GXB_GND connection for Cyclone IV GX

[Altera_Forum]

Hi,  

I am using Cyclone IV GX FPGA. I am making use of the PCIe hard IP.  I want to know how the GXB_GND pins need to be connected. Can I connect it directly to GND. The pin file shows that unused GXB Receiver or dedicated reference clock pin are to be connected to GXB_GND through a 10 KOhm resistor.  But I don't find anywhere in the Cyclone IV handbook how to connect the GXB_GND.  Can someone please help me out. regards, rajesh

[Altera_Forum]

--- Quote Start ---  Hi,  I am using Cyclone IV GX FPGA. I am making use of the PCIe hard IP.  I want to know how the GXB_GND pins need to be connected. Can I connect it directly to GND. The pin file shows that unused GXB Receiver or dedicated reference clock pin are to be connected to GXB_GND through a 10 KOhm resistor.  But I don't find anywhere in the Cyclone IV handbook how to connect the GXB_GND.  Can someone please help me out. regards, rajesh  --- Quote End ---   Hello, atrajesh ! I have the same question.  Did You find the answer?

[Altera_Forum]

Which of the 2 solutions are legal for Cyclone IV GX FPGA: 

 1). connect both unused dedicated reference clock ( REFCLK1n and REFCLK1p ) pins directly to PCB GND plane. 2). connect one unused dedicated reference clock REFCLK1p pin directly to PCB GND plane, but use another one from the pair ( REFCLK1n ) for reference clock.  P.S. The question is because I don't have enough space on PCB to place 10 KOhm resistor from unused REFCLK to GND.