Version Found: MIG 1.6
The MIG 7 Series DDR2 and DDR3 designs enable an I/O setting called DQS_BIAS. This is set to "TRUE" on all DQS I/O pairs and can be viewed by looking at the I/O attributes in FPGA Editor ormanually through a design.xdl file. When viewing the DQS I/O setting on an IOBUFDS primitive, the p-side properly displays the DQS_BIAS="TRUE" setting. However, the n-side shows DQS_BIAS="OFF".
This is only an issue for designs that select "OFF" for the "IO Power Reduction" option within the MIG 7 Series tool. The "OFF" selection uses IOBUFDS primitives while "ON" uses IOBUFDS_DCIEN or IOBUFDS_INTERMDISABLE primitives based on HR or HP I/O usage.