ddrwdith:	64	data width of off-chip memory
ddrsizewidth:	24	total address width of off-chip memory
ddrrowwidth:	13	row address width of off-chip memory
ddrburstlen:	4	burst length of off-chip memory
DQperDQS:	8	number of DQ per DQS in off-chip memory controller
diffDQS:	1	use of differential DQS in off-chip memory controller