XEM6310: pin for SDRAM Controller is already in use by okHost

Spartan-6 USB 3.0 Modules
1

Hello,

I have a problem using SDRAM in XEM6310.
I generated SDRAM MCB(Memory Control Block) using Xilinx MIG with the information provided by XEM6310 manual.
I’m pretty sure I generated it properly.

The problem is that a pin(Y12) for MCB’s system clock(cyc_clk_n) is already occupied by okUH[0] as you can see below :

NET “okUH[0]” LOC=“Y12” | IOSTANDARD=“LVCMOS18”;
NET “c3_sys_clk_n” LOC = “Y12” ;

I couldn’t find any substitute pin for Y12.
Is there any alternative option for okUH[0] or c3_sys_clk_n?

I would be glad with any suggestions.

Thank you.

2

I believe the system clock for the memory controller on the XEM6310 should be provided by the oscillator available on pins Y11/AB11 (documented here: https://docs.opalkelly.com/display/XEM6310/Low-Jitter+100+MHz+Oscillator). Does the design build properly when using these pins?

3

Thank you tom_mcleod!
It works well now.
I really appreciate it!