diff --git a/minitests/roi_harness/fasm2bit.sh b/minitests/roi_harness/fasm2bit.sh
index ee1d389..3b5e5ff 100755
--- a/minitests/roi_harness/fasm2bit.sh
+++ b/minitests/roi_harness/fasm2bit.sh
@@ -1,6 +1,6 @@
 # Example pre-req
 # ./runme.sh
-# XRAY_ROIV=roi_inv.v XRAY_FIXED_XDC=out_xc7a35tcpg236-1_BASYS3-SWBUT_roi_basev/fixed_noclk.xdc ./runme.sh
+# URAY_ROIV=roi_inv.v URAY_FIXED_XDC=out_xc7a35tcpg236-1_BASYS3-SWBUT_roi_basev/fixed_noclk.xdc ./runme.sh
 
 set -ex
 
@@ -27,14 +27,14 @@
 echo "Harness .bit: $bit_in"
 echo "Out .bit: $bit_out"
 
-${XRAY_FASM2FRAMES} --sparse $fasm_in roi_partial.frm
+${URAY_FASM2FRAMES} --sparse $fasm_in roi_partial.frm
 
-${XRAY_TOOLS_DIR}/xc7patch \
-	--part_name ${XRAY_PART} \
-	--part_file ${XRAY_PART_YAML} \
+${URAY_TOOLS_DIR}/xc7patch \
+	--part_name ${URAY_PART} \
+	--part_file ${URAY_PART_YAML} \
 	--bitstream_file $bit_in \
 	--frm_file roi_partial.frm \
 	--output_file $bit_out
 
-#openocd -f $XRAY_DIR/utils/openocd/board-digilent-basys3.cfg -c "init; pld load 0 $bit_out; exit"
+#openocd -f $URAY_DIR/utils/openocd/board-digilent-basys3.cfg -c "init; pld load 0 $bit_out; exit"
 
diff --git a/utils/fasm2frames.py b/utils/fasm2frames.py
new file mode 100755
index 0000000..25cd6bc
--- /dev/null
+++ b/utils/fasm2frames.py
@@ -0,0 +1,306 @@
+#!/usr/bin/env python3
+
+from __future__ import print_function
+
+import fasm
+import argparse
+import json
+import os
+import os.path
+import csv
+
+from collections import defaultdict
+
+from utils import fasm_assembler, util
+from utils.db import Database
+from utils.roi import Roi
+
+import sys
+
+
+def eprint(*args, **kwargs):
+    print(*args, file=sys.stderr, **kwargs)
+
+
+class FASMSyntaxError(SyntaxError):
+    pass
+
+
+def dump_frames_verbose(frames):
+    print()
+    print("Frames: %d" % len(frames))
+    for addr in sorted(frames.keys()):
+        words = frames[addr]
+        print(
+            '0x%08X ' % addr + ', '.join(['0x%08X' % w for w in words]) +
+            '...')
+
+
+def dump_frames_sparse(frames):
+    print()
+    print("Frames: %d" % len(frames))
+    for addr in sorted(frames.keys()):
+        words = frames[addr]
+
+        # Skip frames without filled words
+        for w in words:
+            if w:
+                break
+        else:
+            continue
+
+        print('Frame @ 0x%08X' % addr)
+        for i, w in enumerate(words):
+            if w:
+                print('  % 3d: 0x%08X' % (i, w))
+
+
+def dump_frm(f, frames):
+    '''Write a .frm file given a list of frames, each containing a list of 101 32 bit words'''
+    for addr in sorted(frames.keys()):
+        words = frames[addr]
+        f.write(
+            '0x%08X ' % addr + ','.join(['0x%08X' % w for w in words]) + '\n')
+
+
+def find_pudc_b(db):
+    """ Find PUDC_B pin func in grid, and return the tile and site prefix.
+
+    The PUDC_B pin is a special 7-series pin that controls unused pin pullup.
+
+    If the PUDC_B is unused, it is configured as an input with a PULLUP.
+
+    """
+    grid = db.grid()
+
+    pudc_b_tile_site = None
+    for tile in grid.tiles():
+        gridinfo = grid.gridinfo_at_tilename(tile)
+
+        for site, pin_function in gridinfo.pin_functions.items():
+            if 'PUDC_B' in pin_function:
+                assert pudc_b_tile_site == None, (
+                    pudc_b_tile_site, (tile, site))
+                iob_y = int(site[-1]) % 2
+
+                pudc_b_tile_site = (tile, 'IOB_Y{}'.format(iob_y))
+
+    return pudc_b_tile_site
+
+
+def get_iob_sites(db, tile_name):
+    """
+    Yields prjxray site names for given IOB tile name
+    """
+    grid = db.grid()
+    gridinfo = grid.gridinfo_at_tilename(tile_name)
+
+    for site in gridinfo.sites:
+        site_y = int(site[-1]) % 2
+        yield "IOB_Y{}".format(site_y)
+
+
+def run(
+        db_root,
+        part,
+        filename_in,
+        f_out,
+        sparse=False,
+        roi=None,
+        debug=False,
+        emit_pudc_b_pullup=False):
+    db = Database(db_root, part)
+    assembler = fasm_assembler.FasmAssembler(db)
+
+    set_features = set()
+
+    def feature_callback(feature):
+        set_features.add(feature)
+
+    assembler.set_feature_callback(feature_callback)
+
+    # Build mapping of tile to IO bank
+    tile_to_bank = {}
+    bank_to_tile = defaultdict(lambda: set())
+
+    if part is not None:
+        with open(os.path.join(db_root, part, "package_pins.csv"), "r") as fp:
+            reader = csv.DictReader(fp)
+            package_pins = [l for l in reader]
+
+        with open(os.path.join(db_root, part, "part.json"), "r") as fp:
+            part_data = json.load(fp)
+
+        for bank, loc in part_data["iobanks"].items():
+            tile = "HCLK_IOI3_" + loc
+            bank_to_tile[bank].add(tile)
+            tile_to_bank[tile] = bank
+
+        for pin in package_pins:
+            bank_to_tile[pin["bank"]].add(pin["tile"])
+            tile_to_bank[pin["tile"]] = pin["bank"]
+
+    if emit_pudc_b_pullup:
+        pudc_b_in_use = False
+        pudc_b_tile_site = find_pudc_b(db)
+
+        def check_for_pudc_b(set_feature):
+            feature_callback(set_feature)
+            parts = set_feature.feature.split('.')
+
+            if parts[0] == pudc_b_tile_site[0] and parts[
+                    1] == pudc_b_tile_site[1]:
+                nonlocal pudc_b_in_use
+                pudc_b_in_use = True
+
+        if pudc_b_tile_site is not None:
+            assembler.set_feature_callback(check_for_pudc_b)
+
+    extra_features = []
+    if roi:
+        with open(roi) as f:
+            roi_j = json.load(f)
+        x1 = roi_j['info']['GRID_X_MIN']
+        x2 = roi_j['info']['GRID_X_MAX']
+        y1 = roi_j['info']['GRID_Y_MIN']
+        y2 = roi_j['info']['GRID_Y_MAX']
+
+        assembler.mark_roi_frames(Roi(db=db, x1=x1, x2=x2, y1=y1, y2=y2))
+
+        if 'required_features' in roi_j:
+            extra_features = list(
+                fasm.parse_fasm_string('\n'.join(roi_j['required_features'])))
+
+    # Get required extra features for the part
+    required_features = db.get_required_fasm_features(part)
+    extra_features += list(
+        fasm.parse_fasm_string('\n'.join(required_features)))
+
+    assembler.parse_fasm_filename(filename_in, extra_features=extra_features)
+
+    if emit_pudc_b_pullup and not pudc_b_in_use and pudc_b_tile_site is not None:
+        # Enable IN-only and PULLUP on PUDC_B IOB.
+        #
+        # TODO: The following FASM string only works on Artix 50T and Zynq 10
+        # fabrics.  It is known to be wrong for the K70T fabric, but it is
+        # unclear how to know which IOSTANDARD to use.
+        missing_features = []
+        for line in fasm.parse_fasm_string("""
+{tile}.{site}.LVCMOS12_LVCMOS15_LVCMOS18_LVCMOS25_LVCMOS33_LVTTL_SSTL135.IN_ONLY
+{tile}.{site}.LVCMOS25_LVCMOS33_LVTTL.IN
+{tile}.{site}.PULLTYPE.PULLUP
+""".format(
+                tile=pudc_b_tile_site[0],
+                site=pudc_b_tile_site[1],
+        )):
+            assembler.add_fasm_line(line, missing_features)
+
+        if missing_features:
+            raise fasm_assembler.FasmLookupError('\n'.join(missing_features))
+
+    if part is not None:
+        # Make a set of all used IOB tiles and sites. Look for the "STEPDOWN"
+        # feature. If one is set for an IOB then set it for all other IOBs of
+        # the same bank.
+        stepdown_tags = defaultdict(lambda: set())
+        stepdown_banks = set()
+        used_iob_sites = set()
+
+        for set_feature in set_features:
+            if set_feature.value == 0:
+                continue
+
+            feature = set_feature.feature
+            parts = feature.split(".")
+            if len(parts) >= 3:
+                tile, site, tag = feature.split(".", maxsplit=2)
+                if "IOB33" in tile:
+                    used_iob_sites.add((
+                        tile,
+                        site,
+                    ))
+
+                # Store STEPDOWN related tags.
+                if "STEPDOWN" in tag:
+                    bank = tile_to_bank[tile]
+                    stepdown_banks.add(bank)
+                    stepdown_tags[bank].add(tag)
+
+        # Set the feature for unused IOBs, loop over all banks which were
+        # observed to have the STEPDOWN feature set.
+        missing_features = []
+
+        for bank in stepdown_banks:
+            for tile in bank_to_tile[bank]:
+
+                # This is an IOB33 tile. Set the STEPDOWN feature in it but
+                # only if it is unused.
+                if "IOB33" in tile:
+                    for site in get_iob_sites(db, tile):
+
+                        if (tile, site) in used_iob_sites:
+                            continue
+
+                        for tag in stepdown_tags[bank]:
+                            feature = "{}.{}.{}".format(tile, site, tag)
+                            for line in fasm.parse_fasm_string(feature):
+                                assembler.add_fasm_line(line, missing_features)
+
+                # This is a HCLK_IOI3 tile, set the stepdown feature for it
+                # too.
+                if "HCLK_IOI3" in tile:
+                    feature = "{}.STEPDOWN".format(tile)
+                    for line in fasm.parse_fasm_string(feature):
+                        assembler.add_fasm_line(line, missing_features)
+
+        if missing_features:
+            raise fasm_assembler.FasmLookupError('\n'.join(missing_features))
+
+    frames = assembler.get_frames(sparse=sparse)
+
+    if debug:
+        dump_frames_sparse(frames)
+
+    dump_frm(f_out, frames)
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description=
+        'Convert FPGA configuration description ("FPGA assembly") into binary frame equivalent'
+    )
+
+    util.db_root_arg(parser)
+    util.part_arg(parser)
+    parser.add_argument(
+        '--sparse', action='store_true', help="Don't zero fill all frames")
+    parser.add_argument(
+        '--roi',
+        help="ROI design.json file defining which tiles are within the ROI.")
+    parser.add_argument(
+        '--emit_pudc_b_pullup',
+        help="Emit an IBUF and PULLUP on the PUDC_B pin if unused",
+        action='store_true')
+    parser.add_argument(
+        '--debug', action='store_true', help="Print debug dump")
+    parser.add_argument('fn_in', help='Input FPGA assembly (.fasm) file')
+    parser.add_argument(
+        'fn_out',
+        default='/dev/stdout',
+        nargs='?',
+        help='Output FPGA frame (.frm) file')
+
+    args = parser.parse_args()
+    run(
+        db_root=args.db_root,
+        part=args.part,
+        filename_in=args.fn_in,
+        f_out=open(args.fn_out, 'w'),
+        sparse=args.sparse,
+        roi=args.roi,
+        debug=args.debug,
+        emit_pudc_b_pullup=args.emit_pudc_b_pullup)
+
+
+if __name__ == '__main__':
+    main()