diff --git a/doc/OpenSTA.odt b/doc/OpenSTA.odt
index 05b5afd3..0b0f3174 100644
Binary files a/doc/OpenSTA.odt and b/doc/OpenSTA.odt differ
diff --git a/liberty/LibertyWriter.cc b/liberty/LibertyWriter.cc
index 00ecc0ae..e14b5792 100644
--- a/liberty/LibertyWriter.cc
+++ b/liberty/LibertyWriter.cc
@@ -52,6 +52,7 @@ protected:
                          RiseFall *rf);
   void writeTableModel(const TableModel *model);
   void writeTableModel0(const TableModel *model);
+  void writeTableModel1(const TableModel *model);
   void writeTableModel2(const TableModel *model);
   void writeTableAxis(TableAxis *axis,
                       int index);
@@ -373,6 +374,7 @@ LibertyWriter::writeTableModel(const TableModel *model)
     writeTableModel0(model);
     break;
   case 1:
+    writeTableModel1(model);
     break;
   case 2:
     writeTableModel2(model);
@@ -391,6 +393,21 @@ LibertyWriter::writeTableModel0(const TableModel *model)
           time_unit_->asString(value, 5));
 }
 
+void
+LibertyWriter::writeTableModel1(const TableModel *model)
+{
+  fprintf(stream_, "          values(\"");
+  bool first_col = true;
+  for (size_t index1 = 0; index1 < model->axis1()->size(); index1++) {
+    float value = model->value(index1, 0, 0);
+    if (!first_col)
+      fprintf(stream_, ",");
+    fprintf(stream_, "%s", time_unit_->asString(value, 5));
+    first_col = false;
+  }
+  fprintf(stream_, "\");\n");
+}
+
 void
 LibertyWriter::writeTableModel2(const TableModel *model)
 {
diff --git a/liberty/TableModel.cc b/liberty/TableModel.cc
index 6ae924d8..e5a6f7ee 100644
--- a/liberty/TableModel.cc
+++ b/liberty/TableModel.cc
@@ -46,8 +46,8 @@ GateTableModel::GateTableModel(TableModel *delay_model,
   slew_model_(slew_model)
 {
   for (auto el_index : EarlyLate::rangeIndex()) {
-    slew_sigma_models_[el_index] = slew_sigma_models[el_index];
-    delay_sigma_models_[el_index] = delay_sigma_models[el_index];
+    slew_sigma_models_[el_index] = slew_sigma_models ? slew_sigma_models[el_index] : nullptr;
+    delay_sigma_models_[el_index] = delay_sigma_models ? delay_sigma_models[el_index] : nullptr;
   }
 }
 
diff --git a/search/MakeTimingModel.cc b/search/MakeTimingModel.cc
index cb0015ec..8c3c9eff 100644
--- a/search/MakeTimingModel.cc
+++ b/search/MakeTimingModel.cc
@@ -23,7 +23,6 @@
 #include "TimingArc.hh"
 #include "TableModel.hh"
 #include "liberty/LibertyBuilder.hh"
-#include "LibertyWriter.hh"
 #include "Network.hh"
 #include "PortDirection.hh"
 #include "Corner.hh"
@@ -36,16 +35,6 @@
 
 namespace sta {
 
-void
-writeTimingModel(const char *cell_name,
-                 const char *filename,
-                 const Corner *corner,
-                 Sta *sta)
-{
-  MakeTimingModel writer(corner, sta);
-  writer.writeTimingModel(cell_name, filename);
-}
-
 MakeTimingModel::MakeTimingModel(const Corner *corner,
                                  Sta *sta) :
   StaState(sta),
@@ -61,21 +50,7 @@ MakeTimingModel::~MakeTimingModel()
   delete lib_builder_;
 }
 
-void
-MakeTimingModel::writeTimingModel(const char *cell_name,
-                                  const char *filename)
-{
-  makeTimingModel(cell_name, filename);
-  writeLibertyFile(filename);
-}
-
-void
-MakeTimingModel::writeLibertyFile(const char *filename)
-{
-  writeLiberty(library_, filename, this);
-}
-
-void
+LibertyLibrary *
 MakeTimingModel::makeTimingModel(const char *cell_name,
                                  const char *filename)
 {
@@ -86,13 +61,11 @@ MakeTimingModel::makeTimingModel(const char *cell_name,
   for (Clock *clk : *sdc_->clocks())
     sta_->setPropagatedClock(clk);
 
-#if 0
   findInputToOutputPaths();
   findInputSetupHolds();
   findClkedOutputPaths();
-#endif
-  findClkedOutputPaths();
   cell_->finish(false, report_, debug_);
+  return library_;
 }
 
 void
@@ -269,37 +242,52 @@ MakeTimingModel::findClkedOutputPaths()
   while (output_iter->hasNext()) {
     Pin *output_pin = output_iter->next();    
     if (network_->direction(output_pin)->isOutput()) {
+      LibertyPort *output_port = modelPort(output_pin);
       for (Clock *clk : *sdc_->clocks()) {
-        for (RiseFall *clk_rf : RiseFall::range()) {
-          for (RiseFall *output_rf : RiseFall::range()) {
-            RiseFallBoth *output_rf1 = output_rf->asRiseFallBoth();
-            MinMax *min_max = MinMax::max();
-            MinMaxAll *min_max1 = min_max->asMinMaxAll();
-            sta_->setOutputDelay(output_pin, output_rf1, clk, clk_rf,
-                                 nullptr, false, false, min_max1, false, 0.0);
+        for (const Pin *clk_pin : clk->pins()) {
+          LibertyPort *clk_port = modelPort(clk_pin);
+          for (RiseFall *clk_rf : RiseFall::range()) {
+            TimingArcAttrs *attrs = nullptr;
+            for (RiseFall *output_rf : RiseFall::range()) {
+              RiseFallBoth *output_rf1 = output_rf->asRiseFallBoth();
+              MinMax *min_max = MinMax::max();
+              MinMaxAll *min_max1 = min_max->asMinMaxAll();
+              sta_->setOutputDelay(output_pin, output_rf1, clk, clk_rf,
+                                   nullptr, false, false, min_max1, false, 0.0);
         
-            ClockSet *from_clks = new ClockSet;
-            from_clks->insert(clk);
-            ExceptionFrom *from = sta_->makeExceptionFrom(nullptr, from_clks, nullptr,
-                                                          clk_rf->asRiseFallBoth());
-            PinSet *to_pins = new PinSet;
-            to_pins->insert(output_pin);
-            ExceptionTo *to = sta_->makeExceptionTo(to_pins, nullptr, nullptr,
-                                                    output_rf1, output_rf1);
+              ClockSet *from_clks = new ClockSet;
+              from_clks->insert(clk);
+              ExceptionFrom *from = sta_->makeExceptionFrom(nullptr, from_clks, nullptr,
+                                                            clk_rf->asRiseFallBoth());
+              PinSet *to_pins = new PinSet;
+              to_pins->insert(output_pin);
+              ExceptionTo *to = sta_->makeExceptionTo(to_pins, nullptr, nullptr,
+                                                      output_rf1, output_rf1);
 
-            PathEndSeq *ends = sta_->findPathEnds(from, nullptr, to, false, corner_, min_max1,
-                                                  1, 1, false, -INF, INF, false, nullptr,
-                                                  true, false, false, false, false, false);
-            if (!ends->empty()) {
-              debugPrint(debug_, "make_timing_model", 1, "clock %s -> output %s",
-                         clk->name(),
-                         network_->pathName(output_pin));
-              PathEnd *end = (*ends)[0];
-              if (debug_->check("make_timing_model", 2))
-                sta_->reportPathEnd(end);
+              PathEndSeq *ends = sta_->findPathEnds(from, nullptr, to, false, corner_, min_max1,
+                                                    1, 1, false, -INF, INF, false, nullptr,
+                                                    true, false, false, false, false, false);
+              if (!ends->empty()) {
+                debugPrint(debug_, "make_timing_model", 1, "clock %s -> output %s",
+                           clk->name(),
+                           network_->pathName(output_pin));
+                PathEnd *end = (*ends)[0];
+                if (debug_->check("make_timing_model", 2))
+                  sta_->reportPathEnd(end);
+                Arrival delay = end->path()->arrival(sta_);
+                Slew slew = end->path()->slew(sta_);
+                TimingModel *check_model = makeScalarGateModel(delay, slew, output_rf);
+                if (attrs == nullptr)
+                  attrs = new TimingArcAttrs();
+                attrs->setModel(output_rf, check_model);
+              }
+              sta_->removeOutputDelay(output_pin, output_rf1, clk, clk_rf, MinMaxAll::max());
             }
-            sta_->removeOutputDelay(output_pin, RiseFallBoth::riseFall(),
-                                    clk, clk_rf, MinMaxAll::max());
+            if (attrs)
+              lib_builder_->makeFromTransitionArcs(cell_, clk_port,
+                                                   output_port, nullptr,
+                                                   clk_rf, TimingRole::regClkToQ(),
+                                                   attrs);
           }
         }
       }
@@ -327,4 +315,22 @@ MakeTimingModel::makeScalarCheckModel(float value,
   return check_model;
 }
 
+TimingModel *
+MakeTimingModel::makeScalarGateModel(Delay delay,
+                                     Slew slew,
+                                     RiseFall *rf)
+{
+  Table *delay_table = new Table0(delay);
+  Table *slew_table = new Table0(slew);
+  TableTemplate *tbl_template =
+    library_->findTableTemplate("scalar", TableTemplateType::delay);
+  TableModel *delay_model = new TableModel(delay_table, tbl_template,
+                                           ScaleFactorType::cell, rf);
+  TableModel *slew_model = new TableModel(slew_table, tbl_template,
+                                          ScaleFactorType::cell, rf);
+  GateTableModel *gate_model = new GateTableModel(delay_model, nullptr,
+                                                  slew_model, nullptr);
+  return gate_model;
+}
+
 } // namespace
diff --git a/search/MakeTimingModel.hh b/search/MakeTimingModel.hh
index ac284a2b..53b041cd 100644
--- a/search/MakeTimingModel.hh
+++ b/search/MakeTimingModel.hh
@@ -31,11 +31,8 @@ public:
   MakeTimingModel(const Corner *corner,
                    Sta *sta);
   ~MakeTimingModel();
-  void writeTimingModel(const char *cell_name,
-                        const char *filename);
-  void makeTimingModel(const char *cell_name,
-                       const char *filename);
-  void writeLibertyFile(const char *filename);
+  LibertyLibrary *makeTimingModel(const char *cell_name,
+                                  const char *filename);
 
 private:
   void makeLibrary(const char *cell_name,
@@ -51,6 +48,9 @@ private:
   TimingModel *makeScalarCheckModel(float value,
                                     ScaleFactorType scale_factor_type,
                                     RiseFall *rf);
+  TimingModel *makeScalarGateModel(Delay delay,
+                                   Slew slew,
+                                   RiseFall *rf);
 
   Sta *sta_;
   LibertyLibrary *library_;
diff --git a/search/Sta.cc b/search/Sta.cc
index d56036e7..0d3d0217 100644
--- a/search/Sta.cc
+++ b/search/Sta.cc
@@ -28,6 +28,7 @@
 #include "EquivCells.hh"
 #include "Liberty.hh"
 #include "liberty/LibertyReader.hh"
+#include "LibertyWriter.hh"
 #include "SdcNetwork.hh"
 #include "MakeConcreteNetwork.hh"
 #include "PortDirection.hh"
@@ -5572,7 +5573,9 @@ Sta::writeTimingModel(const char *cell_name,
                       const char *filename,
                       const Corner *corner)
 {
-  sta::writeTimingModel(cell_name, filename, corner, this);
+  MakeTimingModel maker(corner, this);
+  LibertyLibrary *library = maker.makeTimingModel(cell_name, filename);
+  writeLiberty(library, filename, this);
 }
 
 ////////////////////////////////////////////////////////////////