diff --git a/tools/segprint2fasm.py b/tools/segprint2fasm.py
new file mode 100644
index 00000000..198f795b
--- /dev/null
+++ b/tools/segprint2fasm.py
@@ -0,0 +1,107 @@
+#!/usr/bin/env python3
+
+import os
+import re
+import sys
+import json
+
+
+def tag2fasm(grid, seg, tag):
+    '''Given tilegrid, segment name and tag, return fasm directive'''
+    segj = grid['segments'][seg]
+
+    def clbf(seg, tile, tag_post):
+        # seg: SEG_CLBLM_L_X10Y102
+        # tile_type: CLBLM_L
+        # tag_post: SLICEM_X0.ALUT.INIT[43]
+        # To: CLBLM_L_X10Y102.SLICE_X12Y102.ALUT.INIT[43] 1
+        m = re.match(r'(SLICE[LM])_X([01])[.](.*)', tag_post)
+        slicelm = m.group(1)
+        off01 = int(m.group(2))
+        post = m.group(3)
+
+        # xxx: actually this might not work on decimal overflow (9 => 10)
+        for site in grid['tiles'][tile]['sites'].keys():
+            m = re.match(r'SLICE_X(.*)Y.*', site)
+            sitex = int(m.group(1))
+            if sitex % 2 == off01:
+                break
+        else:
+            raise Exception("Failed to match site")
+
+        return '%s.%s.%s 1' % (tile, site, post)
+
+    def intf(seg, tile, tag_post):
+        # Make the selection an argument of the configruation
+        m = re.match(r'(.*)[.]([A-Za-z0-9_]+)', tag_post)
+        which = m.group(1)
+        value = m.group(2)
+        site = {
+            'clblm_l': 'CENTER_INTER_L',
+            'clblm_r': 'CENTER_INTER_R',
+            'hclk_l': 'HCLK_L',
+            'hclk_r': 'HCLK_R',
+        }[segj['type']]
+        return '%s.%s.%s %s' % (tile, site, which, value)
+
+    m = re.match(r'([A-Za-z0-9_]+)[.](.*)', tag)
+    tile_type = m.group(1)
+    tag_post = m.group(2)
+
+    # Find associated tile
+    for tile in segj['tiles']:
+        if grid['tiles'][tile]['type'] == tile_type:
+            break
+    else:
+        raise Exception("Couldn't find tile type %s" % tile_type)
+
+    tag2asm = {
+        'CLBLM_L': clbf,
+        'CLBLM_R': clbf,
+        'INT_L': intf,
+        'INT_R': intf,
+        'HCLK_L': intf,
+    }
+    f = tag2asm.get(tile_type, None)
+    if f is None:
+        raise Exception("Unhandled segment type %s" % tilej['type'])
+    return f(seg, tile, tag_post)
+
+
+def run(f_in, f_out, sparse=False):
+    with open("%s/%s/tilegrid.json" % (os.getenv("XRAY_DATABASE_DIR"),
+                                       os.getenv("XRAY_DATABASE")), "r") as f:
+        grid = json.load(f)
+
+    seg = None
+    for l in f_in:
+        l = l.strip()
+        if not l:
+            continue
+        # seg SEG_CLBLM_L_X10Y102
+        # tag CLBLM_L.SLICEM_X0.ALUT.INIT[00]
+        m = re.match('(seg|tag) (.*)', l)
+        if not m:
+            raise Exception("Invalid line %s" % l)
+        type = m.group(1)
+        if type == 'seg':
+            seg = m.group(2)
+        elif type == 'tag':
+            f_out.write(tag2fasm(grid, seg, m.group(2)) + '\n')
+        else:
+            raise Exception("Invalid type %s" % type)
+
+
+if __name__ == '__main__':
+    import argparse
+
+    parser = argparse.ArgumentParser(
+        description='Convert segprint -d output to .fasm file (FPGA assembly)')
+
+    parser.add_argument(
+        'fn_in', default='/dev/stdin', nargs='?', help='Input segment file')
+    parser.add_argument(
+        'fn_out', default='/dev/stdout', nargs='?', help='Output .fasm file')
+
+    args = parser.parse_args()
+    run(open(args.fn_in, 'r'), open(args.fn_out, 'w'))