diff --git a/prjxray/grid.py b/prjxray/grid.py
index a751e966..04179e36 100644
--- a/prjxray/grid.py
+++ b/prjxray/grid.py
@@ -1,6 +1,9 @@
 from prjxray import segment_map
-from prjxray.grid_types import BlockType, GridLoc, GridInfo, BitAlias, Bits, BitsInfo
+from prjxray.grid_types import BlockType, GridLoc, GridInfo, BitAlias, Bits, BitsInfo, ClockRegion
 from prjxray.tile_segbits_alias import TileSegbitsAlias
+import re
+
+CLOCK_REGION_RE = re.compile('X([0-9])Y([0-9])')
 
 
 class Grid(object):
@@ -16,6 +19,8 @@ class Grid(object):
         self.loc = {}
         self.tileinfo = {}
 
+        clock_regions = {}
+
         for tile in self.tilegrid:
             tileinfo = self.tilegrid[tile]
             grid_loc = GridLoc(tileinfo['grid_x'], tileinfo['grid_y'])
@@ -46,11 +51,26 @@ class Grid(object):
                         alias=alias,
                     )
 
+            clock_region = None
+            if 'clock_region' in tileinfo:
+                if tileinfo['clock_region'] is not None:
+                    if tileinfo['clock_region'] not in clock_regions:
+                        m = CLOCK_REGION_RE.fullmatch(tileinfo['clock_region'])
+                        assert m is not None, tileinfo['clock_region']
+
+                        clock_regions[tileinfo['clock_region']] = ClockRegion(
+                            name=tileinfo['clock_region'],
+                            x=int(m.group(1)),
+                            y=int(m.group(2)))
+
+                    clock_region = clock_regions[tileinfo['clock_region']]
+
             self.tileinfo[tile] = GridInfo(
                 bits=bits,
                 sites=tileinfo['sites'],
                 tile_type=tileinfo['type'],
                 pin_functions=tileinfo.get('pin_functions', {}),
+                clock_region=clock_region,
             )
 
         x, y = zip(*self.loc.keys())
diff --git a/prjxray/grid_types.py b/prjxray/grid_types.py
index 04c9beb8..a27c3ac8 100644
--- a/prjxray/grid_types.py
+++ b/prjxray/grid_types.py
@@ -11,7 +11,9 @@ class BlockType(enum.Enum):
 
 
 GridLoc = namedtuple('GridLoc', 'grid_x grid_y')
-GridInfo = namedtuple('GridInfo', 'bits sites tile_type pin_functions')
+ClockRegion = namedtuple('ClockRegion', 'name x y')
+GridInfo = namedtuple(
+    'GridInfo', 'bits sites tile_type pin_functions clock_region')
 BitAlias = namedtuple('BitAlias', 'tile_type start_offset sites')
 Bits = namedtuple('Bits', 'base_address frames offset words alias')
 BitsInfo = namedtuple('BitsInfo', 'block_type tile bits')