08-21-2013 03:01 PM
I can not get Nexys3 to function its integrated Ethernet Phy in any mode. I tried RMII mode (RXD2/RMIISEL kept high with a pullup resistor using the .ucf file with '<NET> ....... | Pullup') with settings as in datasheet but nothing to indicate if the Ethernet Phy is active. I have a router (DHCP) and it does not detect the board.
The nRST is kept high by logic. I also added a switch input to reset it manually.
The Tx and Rx LEDS are not functionning on the RJ-45 connector.
The PhyClk25Mhz output has no signal (converted by logic and sent on to a LED).
The PhyTxClk has no signal (connected to the 25MHz crystal on board).
The bank 0 power jumper is set to 3.3 V.
Some configuration signals are kept low or hight by default by pull up/down resistors. To change the default configuration would another pullup/pulldown resistor in .ucf file be enough or must tie signal to Vcc or GND ?
What is missing ?
08-22-2013 04:05 PM
Is there a simple way to verify that the Phy is functional ? According to the data sheet the Digilent board has a 25 MHz crystal X3 at the input CLKIN of the Phy chip LAN8710Ai. The same clock pin is connected to an IO pin N4 of the FPGA. I used this pin as input and divided its frequency and displayed it on a LED (shows nothing). Could it be a faulty crystal X3 ?
Any help ?