)
25MHZ_OUT = 50 MHz coming out.
RESET_N = 3.3V
PWR_DOWN_INT = 3.3V
RBIAS = 1.17V
Speed LED light is on. Other LEDs are off.
Issues
PHYAD0 (Pin 42) = 0.012V (It is a floating pin by default, but still measures low. I blue wired this pin to 2K pull up and still measures low)
MII_MODE (Pin 39) = 0.012V (Although it has pull up, it measures low.)
Here is how pins are connected.
Thanks,
Kyu
