diff --git a/fuzzers/005-tilegrid/gtx_common/Makefile b/fuzzers/005-tilegrid/gtx_common/Makefile
new file mode 100644
index 0000000..82d266c
--- /dev/null
+++ b/fuzzers/005-tilegrid/gtx_common/Makefile
@@ -0,0 +1,10 @@
+# Copyright (C) 2017-2020  The Project X-Ray Authors.
+#
+# Use of this source code is governed by a ISC-style
+# license that can be found in the LICENSE file or at
+# https://opensource.org/licenses/ISC
+#
+# SPDX-License-Identifier: ISC
+N ?= 8
+GENERATE_ARGS?="--oneval 0 --design params.csv --dword 45 --dbit 27 --dframe 1e"
+include ../fuzzaddr/common.mk
diff --git a/fuzzers/005-tilegrid/gtx_common/generate.tcl b/fuzzers/005-tilegrid/gtx_common/generate.tcl
new file mode 100644
index 0000000..eea37d7
--- /dev/null
+++ b/fuzzers/005-tilegrid/gtx_common/generate.tcl
@@ -0,0 +1,36 @@
+# Copyright (C) 2017-2020  The Project X-Ray Authors
+#
+# Use of this source code is governed by a ISC-style
+# license that can be found in the LICENSE file or at
+# https://opensource.org/licenses/ISC
+#
+# SPDX-License-Identifier: ISC
+source "$::env(XRAY_DIR)/utils/utils.tcl"
+
+proc run {} {
+    create_project -force -part $::env(XRAY_PART) design design
+    read_verilog top.v
+    synth_design -top top
+
+    set_property CFGBVS VCCO [current_design]
+    set_property CONFIG_VOLTAGE 3.3 [current_design]
+    set_property BITSTREAM.GENERAL.PERFRAMECRC YES [current_design]
+
+    # Disable MMCM frequency etc sanity checks
+    set_property IS_ENABLED 0 [get_drc_checks {PDRC-29}]
+    set_property IS_ENABLED 0 [get_drc_checks {PDRC-30}]
+    set_property IS_ENABLED 0 [get_drc_checks {AVAL-50}]
+    set_property IS_ENABLED 0 [get_drc_checks {AVAL-53}]
+    set_property IS_ENABLED 0 [get_drc_checks {REQP-126}]
+    set_property IS_ENABLED 0 [get_drc_checks {REQP-48}]
+    set_property IS_ENABLED 0 [get_drc_checks {NSTD-1}]
+    set_property IS_ENABLED 0 [get_drc_checks {UCIO-1}]
+
+    place_design
+    route_design
+
+    write_checkpoint -force design.dcp
+    write_bitstream -force design.bit
+}
+
+run
diff --git a/fuzzers/005-tilegrid/gtx_common/top.py b/fuzzers/005-tilegrid/gtx_common/top.py
new file mode 100644
index 0000000..c20ea2f
--- /dev/null
+++ b/fuzzers/005-tilegrid/gtx_common/top.py
@@ -0,0 +1,62 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2017-2020  The Project X-Ray Authors.
+#
+# Use of this source code is governed by a ISC-style
+# license that can be found in the LICENSE file or at
+# https://opensource.org/licenses/ISC
+#
+# SPDX-License-Identifier: ISC
+import os
+import random
+random.seed(int(os.getenv("SEED"), 16))
+from prjxray import util
+from prjxray.db import Database
+
+
+def gen_sites():
+    db = Database(util.get_db_root(), util.get_part())
+    grid = db.grid()
+    for tile_name in sorted(grid.tiles()):
+        loc = grid.loc_of_tilename(tile_name)
+        gridinfo = grid.gridinfo_at_loc(loc)
+
+        for site_name, site_type in gridinfo.sites.items():
+            if site_type in ['GTXE2_COMMON']:
+                yield tile_name, site_name
+
+
+def write_params(params):
+    pinstr = 'tile,val,site\n'
+    for tile, (site, val) in sorted(params.items()):
+        pinstr += '%s,%s,%s\n' % (tile, val, site)
+    open('params.csv', 'w').write(pinstr)
+
+
+def run():
+    print('''
+module top(input wire in, output wire out);
+    ''')
+
+    params = {}
+
+    sites = list(gen_sites())
+    for (tile_name, site_name), isone in zip(sites,
+                                             util.gen_fuzz_states(len(sites))):
+        params[tile_name] = (site_name, isone)
+
+        attr = 4 if isone else 5
+        print(
+            '''
+    (* KEEP, DONT_TOUCH, LOC="{site}" *)
+    GTXE2_COMMON #(
+        .QPLL_FBDIV({attr})
+    ) {site} ();'''.format(attr=attr, site=site_name))
+
+    print("endmodule")
+    write_params(params)
+
+
+if __name__ == '__main__':
+    run()