Merge pull request #10488 from gadfort/pdn-min-area

pdn: add basic handling of lef58 area rule

Author: maliberty

src/odb/src/swig/common/containers.i

@@ -39,6 +39,7 @@ WRAP_DB_CONTAINER(odb::dbSite)
 WRAP_DB_CONTAINER(odb::dbTarget)
 WRAP_DB_CONTAINER(odb::dbTech)
 WRAP_DB_CONTAINER(odb::dbTechLayer)
+WRAP_DB_CONTAINER(odb::dbTechLayerAreaRule)
 WRAP_DB_CONTAINER(odb::dbTechLayerArraySpacingRule)
 WRAP_DB_CONTAINER(odb::dbTechLayerCornerSpacingRule)
 WRAP_DB_CONTAINER(odb::dbTechLayerCutClassRule)

src/pdn/src/techlayer.cpp

@@ -235,18 +235,35 @@ odb::Rect TechLayer::adjustToMinArea(
     const odb::Rect& rect,
     const std::optional<odb::dbTechLayerDir>& dir) const
 {
-  if (!layer_->hasArea()) {
+  const bool has_rules = !layer_->getTechLayerAreaRules().empty();
+  if (!has_rules && !layer_->hasArea()) {
     return rect;
   }
 
-  const double min_area = layer_->getArea();
-  if (min_area == 0.0) {
+  const int dbu_per_micron = getLefUnits();
+  int min_area = 0;
+  if (has_rules) {
+    for (auto* rule : layer_->getTechLayerAreaRules()) {
+      const int layer_min_area = rule->getArea();
+      if (layer_min_area == 0) {
+        continue;
+      }
+      // TODO: Check width rules
+      // TODO: Check length rules
+      // TODO: Check except rules
+      min_area = std::max(min_area, layer_min_area * dbu_per_micron);
+    }
+  } else {
+    const double layer_min_area = layer_->getArea();
+    min_area = layer_min_area * dbu_per_micron * dbu_per_micron;
+  }
+
+  if (min_area == 0) {
     return rect;
   }
 
   // make sure minimum area is honored
-  const int dbu_per_micron = getLefUnits();
-  const double area = min_area * dbu_per_micron * dbu_per_micron;
+  const double area = min_area;
 
   odb::Rect new_rect = rect;
 

src/pdn/test/BUILD

@@ -53,6 +53,7 @@ COMPULSORY_TESTS = [
     "core_grid_strap_outside_core",
     "core_grid_via_snap",
     "core_grid_with_M6_min_area",
+    "core_grid_with_M6_min_area_rule",
     "core_grid_with_M7_pins",
     "core_grid_with_bterms",
     "core_grid_with_dual_rings",
@@ -203,6 +204,7 @@ filegroup(
         "nangate_bsg_black_parrot/floorplan_flipchip.def",
         "nangate_bsg_black_parrot/floorplan_flipchip_nogrid.def",
         "nangate_bsg_black_parrot/floorplan_flipchip_short.def",
+        "nangate_data/Nangate45.lef",
         "nangate_existing/floorplan.def",
         "nangate_gcd/floorplan.def",
         "nangate_gcd/floorplan_obstructions.def",
@@ -281,6 +283,7 @@ filegroup(
             "asap7_macro_covered_partial": ["asap7_failed_macro_grid.def"],
             "asap7_macro_notcovered": ["asap7_failed_macro_grid.def"],
             "core_grid_auto_domain": ["core_grid.defok"],
+            "core_grid_with_M6_min_area_rule": ["core_grid_with_M6_min_area.defok"],
             "core_grid_with_rings_connect": ["core_grid_with_rings.defok"],
             "macros_channel_recursive_repair": [
                 "ihp_ethmac/tech.lef",

src/pdn/test/CMakeLists.txt

@@ -49,6 +49,7 @@ or_integration_tests(
     core_grid_strap_outside_core
     core_grid_via_snap
     core_grid_with_M6_min_area
+    core_grid_with_M6_min_area_rule
     core_grid_with_M7_pins
     core_grid_with_bterms
     core_grid_with_dual_rings

src/pdn/test/core_grid_with_M6_min_area_rule.ok

@@ -0,0 +1,7 @@
+[INFO ODB-0227] LEF file: nangate_data/Nangate45.lef, created 22 layers, 27 vias, 135 library cells
+[INFO ODB-0128] Design: gcd
+[INFO ODB-0130]     Created 54 pins.
+[INFO ODB-0131]     Created 482 components and 2074 component-terminals.
+[INFO ODB-0133]     Created 385 nets and 1110 connections.
+[INFO PDN-0001] Inserting grid: Core
+No differences found.

src/pdn/test/core_grid_with_M6_min_area_rule.tcl

@@ -0,0 +1,27 @@
+# test for rounding on M6 for min area
+source "helpers.tcl"
+
+read_lef nangate_data/Nangate45.lef
+read_def nangate_gcd/floorplan.def
+
+add_global_connection -net VDD -pin_pattern VDD -power
+add_global_connection -net VSS -pin_pattern VSS -ground
+
+set_voltage_domain -power VDD -ground VSS
+
+define_pdn_grid -name "Core" -pins metal7
+add_pdn_stripe -followpins -layer metal1
+add_pdn_stripe -followpins -layer metal2
+
+add_pdn_stripe -layer metal4 -width 0.48 -pitch 15.0 -offset 2.0
+add_pdn_stripe -layer metal7 -width 1.40 -pitch 20.0 -offset 2.0
+
+add_pdn_connect -layers {metal1 metal2}
+add_pdn_connect -layers {metal2 metal4}
+add_pdn_connect -layers {metal4 metal7}
+
+pdngen
+
+set def_file [make_result_file core_grid_with_M6_min_area.def]
+write_def $def_file
+diff_files core_grid_with_M6_min_area.defok $def_file