diff --git a/libs/libarchopenfpga/src/bitstream_setting.h b/libs/libarchopenfpga/src/bitstream_setting.h
index 3239661eb..8b676e272 100644
--- a/libs/libarchopenfpga/src/bitstream_setting.h
+++ b/libs/libarchopenfpga/src/bitstream_setting.h
@@ -109,9 +109,7 @@ class BitstreamSetting {
     const BitstreamDefaultModeSettingId& default_mode_setting_id) const;
   std::vector<std::string> default_mode_parent_mode_names(
     const BitstreamDefaultModeSettingId& default_mode_setting_id) const;
-  vtr::Rect<size_t> default_mode_coord(
-    const BitstreamDefaultModeSettingId& default_mode_setting_id) const;
-  vtr::Point<size_t> default_mode_subtile(
+  std::string default_mode_bits(
     const BitstreamDefaultModeSettingId& default_mode_setting_id) const;
 
   std::string interconnect_name(
@@ -142,8 +140,7 @@ class BitstreamSetting {
     const std::string& pb_type_name,
     const std::vector<std::string>& parent_pb_type_names,
     const std::vector<std::string>& parent_mode_names,
-    const std::string& mode_bits, const vtr::Rect<size_t>& coord, const vtr::Point<size_t>& subtile_range);
-
+    const std::string& mode_bits);
 
   BitstreamInterconnectSettingId add_bitstream_interconnect_setting(
     const std::string& interconnect_name,
@@ -194,8 +191,6 @@ class BitstreamSetting {
   vtr::vector<BitstreamDefaultModeSettingId, std::vector<std::string>>
     default_mode_parent_mode_names_;
   vtr::vector<BitstreamDefaultModeSettingId, std::string> pb_type_default_mode_bits_;
-  vtr::vector<BitstreamDefaultModeSettingId, vtr::Rect<size_t>> pb_type_coords_;
-  vtr::vector<BitstreamDefaultModeSettingId, vtr::Point<size_t>> pb_type_subtile_ranges_;
 
   /* Interconnect-related settings:
    * - Name of interconnect under a given pb_type
diff --git a/libs/libarchopenfpga/src/read_xml_bitstream_setting.cpp b/libs/libarchopenfpga/src/read_xml_bitstream_setting.cpp
index 244703fc1..3a2b43d6d 100644
--- a/libs/libarchopenfpga/src/read_xml_bitstream_setting.cpp
+++ b/libs/libarchopenfpga/src/read_xml_bitstream_setting.cpp
@@ -56,6 +56,26 @@ static void read_xml_bitstream_pb_type_setting(
   bitstream_setting.set_bitstream_offset(bitstream_pb_type_id, offset);
 }
 
+/********************************************************************
+ * Parse XML description for a pb_type annotation under a <default_mode_bits> XML node
+ *******************************************************************/
+static void read_xml_bitstream_default_mode_setting(
+  pugi::xml_node& xml_pb_type, const pugiutil::loc_data& loc_data,
+  openfpga::BitstreamSetting& bitstream_setting) {
+  const std::string& name_attr =
+    get_attribute(xml_pb_type, "name", loc_data).as_string();
+  /* Parse the attributes for operating pb_type */
+  openfpga::PbParser operating_pb_parser(name_attr);
+
+  const std::string& mode_bits_attr =
+    get_attribute(xml_pb_type, "mode_bits", loc_data).as_string();
+
+  /* Add to bitstream setting */
+  bitstream_setting.add_bitstream_default_mode_setting(
+    operating_pb_parser.leaf(), operating_pb_parser.parents(),
+    operating_pb_parser.modes(), mode_bits_attr);
+}
+
 /********************************************************************
  * Parse XML description for a pb_type annotation under a <interconect> XML node
  *******************************************************************/
@@ -137,18 +157,24 @@ openfpga::BitstreamSetting read_xml_bitstream_setting(
    * each child should be named after <pb_type>
    */
   for (pugi::xml_node xml_child : Node.children()) {
-    /* Error out if the XML child has an invalid name! */
+    /* Error out if the XML child has an invalid name! 
+     * TODO: Use std::map or something similar to apply checks!
+     */
     if ((xml_child.name() != std::string("pb_type")) &&
+        (xml_child.name() != std::string("default_mode_bits")) &&
         (xml_child.name() != std::string("interconnect")) &&
         (xml_child.name() != std::string("non_fabric")) &&
         (xml_child.name() != std::string("overwrite_bitstream"))) {
       bad_tag(xml_child, loc_data, Node,
-              {"pb_type | interconnect | non_fabric | overwrite_bitstream"});
+              {"pb_type | interconnect | default_mode_bits | non_fabric | overwrite_bitstream"});
     }
 
     if (xml_child.name() == std::string("pb_type")) {
       read_xml_bitstream_pb_type_setting(xml_child, loc_data,
                                          bitstream_setting);
+    } else if (xml_child.name() == std::string("default_mode_bits")) {
+      read_xml_bitstream_default_mode_setting(xml_child, loc_data,
+                                              bitstream_setting);
     } else if (xml_child.name() == std::string("interconnect")) {
       read_xml_bitstream_interconnect_setting(xml_child, loc_data,
                                               bitstream_setting);
diff --git a/libs/libarchopenfpga/src/write_xml_bitstream_setting.cpp b/libs/libarchopenfpga/src/write_xml_bitstream_setting.cpp
index f9268e653..b0c6973cc 100644
--- a/libs/libarchopenfpga/src/write_xml_bitstream_setting.cpp
+++ b/libs/libarchopenfpga/src/write_xml_bitstream_setting.cpp
@@ -118,6 +118,33 @@ static void write_xml_bitstream_pb_type_setting(
      << "\n";
 }
 
+/********************************************************************
+ * A writer to output a bitstream pb_type setting to XML format
+ *******************************************************************/
+static void write_xml_bitstream_pb_type_setting(
+  std::fstream& fp, const char* fname,
+  const openfpga::BitstreamSetting& bitstream_setting,
+  const BitstreamDefaultModeSettingId& bitstream_default_mode_setting_id) {
+  /* Validate the file stream */
+  openfpga::check_file_stream(fname, fp);
+
+  fp << "\t"
+     << "<default_mode_bits";
+
+  /* Generate the full hierarchy name of the pb_type */
+  write_xml_attribute(fp, "name",
+                      generate_bitstream_setting_pb_type_hierarchy_name(
+                        bitstream_setting, bitstream_default_mode_setting_id)
+                        .c_str());
+
+  write_xml_attribute(
+    fp, "mode_bits",
+    bitstream_setting.default_mode_bits(bitstream_default_mode_setting_id)
+      .c_str());
+  fp << "/>"
+     << "\n";
+}
+
 /********************************************************************
  * A writer to output a bitstream interconnect setting to XML format
  *******************************************************************/
@@ -166,6 +193,13 @@ void write_xml_bitstream_setting(
                                         bitstream_pb_type_setting_id);
   }
 
+  /* Write default_mode -related settings */
+  for (const auto& bitstream_default_mode_setting_id :
+       bitstream_setting.default_mode_settings()) {
+    write_xml_bitstream_default_mode_setting(fp, fname, bitstream_setting,
+                                        bitstream_default_mode_setting_id);
+  }
+
   /* Write interconnect -related settings */
   for (const auto& bitstream_interc_setting_id :
        bitstream_setting.interconnect_settings()) {