odb: impl 3dblox verilog writer

include/ord/OpenRoad.hh

@@ -3,8 +3,7 @@
 
 #pragma once
 
-#include <memory>
-#include <set>
+#include <iostream>
 #include <string>
 #include <vector>
 
@@ -226,6 +225,7 @@ class OpenRoad
   void read3Dbx(const std::string& filename);
   void write3Dbv(const std::string& filename);
   void write3Dbx(const std::string& filename);
+  void write3DbloxVerilog(const std::string& filename);
   void read3DBloxBMap(const std::string& filename);
   void check3DBlox();
 

src/OpenRoad.cc

@@ -79,7 +79,6 @@
 #include "rsz/MakeResizer.hh"
 #include "rsz/Resizer.hh"
 #include "sta/VerilogReader.hh"
-#include "sta/VerilogWriter.hh"
 #include "stt/MakeSteinerTreeBuilder.h"
 #include "tap/MakeTapcell.h"
 #include "tap/tapcell.h"
@@ -532,6 +531,12 @@ void OpenRoad::write3Dbx(const std::string& filename)
   writer.writeDbx(filename, db_->getChip());
 }
 
+void OpenRoad::write3DbloxVerilog(const std::string& filename)
+{
+  odb::ThreeDBlox writer(logger_, db_, sta_);
+  writer.writeVerilog(filename, db_->getChip());
+}
+
 // TODO: bool hierarchy should be removed in the future.
 // It is retained for a while for backward compatibility.
 void OpenRoad::readDb(const char* filename, bool hierarchy)

src/OpenRoad.i

@@ -404,6 +404,13 @@ write_3dbx_cmd(const char *filename)
   ord->write3Dbx(filename);
 }
 
+void
+write_3dblox_verilog_cmd(const char *filename)
+{
+  OpenRoad *ord = getOpenRoad();
+  ord->write3DbloxVerilog(filename);
+}
+
 void
 read_db_cmd(const char *filename, bool hierarchy)
 {

src/OpenRoad.tcl

@@ -198,6 +198,15 @@ proc write_3dbx { args } {
   ord::write_3dbx_cmd $filename
 }
 
+sta::define_cmd_args "write_3dblox_verilog" {filename}
+
+proc write_3dblox_verilog { args } {
+  sta::parse_key_args "write_3dblox_verilog" args keys {} flags {}
+  sta::check_argc_eq1 "write_3dblox_verilog" $args
+  set filename [file nativename [lindex $args 0]]
+  ord::write_3dblox_verilog_cmd $filename
+}
+
 sta::define_cmd_args "read_3dbx" {filename}
 
 proc read_3dbx { args } {

src/odb/include/odb/3dblox.h

@@ -46,6 +46,7 @@ class ThreeDBlox
   void writeDbv(const std::string& dbv_file, odb::dbChip* chip);
   void writeDbx(const std::string& dbx_file, odb::dbChip* chip);
   void writeBMap(const std::string& bmap_file, odb::dbChipRegion* region);
+  void writeVerilog(const std::string& verilog_file, odb::dbChip* chip);
 
  private:
   void createChiplet(const ChipletDef& chiplet);

src/odb/src/3dblox/3dblox.cpp

@@ -37,6 +37,7 @@
 #include "sta/VerilogReader.hh"
 #include "utl/Logger.h"
 #include "utl/ScopedTemporaryFile.h"
+#include "verilogWriter.h"
 namespace odb {
 
 static std::map<std::string, std::string> dup_orient_map
@@ -301,10 +302,23 @@ void ThreeDBlox::writeDbx(const std::string& dbx_file, odb::dbChip* chip)
 
   writeDbv(current_dir_path + chip->getName() + ".3dbv", chip);
 
+  // Write the Verilog connectivity file for this HIER chiplet.
+  writeVerilog(current_dir_path + chip->getName() + ".v", chip);
+
   DbxWriter writer(logger_, db_);
   writer.writeChiplet(dbx_file, chip);
 }
 
+void ThreeDBlox::writeVerilog(const std::string& verilog_file,
+                              odb::dbChip* chip)
+{
+  if (chip == nullptr) {
+    return;
+  }
+  VerilogWriter writer(logger_);
+  writer.writeChiplet(verilog_file, chip);
+}
+
 void ThreeDBlox::writeBMap(const std::string& bmap_file,
                            odb::dbChipRegion* region)
 {

src/odb/src/3dblox/CMakeLists.txt

@@ -12,6 +12,7 @@ add_library(3dblox
   bmapWriter.cpp
   dbvWriter.cpp
   dbxWriter.cpp
+  verilogWriter.cpp
   3dblox.cpp
   checker.cpp
 )

src/odb/src/3dblox/dbxWriter.cpp

@@ -49,6 +49,8 @@ void DbxWriter::writeYamlContent(YAML::Node& root, odb::dbChip* chiplet)
 void DbxWriter::writeDesign(YAML::Node& design_node, odb::dbChip* chiplet)
 {
   design_node["name"] = chiplet->getName();
+  YAML::Node external_node = design_node["external"];
+  external_node["verilog_file"] = std::string(chiplet->getName()) + ".v";
 }
 
 void DbxWriter::writeChipletInsts(YAML::Node& instances_node,

src/odb/src/3dblox/verilogWriter.cpp

@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: BSD-3-Clause
+// Copyright (c) 2019-2025, The OpenROAD Authors
+
+#include "verilogWriter.h"
+
+#include <algorithm>
+#include <cstddef>
+#include <cstdint>
+#include <fstream>
+#include <map>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "odb/db.h"
+#include "utl/Logger.h"
+
+namespace odb {
+
+VerilogWriter::VerilogWriter(utl::Logger* logger) : logger_(logger)
+{
+}
+
+void VerilogWriter::writeChiplet(const std::string& filename, odb::dbChip* chip)
+{
+  std::ofstream verilog_file(filename);
+  if (!verilog_file.is_open()) {
+    logger_->error(
+        utl::ODB, 563, "Unable to open Verilog file for writing: {}", filename);
+    return;
+  }
+
+  // chip_inst -> list of (port_name, net_name)
+  std::map<dbChipInst*, std::vector<std::pair<std::string, std::string>>>
+      inst_connections;
+
+  for (dbChipNet* net : chip->getChipNets()) {
+    const std::string net_name = net->getName();
+    const uint32_t num_bumps = net->getNumBumpInsts();
+    for (uint32_t i = 0; i < num_bumps; i++) {
+      std::vector<dbChipInst*> path;
+      dbChipBumpInst* bump_inst = net->getBumpInst(i, path);
+      if (bump_inst == nullptr || path.size() != 1) {
+        continue;
+      }
+      // Only handle direct children (path length 1) — "single bump
+      // connections".
+      dbChipInst* chip_inst = path[0];
+      dbChipBump* bump = bump_inst->getChipBump();
+      if (bump == nullptr) {
+        continue;
+      }
+      dbBTerm* bterm = bump->getBTerm();
+      if (bterm == nullptr) {
+        continue;
+      }
+      inst_connections[chip_inst].emplace_back(bterm->getName(), net_name);
+    }
+  }
+
+  // Sort each instance's port connections alphabetically by port name.
+  for (std::pair<dbChipInst* const,
+                 std::vector<std::pair<std::string, std::string>>>& entry :
+       inst_connections) {
+    std::ranges::sort(entry.second);
+  }
+
+  // Write module header.
+  fmt::print(verilog_file, "module {} ();\n", chip->getName());
+
+  // Collect and sort net names alphabetically for deterministic wire order.
+  std::vector<std::string> net_names;
+  for (dbChipNet* net : chip->getChipNets()) {
+    net_names.push_back(net->getName());
+  }
+  std::ranges::sort(net_names);
+
+  // Write wire declarations in sorted order.
+  for (const std::string& name : net_names) {
+    fmt::print(verilog_file, "  wire {};\n", name);
+  }
+
+  // Collect and sort instances alphabetically by instance name.
+  std::vector<dbChipInst*> chip_insts;
+  for (dbChipInst* chip_inst : chip->getChipInsts()) {
+    chip_insts.push_back(chip_inst);
+  }
+  std::ranges::sort(chip_insts, [](dbChipInst* a, dbChipInst* b) {
+    return a->getName() < b->getName();
+  });
+
+  // Write instance declarations in sorted order.
+  for (dbChipInst* chip_inst : chip_insts) {
+    fmt::print(verilog_file,
+               "  {} {} (\n",
+               chip_inst->getMasterChip()->getName(),
+               chip_inst->getName());
+    const std::map<
+        dbChipInst*,
+        std::vector<std::pair<std::string, std::string>>>::const_iterator it
+        = inst_connections.find(chip_inst);
+    if (it != inst_connections.end()) {
+      const std::vector<std::pair<std::string, std::string>>& conns
+          = it->second;
+      for (size_t j = 0; j < conns.size(); j++) {
+        const bool is_last = (j + 1 == conns.size());
+        fmt::print(verilog_file,
+                   "    .{}({}){}\n",
+                   conns[j].first,
+                   conns[j].second,
+                   is_last ? "" : ",");
+      }
+    }
+    fmt::print(verilog_file, "  );\n");
+  }
+
+  fmt::print(verilog_file, "endmodule\n");
+  verilog_file.close();
+}
+
+}  // namespace odb

src/odb/src/3dblox/verilogWriter.h

@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: BSD-3-Clause
+// Copyright (c) 2019-2025, The OpenROAD Authors
+
+#pragma once
+
+#include <string>
+
+namespace utl {
+class Logger;
+}
+namespace odb {
+class dbChip;
+
+class VerilogWriter
+{
+ public:
+  VerilogWriter(utl::Logger* logger);
+  void writeChiplet(const std::string& filename, odb::dbChip* chip);
+
+ private:
+  utl::Logger* logger_ = nullptr;
+};
+
+}  // namespace odb

src/odb/test/BUILD

@@ -207,6 +207,8 @@ COMPULSORY_TESTS = [
     "write_cdl",
     "write_3dbv",
     "write_3dbx",
+    "write_3dblox_verilog",
+    "write_3dblox_verilog_nets",
     "write_def58",
     "write_def58_gzip",
     "write_lef_and_def",
@@ -293,6 +295,9 @@ filegroup(
         "data/example2.bmap",
         "data/example3.bmap",
         "data/example4.bmap",
+        "data/example_nets.3dbv",
+        "data/example_nets.3dbx",
+        "data/example_nets.bmap",
         "data/floorplan_initialize.def",
         "data/floorplan_initialize.v",
         "data/floorplan_initialize2.def",
@@ -313,6 +318,7 @@ filegroup(
         "data/rounding.def",
         "data/sky130_fd_sc_hd__inv_1.gds",
         "data/sky130hd_multi_patterned.def",
+        "data/top_nets.v",
         "dump_netlists.tcl",
         "dump_netlists_withfill.tcl",
         "fake_macros.def",

src/odb/test/CMakeLists.txt

@@ -63,6 +63,8 @@ or_integration_tests(
     write_cdl
     write_3dbv
     write_3dbx
+    write_3dblox_verilog
+    write_3dblox_verilog_nets
     write_def58
     write_def58_gzip
     write_lef_and_def

src/odb/test/cpp/BUILD

@@ -257,6 +257,7 @@ cc_test(
     name = "Test3DBloxParser",
     srcs = [
         "Test3DBloxParser.cpp",
+        "Test3DBloxVerilogWriter.cpp",
     ],
     data = [
         "//src/odb/test:regression_resources",

src/odb/test/cpp/CMakeLists.txt

@@ -35,7 +35,7 @@ add_executable(TestNetTrack TestNetTrack.cpp)
 add_executable(TestMaster TestMaster.cpp)
 add_executable(TestGDSIn TestGDSIn.cpp)
 add_executable(TestChips TestChips.cpp)
-add_executable(Test3DBloxParser Test3DBloxParser.cpp)
+add_executable(Test3DBloxParser Test3DBloxParser.cpp Test3DBloxVerilogWriter.cpp)
 add_executable(Test3DBloxChecker Test3DBloxChecker.cpp Test3DBloxCheckerLogicalConn.cpp Test3DBloxCheckerBumps.cpp)
 add_executable(TestSwapMaster TestSwapMaster.cpp)
 add_executable(TestSwapMasterUnusedPort TestSwapMasterUnusedPort.cpp)