diff --git a/fuzzers/035b-iob-iserdes/Makefile b/fuzzers/035b-iob-iserdes/Makefile
index 9254d710..1bc5957e 100644
--- a/fuzzers/035b-iob-iserdes/Makefile
+++ b/fuzzers/035b-iob-iserdes/Makefile
@@ -1,4 +1,4 @@
-N := 50
+N := 60
 include ../fuzzer.mk
 
 database: build/segbits_xiob33.db
diff --git a/fuzzers/035b-iob-iserdes/bits.dbf b/fuzzers/035b-iob-iserdes/bits.dbf
index 45784510..7a400432 100644
--- a/fuzzers/035b-iob-iserdes/bits.dbf
+++ b/fuzzers/035b-iob-iserdes/bits.dbf
@@ -1,3 +1,6 @@
-26_99 26_101 26_107 26_109 26_111 26_115 26_121 26_71 27_102 27_108 27_110 27_112 27_70 27_98 28_110 28_67 28_77 28_126 29_67 31_67 31_77
-26_15 26_17 26_19 26_25 26_29 26_57 27_06 27_12 27_16 27_18 27_20 27_26 27_28 27_56 28_02 28_04 28_60 29_01 29_17 29_50 29_60 30_50 30_60
-
+26_99 27_98 ,IOB_Y0.IFF.DDR_CLK_EDGE.OPPOSITE_EDGE
+26_99 27_98 ,IOB_Y0.IFF.DDR_CLK_EDGE.SAME_EDGE
+26_29 27_28 ,IOB_Y1.IFF.DDR_CLK_EDGE.OPPOSITE_EDGE
+26_29 27_28 ,IOB_Y1.IFF.DDR_CLK_EDGE.SAME_EDGE
+26_101 26_107 26_109 26_111 26_115 26_117 26_121 27_108 27_110 27_112
+26_15 26_17 26_19 27_6 27_10 27_12 27_16 27_18 27_20 27_26
diff --git a/fuzzers/035b-iob-iserdes/generate.py b/fuzzers/035b-iob-iserdes/generate.py
index b24c9168..606eb6ea 100644
--- a/fuzzers/035b-iob-iserdes/generate.py
+++ b/fuzzers/035b-iob-iserdes/generate.py
@@ -85,7 +85,7 @@ for param_list in data:
 #            segmk.add_site_tag(loc, "IFF.SUSED", 0)
 #            segmk.add_site_tag(loc, "IFF.RUSED", 0)
 
-# Site used as ISERDESE2
+        # Site used as ISERDESE2
         elif verilog.unquote(params["BEL_TYPE"]) == "ISERDESE2":
 
             segmk.add_site_tag(loc, "IDDR_OR_ISERDES.IN_USE", 1)
@@ -110,9 +110,6 @@ for param_list in data:
             data_rate = verilog.unquote(params["DATA_RATE"])
             data_width = int(params["DATA_WIDTH"])
 
-            #segmk.add_site_tag(loc, "ISERDES.SDR", int(data_rate == "SDR"))
-            #segmk.add_site_tag(loc, "ISERDES.DDR", int(data_rate == "DDR"))
-
             for i in iface_types:
                 if i == "NETWORKING":
                     for j in data_rates:
@@ -125,7 +122,7 @@ for param_list in data:
                                         segmk.add_site_tag(loc, tag, 1)
                 else:
                     if i == iface_type:
-                        segmk.add_site_tag(loc, "ISERDES.%s.DDR.4" % i, 0)
+                        segmk.add_site_tag(loc, "ISERDES.%s.DDR.4" % i, 1)
 
             if "NUM_CE" in params:
                 value = params["NUM_CE"]
@@ -174,25 +171,21 @@ for param_list in data:
             if "IOBDELAY" in params:
                 value = verilog.unquote(params["IOBDELAY"])
                 if value == "NONE":
-                    #segmk.add_site_tag(loc, "IOBDELAY_NONE", 1)
                     segmk.add_site_tag(loc, "IFFDELMUXE3.P0", 0)
                     segmk.add_site_tag(loc, "IFFDELMUXE3.P1", 1)
                     segmk.add_site_tag(loc, "IDELMUXE3.P0", 0)
                     segmk.add_site_tag(loc, "IDELMUXE3.P1", 1)
                 if value == "IBUF":
-                    #segmk.add_site_tag(loc, "IOBDELAY_IBUF", 1)
                     segmk.add_site_tag(loc, "IFFDELMUXE3.P0", 0)
                     segmk.add_site_tag(loc, "IFFDELMUXE3.P1", 1)
                     segmk.add_site_tag(loc, "IDELMUXE3.P0", 1)
                     segmk.add_site_tag(loc, "IDELMUXE3.P1", 0)
                 if value == "IFD":
-                    #segmk.add_site_tag(loc, "IOBDELAY_IFD" , 1)
                     segmk.add_site_tag(loc, "IFFDELMUXE3.P0", 1)
                     segmk.add_site_tag(loc, "IFFDELMUXE3.P1", 0)
                     segmk.add_site_tag(loc, "IDELMUXE3.P0", 0)
                     segmk.add_site_tag(loc, "IDELMUXE3.P1", 1)
                 if value == "BOTH":
-                    #segmk.add_site_tag(loc, "IOBDELAY_BOTH", 1)
                     segmk.add_site_tag(loc, "IFFDELMUXE3.P0", 1)
                     segmk.add_site_tag(loc, "IFFDELMUXE3.P1", 0)
                     segmk.add_site_tag(loc, "IDELMUXE3.P0", 1)
@@ -251,7 +244,7 @@ for param_list in data:
                     segmk.add_site_tag(loc, "IFFDELMUXE3.P0", 0)
                     segmk.add_site_tag(loc, "IFFDELMUXE3.P1", 1)
 
-            segmk.add_site_tag(loc, "ZINV_D", 0)
+            #segmk.add_site_tag(loc, "ZINV_D", 1)
 
             #            if "CE1USED" in params:
             #                segmk.add_site_tag(loc, "CE1USED", params["CE1USED"])
diff --git a/fuzzers/035b-iob-iserdes/top.py b/fuzzers/035b-iob-iserdes/top.py
index e5136fe7..d1690e68 100644
--- a/fuzzers/035b-iob-iserdes/top.py
+++ b/fuzzers/035b-iob-iserdes/top.py
@@ -194,7 +194,7 @@ IDELAYCTRL idelayctrl();
         tile_name = sites[0]
 
         # Use site
-        if random.randint(0, 9) > 0:  # Use more often
+        if random.randint(0, 19) > 0:  # Use more often
 
             # Top sites
             if random.randint(0, 1):
@@ -208,7 +208,7 @@ IDELAYCTRL idelayctrl();
             # Generate cell
             bel_types = ["IDDR", "ISERDESE2"]
             bel_type = bel_types[int(
-                random.randint(0, 4) > 0)]  # ISERDES more often
+                random.randint(0, 19) > 0)]  # ISERDES more often
             if bel_type == "ISERDESE2":
                 params = gen_iserdes(this_sites["ILOGIC"])
             if bel_type == "IDDR":