Hi all,
we copied the schematics of the Microchip Ethernet Starter Kit to design our own board. Same microcontroller (PIX32MX795F512L), ethernet tranceiver (DP83848C) and same RJ45 jack (MagJack SI-60062-F). Running the TCP/IP Demo Stack on the Starter Kit works fine, but running it on my own board doesn't.
Mode of operation should be RMII.
Error description:
- LED_LINK and LED_ACT are always off. LED_SPEED is always on (=100MBit/s, OK)
- ping times out
- firmware still uses the default IP address (meaning it hasn't got a valid one from the DHCP server. On the Starter Kit this works)
What I checked: (after reading lots of Forum entries):
- everything seems to be solderd correctly
- schematics copied correctly
- PFBOUT (pin 23) connected to PFBIN1+2 (pins 18, 37) and having 1.8V
- PWR_DOWN (pin 7) is High
- MDC (pin 31) shows 20 MHz clock
- MDIO (pin 30) shows rectangular pulses (periodically, length=approx. 2us)
- 25MHZ_OUT (pin 25) has 50 MHz (correct, because in RMII mode)
- RX_DV/RMII_MODE (pin 39) is pulled up to VCC(3.3V) by 2.2k, signal is permanetly low (plausible cause no packets received)
- RBIAS (pin 24): 1.2V
- ETXD0+1 (pins 3+4): show rectangular signal (but only for approx. 2s, then nothing for approx. 10s, then signal again...)
- ETXEN (pin 2): repeating high pulse (analog to ETXD0+1)
- RXD_0..1 (pins 43-44): connected via 33R to ERXD0/1
- RXD_2..3 (pins 45-46): open
It seems that the PIC32 communicates with the DP83848, but the DP... couldn't send the data to the PC (or is not correctly configurred, yet).
Does anyone have any ideas? More things to check?
(as I am using the precompiled TCP/IP Demo Stack V5.25 by Microchip so far, I cannot step into the stack and see the responses from the DP83848C. But as the firmware is identical on the Microchip Starter Kit and on my board, it looks more than a hardware issue).
Thanks a lot for any help!
Jürgen
