+Index: s6ddrphy/spartan6_soft_phy.v
+===================================================================
+--- s6ddrphy.orig/spartan6_soft_phy.v
++++ s6ddrphy/spartan6_soft_phy.v
+@@ -116,7 +116,6 @@ module spartan6_soft_phy # (
+ inout [NUM_DQ-1:0] sd_dq, // Data in from SDRAM device
+ output [NUM_DQS-1:0] sd_dm, // Data mask to SDRAM devices
+ inout [NUM_DQS-1:0] sd_dqs, // DQS
+- inout [NUM_DQS-1:0] sd_dqs_n, // complimentary DQS
+
+ // configuration ports
+ input [2:0] cfg_al, // Posted CAS additive latency
+@@ -300,12 +299,11 @@ genvar j;
+ generate
+ for (j = 0; j < NUM_DQ/8*(NIBBLE_DEVICES+1) ; j = j + 1)
+ begin:dqs_iob
+- IOBUFDS iobufds (
++ IOBUF iobufds (
+ .O (sd_dqs_in[j]),
+ .I (sd_dqs_out[j]),
+ .T (sd_dqs_oe_n[j]),
+- .IO (sd_dqs[j]),
+- .IOB (sd_dqs_n[j])
++ .IO (sd_dqs[j])
+ );
+ end
+ endgenerate