diff --git a/libs/libarchfpga/src/read_xml_arch_file.cpp b/libs/libarchfpga/src/read_xml_arch_file.cpp
index b3b4004b2..cf7c97133 100644
--- a/libs/libarchfpga/src/read_xml_arch_file.cpp
+++ b/libs/libarchfpga/src/read_xml_arch_file.cpp
@@ -2536,7 +2536,7 @@ static void ProcessLayout(pugi::xml_node layout_tag, t_arch* arch, const pugiuti
     //Expect only tileable attributes on <layout>
     //expect_only_attributes(layout_tag, {"tileable"}, loc_data);
 
-    arch->tileable = get_attribute(layout_tag, "tileable", loc_data).as_bool();
+    arch->tileable = get_attribute(layout_tag, "tileable", loc_data).as_bool(false);
 
     //Count the number of <auto_layout> or <fixed_layout> tags
     size_t auto_layout_cnt = 0;
diff --git a/openfpga/test_script/and_k6_frac_adder_chain.openfpga b/openfpga/test_script/and_k6_frac_adder_chain.openfpga
index 3f8b65f29..156f49ff0 100644
--- a/openfpga/test_script/and_k6_frac_adder_chain.openfpga
+++ b/openfpga/test_script/and_k6_frac_adder_chain.openfpga
@@ -1,5 +1,5 @@
 # Run VPR for the 'and' design
-vpr ./test_vpr_arch/k6_frac_N10_adder_chain_40nm.xml ./test_blif/and.blif --clock_modeling route #--write_rr_graph example_rr_graph.xml
+vpr ./test_vpr_arch/k6_frac_N10_adder_chain_40nm.xml ./test_blif/and.blif --route_chan_width 40 --clock_modeling route #--write_rr_graph example_rr_graph.xml
 
 # Read OpenFPGA architecture definition
 read_openfpga_arch -f ./test_openfpga_arch/k6_frac_N10_adder_chain_40nm_openfpga.xml
diff --git a/openfpga/test_vpr_arch/k6_frac_N10_adder_chain_40nm.xml b/openfpga/test_vpr_arch/k6_frac_N10_adder_chain_40nm.xml
index ed6e2defc..e390112e7 100644
--- a/openfpga/test_vpr_arch/k6_frac_N10_adder_chain_40nm.xml
+++ b/openfpga/test_vpr_arch/k6_frac_N10_adder_chain_40nm.xml
@@ -160,13 +160,15 @@
   <!-- ODIN II specific config ends -->
   <!-- Physical descriptions begin -->
   <layout tileable="true">
-    <auto_layout aspect_ratio="1.0">
+    <!--auto_layout aspect_ratio="1.0"-->
+    <fixed_layout name="2x2" width="3" height="4">
       <!--Perimeter of 'io' blocks with 'EMPTY' blocks at corners-->
       <perimeter type="io" priority="100"/>
       <corners type="EMPTY" priority="101"/>
       <!--Fill with 'clb'-->
       <fill type="clb" priority="10"/>
-    </auto_layout>
+    </fixed_layout>
+    <!-- /auto_layout -->
   </layout>
   <device>
     <!-- VB & JL: Using Ian Kuon's transistor sizing and drive strength data for routing, at 40 nm. Ian used BPTM 
diff --git a/vpr/src/base/SetupVPR.cpp b/vpr/src/base/SetupVPR.cpp
index 0cf69a9bb..a43f5b80a 100644
--- a/vpr/src/base/SetupVPR.cpp
+++ b/vpr/src/base/SetupVPR.cpp
@@ -321,6 +321,9 @@ static void SetupRoutingArch(const t_arch& Arch,
 
     /* copy over the switch block information */
     RoutingArch->switchblocks = Arch.switchblocks;
+
+    /* Copy the tileable routing setting */
+    RoutingArch->tileable = Arch.tileable;
 }
 
 static void SetupRouterOpts(const t_options& Options, t_router_opts* RouterOpts) {
diff --git a/vpr/src/base/place_and_route.cpp b/vpr/src/base/place_and_route.cpp
index 0f47ebebb..c13a1e393 100644
--- a/vpr/src/base/place_and_route.cpp
+++ b/vpr/src/base/place_and_route.cpp
@@ -88,6 +88,11 @@ int binary_search_place_and_route(const t_placer_opts& placer_opts_ref,
         graph_type = GRAPH_GLOBAL;
     } else {
         graph_type = (det_routing_arch->directionality == BI_DIRECTIONAL ? GRAPH_BIDIR : GRAPH_UNIDIR);
+        /* Branch on tileable routing */
+        if ( (UNI_DIRECTIONAL == det_routing_arch->directionality)
+          && (true == det_routing_arch->tileable) ) {
+            graph_type = GRAPH_UNIDIR_TILEABLE;
+        }
     }
 
     best_routing = alloc_saved_routing();
diff --git a/vpr/src/base/vpr_api.cpp b/vpr/src/base/vpr_api.cpp
index 53ec0e732..16a6cc708 100644
--- a/vpr/src/base/vpr_api.cpp
+++ b/vpr/src/base/vpr_api.cpp
@@ -831,7 +831,7 @@ void vpr_create_rr_graph(t_vpr_setup& vpr_setup, const t_arch& arch, int chan_wi
         graph_type = (det_routing_arch->directionality == BI_DIRECTIONAL ? GRAPH_BIDIR : GRAPH_UNIDIR);
         /* Branch on tileable routing */
         if ( (UNI_DIRECTIONAL == det_routing_arch->directionality)
-          && (true == arch.tileable) ) {
+          && (true == det_routing_arch->tileable) ) {
             graph_type = GRAPH_UNIDIR_TILEABLE;
         }
     }
diff --git a/vpr/src/base/vpr_types.h b/vpr/src/base/vpr_types.h
index 009887d71..8d03979fd 100644
--- a/vpr/src/base/vpr_types.h
+++ b/vpr/src/base/vpr_types.h
@@ -1009,6 +1009,9 @@ struct t_det_routing_arch {
      */
     int subFs;
     enum e_switch_block_type switch_block_subtype;
+    
+    /* Xifan Tang: tileable routing */
+    bool tileable;
 
     short global_route_switch;
     short delayless_switch;
diff --git a/vpr/src/route/route_common.cpp b/vpr/src/route/route_common.cpp
index 30fd9811a..5ef55df61 100644
--- a/vpr/src/route/route_common.cpp
+++ b/vpr/src/route/route_common.cpp
@@ -269,6 +269,11 @@ bool try_route(int width_fac,
         graph_type = GRAPH_GLOBAL;
     } else {
         graph_type = (det_routing_arch->directionality == BI_DIRECTIONAL ? GRAPH_BIDIR : GRAPH_UNIDIR);
+        /* Branch on tileable routing */
+        if ( (UNI_DIRECTIONAL == det_routing_arch->directionality)
+          && (true == det_routing_arch->tileable) ) {
+            graph_type = GRAPH_UNIDIR_TILEABLE;
+        }
     }
 
     /* Set the channel widths */
diff --git a/vpr/src/tileable_rr_graph/rr_graph_builder_utils.cpp b/vpr/src/tileable_rr_graph/rr_graph_builder_utils.cpp
index 446518faf..6ec00466b 100644
--- a/vpr/src/tileable_rr_graph/rr_graph_builder_utils.cpp
+++ b/vpr/src/tileable_rr_graph/rr_graph_builder_utils.cpp
@@ -59,6 +59,20 @@ e_side determine_io_grid_pin_side(const vtr::Point<size_t>& device_size,
   }
 }
 
+/* Deteremine the side of a pin of a grid */
+std::vector<e_side> find_grid_pin_sides(const t_grid_tile& grid, 
+                                        const size_t& pin_id) {
+  std::vector<e_side> pin_sides;
+
+  for (const e_side& side : {TOP, RIGHT, BOTTOM, LEFT} ) {
+    if (true == grid.type->pinloc[grid.width_offset][grid.height_offset][size_t(side)][pin_id]) {
+      pin_sides.push_back(side);
+    }
+  }
+
+  return pin_sides;
+}
+
 /************************************************************************
  * Get a list of pin_index for a grid (either OPIN or IPIN)
  * For IO_TYPE, only one side will be used, we consider one side of pins 
diff --git a/vpr/src/tileable_rr_graph/rr_graph_builder_utils.h b/vpr/src/tileable_rr_graph/rr_graph_builder_utils.h
index b63afa59d..8a903f97a 100644
--- a/vpr/src/tileable_rr_graph/rr_graph_builder_utils.h
+++ b/vpr/src/tileable_rr_graph/rr_graph_builder_utils.h
@@ -20,6 +20,9 @@ size_t find_unidir_routing_channel_width(const size_t& chan_width);
 int get_grid_pin_class_index(const t_grid_tile& cur_grid,
                              const int pin_index);
 
+std::vector<e_side> find_grid_pin_sides(const t_grid_tile& grid, 
+                                        const size_t& pin_id);
+
 e_side determine_io_grid_pin_side(const vtr::Point<size_t>& device_size, 
                                   const vtr::Point<size_t>& grid_coordinate);
 
diff --git a/vpr/src/tileable_rr_graph/rr_gsb.cpp b/vpr/src/tileable_rr_graph/rr_gsb.cpp
index 009da112a..200711e35 100644
--- a/vpr/src/tileable_rr_graph/rr_gsb.cpp
+++ b/vpr/src/tileable_rr_graph/rr_gsb.cpp
@@ -822,6 +822,14 @@ void RRGSB::sort_chan_node_in_edges(const RRGraph& rr_graph,
     get_node_side_and_index(rr_graph, src_node, IN_PORT, side, index);
 
     /* Must have valid side and index */
+    if (NUM_SIDES == side) {
+      VTR_LOG("GSB[%lu][%lu]:\n", get_x(), get_y());
+      VTR_LOG("SRC node:\n");
+      rr_graph.print_node(src_node);
+      VTR_LOG("Channel node:\n");
+      rr_graph.print_node(chan_node);
+    }
+
     VTR_ASSERT(NUM_SIDES != side);
     VTR_ASSERT(OPEN != index);
 
diff --git a/vpr/src/tileable_rr_graph/tileable_rr_graph_gsb.cpp b/vpr/src/tileable_rr_graph/tileable_rr_graph_gsb.cpp
index b37265dfb..ad4944bb4 100755
--- a/vpr/src/tileable_rr_graph/tileable_rr_graph_gsb.cpp
+++ b/vpr/src/tileable_rr_graph/tileable_rr_graph_gsb.cpp
@@ -1391,12 +1391,32 @@ void build_direct_connections_for_one_gsb(RRGraph& rr_graph,
         int from_grid_height_ofs = from_grid.height_offset;
         int to_grid_width_ofs = grids[to_grid_coordinate.x()][to_grid_coordinate.y()].width_offset;
         int to_grid_height_ofs = grids[to_grid_coordinate.x()][to_grid_coordinate.y()].height_offset;
+ 
+        /* Find the side of grid pins, the pin location should be unique!
+         * Pin location is required by searching a node in rr_graph 
+         */
+        std::vector<e_side> opin_grid_side = find_grid_pin_sides(from_grid, opin); 
+        VTR_ASSERT(1 == opin_grid_side.size());
+
+        std::vector<e_side> ipin_grid_side = find_grid_pin_sides(grids[to_grid_coordinate.x()][to_grid_coordinate.y()], ipin); 
+        VTR_ASSERT(1 == ipin_grid_side.size());
+
         const RRNodeId& opin_node_id = rr_graph.find_node(from_grid_coordinate.x() - from_grid_width_ofs, 
                                                           from_grid_coordinate.y() - from_grid_height_ofs, 
-                                                          OPIN, opin);
+                                                          OPIN, opin, opin_grid_side[0]);
         const RRNodeId& ipin_node_id = rr_graph.find_node(to_grid_coordinate.x() - to_grid_width_ofs, 
                                                           to_grid_coordinate.y() - to_grid_height_ofs, 
-                                                          IPIN, ipin);
+                                                          IPIN, ipin, ipin_grid_side[0]);
+        /*
+        VTR_LOG("Direct connection: from grid[%lu][%lu].pin[%lu] at side %s to grid[%lu][%lu].pin[%lu] at side %s\n",
+                from_grid_coordinate.x() - from_grid_width_ofs,
+                from_grid_coordinate.y() - from_grid_height_ofs,
+                opin, SIDE_STRING[opin_grid_side[0]],
+                to_grid_coordinate.x() - to_grid_width_ofs,
+                to_grid_coordinate.y() - to_grid_height_ofs,
+                ipin, SIDE_STRING[ipin_grid_side[0]]);
+         */
+     
         /* add edges to the opin_node */
         rr_graph.create_edge(opin_node_id, ipin_node_id,
                              delayless_switch);