diff --git a/include/sta/Liberty.hh b/include/sta/Liberty.hh
index 7ebdc882..253927c8 100644
--- a/include/sta/Liberty.hh
+++ b/include/sta/Liberty.hh
@@ -88,6 +88,12 @@ constexpr int scale_factor_pvt_count = int(ScaleFactorPvt::unknown) + 1;
 enum class TableTemplateType { delay, power, output_current, ocv };
 constexpr int table_template_type_count = int(TableTemplateType::ocv) + 1;
 
+enum class LevelShifterType { HL, LH, HL_LH };
+
+enum class SwitchCellType { coarse_grain, fine_grain };
+
+////////////////////////////////////////////////////////////////
+
 void
 initLiberty();
 void
@@ -117,6 +123,8 @@ timingSenseString(TimingSense sense);
 TimingSense
 timingSenseOpposite(TimingSense sense);
 
+////////////////////////////////////////////////////////////////
+
 class LibertyLibrary : public ConcreteLibrary
 {
 public:
@@ -145,6 +153,7 @@ public:
   void setNominalVoltage(float voltage);
   float nominalTemperature() const { return nominal_temperature_; }
   void setNominalTemperature(float temperature);
+
   void setScaleFactors(ScaleFactors *scales);
   // Add named scale factor group.
   void addScaleFactors(ScaleFactors *scales);
@@ -159,6 +168,7 @@ public:
 		    int tr_index,
 		    const LibertyCell *cell,
 		    const Pvt *pvt) const;
+
   void setWireSlewDegradationTable(TableModel *model,
 				   RiseFall *rf);
   TableModel *wireSlewDegradationTable(const RiseFall *rf) const;
@@ -173,8 +183,10 @@ public:
 
   float defaultInputPinCap() const { return default_input_pin_cap_; }
   void setDefaultInputPinCap(float cap);
+
   float defaultOutputPinCap() const { return default_output_pin_cap_; }
   void setDefaultOutputPinCap(float cap);
+
   float defaultBidirectPinCap() const { return default_bidirect_pin_cap_; }
   void setDefaultBidirectPinCap(float cap);
 
@@ -196,6 +208,7 @@ public:
 			     bool &exists) const;
   void setDefaultBidirectPinRes(const RiseFall *rf,
 				float value);
+
   void defaultOutputPinRes(const RiseFall *rf,
 			   // Return values.
 			   float &res,
@@ -206,12 +219,15 @@ public:
   void defaultMaxSlew(float &slew,
 		      bool &exists) const;
   void setDefaultMaxSlew(float slew);
+
   void defaultMaxCapacitance(float &cap,
 			     bool &exists) const;
   void setDefaultMaxCapacitance(float cap);
+
   void defaultMaxFanout(float &fanout,
 			bool &exists) const;
   void setDefaultMaxFanout(float fanout);
+
   void defaultFanoutLoad(// Return values.
 			 float &fanout,
 			 bool &exists) const;
@@ -248,7 +264,6 @@ public:
   Wireload *defaultWireload() const;
   WireloadSelection *findWireloadSelection(const char *name) const;
   WireloadSelection *defaultWireloadSelection() const;
-
   void addWireload(Wireload *wireload);
   WireloadMode defaultWireloadMode() const;
   void setDefaultWireloadMode(WireloadMode mode);
@@ -405,6 +420,14 @@ public:
   void setIsPad(bool is_pad);
   bool isLevelShifter() const { return is_level_shifter_; }
   void setIsLevelShifter(bool is_level_shifter);
+  LevelShifterType levelShifterType() const { return level_shifter_type_; }
+  void setLevelShifterType(LevelShifterType level_shifter_type);
+  bool isIsolationCell() const { return is_isolation_cell_; }
+  void setIsIsolationCell(bool is_isolation_cell);
+  bool alwaysOn() const { return always_on_; }
+  void setAlwaysOn(bool always_on);
+  SwitchCellType switchCellType() const { return switch_cell_type_; }
+  void setSwitchCellType(SwitchCellType switch_cell_type);
   bool interfaceTiming() const { return interface_timing_; }
   void setInterfaceTiming(bool value);
   bool isClockGateLatchPosedge() const;
@@ -537,7 +560,10 @@ protected:
   bool is_memory_;
   bool is_pad_;
   bool is_level_shifter_;
-  bool has_internal_ports_;
+  LevelShifterType level_shifter_type_;
+  bool is_isolation_cell_;
+  bool always_on_;
+  SwitchCellType switch_cell_type_;
   bool interface_timing_;
   ClockGateType clock_gate_type_;
   TimingArcSetSeq timing_arc_sets_;
@@ -571,6 +597,7 @@ protected:
   float leakage_power_;
   bool leakage_power_exists_;
   LibertyPgPortMap pg_port_map_;
+  bool has_internal_ports_;
 
 private:
   friend class LibertyLibrary;
@@ -713,6 +740,19 @@ public:
   void setIsClockGateOutPin(bool is_clk_gate_out);
   bool isPllFeedbackPin() const { return is_pll_feedback_pin_; }
   void setIsPllFeedbackPin(bool is_pll_feedback_pin);
+
+  bool isolationCellDataPin() const { return isolation_cell_data_pin_; }
+  void setIsolationCellDataPin(bool isolation_cell_data_pin);
+
+  bool isolationCellEnablePin() const { return isolation_cell_enable_pin_; }
+  void setIsolationCellEnablePin(bool isolation_cell_enable_pin);
+
+  bool levelShifterDataPin() const { return level_shifter_data_pin_; }
+  void setLevelShifterDataPin(bool level_shifter_data_pin);
+
+  bool switchPin() const { return switch_pin_; }
+  void setSwitchPin(bool switch_pin);
+
   // Has register/latch rise/fall edges from pin.
   bool isRegClk() const { return is_reg_clk_; }
   void setIsRegClk(bool is_clk);
@@ -789,6 +829,10 @@ protected:
   bool is_clk_gate_enable_pin_:1;
   bool is_clk_gate_out_pin_:1;
   bool is_pll_feedback_pin_:1;
+  bool isolation_cell_data_pin_:1;
+  bool isolation_cell_enable_pin_:1;
+  bool level_shifter_data_pin_:1;
+  bool switch_pin_:1;
   bool is_disabled_constraint_:1;
 
 private:
diff --git a/liberty/Liberty.cc b/liberty/Liberty.cc
index e87ba253..a92cb98f 100644
--- a/liberty/Liberty.cc
+++ b/liberty/Liberty.cc
@@ -891,7 +891,10 @@ LibertyCell::LibertyCell(LibertyLibrary *library,
   is_memory_(false),
   is_pad_(false),
   is_level_shifter_(false),
-  has_internal_ports_(false),
+  level_shifter_type_(LevelShifterType::HL_LH),
+  is_isolation_cell_(false),
+  always_on_(false),
+  switch_cell_type_(SwitchCellType::fine_grain),
   interface_timing_(false),
   clock_gate_type_(ClockGateType::none),
   has_infered_reg_timing_arcs_(false),
@@ -901,7 +904,8 @@ LibertyCell::LibertyCell(LibertyLibrary *library,
   ocv_derate_(nullptr),
   is_disabled_constraint_(false),
   leakage_power_(0.0),
-  leakage_power_exists_(false)
+  leakage_power_exists_(false),
+  has_internal_ports_(false)
 {
   liberty_cell_ = this;
 }
@@ -1038,11 +1042,35 @@ LibertyCell::LibertyCell::setIsPad(bool is_pad)
 }
 
 void
-LibertyCell::LibertyCell::setIsLevelShifter(bool is_level_shifter)
+LibertyCell::setIsLevelShifter(bool is_level_shifter)
 {
   is_level_shifter_ = is_level_shifter;
 }
 
+void
+LibertyCell::setLevelShifterType(LevelShifterType level_shifter_type)
+{
+  level_shifter_type_ = level_shifter_type;
+}
+
+void
+LibertyCell::setIsIsolationCell(bool is_isolation_cell)
+{
+  is_isolation_cell_ = is_isolation_cell;
+}
+
+void
+LibertyCell::setAlwaysOn(bool always_on)
+{
+  always_on_ = always_on;
+}
+
+void
+LibertyCell::setSwitchCellType(SwitchCellType switch_cell_type)
+{
+  switch_cell_type_ = switch_cell_type;
+}
+
 void
 LibertyCell::setInterfaceTiming(bool value)
 {
@@ -1898,6 +1926,10 @@ LibertyPort::LibertyPort(LibertyCell *cell,
   is_clk_gate_enable_pin_(false),
   is_clk_gate_out_pin_(false),
   is_pll_feedback_pin_(false),
+  isolation_cell_data_pin_(false),
+  isolation_cell_enable_pin_(false),
+  level_shifter_data_pin_(false),
+  switch_pin_(false),
   is_disabled_constraint_(false)
 {
   liberty_port_ = this;
@@ -2351,6 +2383,30 @@ LibertyPort::setIsPllFeedbackPin(bool is_pll_feedback_pin)
   is_pll_feedback_pin_ = is_pll_feedback_pin;
 }
 
+void
+LibertyPort::setIsolationCellDataPin(bool isolation_cell_data_pin)
+{
+  isolation_cell_data_pin_ = isolation_cell_data_pin;
+}
+
+void
+LibertyPort::setIsolationCellEnablePin(bool isolation_cell_enable_pin)
+{
+  isolation_cell_enable_pin_ = isolation_cell_enable_pin;
+}
+
+void
+LibertyPort::setLevelShifterDataPin(bool level_shifter_data_pin)
+{
+  level_shifter_data_pin_ = level_shifter_data_pin;
+}
+
+void
+LibertyPort::setSwitchPin(bool switch_pin)
+{
+  switch_pin_ = switch_pin;
+}
+
 void
 LibertyPort::setPulseClk(RiseFall *trigger,
 			 RiseFall *sense)
diff --git a/liberty/LibertyReader.cc b/liberty/LibertyReader.cc
index 4fd2fbe0..44777696 100644
--- a/liberty/LibertyReader.cc
+++ b/liberty/LibertyReader.cc
@@ -164,6 +164,7 @@ LibertyReader::defineAttrVisitor(const char *attr_name,
 void
 LibertyReader::defineVisitors()
 {
+  // Library
   defineGroupVisitor("library", &LibertyReader::beginLibrary,
 		     &LibertyReader::endLibrary);
   defineAttrVisitor("time_unit", &LibertyReader::visitTimeUnit);
@@ -281,6 +282,7 @@ LibertyReader::defineVisitors()
   defineAttrVisitor("wire_load_from_area",
 		    &LibertyReader::visitWireloadFromArea);
 
+  // Cells
   defineGroupVisitor("cell", &LibertyReader::beginCell,
 		     &LibertyReader::endCell);
   defineGroupVisitor("scaled_cell", &LibertyReader::beginScaledCell,
@@ -293,9 +295,14 @@ LibertyReader::defineVisitors()
   defineAttrVisitor("is_memory", &LibertyReader::visitIsMemory);
   defineAttrVisitor("is_pad", &LibertyReader::visitIsPad);
   defineAttrVisitor("is_level_shifter", &LibertyReader::visitIsLevelShifter);
+  defineAttrVisitor("level_shifter_type", &LibertyReader::visitLevelShifterType);
+  defineAttrVisitor("is_isolation_cell", &LibertyReader::visitIsIsolationCell);
+  defineAttrVisitor("always_on", &LibertyReader::visitAlwaysOn);
+  defineAttrVisitor("switch_cell_type", &LibertyReader::visitSwitchCellType);
   defineAttrVisitor("interface_timing", &LibertyReader::visitInterfaceTiming);
   defineAttrVisitor("scaling_factors", &LibertyReader::visitScalingFactors);
 
+  // Pins
   defineGroupVisitor("pin", &LibertyReader::beginPin,&LibertyReader::endPin);
   defineGroupVisitor("bus", &LibertyReader::beginBus,&LibertyReader::endBus);
   defineGroupVisitor("bundle", &LibertyReader::beginBundle,
@@ -337,6 +344,15 @@ LibertyReader::defineVisitors()
 		    &LibertyReader::visitIsPllFeedbackPin);
   defineAttrVisitor("signal_type", &LibertyReader::visitSignalType);
 
+  defineAttrVisitor("isolation_cell_data_pin",
+                    &LibertyReader::visitIsolationCellDataPin);
+  defineAttrVisitor("isolation_cell_enable_pin",
+                    &LibertyReader::visitIsolationCellEnablePin);
+  defineAttrVisitor("level_shifter_data_pin",
+                    &LibertyReader::visitLevelShifterDataPin);
+  defineAttrVisitor("switch_pin", &LibertyReader::visitSwitchPin);
+
+  // Register/latch
   defineGroupVisitor("ff", &LibertyReader::beginFF, &LibertyReader::endFF);
   defineGroupVisitor("ff_bank", &LibertyReader::beginFFBank,
 		     &LibertyReader::endFFBank);
@@ -2502,6 +2518,58 @@ LibertyReader::visitIsLevelShifter(LibertyAttr *attr)
   }
 }
 
+void
+LibertyReader::visitLevelShifterType(LibertyAttr *attr)
+{
+  if (cell_) {
+    const char *level_shifter_type = getAttrString(attr);
+    if (stringEq(level_shifter_type, "HL"))
+      cell_->setLevelShifterType(LevelShifterType::HL);
+    else if (stringEq(level_shifter_type, "LH"))
+      cell_->setLevelShifterType(LevelShifterType::LH);
+    else if (stringEq(level_shifter_type, "HL_LH"))
+      cell_->setLevelShifterType(LevelShifterType::HL_LH);
+    else
+      libWarn(900, attr, "level_shifter_type must be HL, LH, or HL_LH");
+  }
+}
+
+void
+LibertyReader::visitIsIsolationCell(LibertyAttr *attr)
+{
+  if (cell_) {
+    bool is_isolation_cell, exists;
+    getAttrBool(attr, is_isolation_cell, exists);
+    if (exists)
+      cell_->setIsIsolationCell(is_isolation_cell);
+  }
+}
+
+void
+LibertyReader::visitAlwaysOn(LibertyAttr *attr)
+{
+  if (cell_) {
+    bool always_on, exists;
+    getAttrBool(attr, always_on, exists);
+    if (exists)
+      cell_->setAlwaysOn(always_on);
+  }
+}
+
+void
+LibertyReader::visitSwitchCellType(LibertyAttr *attr)
+{
+  if (cell_) {
+    const char *switch_cell_type = getAttrString(attr);
+    if (stringEq(switch_cell_type, "coarse_grain"))
+      cell_->setSwitchCellType(SwitchCellType::coarse_grain);
+    else if (stringEq(switch_cell_type, "fine_grain"))
+      cell_->setSwitchCellType(SwitchCellType::fine_grain);
+    else
+      libWarn(901, attr, "switch_cell_type must be coarse_grain or fine_grain");
+  }
+}
+
 void
 LibertyReader::visitInterfaceTiming(LibertyAttr *attr)
 {
@@ -3223,65 +3291,25 @@ LibertyReader::visitPulseClock(LibertyAttr *attr)
 void
 LibertyReader::visitClockGateClockPin(LibertyAttr *attr)
 {
-  if (cell_) {
-    bool value, exists;
-    getAttrBool(attr, value, exists);
-    if (exists) {
-      LibertyPortSeq::Iterator port_iter(ports_);
-      while (port_iter.hasNext()) {
-	LibertyPort *port = port_iter.next();
-	port->setIsClockGateClockPin(value);
-      }
-    }
-  }
+  visitPortBoolAttr(attr, &LibertyPort::setIsClockGateClockPin);
 }
 
 void
 LibertyReader::visitClockGateEnablePin(LibertyAttr *attr)
 {
-  if (cell_) {
-    bool value, exists;
-    getAttrBool(attr, value, exists);
-    if (exists) {
-      LibertyPortSeq::Iterator port_iter(ports_);
-      while (port_iter.hasNext()) {
-	LibertyPort *port = port_iter.next();
-	port->setIsClockGateEnablePin(value);
-      }
-    }
-  }
+  visitPortBoolAttr(attr, &LibertyPort::setIsClockGateEnablePin);
 }
 
 void
 LibertyReader::visitClockGateOutPin(LibertyAttr *attr)
 {
-  if (cell_) {
-    bool value, exists;
-    getAttrBool(attr, value, exists);
-    if (exists) {
-      LibertyPortSeq::Iterator port_iter(ports_);
-      while (port_iter.hasNext()) {
-	LibertyPort *port = port_iter.next();
-	port->setIsClockGateOutPin(value);
-      }
-    }
-  }
+  visitPortBoolAttr(attr, &LibertyPort::setIsClockGateOutPin);
 }
 
 void
 LibertyReader::visitIsPllFeedbackPin(LibertyAttr *attr)
 {
-  if (cell_) {
-    bool value, exists;
-    getAttrBool(attr, value, exists);
-    if (exists) {
-      LibertyPortSeq::Iterator port_iter(ports_);
-      while (port_iter.hasNext()) {
-	LibertyPort *port = port_iter.next();
-	port->setIsPllFeedbackPin(value);
-      }
-    }
-  }
+  visitPortBoolAttr(attr, &LibertyPort::setIsPllFeedbackPin);
 }
 
 void
@@ -3302,6 +3330,47 @@ LibertyReader::visitSignalType(LibertyAttr *attr)
   }
 }
 
+void
+LibertyReader::visitIsolationCellDataPin(LibertyAttr *attr)
+{
+  visitPortBoolAttr(attr, &LibertyPort::setIsolationCellDataPin);
+}
+
+void
+LibertyReader::visitIsolationCellEnablePin(LibertyAttr *attr)
+{
+  visitPortBoolAttr(attr, &LibertyPort::setIsolationCellEnablePin);
+}
+
+void
+LibertyReader::visitLevelShifterDataPin(LibertyAttr *attr)
+{
+  visitPortBoolAttr(attr, &LibertyPort::setLevelShifterDataPin);
+}
+
+void
+LibertyReader::visitSwitchPin(LibertyAttr *attr)
+{
+  visitPortBoolAttr(attr, &LibertyPort::setSwitchPin);
+}
+
+void
+LibertyReader::visitPortBoolAttr(LibertyAttr *attr,
+                                 LibertyPortBoolSetter setter)
+{
+  if (cell_) {
+    bool value, exists;
+    getAttrBool(attr, value, exists);
+    if (exists) {
+      LibertyPortSeq::Iterator port_iter(ports_);
+      while (port_iter.hasNext()) {
+	LibertyPort *port = port_iter.next();
+	(port->*setter)(value);
+      }
+    }
+  }
+}
+
 ////////////////////////////////////////////////////////////////
 
 void
diff --git a/liberty/LibertyReaderPvt.hh b/liberty/LibertyReaderPvt.hh
index cd6a99c6..663f35f5 100644
--- a/liberty/LibertyReaderPvt.hh
+++ b/liberty/LibertyReaderPvt.hh
@@ -56,6 +56,7 @@ typedef Vector<LibertyFunc*> LibertyFuncSeq;
 typedef Vector<TimingGroup*> TimingGroupSeq;
 typedef Vector<InternalPowerGroup*> InternalPowerGroupSeq;
 typedef Vector<LeakagePowerGroup*> LeakagePowerGroupSeq;
+typedef void (LibertyPort::*LibertyPortBoolSetter)(bool value);
 
 class LibertyReader : public LibertyGroupVisitor
 {
@@ -182,7 +183,11 @@ public:
   virtual void visitIsMacro(LibertyAttr *attr);
   virtual void visitIsMemory(LibertyAttr *attr);
   virtual void visitIsPad(LibertyAttr *attr);
-  void visitIsLevelShifter(LibertyAttr *attr);
+  virtual void visitIsLevelShifter(LibertyAttr *attr);
+  virtual void visitLevelShifterType(LibertyAttr *attr);
+  virtual void visitIsIsolationCell(LibertyAttr *attr);
+  virtual void visitAlwaysOn(LibertyAttr *attr);
+  virtual void visitSwitchCellType(LibertyAttr *attr);
   virtual void visitInterfaceTiming(LibertyAttr *attr);
   virtual void visitScalingFactors(LibertyAttr *attr);
   virtual void visitCellLeakagePower(LibertyAttr *attr);
@@ -233,6 +238,12 @@ public:
   virtual void visitSignalType(LibertyAttr *attr);
   EarlyLateAll *getAttrEarlyLate(LibertyAttr *attr);
   virtual void visitClock(LibertyAttr *attr);
+  virtual void visitIsolationCellDataPin(LibertyAttr *attr);
+  virtual void visitIsolationCellEnablePin(LibertyAttr *attr);
+  virtual void visitLevelShifterDataPin(LibertyAttr *attr);
+  virtual void visitSwitchPin(LibertyAttr *attr);
+  void visitPortBoolAttr(LibertyAttr *attr,
+                         LibertyPortBoolSetter setter);
 
   virtual void beginScalingFactors(LibertyGroup *group);
   virtual void endScalingFactors(LibertyGroup *group);