diff --git a/openfpga/src/annotation/device_rr_gsb.cpp b/openfpga/src/annotation/device_rr_gsb.cpp
index 6af394bba..50e1cab33 100644
--- a/openfpga/src/annotation/device_rr_gsb.cpp
+++ b/openfpga/src/annotation/device_rr_gsb.cpp
@@ -621,7 +621,7 @@ void DeviceRRGSB::preload_unique_sb_module(
   }
 }
 
-void DeviceRRGSB::get_id_unique_block_map(
+void DeviceRRGSB::get_id_unique_sb_block_map(
   std::map<int, vtr::Point<size_t>>& id_unique_block_map) const {
   for (size_t id = 0; id < get_num_sb_unique_module(); ++id) {
     const auto& unique_block_coord = sb_unique_module_[id];
@@ -631,7 +631,7 @@ void DeviceRRGSB::get_id_unique_block_map(
   }
 }
 
-void DeviceRRGSB::get_id_instance_map(
+void DeviceRRGSB::get_id_sb_instance_map(
   std::map<int, std::vector<vtr::Point<size_t>>>& id_instance_map) const {
   for (size_t location_x = 0; location_x < sb_unique_module_id_.size();
        ++location_x) {
@@ -643,4 +643,51 @@ void DeviceRRGSB::get_id_instance_map(
     }
   }
 }
+
+void DeviceRRGSB::get_id_unique_cbx_block_map(
+  std::map<int, vtr::Point<size_t>>& id_unique_block_map) const {
+  for (size_t id = 0; id < get_num_cb_unique_module(CHANX); ++id) {
+    const auto& unique_block_coord = cbx_unique_module_[id];
+    auto unique_module_id =
+      cbx_unique_module_id_[unique_block_coord.x()][unique_block_coord.y()];
+    id_unique_block_map[unique_module_id] = unique_block_coord;
+  }
+}
+
+void DeviceRRGSB::get_id_cbx_instance_map(
+  std::map<int, std::vector<vtr::Point<size_t>>>& id_instance_map) const {
+  for (size_t location_x = 0; location_x < cbx_unique_module_id_.size();
+       ++location_x) {
+    for (size_t location_y = 0; location_y < cbx_unique_module_id_[0].size();
+         ++location_y) {
+      auto unique_module_id = cbx_unique_module_id_[location_x][location_y];
+      vtr::Point<size_t> instance_coord(location_x, location_y);
+      id_instance_map[unique_module_id].push_back(instance_coord);
+    }
+  }
+}
+
+void DeviceRRGSB::get_id_unique_cby_block_map(
+  std::map<int, vtr::Point<size_t>>& id_unique_block_map) const {
+  for (size_t id = 0; id < get_num_cb_unique_module(CHANY); ++id) {
+    const auto& unique_block_coord = cby_unique_module_[id];
+    auto unique_module_id =
+      cby_unique_module_id_[unique_block_coord.x()][unique_block_coord.y()];
+    id_unique_block_map[unique_module_id] = unique_block_coord;
+  }
+}
+
+void DeviceRRGSB::get_id_cby_instance_map(
+  std::map<int, std::vector<vtr::Point<size_t>>>& id_instance_map) const {
+  for (size_t location_x = 0; location_x < cby_unique_module_id_.size();
+       ++location_x) {
+    for (size_t location_y = 0; location_y < cby_unique_module_id_[0].size();
+         ++location_y) {
+      auto unique_module_id = cby_unique_module_id_[location_x][location_y];
+      vtr::Point<size_t> instance_coord(location_x, location_y);
+      id_instance_map[unique_module_id].push_back(instance_coord);
+    }
+  }
+}
+
 } /* End namespace openfpga*/
diff --git a/openfpga/src/annotation/device_rr_gsb.h b/openfpga/src/annotation/device_rr_gsb.h
index 874c08c0e..513d4b003 100644
--- a/openfpga/src/annotation/device_rr_gsb.h
+++ b/openfpga/src/annotation/device_rr_gsb.h
@@ -103,9 +103,17 @@ class DeviceRRGSB {
     const vtr::Point<size_t> block_coordinate,
     const std::vector<vtr::Point<size_t>> instance_coords);
 
-  void get_id_instance_map(
+  void get_id_sb_instance_map(
     std::map<int, std::vector<vtr::Point<size_t>>>& id_instance_map) const;
-  void get_id_unique_block_map(
+  void get_id_unique_sb_block_map(
+    std::map<int, vtr::Point<size_t>>& id_unique_block_map) const;
+  void get_id_cbx_instance_map(
+    std::map<int, std::vector<vtr::Point<size_t>>>& id_instance_map) const;
+  void get_id_unique_cbx_block_map(
+    std::map<int, vtr::Point<size_t>>& id_unique_block_map) const;
+  void get_id_cby_instance_map(
+    std::map<int, std::vector<vtr::Point<size_t>>>& id_instance_map) const;
+  void get_id_unique_cby_block_map(
     std::map<int, vtr::Point<size_t>>& id_unique_block_map) const;
 
  private:                                                /* Internal cleaners */
diff --git a/openfpga/src/fabric/read_xml_unique_blocks.h b/openfpga/src/fabric/read_xml_unique_blocks.h
index 59ba8d106..395f44afd 100644
--- a/openfpga/src/fabric/read_xml_unique_blocks.h
+++ b/openfpga/src/fabric/read_xml_unique_blocks.h
@@ -4,7 +4,7 @@
 /********************************************************************
  * This file includes the top-level function of this library
  * which reads an XML of unique routing blocks to the associated
- * data structures
+ * data structures device_rr_gsb
  *******************************************************************/
 
 #include <string>
@@ -24,14 +24,15 @@
 /* Headers from libarchfpga */
 #include "arch_error.h"
 #include "device_rr_gsb_utils.h"
+#include "openfpga_digest.h"
 #include "read_xml_unique_blocks.h"
 #include "read_xml_util.h"
 #include "rr_gsb.h"
 #include "write_xml_utils.h"
-#include "openfpga_digest.h"
 
 /********************************************************************
- * Parse XML codes of a <instance> to an object of unique_blocks
+ * Parse XML codes of a <instance> to an object of device_rr_gsb
+ * instance is the mirror module of unique module. 
  *******************************************************************/
 vtr::Point<size_t> read_xml_unique_instance_info(
   pugi::xml_node& xml_instance_info, const pugiutil::loc_data& loc_data) {
@@ -93,8 +94,7 @@ void report_unique_module_status(T& openfpga_ctx, bool verbose_output) {
             1.));
 }
 /********************************************************************
- * Parse XML codes about <repack_design_constraints> to an object of
- *RepackDesignConstraints
+ * Parse XML codes about <unique_blocks> to an object of device_rr_gsb
  *******************************************************************/
 template <class T>
 int read_xml_unique_blocks(T& openfpga_ctx, const char* file_name,
@@ -159,14 +159,10 @@ int read_xml_unique_blocks(T& openfpga_ctx, const char* file_name,
   return 0;
 }
 
-
-template <class T>
-int write_xml_sb_blocks(std::fstream& fp, const T& openfpga_ctx) {
-  std::map<int, vtr::Point<size_t>> id_unique_block_map;
-  std::map<int, std::vector<vtr::Point<size_t>>> id_instance_map;
-  openfpga_ctx.device_rr_gsb().get_id_unique_block_map(id_unique_block_map);
-  openfpga_ctx.device_rr_gsb().get_id_instance_map(id_instance_map);
-
+int write_xml_block(
+  std::map<int, vtr::Point<size_t>>& id_unique_block_map,
+  std::map<int, std::vector<vtr::Point<size_t>>>& id_instance_map,
+  std::fstream& fp, std::string type) {
   /* Validate the file stream */
   if (false == openfpga::valid_file_stream(fp)) {
     return 2;
@@ -174,11 +170,11 @@ int write_xml_sb_blocks(std::fstream& fp, const T& openfpga_ctx) {
   for (const auto& pair : id_unique_block_map) {
     openfpga::write_tab_to_file(fp, 1);
     fp << "<block";
-    write_xml_attribute(fp, "type", "sb");
+    write_xml_attribute(fp, "type", type.c_str());
     write_xml_attribute(fp, "x", pair.second.x());
     write_xml_attribute(fp, "y", pair.second.y());
 
-    fp << "/>"
+    fp << ">"
        << "\n";
 
     for (const auto& instance_info : id_instance_map[pair.first]) {
@@ -190,6 +186,9 @@ int write_xml_sb_blocks(std::fstream& fp, const T& openfpga_ctx) {
       fp << "/>"
          << "\n";
     }
+    openfpga::write_tab_to_file(fp, 1);
+    fp << "</block>"
+       << "\n";
   }
 
   return 0;
@@ -213,8 +212,23 @@ int write_xml_unique_blocks(const T& openfpga_ctx, const char* fname,
      << "\n";
 
   int err_code = 0;
-  
-  err_code += write_xml_sb_blocks(fp, openfpga_ctx);
+  std::map<int, vtr::Point<size_t>> id_unique_block_map;
+  std::map<int, std::vector<vtr::Point<size_t>>> id_instance_map;
+  openfpga_ctx.device_rr_gsb().get_id_unique_sb_block_map(id_unique_block_map);
+  openfpga_ctx.device_rr_gsb().get_id_sb_instance_map(id_instance_map);
+  err_code += write_xml_block(id_unique_block_map, id_instance_map, fp, "sb");
+
+  id_unique_block_map.clear();
+  id_instance_map.clear();
+  openfpga_ctx.device_rr_gsb().get_id_unique_cbx_block_map(id_unique_block_map);
+  openfpga_ctx.device_rr_gsb().get_id_cbx_instance_map(id_instance_map);
+  err_code += write_xml_block(id_unique_block_map, id_instance_map, fp, "cbx");
+
+  id_unique_block_map.clear();
+  id_instance_map.clear();
+  openfpga_ctx.device_rr_gsb().get_id_unique_cby_block_map(id_unique_block_map);
+  openfpga_ctx.device_rr_gsb().get_id_cby_instance_map(id_instance_map);
+  err_code += write_xml_block(id_unique_block_map, id_instance_map, fp, "cby");
 
   /* Finish writing the root node */
   fp << "</unique_blocks>"