[casper] The max frequency of DD2 DRAM of ROACH

[Wan.Cheng]

Hi:

What's the max frequency of DRAM on Roach? From Xilinx MIG user guide page 323, 
it seems that only 150MHz is possible. Any idea?

By the way, what's the current status of DRAM of Roach? All library working, or 
still in development.

Thanks

Wan