Implemented #579 (perimeter_only mode for antenna check) (#582)

* WIP: added basic feature and tests.

* WIP: provide tests are GSI binding of new antenna check

* Fixed issue #579 (perimeter_only mode for antenna check)

* Updated DRC doc for 'perimeter_only'

src/db/db/dbLayoutToNetlist.cc

@@ -1180,7 +1180,7 @@ db::Net *LayoutToNetlist::probe_net (const db::Region &of_region, const db::Poin
   }
 }
 
-db::Region LayoutToNetlist::antenna_check (const db::Region &gate, double gate_perimeter_factor, const db::Region &metal, double metal_perimeter_factor, double ratio, const std::vector<std::pair<const db::Region *, double> > &diodes)
+db::Region LayoutToNetlist::antenna_check (const db::Region &gate, double gate_area_factor, double gate_perimeter_factor, const db::Region &metal, double metal_area_factor, double metal_perimeter_factor, double ratio, const std::vector<std::pair<const db::Region *, double> > &diodes)
 {
   //  TODO: that's basically too much .. we only need the clusters
   if (! m_netlist_extracted) {
@@ -1210,12 +1210,18 @@ db::Region LayoutToNetlist::antenna_check (const db::Region &gate, double gate_p
       deliver_shapes_of_net_recursive (0, m_net_clusters, *cid, *c, layer_of (gate), db::ICplxTrans (), rgate, 0);
       deliver_shapes_of_net_recursive (0, m_net_clusters, *cid, *c, layer_of (metal), db::ICplxTrans (), rmetal, 0);
 
-      double agate = rgate.area () * dbu * dbu;
+      double agate = 0.0;
+      if (fabs (gate_area_factor) > 1e-6) {
+        agate += rgate.area () * dbu * dbu * gate_area_factor;
+      }
       if (fabs (gate_perimeter_factor) > 1e-6) {
         agate += rgate.perimeter () * dbu * gate_perimeter_factor;
       }
 
-      double ametal = rmetal.area () * dbu * dbu;
+      double ametal = 0.0;
+      if (fabs (metal_area_factor) > 1e-6) {
+        ametal += rmetal.area () * dbu * dbu * metal_area_factor;
+      }
       if (fabs (metal_perimeter_factor) > 1e-6) {
         ametal += rmetal.perimeter () * dbu * metal_perimeter_factor;
       }

src/db/db/dbLayoutToNetlist.h

@@ -733,9 +733,9 @@ public:
    *  The area computation of gate and metal happens by taking the polygon
    *  area (A) and perimeter (P) into account:
    *
-   *    A(antenna) = A + P * f
+   *    A(antenna) = A + P * t
    *
-   *  where f is the perimeter factor. The unit of the area factor is
+   *  where t is the perimeter factor. The unit of this area factor is
    *  micrometers.
    *
    *  The limit ratio can be modified by the presence of connections to
@@ -750,7 +750,10 @@ public:
    *  regardless of the diode's area.
    *  In other words: any diode will make the net safe against antenna discharge.
    */
-  db::Region antenna_check (const db::Region &gate, double gate_perimeter_factor, const db::Region &metal, double metal_perimeter_factor, double ratio, const std::vector<std::pair<const db::Region *, double> > &diodes = std::vector<std::pair<const db::Region *, double> > ());
+  db::Region antenna_check (const db::Region &gate, double gate_perimeter_factor, const db::Region &metal, double metal_perimeter_factor, double ratio, const std::vector<std::pair<const db::Region *, double> > &diodes = std::vector<std::pair<const db::Region *, double> > ())
+  {
+    return antenna_check (gate, 1.0, gate_perimeter_factor, metal, 1.0, metal_perimeter_factor, ratio, diodes);
+  }
 
   /**
    *  @brief Variant of the antennna check not using the perimeter
@@ -758,9 +761,21 @@ public:
    */
   db::Region antenna_check (const db::Region &gate, const db::Region &metal, double ratio, const std::vector<std::pair<const db::Region *, double> > &diodes = std::vector<std::pair<const db::Region *, double> > ())
   {
-    return antenna_check (gate, 0.0, metal, 0.0, ratio, diodes);
+    return antenna_check (gate, 1.0, 0.0, metal, 1.0, 0.0, ratio, diodes);
   }
 
+  /**
+   *  @brief Variant of the antenna check providing an area scale factor
+   *
+   *  This version provides an additional area scale factor f, so the effective area becomes
+   *
+   *    A(antenna) = A * f + P * t
+   *
+   *  where f is the area scale factor and t the perimeter scale factor. This version allows to ignore the
+   *  area contribution entirely and switch to a perimeter-based antenna check by setting f to zero.
+   */
+  db::Region antenna_check (const db::Region &gate, double gate_area_factor, double gate_perimeter_factor, const db::Region &metal, double metal_area_factor, double metal_perimeter_factor, double ratio, const std::vector<std::pair<const db::Region *, double> > &diodes = std::vector<std::pair<const db::Region *, double> > ());
+
   /**
    *  @brief Saves the database to the given path
    *

src/db/db/gsiDeclDbLayoutToNetlist.cc

@@ -98,7 +98,7 @@ static std::vector<std::string> l2n_layer_names (const db::LayoutToNetlist *l2n)
   return ln;
 }
 
-static db::Region antenna_check2 (db::LayoutToNetlist *l2n, const db::Region &poly, double poly_perimeter_factor, const db::Region &metal, double metal_perimeter_factor, double ratio, const std::vector<tl::Variant> &diodes)
+static db::Region antenna_check3 (db::LayoutToNetlist *l2n, const db::Region &poly, double poly_area_factor, double poly_perimeter_factor, const db::Region &metal, double metal_area_factor, double metal_perimeter_factor, double ratio, const std::vector<tl::Variant> &diodes)
 {
   std::vector<std::pair<const db::Region *, double> > diode_pairs;
 
@@ -127,12 +127,17 @@ static db::Region antenna_check2 (db::LayoutToNetlist *l2n, const db::Region &po
 
   }
 
-  return l2n->antenna_check (poly, poly_perimeter_factor, metal, metal_perimeter_factor, ratio, diode_pairs);
+  return l2n->antenna_check (poly, poly_area_factor, poly_perimeter_factor, metal, metal_area_factor, metal_perimeter_factor, ratio, diode_pairs);
+}
+
+static db::Region antenna_check2 (db::LayoutToNetlist *l2n, const db::Region &poly, double poly_perimeter_factor, const db::Region &metal, double metal_perimeter_factor, double ratio, const std::vector<tl::Variant> &diodes)
+{
+  return antenna_check3 (l2n, poly, 1, poly_perimeter_factor, metal, 1, metal_perimeter_factor, ratio, diodes);
 }
 
 static db::Region antenna_check (db::LayoutToNetlist *l2n, const db::Region &poly, const db::Region &metal, double ratio, const std::vector<tl::Variant> &diodes)
 {
-  return antenna_check2 (l2n, poly, 0, metal, 0, ratio, diodes);
+  return antenna_check3 (l2n, poly, 1, 0, metal, 1, 0, ratio, diodes);
 }
 
 Class<db::LayoutToNetlist> decl_dbLayoutToNetlist ("db", "LayoutToNetlist",
@@ -617,15 +622,32 @@ Class<db::LayoutToNetlist> decl_dbLayoutToNetlist ("db", "LayoutToNetlist",
    "The effective area is computed using:\n"
    "\n"
    "@code\n"
-   "Aeff = A + P * f\n"
+   "Aeff = A + P * t\n"
    "@/code\n"
    "\n"
-   "Here Aeff is the area used in the check, A is the polygon area, P the perimeter and f the perimeter factor. "
-   "This formula applies to gate polygon area/perimeter with 'gate_perimeter_factor' for f and metal polygon area/perimeter "
+   "Here Aeff is the area used in the check, A is the polygon area, P the perimeter and t the perimeter factor. "
+   "This formula applies to gate polygon area/perimeter with 'gate_perimeter_factor' for t and metal polygon area/perimeter "
    "with 'metal_perimeter_factor'. The perimeter_factor has the dimension of micrometers and can be thought of as the width "
    "of the material. Essentially the side walls of the material are taking into account for the surface area as well.\n"
    "\n"
    "This variant has been introduced in version 0.26.6.\n"
+  ) +
+  gsi::method_ext ("antenna_check", &antenna_check3, gsi::arg ("gate"), gsi::arg ("gate_area_factor"), gsi::arg ("gate_perimeter_factor"), gsi::arg ("metal"), gsi::arg ("metal_area_factor"), gsi::arg ("metal_perimeter_factor"), gsi::arg ("ratio"), gsi::arg ("diodes", std::vector<tl::Variant> (), "[]"),
+   "@brief Runs an antenna check on the extracted clusters taking the perimeter into account and providing an area factor\n"
+   "\n"
+   "This (most generic) version of the \\antenna_check method allows taking the perimeter of gate or metal into account and also "
+   "provides a scaling factor for the area part.\n"
+   "The effective area is computed using:\n"
+   "\n"
+   "@code\n"
+   "Aeff = A * f + P * t\n"
+   "@/code\n"
+   "\n"
+   "Here f is the area factor and t the perimeter factor. A is the polygon area and P the polygon perimeter. "
+   "A use case for this variant is to set the area factor to zero. This way, only perimeter contributions are "
+   "considered.\n"
+   "\n"
+   "This variant has been introduced in version 0.26.6.\n"
   ),
   "@brief A generic framework for extracting netlists from layouts\n"
   "\n"

src/db/unit_tests/dbLayoutToNetlistTests.cc

@@ -2639,8 +2639,16 @@ TEST(10_Antenna)
     a5_5.insert_into (&ly2, top2.cell_index (), ly2.insert_layer (db::LayerProperties (500, 0)));
     a5_15.insert_into (&ly2, top2.cell_index (), ly2.insert_layer (db::LayerProperties (501, 0)));
     a5_29.insert_into (&ly2, top2.cell_index (), ly2.insert_layer (db::LayerProperties (502, 0)));
-  }
 
+    //  with area factor
+    db::Region b5_5 = l2n.antenna_check (*rpoly, 2.0, 0.0, *rmetal2, 1.0, 1.0, 2.5);
+    db::Region b5_15 = l2n.antenna_check (*rpoly, 2.0, 0.0, *rmetal2, 1.0, 1.0, 7.5);
+    db::Region b5_29 = l2n.antenna_check (*rpoly, 2.0, 0.0, *rmetal2, 1.0, 1.0, 14.5);
+
+    b5_5.insert_into (&ly2, top2.cell_index (), ly2.insert_layer (db::LayerProperties (550, 0)));
+    b5_15.insert_into (&ly2, top2.cell_index (), ly2.insert_layer (db::LayerProperties (551, 0)));
+    b5_29.insert_into (&ly2, top2.cell_index (), ly2.insert_layer (db::LayerProperties (552, 0)));
+  }
 
   {
     db::LayoutToNetlist l2n (&dss);
@@ -2672,6 +2680,15 @@ TEST(10_Antenna)
     a6_3.insert_into (&ly2, top2.cell_index (), ly2.insert_layer (db::LayerProperties (600, 0)));
     a6_5.insert_into (&ly2, top2.cell_index (), ly2.insert_layer (db::LayerProperties (601, 0)));
     a6_9.insert_into (&ly2, top2.cell_index (), ly2.insert_layer (db::LayerProperties (602, 0)));
+
+    //  with area factor
+    db::Region b6_3 = l2n.antenna_check (*rpoly, 1.0, 0.3, *rmetal2, 2.0, 0.0, 6);
+    db::Region b6_5 = l2n.antenna_check (*rpoly, 1.0, 0.3, *rmetal2, 2.0, 0.0, 10);
+    db::Region b6_9 = l2n.antenna_check (*rpoly, 1.0, 0.3, *rmetal2, 2.0, 0.0, 18);
+
+    b6_3.insert_into (&ly2, top2.cell_index (), ly2.insert_layer (db::LayerProperties (650, 0)));
+    b6_5.insert_into (&ly2, top2.cell_index (), ly2.insert_layer (db::LayerProperties (651, 0)));
+    b6_9.insert_into (&ly2, top2.cell_index (), ly2.insert_layer (db::LayerProperties (652, 0)));
   }
 
   std::string au = tl::testsrc ();

src/drc/drc/built-in-macros/_drc_engine.rb

@@ -122,11 +122,15 @@ module DRC
     end
     
     def area_only(r)
-      DRCAreaAndPerimeter::new(r, 0.0)
+      DRCAreaAndPerimeter::new(r, 1.0, 0.0)
+    end
+    
+    def perimeter_only(r, f)
+      DRCAreaAndPerimeter::new(r, 0.0, f)
     end
     
     def area_and_perimeter(r, f)
-      DRCAreaAndPerimeter::new(r, f)
+      DRCAreaAndPerimeter::new(r, 1.0, f)
     end
     
     # %DRC%

src/drc/drc/built-in-macros/_drc_netter.rb

@@ -370,6 +370,18 @@ module DRC
     # errors = antenna_check(gate, ...)
     # @/code
     #
+    # Finally there is also "perimeter_only". When using this 
+    # specification with a thickness value, the area is computed
+    # from the perimeter alone:
+    #
+    # @code
+    # A(eff) = P * t
+    # @/code
+    #
+    # @code
+    # errors = antenna_check(perimeter_only(gate, 0.5), ...)
+    # @/code
+    #
     # The error shapes produced by the antenna check are copies
     # of the metal shapes on the metal layers of each network 
     # violating the antenna rule.
@@ -377,11 +389,13 @@ module DRC
     def antenna_check(agate, ametal, ratio, *diodes)
 
       gate_perimeter_factor = 0.0
+      gate_area_factor = 1.0
       if agate.is_a?(DRC::DRCLayer)
         gate = agate
       elsif agate.is_a?(DRC::DRCAreaAndPerimeter)
         gate = agate.region
         gate_perimeter_factor = agate.perimeter_factor
+        gate_area_factor = agate.area_factor
         if ! gate.is_a?(DRC::DRCLayer)
           raise("gate with area or area_and_perimeter: input argument must be a layer")
         end
@@ -392,11 +406,13 @@ module DRC
       gate.requires_region("Netter#antenna_check (gate argument)")
 
       metal_perimeter_factor = 0.0
+      metal_area_factor = 1.0
       if ametal.is_a?(DRC::DRCLayer)
         metal = ametal
       elsif ametal.is_a?(DRC::DRCAreaAndPerimeter)
         metal = ametal.region
         metal_perimeter_factor = ametal.perimeter_factor
+        metal_area_factor = ametal.area_factor
         if ! metal.is_a?(DRC::DRCLayer)
           raise("metal with area or area_and_perimeter: input argument must be a layer")
         end
@@ -421,7 +437,7 @@ module DRC
         end
       end
 
-      DRC::DRCLayer::new(@engine, @engine._cmd(l2n_data, :antenna_check, gate.data, gate_perimeter_factor, metal.data, metal_perimeter_factor, ratio, dl))
+      DRC::DRCLayer::new(@engine, @engine._cmd(l2n_data, :antenna_check, gate.data, gate_area_factor, gate_perimeter_factor, metal.data, metal_area_factor, metal_perimeter_factor, ratio, dl))
 
     end
 

src/drc/drc/built-in-macros/_drc_tags.rb

@@ -117,10 +117,12 @@ module DRC
   # optional perimeter factor
   class DRCAreaAndPerimeter
     attr_accessor :region
+    attr_accessor :area_factor
     attr_accessor :perimeter_factor
-    def initialize(r, f)
+    def initialize(r, f, t)
       self.region = r
-      self.perimeter_factor = f
+      self.area_factor = f
+      self.perimeter_factor = t
     end
   end
 

src/lay/lay/doc/about/drc_ref_netter.xml

@@ -167,6 +167,18 @@ errors = antenna_check(area_and_perimeter(gate, 0.0), ...)
 errors = antenna_check(gate, ...)
 </pre>
 </p><p>
+Finally there is also "perimeter_only". When using this 
+specification with a thickness value, the area is computed
+from the perimeter alone:
+</p><p>
+<pre>
+A(eff) = P * t
+</pre>
+</p><p>
+<pre>
+errors = antenna_check(perimeter_only(gate, 0.5), ...)
+</pre>
+</p><p>
 The error shapes produced by the antenna check are copies
 of the metal shapes on the metal layers of each network 
 violating the antenna rule.