diff --git a/Changes b/Changes
index 558f81a11..b949dba1e 100644
--- a/Changes
+++ b/Changes
@@ -7,6 +7,8 @@ The contributors that suggested a given feature are shown in []. Thanks!
 
 **    Add split_var metacomment to assist UNOPTFLAT fixes, #2066. [Yutetsu TAKATSUKASA]
 
+**    Add support for $dumpfile and $dumpvars, #2126. [Alexander Grobman]
+
 ***   Add +verilator+noassert flag to disable assertion checking. [Tobias Wölfel]
 
 ***   Add check for assertOn for asserts, #2162. [Tobias Wölfel]
diff --git a/bin/verilator b/bin/verilator
index a50add371..1714ed230 100755
--- a/bin/verilator
+++ b/bin/verilator
@@ -3782,17 +3782,29 @@ $unsigned, $warning.
 
 Generally supported.
 
-=item $display, $write, $fdisplay, $fwrite, $swrite
-
-$display and friends must have a constant format string as the first
-argument (as with C's printf).  The rare usage which lists variables
-standalone without a format is not supported.
-
 =item $displayb, $displayh, $displayo, $writeb, $writeh, $writeo, etc
 
 The sized display functions are rarely used and so not supported.  Replace
 them with a $write with the appropriate format specifier.
 
+=item $dump/$dumpports and related
+
+$dumpfile or $dumpports will create a VCD or FST file (which is based on
+the --trace argument given when the model was Verilated). This will take
+effect starting at the next eval() call.  If you have multiple Verilated
+designs under the same C model, then this will dump signals only from the
+design containing the $dumpvar.
+
+$dumpvars and $dumpports module identifier is ignored; the traced instances
+will always start at the top of the design. The levels argument is also
+ignored, use tracing_on/tracing_off pragmas instead.
+
+$dumpportson/$dumpportsoff/$dumpportsall/$dumpportslimit filename argument
+is ignored, only a single trace file may be active at once.
+
+$dumpall/$dumpportsall, $dumpon/$dumpportson, $dumpoff/$dumpportsoff, and
+$dumplimit/$dumpportlimit are currently ignored.
+
 =item $finish, $stop
 
 The rarely used optional parameter to $finish and $stop is ignored.
@@ -4835,19 +4847,20 @@ designs have topped 16GB.
 
 See the next question for tracing in SystemC mode.
 
-Add the --trace switch to Verilator, and in your top level C code, call
-Verilated::traceEverOn(true).  Then create a VerilatedVcdC object, and
-in your main loop call "trace_object->dump(time)" every time step, and
-finally call "trace_object->close()".  For an example, see below and the
-examples/make_tracing_c/sim_main.cpp file of the distribution.
+A. Add the --trace switch to Verilator, and in your top level C code, call
+Verilated::traceEverOn(true).  Then you may use $dumpfile and $dumpvars to
+enable traces, same as with any Verilog simulator. See
+C<examples/make_tracing_c>.
 
-You also need to compile verilated_vcd_c.cpp and add it to your link,
-preferably by adding the dependencies in $(VK_GLOBAL_OBJS) to your
-Makefile's link rule.  This is done for you if using the Verilator --exe
-flag.
-
-Note you can also call ->trace on multiple Verilated objects with the same
-trace file if you want all data to land in the same output file.
+B. Or, for finer-grained control, or C++ files with multiple Verilated
+modules you may also create the trace purely from C++.  Create a
+VerilatedVcdC object, and in your main loop call "trace_object->dump(time)"
+every time step, and finally call "trace_object->close()".  You also need
+to compile verilated_vcd_c.cpp and add it to your link, preferably by
+adding the dependencies in $(VK_GLOBAL_OBJS) to your Makefile's link rule.
+This is done for you if using the Verilator --exe flag.  Note you can also
+call ->trace on multiple Verilated objects with the same trace file if you
+want all data to land in the same output file.
 
     #include "verilated_vcd_c.h"
     ...
@@ -4867,11 +4880,17 @@ trace file if you want all data to land in the same output file.
 
 =item How do I generate waveforms (traces) in SystemC?
 
-Add the --trace switch to Verilator, and in your top level C sc_main code,
-include verilated_vcd_sc.h.  Then call Verilated::traceEverOn(true).  Then
-create a VerilatedVcdSc object as you would create a normal SystemC trace
-file.  For an example, see the call to VerilatedVcdSc in the
-examples/make_tracing_sc/sc_main.cpp file of the distribution, and below.
+A. Add the --trace switch to Verilator, and in your top level sc_main, call
+Verilated::traceEverOn(true).  Then you may use $dumpfile and $dumpvars to
+enable traces, same as with any Verilog simulator, see the non-SystemC
+example in C<examples/make_tracing_c>. This will trace only the module
+containing the $dumpvar.
+
+B. Or, you may create a trace purely from SystemC, which may trace all
+Verilated designs in the SystemC model. Create a VerilatedVcdSc object as
+you would create a normal SystemC trace file.  For an example, see the call
+to VerilatedVcdSc in the examples/make_tracing_sc/sc_main.cpp file of the
+distribution, and below.
 
 Alternatively you may use the C++ trace mechanism described in the previous
 question, however the timescale and timeprecision will not inherited from
@@ -4901,23 +4920,23 @@ trace file if you want all data to land in the same output file.
 
 =item How do I generate FST waveforms (traces) in C++?
 
-FST a format by GTKWave.
-This version provides a basic FST support.
-To dump FST format, add the --trace-fst switch to Verilator and change the include
-path in the testbench to:
+FST a format by GTKWave.  This version provides a basic FST support.  To
+dump FST format, add the --trace-fst switch to Verilator and either A. use
+$dumpfile/$dumpvars in Verilog as described in the VCD example above, or
+B. in C++ change the include described in the VCD example above:
 
     #include "verilated_fst_c.h"
     VerilatedFstC* tfp = new VerilatedFstC;
 
-Note that currently supporting both FST and VCD in a single simulation is impossible,
-but such requirement could be rare.
+Note that currently supporting both FST and VCD in a single simulation is
+impossible, but such requirement should be rare.
 
-=item How do I generate FST waveforms (traces) in SystemC?
+=item How do I generate FST waveforms (aka dumps or traces) in SystemC?
 
 The FST library from GTKWave does not currently support SystemC; use VCD
 format instead.
 
-=item How do I view waveforms (traces)?
+=item How do I view waveforms (aka dumps or traces)?
 
 Verilator makes standard VCD (Value Change Dump) and FST files.  VCD files are viewable
 with the public domain GTKWave (recommended) or Dinotrace (legacy)
diff --git a/examples/make_tracing_c/sim_main.cpp b/examples/make_tracing_c/sim_main.cpp
index c8003611e..1e75819f4 100644
--- a/examples/make_tracing_c/sim_main.cpp
+++ b/examples/make_tracing_c/sim_main.cpp
@@ -10,11 +10,6 @@
 // Include model header, generated from Verilating "top.v"
 #include "Vtop.h"
 
-// If "verilator --trace" is used, include the tracing class
-#if VM_TRACE
-# include <verilated_vcd_c.h>
-#endif
-
 // Current simulation time (64-bit unsigned)
 vluint64_t main_time = 0;
 // Called by $time in Verilog
@@ -36,28 +31,19 @@ int main(int argc, char** argv, char** env) {
     // May be overridden by commandArgs
     Verilated::randReset(2);
 
+    // Verilator must compute traced signals
+    Verilated::traceEverOn(true);
+
     // Pass arguments so Verilated code can see them, e.g. $value$plusargs
     // This needs to be called before you create any model
     Verilated::commandArgs(argc, argv);
 
+    // Create logs/ directory in case we have traces to put under it
+    Verilated::mkdir("logs");
+
     // Construct the Verilated model, from Vtop.h generated from Verilating "top.v"
     Vtop* top = new Vtop;  // Or use a const unique_ptr, or the VL_UNIQUE_PTR wrapper
 
-#if VM_TRACE
-    // If verilator was invoked with --trace argument,
-    // and if at run time passed the +trace argument, turn on tracing
-    VerilatedVcdC* tfp = NULL;
-    const char* flag = Verilated::commandArgsPlusMatch("trace");
-    if (flag && 0==strcmp(flag, "+trace")) {
-        Verilated::traceEverOn(true);  // Verilator must compute traced signals
-        VL_PRINTF("Enabling waves into logs/vlt_dump.vcd...\n");
-        tfp = new VerilatedVcdC;
-        top->trace(tfp, 99);  // Trace 99 levels of hierarchy
-        Verilated::mkdir("logs");
-        tfp->open("logs/vlt_dump.vcd");  // Open the dump file
-    }
-#endif
-
     // Set some inputs
     top->reset_l = !0;
     top->fastclk = 0;
@@ -90,13 +76,11 @@ int main(int argc, char** argv, char** env) {
         top->in_quad += 0x12;
 
         // Evaluate model
+        // (If you have multiple models being simulated in the same
+        // timestep then instead of eval(), call eval_step() on each, then
+        // eval_end_step() on each.)
         top->eval();
 
-#if VM_TRACE
-        // Dump trace data for this cycle
-        if (tfp) tfp->dump(main_time);
-#endif
-
         // Read outputs
         VL_PRINTF("[%" VL_PRI64 "d] clk=%x rstl=%x iquad=%" VL_PRI64 "x"
                   " -> oquad=%" VL_PRI64"x owide=%x_%08x_%08x\n",
@@ -107,11 +91,6 @@ int main(int argc, char** argv, char** env) {
     // Final model cleanup
     top->final();
 
-    // Close trace if opened
-#if VM_TRACE
-    if (tfp) { tfp->close(); tfp = NULL; }
-#endif
-
     //  Coverage analysis (since test passed)
 #if VM_COVERAGE
     Verilated::mkdir("logs");
diff --git a/examples/make_tracing_c/top.v b/examples/make_tracing_c/top.v
index beae05605..0dc22d9cc 100644
--- a/examples/make_tracing_c/top.v
+++ b/examples/make_tracing_c/top.v
@@ -36,6 +36,11 @@ module top
 
    // Print some stuff as an example
    initial begin
+      if ($test$plusargs("trace") != 0) begin
+         $display("[%0t] Tracing to logs/vlt_dump.vcd...\n", $time);
+         $dumpfile("logs/vlt_dump.vcd");
+         $dumpvars();
+      end
       $display("[%0t] Model running...\n", $time);
    end
 
diff --git a/examples/make_tracing_sc/sc_main.cpp b/examples/make_tracing_sc/sc_main.cpp
index b2d704aec..381d321bf 100644
--- a/examples/make_tracing_sc/sc_main.cpp
+++ b/examples/make_tracing_sc/sc_main.cpp
@@ -37,6 +37,9 @@ int sc_main(int argc, char* argv[]) {
     // This needs to be called before you create any model
     Verilated::commandArgs(argc, argv);
 
+    // Create logs/ directory in case we have traces to put under it
+    Verilated::mkdir("logs");
+
     // General logfile
     ios::sync_with_stdio();
 
diff --git a/include/verilated.cpp b/include/verilated.cpp
index 90eecfb25..c242b5ab5 100644
--- a/include/verilated.cpp
+++ b/include/verilated.cpp
@@ -1602,6 +1602,25 @@ IData VL_ATOI_N(const std::string& str, int base) VL_PURE {
     return static_cast<IData>(v);
 }
 
+//===========================================================================
+// Dumping
+
+const char* vl_dumpctl_filenamep(bool setit, const std::string& filename) VL_MT_SAFE {
+    // This function performs both accessing and setting so it's easy to make an in-function static
+    static VL_THREAD_LOCAL std::string t_filename;
+    if (setit) {
+        t_filename = filename;
+    } else {
+        static VL_THREAD_LOCAL bool t_warned = false;
+        if (VL_UNLIKELY(t_filename.empty() && !t_warned)) {
+            t_warned = true;
+            VL_PRINTF_MT("%%Warning: $dumpvar ignored as not proceeded by $dumpfile\n");
+            return "";
+        }
+    }
+    return t_filename.c_str();
+}
+
 //===========================================================================
 // Readmem/writemem
 
diff --git a/include/verilated.h b/include/verilated.h
index c039d3878..97becf9c3 100644
--- a/include/verilated.h
+++ b/include/verilated.h
@@ -83,6 +83,7 @@ class VerilatedVar;
 class VerilatedVarNameMap;
 class VerilatedVcd;
 class VerilatedVcdC;
+class VerilatedVcdSc;
 class VerilatedFst;
 class VerilatedFstC;
 
diff --git a/include/verilated_fst_c.cpp b/include/verilated_fst_c.cpp
index 2e2533cbc..5eb69fe04 100644
--- a/include/verilated_fst_c.cpp
+++ b/include/verilated_fst_c.cpp
@@ -64,9 +64,12 @@ protected:
     vluint32_t m_code;  ///< Starting code number
     // CONSTRUCTORS
     VerilatedFstCallInfo(VerilatedFstCallback_t icb, VerilatedFstCallback_t fcb,
-                         VerilatedFstCallback_t changecb,
-                         void* ut, vluint32_t code)
-        : m_initcb(icb), m_fullcb(fcb), m_changecb(changecb), m_userthis(ut), m_code(code) {}
+                         VerilatedFstCallback_t changecb, void* ut)
+        : m_initcb(icb)
+        , m_fullcb(fcb)
+        , m_changecb(changecb)
+        , m_userthis(ut)
+        , m_code(1) {}
     ~VerilatedFstCallInfo() {}
 };
 
@@ -173,17 +176,16 @@ void VerilatedFst::declSymbol(vluint32_t code, const char* name,
 //=============================================================================
 // Callbacks
 
-void VerilatedFst::addCallback(
-    VerilatedFstCallback_t initcb, VerilatedFstCallback_t fullcb,
-    VerilatedFstCallback_t changecb, void* userthis) VL_MT_UNSAFE_ONE {
+void VerilatedFst::addCallback(VerilatedFstCallback_t initcb, VerilatedFstCallback_t fullcb,
+                               VerilatedFstCallback_t changecb, void* userthis) VL_MT_UNSAFE_ONE {
     m_assertOne.check();
     if (VL_UNLIKELY(isOpen())) {
-        std::string msg = (std::string("Internal: ")+__FILE__+"::"+__FUNCTION__
-                           +" called with already open file");
+        std::string msg = (std::string("Internal: ") + __FILE__ + "::" + __FUNCTION__
+                           + " called with already open file");
         VL_FATAL_MT(__FILE__, __LINE__, "", msg.c_str());
     }
-    VerilatedFstCallInfo* vci = new VerilatedFstCallInfo(initcb, fullcb, changecb, userthis, 1);
-    m_callbacks.push_back(vci);
+    VerilatedFstCallInfo* cip = new VerilatedFstCallInfo(initcb, fullcb, changecb, userthis);
+    m_callbacks.push_back(cip);
 }
 
 //=============================================================================
@@ -192,7 +194,7 @@ void VerilatedFst::addCallback(
 void VerilatedFst::dump(vluint64_t timeui) {
     if (!isOpen()) return;
     if (VL_UNLIKELY(m_fullDump)) {
-        m_fullDump = false;  // No need for more full dumps
+        m_fullDump = false;  // No more need for next dump to be full
         for (vluint32_t ent = 0; ent< m_callbacks.size(); ++ent) {
             VerilatedFstCallInfo* cip = m_callbacks[ent];
             (cip->m_fullcb)(this, cip->m_userthis, cip->m_code);
diff --git a/include/verilated_fst_c.h b/include/verilated_fst_c.h
index 5fc4aeaff..f6de80bb9 100644
--- a/include/verilated_fst_c.h
+++ b/include/verilated_fst_c.h
@@ -198,7 +198,7 @@ class VerilatedFstC {
     VL_UNCOPYABLE(VerilatedFstC);
 public:
     explicit VerilatedFstC(void* filep=NULL) : m_sptrace(filep) {}
-    ~VerilatedFstC() {}
+    ~VerilatedFstC() { close(); }
 public:
     // ACCESSORS
     /// Is file open?
diff --git a/include/verilated_heavy.h b/include/verilated_heavy.h
index c04ee3214..ef9f2b8bc 100644
--- a/include/verilated_heavy.h
+++ b/include/verilated_heavy.h
@@ -441,4 +441,10 @@ inline IData VL_CMP_NN(const std::string& lhs, const std::string& rhs, bool igno
 
 extern IData VL_ATOI_N(const std::string& str, int base) VL_PURE;
 
+//======================================================================
+// Dumping
+
+extern const char* vl_dumpctl_filenamep(bool setit = false,
+                                        const std::string& filename = "") VL_MT_SAFE;
+
 #endif  // Guard
diff --git a/include/verilated_vcd_c.cpp b/include/verilated_vcd_c.cpp
index 87c4e8baa..c9406686a 100644
--- a/include/verilated_vcd_c.cpp
+++ b/include/verilated_vcd_c.cpp
@@ -119,7 +119,7 @@ protected:
 
 bool VerilatedVcdFile::open(const std::string& name) VL_MT_UNSAFE {
     m_fd = ::open(name.c_str(), O_CREAT|O_WRONLY|O_TRUNC|O_LARGEFILE|O_NONBLOCK|O_CLOEXEC, 0666);
-    return (m_fd>=0);
+    return m_fd >= 0;
 }
 
 void VerilatedVcdFile::close() VL_MT_UNSAFE {
@@ -136,7 +136,10 @@ ssize_t VerilatedVcdFile::write(const char* bufp, ssize_t len) VL_MT_UNSAFE {
 // Opening/Closing
 
 VerilatedVcd::VerilatedVcd(VerilatedVcdFile* filep)
-    : m_isOpen(false), m_rolloverMB(0), m_modDepth(0), m_nextCode(1) {
+    : m_isOpen(false)
+    , m_rolloverMB(0)
+    , m_modDepth(0)
+    , m_nextCode(1) {
     // Not in header to avoid link issue if header is included without this .cpp file
     m_fileNewed = (filep == NULL);
     m_filep = m_fileNewed ? new VerilatedVcdFile : filep;
@@ -156,7 +159,7 @@ VerilatedVcd::VerilatedVcd(VerilatedVcdFile* filep)
 
 void VerilatedVcd::open(const char* filename) {
     m_assertOne.check();
-    if (isOpen()) return;
+    if (isOpen() || !filename || !*filename) return;
 
     // Set member variables
     m_filename = filename;
@@ -690,7 +693,7 @@ void VerilatedVcd::dump(vluint64_t timeui) {
     m_assertOne.check();
     if (!isOpen()) return;
     if (VL_UNLIKELY(m_fullDump)) {
-        m_fullDump = false;  // No need for more full dumps
+        m_fullDump = false;  // No more need for next dump to be full
         dumpFull(timeui);
         return;
     }
diff --git a/include/verilated_vcd_c.h b/include/verilated_vcd_c.h
index 835af7b71..690e3ec31 100644
--- a/include/verilated_vcd_c.h
+++ b/include/verilated_vcd_c.h
@@ -103,9 +103,9 @@ private:
     typedef std::vector<VerilatedVcdSig>  SigVec;
     SigVec              m_sigs;         ///< Pointer to signal information
     typedef std::vector<VerilatedVcdCallInfo*>  CallbackVec;
-    CallbackVec         m_callbacks;    ///< Routines to perform dumping
+    CallbackVec m_callbacks;  ///< Routines to perform dumping
     typedef std::map<std::string,std::string>  NameMap;
-    NameMap*            m_namemapp;     ///< List of names for the header
+    NameMap* m_namemapp;  ///< List of names for the header
 
     VerilatedAssertOneThread m_assertOne;  ///< Assert only called from single thread
 
@@ -445,7 +445,7 @@ class VerilatedVcdC {
 public:
     explicit VerilatedVcdC(VerilatedVcdFile* filep = NULL)
         : m_sptrace(filep) {}
-    ~VerilatedVcdC() {}
+    ~VerilatedVcdC() { close(); }
 public:
     // ACCESSORS
     /// Is file open?
diff --git a/include/verilated_vcd_sc.h b/include/verilated_vcd_sc.h
index f5ab1efe1..48c961c8d 100644
--- a/include/verilated_vcd_sc.h
+++ b/include/verilated_vcd_sc.h
@@ -62,7 +62,7 @@ public:
         spTrace()->set_time_resolution(sc_get_time_resolution().to_string());
 # endif
     }
-    virtual ~VerilatedVcdSc() {}
+    virtual ~VerilatedVcdSc() { close(); }
 
     // METHODS
     /// Called by SystemC simulate()
diff --git a/src/V3Ast.h b/src/V3Ast.h
index 356df43d3..f877e4056 100644
--- a/src/V3Ast.h
+++ b/src/V3Ast.h
@@ -815,6 +815,32 @@ inline bool operator==(AstDisplayType::en lhs, const AstDisplayType& rhs) {
 
 //######################################################################
 
+class VDumpCtlType {
+public:
+    enum en { FILE, VARS, ALL, FLUSH, LIMIT, OFF, ON };
+    enum en m_e;
+    inline VDumpCtlType()
+        : m_e(ON) {}
+    // cppcheck-suppress noExplicitConstructor
+    inline VDumpCtlType(en _e)
+        : m_e(_e) {}
+    explicit inline VDumpCtlType(int _e)
+        : m_e(static_cast<en>(_e)) {}
+    operator en() const { return m_e; }
+    const char* ascii() const {
+        static const char* const names[] = {"$dumpfile", "$dumpvars", "$dumpall", "$dumpflush",
+                                            "$dumplimit", "$dumpoff", "$dumpon"};
+        return names[m_e];
+    }
+};
+inline bool operator==(const VDumpCtlType& lhs, const VDumpCtlType& rhs) {
+    return lhs.m_e == rhs.m_e;
+}
+inline bool operator==(const VDumpCtlType& lhs, VDumpCtlType::en rhs) { return lhs.m_e == rhs; }
+inline bool operator==(VDumpCtlType::en lhs, const VDumpCtlType& rhs) { return lhs == rhs.m_e; }
+
+//######################################################################
+
 class VParseRefExp {
 public:
     enum en {
diff --git a/src/V3AstNodes.h b/src/V3AstNodes.h
index 448589c9b..7365d6430 100644
--- a/src/V3AstNodes.h
+++ b/src/V3AstNodes.h
@@ -3033,6 +3033,31 @@ public:
     void filep(AstNodeVarRef* nodep) { setNOp3p(nodep); }
 };
 
+class AstDumpCtl : public AstNodeStmt {
+    // $dumpon etc
+    // Parents: expr
+    // Child: expr based on type of control statement
+    VDumpCtlType m_ctlType;  // Type of operation
+public:
+    AstDumpCtl(FileLine* fl, VDumpCtlType ctlType, AstNode* exprp = NULL)
+        : ASTGEN_SUPER(fl), m_ctlType(ctlType) {
+        setNOp1p(exprp);
+    }
+    ASTNODE_NODE_FUNCS(DumpCtl)
+    virtual string verilogKwd() const { return ctlType().ascii(); }
+    virtual string emitVerilog() { return "%f" + verilogKwd() + "(%l)"; }
+    virtual string emitC() { V3ERROR_NA; return ""; }
+    virtual bool isGateOptimizable() const { return false; }
+    virtual bool isPredictOptimizable() const { return false; }
+    virtual bool isOutputter() const { return true; }
+    virtual bool cleanOut() const { return true; }
+    virtual V3Hash sameHash() const { return V3Hash(); }
+    virtual bool same(const AstNode* samep) const { return true; }
+    VDumpCtlType ctlType() const { return m_ctlType; }
+    AstNode* exprp() const { return op1p(); }  // op2 = Expressions to output
+    void exprp(AstNode* nodep) { setOp1p(nodep); }
+};
+
 class AstElabDisplay : public AstNode {
     // Parents: stmtlist
     // Children: SFORMATF to generate print string
diff --git a/src/V3EmitC.cpp b/src/V3EmitC.cpp
index cd424a131..e4efa36e9 100644
--- a/src/V3EmitC.cpp
+++ b/src/V3EmitC.cpp
@@ -402,6 +402,44 @@ public:
         if (nodep->addNewline()) text += "\n";
         displayNode(nodep, nodep->fmtp()->scopeNamep(), text, nodep->fmtp()->exprsp(), false);
     }
+    virtual void visit(AstDumpCtl* nodep) VL_OVERRIDE {
+        switch (nodep->ctlType()) {
+        case VDumpCtlType::FILE:
+            puts("vl_dumpctl_filenamep(true, ");
+            emitCvtPackStr(nodep->exprp());
+            puts(");\n");
+            break;
+        case VDumpCtlType::VARS:
+            // We ignore number of levels to dump in exprp()
+            if (v3Global.opt.trace()) {
+                puts("vlSymsp->TOPp->_traceDumpOpen();\n");
+            } else {
+                puts("VL_PRINTF_MT(\"-Info: ");
+                puts(protect(nodep->fileline()->filename()));
+                puts(":");
+                puts(cvtToStr(nodep->fileline()->lineno()));
+                puts(": $dumpvar ignored, as Verilated without --trace");
+                puts("\\n\");\n");
+            }
+            break;
+        case VDumpCtlType::ALL:
+            // $dumpall currently ignored
+            break;
+        case VDumpCtlType::FLUSH:
+            puts("Verilated::flushCall();\n");  // Also flush stdio, as need lock
+            break;
+        case VDumpCtlType::LIMIT:
+            // $dumplimit currently ignored
+            break;
+        case VDumpCtlType::OFF:
+            // Currently ignored as both Vcd and Fst do not support them, as would need "X" dump
+            break;
+        case VDumpCtlType::ON:
+            // Currently ignored as $dumpoff is also ignored
+            break;
+        default: nodep->v3fatalSrc("Bad case, unexpected " << nodep->ctlType().ascii());
+        }
+    }
     virtual void visit(AstScopeName* nodep) VL_OVERRIDE {
         // For use under AstCCalls for dpiImports.  ScopeNames under
         // displays are handled in AstDisplay
@@ -2110,8 +2148,16 @@ void EmitCImp::emitCoverageImp(AstNodeModule* modp) {
 void EmitCImp::emitDestructorImp(AstNodeModule* modp) {
     puts("\n");
     puts(prefixNameProtect(modp) + "::~" + prefixNameProtect(modp) + "() {\n");
-    if (modp->isTop() && v3Global.opt.mtasks()) {
-        puts("delete __Vm_threadPoolp; __Vm_threadPoolp = NULL;\n");
+    if (modp->isTop()) {
+        if (v3Global.opt.mtasks()) {
+            puts("delete __Vm_threadPoolp; __Vm_threadPoolp = NULL;\n");
+        }
+        // Call via function in __Trace.cpp as this .cpp file does not have trace header
+        if (v3Global.needTraceDumper()) {
+            puts("#ifdef VM_TRACE\n");
+            puts("if (VL_UNLIKELY(__VlSymsp->__Vm_dumperp)) _traceDumpClose();\n");
+            puts("#endif  // VM_TRACE\n");
+        }
     }
     emitTextSection(AstType::atScDtor);
     if (modp->isTop()) puts("delete __VlSymsp; __VlSymsp=NULL;\n");
@@ -2304,7 +2350,7 @@ void EmitCImp::emitSettleLoop(const std::string& eval_call, bool initial) {
 }
 
 void EmitCImp::emitWrapEval(AstNodeModule* modp) {
-    puts("\nvoid " + prefixNameProtect(modp) + "::eval() {\n");
+    puts("\nvoid " + prefixNameProtect(modp) + "::eval_step() {\n");
     puts("VL_DEBUG_IF(VL_DBG_MSGF(\"+++++TOP Evaluate " + prefixNameProtect(modp)
          + "::eval\\n\"); );\n");
     puts(EmitCBaseVisitor::symClassVar()+" = this->__VlSymsp;  // Setup global symbol table\n");
@@ -2316,6 +2362,15 @@ void EmitCImp::emitWrapEval(AstNodeModule* modp) {
     putsDecoration("// Initialize\n");
     puts("if (VL_UNLIKELY(!vlSymsp->__Vm_didInit)) "
          +protect("_eval_initial_loop")+"(vlSymsp);\n");
+    if (v3Global.opt.trace()) {
+        puts("#ifdef VM_TRACE\n");
+        putsDecoration("// Tracing\n");
+        // SystemC's eval loop deals with calling trace, not us
+        if (v3Global.needTraceDumper() && !optSystemC()) {
+            puts("if (VL_UNLIKELY(vlSymsp->__Vm_dumperp)) _traceDump();\n");
+        }
+        puts("#endif  // VM_TRACE\n");
+    }
     if (v3Global.opt.inhibitSim()) {
         puts("if (VL_UNLIKELY(__Vm_inhibitSim)) return;\n");
     }
@@ -2377,6 +2432,21 @@ void EmitCImp::emitWrapEval(AstNodeModule* modp) {
     puts("}\n");
     splitSizeInc(10);
 
+    //
+    if (v3Global.needTraceDumper() && !optSystemC()) {
+        puts("\nvoid " + prefixNameProtect(modp) + "::eval_end_step() {\n");
+        puts("VL_DEBUG_IF(VL_DBG_MSGF(\"+eval_end_step " + prefixNameProtect(modp)
+             + "::eval_end_step\\n\"); );\n");
+        puts("#ifdef VM_TRACE\n");
+        puts(EmitCBaseVisitor::symClassVar()+" = this->__VlSymsp;  // Setup global symbol table\n");
+        puts(EmitCBaseVisitor::symTopAssign()+"\n");
+        putsDecoration("// Tracing\n");
+        // SystemC's eval loop deals with calling trace, not us
+        puts("if (VL_UNLIKELY(vlSymsp->__Vm_dumperp)) _traceDump();\n");
+        puts("#endif  // VM_TRACE\n");
+        puts("}\n");
+    }
+
     //
     puts("\nvoid " + prefixNameProtect(modp) + "::" + protect("_eval_initial_loop") + "("
          + EmitCBaseVisitor::symClassVar() + ") {\n");
@@ -2693,11 +2763,11 @@ void EmitCImp::emitInt(AstNodeModule* modp) {
     ofp()->putsPrivate(!modp->isTop());  // private: unless top
     puts(symClassName()+"* __VlSymsp;  // Symbol table\n");
     ofp()->putsPrivate(false);  // public:
-    if (modp->isTop() && v3Global.opt.inhibitSim()) {
-        puts("bool __Vm_inhibitSim;  ///< Set true to disable evaluation of module\n");
-    }
-    if (modp->isTop() && v3Global.opt.mtasks()) {
-        emitMTaskState();
+    if (modp->isTop()) {
+        if (v3Global.opt.inhibitSim()) {
+            puts("bool __Vm_inhibitSim;  ///< Set true to disable evaluation of module\n");
+        }
+        if (v3Global.opt.mtasks()) emitMTaskState();
     }
     emitCoverageDecl(modp);  // may flip public/private
 
@@ -2775,14 +2845,26 @@ void EmitCImp::emitInt(AstNodeModule* modp) {
 
     if (modp->isTop()) {
         puts("\n// API METHODS\n");
+        string callEvalEndStep
+            = (v3Global.needTraceDumper() && !optSystemC()) ? "eval_end_step(); " : "";
         if (optSystemC()) ofp()->putsPrivate(true);  ///< eval() is invoked by our sensitive() calls.
-        else puts("/// Evaluate the model.  Application must call when inputs change.\n");
-        puts("void eval();\n");
+        if (!optSystemC()) puts("/// Evaluate the model.  Application must call when inputs change.\n");
+        puts("void eval() { eval_step(); " + callEvalEndStep + "}\n");
+        if (!optSystemC()) puts("/// Evaluate when calling multiple units/models per time step.\n");
+        puts("void eval_step();\n");
+        if (!optSystemC()) {
+            puts("/// Evaluate at end of a timestep for tracing, when using eval_step().\n");
+            puts("/// Application must call after all eval() and before time changes.\n");
+            puts("void eval_end_step()");
+            if (callEvalEndStep == "") puts(" {}\n");
+            else puts(";\n");
+        }
         ofp()->putsPrivate(false);  // public:
         if (!optSystemC()) puts("/// Simulation complete, run final blocks.  Application must call on completion.\n");
         puts("void final();\n");
         if (v3Global.opt.inhibitSim()) {
-            puts("void inhibitSim(bool flag) { __Vm_inhibitSim=flag; }  ///< Set true to disable evaluation of module\n");
+            puts("/// Disable evaluation of module (e.g. turn off)\n");
+            puts("void inhibitSim(bool flag) { __Vm_inhibitSim = flag; }\n");
         }
     }
 
@@ -2791,6 +2873,9 @@ void EmitCImp::emitInt(AstNodeModule* modp) {
         ofp()->putsPrivate(true);  // private:
         puts("static void "+protect("_eval_initial_loop")
              +"("+EmitCBaseVisitor::symClassVar()+");\n");
+        if (v3Global.needTraceDumper() && !optSystemC()) puts("void _traceDump();");
+        if (v3Global.needTraceDumper()) puts("void _traceDumpOpen();");
+        if (v3Global.needTraceDumper()) puts("void _traceDumpClose();");
     }
 
     if (!VN_IS(modp, Class)) {
@@ -2978,14 +3063,43 @@ class EmitCTrace : EmitCStmts {
 
     void emitTraceHeader() {
         // Includes
-        puts("#include \""+v3Global.opt.traceSourceName()+"_c.h\"\n");
-        puts("#include \""+ symClassName() +".h\"\n");
+        puts("#include \"" + v3Global.opt.traceSourceLang() + ".h\"\n");
+        puts("#include \"" + symClassName() + ".h\"\n");
         puts("\n");
     }
 
     void emitTraceSlow() {
         puts("\n//======================\n\n");
 
+        if (v3Global.needTraceDumper() && !optSystemC()) {
+            puts("void " + topClassName() + "::_traceDump() {\n");
+            // Caller checked for __Vm_dumperp non-NULL
+            puts(  "VerilatedLockGuard lock(__VlSymsp->__Vm_dumperMutex);\n");
+            puts(  "__VlSymsp->__Vm_dumperp->dump(VL_TIME_Q());\n");
+            puts("}\n");
+            splitSizeInc(10);
+        }
+
+        if (v3Global.needTraceDumper()) {
+            puts("void " + topClassName() + "::_traceDumpOpen() {\n");
+            puts(  "if (VL_UNLIKELY(!__VlSymsp->__Vm_dumperp)) {\n");
+            puts(    "VerilatedLockGuard lock(__VlSymsp->__Vm_dumperMutex);\n");
+            puts(    "__VlSymsp->__Vm_dumperp = new " + v3Global.opt.traceClassLang() + "();\n");
+            puts(    "const char* cp = vl_dumpctl_filenamep();\n");
+            puts(    "trace(__VlSymsp->__Vm_dumperp, 0, 0);\n");
+            puts(    "__VlSymsp->__Vm_dumperp->open(vl_dumpctl_filenamep());\n");
+            puts(  "}\n");
+            puts("}\n");
+            splitSizeInc(10);
+
+            puts("void " + topClassName() + "::_traceDumpClose() {\n");
+            // Caller checked for __Vm_dumperp non-NULL
+            puts(  "VerilatedLockGuard lock(__VlSymsp->__Vm_dumperMutex);\n");
+            puts(  "delete __VlSymsp->__Vm_dumperp; __VlSymsp->__Vm_dumperp = NULL;\n");
+            puts("}\n");
+            splitSizeInc(10);
+        }
+
         puts("void "+topClassName()+"::trace(");
         puts(v3Global.opt.traceClassBase()+"C* tfp, int, int) {\n");
         puts(  "tfp->spTrace()->addCallback("
diff --git a/src/V3EmitCInlines.cpp b/src/V3EmitCInlines.cpp
index 0090b880a..39a78e140 100644
--- a/src/V3EmitCInlines.cpp
+++ b/src/V3EmitCInlines.cpp
@@ -66,6 +66,11 @@ class EmitCInlines : EmitCBaseVisitor {
         v3Global.needHeavy(true);
         iterateChildren(nodep);
     }
+    virtual void visit(AstDumpCtl* nodep) VL_OVERRIDE {
+        if (v3Global.opt.trace()) v3Global.needTraceDumper(true);
+        v3Global.needHeavy(true);
+        iterateChildren(nodep);
+    }
     virtual void visit(AstPutcN* nodep) VL_OVERRIDE {
         v3Global.needHeavy(true);
         iterateChildren(nodep);
diff --git a/src/V3EmitCMake.cpp b/src/V3EmitCMake.cpp
index 4d2a2a79d..2de114211 100644
--- a/src/V3EmitCMake.cpp
+++ b/src/V3EmitCMake.cpp
@@ -160,13 +160,13 @@ class CMakeEmitter {
         }
         if (v3Global.opt.trace()) {
             global.push_back("${VERILATOR_ROOT}/include/"
-                             + v3Global.opt.traceSourceName()+"_c.cpp");
+                             + v3Global.opt.traceSourceBase() + "_c.cpp");
             if (v3Global.opt.systemC()) {
                 if (v3Global.opt.traceFormat() != TraceFormat::VCD) {
                     v3error("Unsupported: This trace format is not supported in SystemC, use VCD format.");
                 }
                 global.push_back("${VERILATOR_ROOT}/include/"
-                                    + v3Global.opt.traceSourceName()+"_sc.cpp");
+                                    + v3Global.opt.traceSourceLang() + ".cpp");
             }
         }
         if (v3Global.opt.mtasks()) {
diff --git a/src/V3EmitCSyms.cpp b/src/V3EmitCSyms.cpp
index 6cdc1c635..8533060a2 100644
--- a/src/V3EmitCSyms.cpp
+++ b/src/V3EmitCSyms.cpp
@@ -417,6 +417,13 @@ void EmitCSyms::emitSymHdr() {
 
     puts("\n// LOCAL STATE\n");
     puts("const char* __Vm_namep;\n");  // Must be before subcells, as constructor order needed before _vlCoverInsert.
+    if (v3Global.needTraceDumper()) {
+        // __Vm_dumperp is local, otherwise we wouldn't know what design's eval()
+        // should call a global dumpperp
+        puts("VerilatedMutex __Vm_dumperMutex;  // Protect __Vm_dumperp\n");
+        puts(v3Global.opt.traceClassLang()
+             + "* __Vm_dumperp VL_GUARDED_BY(__Vm_dumperMutex);  /// Trace class for $dump*\n");
+    }
     if (v3Global.opt.trace()) {
         puts("bool __Vm_activity;  ///< Used by trace routines to determine change occurred\n");
     }
@@ -582,10 +589,9 @@ void EmitCSyms::emitSymImp() {
     puts("\n// FUNCTIONS\n");
     puts(symClassName()+"::"+symClassName()+"("+topClassName()+"* topp, const char* namep)\n");
     puts("    // Setup locals\n");
-    puts("    : __Vm_namep(namep)\n");  // No leak, as we get destroyed when the top is destroyed
-    if (v3Global.opt.trace()) {
-        puts("    , __Vm_activity(false)\n");
-    }
+    puts("    : __Vm_namep(namep)\n");  // No leak, as gets destroyed when the top is destroyed
+    if (v3Global.needTraceDumper()) puts("    , __Vm_dumperp(NULL)\n");
+    if (v3Global.opt.trace()) puts("    , __Vm_activity(false)\n");
     puts("    , __Vm_didInit(false)\n");
     puts("    // Setup submodule names\n");
     char comma = ',';
diff --git a/src/V3EmitMk.cpp b/src/V3EmitMk.cpp
index 284e02bc4..c8a83ce2a 100644
--- a/src/V3EmitMk.cpp
+++ b/src/V3EmitMk.cpp
@@ -85,12 +85,12 @@ public:
                         putMakeClassEntry(of, "verilated_cov.cpp");
                     }
                     if (v3Global.opt.trace()) {
-                        putMakeClassEntry(of, v3Global.opt.traceSourceName()+"_c.cpp");
+                        putMakeClassEntry(of, v3Global.opt.traceSourceBase() + "_c.cpp");
                         if (v3Global.opt.systemC()) {
                             if (v3Global.opt.traceFormat() != TraceFormat::VCD) {
                                 v3error("Unsupported: This trace format is not supported in SystemC, use VCD format.");
                             } else {
-                                putMakeClassEntry(of, v3Global.opt.traceSourceName()+"_sc.cpp");
+                                putMakeClassEntry(of, v3Global.opt.traceSourceLang() + ".cpp");
                             }
                         }
                     }
diff --git a/src/V3Global.h b/src/V3Global.h
index 0011df4ff..da20b88cd 100644
--- a/src/V3Global.h
+++ b/src/V3Global.h
@@ -71,15 +71,16 @@ inline bool operator==(VWidthMinUsage::en lhs, const VWidthMinUsage& rhs) {
 
 class V3Global {
     // Globals
-    AstNetlist* m_rootp;                // Root of entire netlist
-    VWidthMinUsage m_widthMinUsage;     // What AstNode::widthMin() is used for
+    AstNetlist* m_rootp;  // Root of entire netlist
+    VWidthMinUsage m_widthMinUsage;  // What AstNode::widthMin() is used for
 
-    int         m_debugFileNumber;      // Number to append to debug files created
-    bool        m_assertDTypesResolved; // Tree should have dtypep()'s
-    bool        m_constRemoveXs;        // Const needs to strip any Xs
-    bool        m_needHInlines;         // Need __Inlines file
-    bool        m_needHeavy;            // Need verilated_heavy.h include
-    bool        m_dpi;                  // Need __Dpi include files
+    int m_debugFileNumber;  // Number to append to debug files created
+    bool m_assertDTypesResolved;  // Tree should have dtypep()'s
+    bool m_constRemoveXs;  // Const needs to strip any Xs
+    bool m_needTraceDumper;  // Need __Vm_dumperp in symbols
+    bool m_needHInlines;  // Need __Inlines file
+    bool m_needHeavy;  // Need verilated_heavy.h include
+    bool m_dpi;  // Need __Dpi include files
 
 public:
     // Options
@@ -92,6 +93,7 @@ public:
         m_widthMinUsage = VWidthMinUsage::LINT_WIDTH;
         m_assertDTypesResolved = false;
         m_constRemoveXs = false;
+        m_needTraceDumper = false;
         m_needHInlines = false;
         m_needHeavy = false;
         m_dpi = false;
@@ -119,10 +121,12 @@ public:
         char digits[100]; sprintf(digits, "%03d", m_debugFileNumber);
         return opt.makeDir()+"/"+opt.prefix()+"_"+digits+"_"+nameComment;
     }
+    bool needTraceDumper() const { return m_needTraceDumper; }
+    void needTraceDumper(bool flag) { m_needTraceDumper = flag; }
     bool needHInlines() const { return m_needHInlines; }
-    void needHInlines(bool flag) { m_needHInlines=flag; }
+    void needHInlines(bool flag) { m_needHInlines = flag; }
     bool needHeavy() const { return m_needHeavy; }
-    void needHeavy(bool flag) { m_needHeavy=flag; }
+    void needHeavy(bool flag) { m_needHeavy = flag; }
     bool dpi() const { return m_dpi; }
     void dpi(bool flag) { m_dpi = flag; }
 };
diff --git a/src/V3Options.h b/src/V3Options.h
index dac7c3402..f89ab5a45 100644
--- a/src/V3Options.h
+++ b/src/V3Options.h
@@ -467,7 +467,11 @@ class V3Options {
     bool oTable() const { return m_oTable; }
 
     string traceClassBase() const { return m_traceFormat.classBase(); }
-    string traceSourceName() const { return m_traceFormat.sourceName(); }
+    string traceClassLang() const { return m_traceFormat.classBase() + (systemC() ? "Sc" : "C"); }
+    string traceSourceBase() const { return m_traceFormat.sourceName(); }
+    string traceSourceLang() const {
+        return m_traceFormat.sourceName() + (systemC() ? "_sc" : "_c");
+    }
 
     // METHODS (from main)
     static string version();
diff --git a/src/V3Width.cpp b/src/V3Width.cpp
index 512bb9676..dc4152b46 100644
--- a/src/V3Width.cpp
+++ b/src/V3Width.cpp
@@ -2872,6 +2872,11 @@ private:
             VL_DO_DANGLING(nodep->unlinkFrBack()->deleteTree(), nodep);
         }
     }
+    virtual void visit(AstDumpCtl* nodep) VL_OVERRIDE {
+        assertAtStatement(nodep);
+        // Just let all arguments seek their natural sizes
+        userIterateChildren(nodep, WidthVP(SELF, BOTH).p());
+    }
     virtual void visit(AstFOpen* nodep) VL_OVERRIDE {
         // Although a system function in IEEE, here a statement which sets the file pointer (MCD)
         assertAtStatement(nodep);
diff --git a/src/verilog.l b/src/verilog.l
index 23fad9c63..33b791946 100644
--- a/src/verilog.l
+++ b/src/verilog.l
@@ -197,6 +197,19 @@ vnum    {vnum1}|{vnum2}|{vnum3}|{vnum4}|{vnum5}
   "$cos"                { FL; return yD_COS; }
   "$cosh"               { FL; return yD_COSH; }
   "$display"            { FL; return yD_DISPLAY; }
+  "$dumpall"            { FL; return yD_DUMPALL; }
+  "$dumpfile"           { FL; return yD_DUMPFILE; }
+  "$dumpflush"          { FL; return yD_DUMPFLUSH; }
+  "$dumplimit"          { FL; return yD_DUMPLIMIT; }
+  "$dumpoff"            { FL; return yD_DUMPOFF; }
+  "$dumpon"             { FL; return yD_DUMPON; }
+  "$dumpports"          { FL; return yD_DUMPPORTS; }
+  "$dumpportsall"       { FL; return yD_DUMPALL; }
+  "$dumpportsflush"     { FL; return yD_DUMPFLUSH; }
+  "$dumpportslimit"     { FL; return yD_DUMPLIMIT; }
+  "$dumpportsoff"       { FL; return yD_DUMPOFF; }
+  "$dumpportson"        { FL; return yD_DUMPON; }
+  "$dumpvars"           { FL; return yD_DUMPVARS; }
   "$exp"                { FL; return yD_EXP; }
   "$fclose"             { FL; return yD_FCLOSE; }
   "$fdisplay"           { FL; return yD_FDISPLAY; }
@@ -208,10 +221,10 @@ vnum    {vnum1}|{vnum2}|{vnum3}|{vnum4}|{vnum5}
   "$floor"              { FL; return yD_FLOOR; }
   "$fopen"              { FL; return yD_FOPEN; }
   "$fread"              { FL; return yD_FREAD; }
+  "$frewind"            { FL; return yD_FREWIND; }
   "$fscanf"             { FL; return yD_FSCANF; }
   "$fseek"              { FL; return yD_FSEEK; }
   "$ftell"              { FL; return yD_FTELL; }
-  "$frewind"            { FL; return yD_FREWIND; }
   "$fullskew"           { FL; return yaTIMINGSPEC; }
   "$fwrite"             { FL; return yD_FWRITE; }
   "$hold"               { FL; return yaTIMINGSPEC; }
diff --git a/src/verilog.y b/src/verilog.y
index e23427536..8ad3f5fb9 100644
--- a/src/verilog.y
+++ b/src/verilog.y
@@ -553,6 +553,14 @@ class AstSenTree;
 %token<fl>		yD_COUNTONES	"$countones"
 %token<fl>		yD_DIMENSIONS	"$dimensions"
 %token<fl>		yD_DISPLAY	"$display"
+%token<fl>		yD_DUMPALL	"$dumpall"
+%token<fl>		yD_DUMPFILE	"$dumpfile"
+%token<fl>		yD_DUMPFLUSH	"$dumpflush"
+%token<fl>		yD_DUMPLIMIT	"$dumplimit"
+%token<fl>		yD_DUMPOFF	"$dumpoff"
+%token<fl>		yD_DUMPON	"$dumpon"
+%token<fl>		yD_DUMPPORTS	"$dumpports"
+%token<fl>		yD_DUMPVARS	"$dumpvars"
 %token<fl>		yD_ERROR	"$error"
 %token<fl>		yD_EXP		"$exp"
 %token<fl>		yD_FATAL	"$fatal"
@@ -3154,8 +3162,30 @@ system_t_call<nodep>:		// IEEE: system_tf_call (as task)
 	|	yaD_DPI '(' exprList ')'		{ $$ = new AstTaskRef($<fl>1, *$1, $3);
 							  GRAMMARP->argWrapList(VN_CAST($$, TaskRef)); }
 	//
+	|	yD_DUMPPORTS '(' idDotted ',' expr ')'	{ $$ = new AstDumpCtl($<fl>1, VDumpCtlType::FILE, $5); DEL($3);
+    							  $$->addNext(new AstDumpCtl($<fl>1, VDumpCtlType::VARS,
+										     new AstConst($<fl>1, 1))); }
+	|	yD_DUMPPORTS '(' ',' expr ')'		{ $$ = new AstDumpCtl($<fl>1, VDumpCtlType::FILE, $4);
+    							  $$->addNext(new AstDumpCtl($<fl>1, VDumpCtlType::VARS,
+										     new AstConst($<fl>1, 1))); }
+	|	yD_DUMPFILE '(' expr ')'		{ $$ = new AstDumpCtl($<fl>1, VDumpCtlType::FILE, $3); }
+	|	yD_DUMPVARS parenE			{ $$ = new AstDumpCtl($<fl>1, VDumpCtlType::VARS,
+									      new AstConst($<fl>1, 0)); }
+	|	yD_DUMPVARS '(' expr ')'		{ $$ = new AstDumpCtl($<fl>1, VDumpCtlType::VARS, $3); }
+	|	yD_DUMPVARS '(' expr ',' idDotted ')'	{ $$ = new AstDumpCtl($<fl>1, VDumpCtlType::VARS, $3); DEL($5); }
+	|	yD_DUMPALL parenE			{ $$ = new AstDumpCtl($<fl>1, VDumpCtlType::ALL); }
+	|	yD_DUMPALL '(' expr ')'			{ $$ = new AstDumpCtl($<fl>1, VDumpCtlType::ALL); DEL($3); }
+	|	yD_DUMPFLUSH parenE			{ $$ = new AstDumpCtl($<fl>1, VDumpCtlType::FLUSH); }
+	|	yD_DUMPFLUSH '(' expr ')'		{ $$ = new AstDumpCtl($<fl>1, VDumpCtlType::FLUSH); DEL($3); }
+	|	yD_DUMPLIMIT '(' expr ')'		{ $$ = new AstDumpCtl($<fl>1, VDumpCtlType::LIMIT, $3); }
+	|	yD_DUMPLIMIT '(' expr ',' expr ')'	{ $$ = new AstDumpCtl($<fl>1, VDumpCtlType::LIMIT, $3); DEL($5); }
+	|	yD_DUMPOFF parenE			{ $$ = new AstDumpCtl($<fl>1, VDumpCtlType::OFF); }
+	|	yD_DUMPOFF '(' expr ')'			{ $$ = new AstDumpCtl($<fl>1, VDumpCtlType::OFF); DEL($3); }
+	|	yD_DUMPON parenE			{ $$ = new AstDumpCtl($<fl>1, VDumpCtlType::ON); }
+	|	yD_DUMPON '(' expr ')'			{ $$ = new AstDumpCtl($<fl>1, VDumpCtlType::ON); DEL($3); }
+	//
 	|	yD_C '(' cStrList ')'			{ $$ = (v3Global.opt.ignc() ? NULL : new AstUCStmt($1,$3)); }
-	|	yD_SYSTEM  '(' expr ')'			{ $$ = new AstSystemT($1, $3); }
+	|	yD_SYSTEM '(' expr ')'			{ $$ = new AstSystemT($1, $3); }
 	//
 	|	yD_FCLOSE '(' idClassSel ')'		{ $$ = new AstFClose($1, $3); }
 	|	yD_FFLUSH parenE			{ $$ = NULL; BBUNSUP($1, "Unsupported: $fflush of all handles does not map to C++."); }
diff --git a/test_regress/t/t_leak.cpp b/test_regress/t/t_leak.cpp
index 83db456a1..573286941 100644
--- a/test_regress/t/t_leak.cpp
+++ b/test_regress/t/t_leak.cpp
@@ -64,15 +64,15 @@ int main(int argc, char* argv[]) {
     vluint64_t firstUsage = get_memory_usage();
 
     // Warmup phase
-    for (int i = 0; i < 1000; i++) {
+    for (int i = 0; i < 10; i++) {
         make_and_destroy();
     }
     firstUsage = get_memory_usage();
     printf("Memory size %" VL_PRI64 "d bytes\n", firstUsage);
 
-    int loops = 100*1000;
+    int loops = 10;
     for (int left = loops; left > 0;) {
-        for (int j = 0; j < 1000; ++j, --left) {
+        for (int j = 0; j < 1; ++j, --left) {
             make_and_destroy();
         }
     }
diff --git a/test_regress/t/t_trace_dumporder_bad.out b/test_regress/t/t_trace_dumporder_bad.out
new file mode 100644
index 000000000..f73b7d67a
--- /dev/null
+++ b/test_regress/t/t_trace_dumporder_bad.out
@@ -0,0 +1,2 @@
+%Warning: $dumpvar ignored as not proceeded by $dumpfile
+*-* All Finished *-*
diff --git a/test_regress/t/t_trace_dumporder_bad.pl b/test_regress/t/t_trace_dumporder_bad.pl
new file mode 100755
index 000000000..cae730749
--- /dev/null
+++ b/test_regress/t/t_trace_dumporder_bad.pl
@@ -0,0 +1,22 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+scenarios(vlt => 1);
+
+compile(
+    verilator_flags2 => ["-trace"],
+    );
+
+execute(
+    check_finished => 1,
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;
diff --git a/test_regress/t/t_trace_dumporder_bad.v b/test_regress/t/t_trace_dumporder_bad.v
new file mode 100644
index 000000000..fe443f75e
--- /dev/null
+++ b/test_regress/t/t_trace_dumporder_bad.v
@@ -0,0 +1,13 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2020 by Wilson Snyder.
+
+module t(/*AUTOARG*/);
+   initial begin
+      // Check error when this missing: $dumpfile("/should/not/be/opened");
+      $dumpvars;
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+endmodule
diff --git a/test_regress/t/t_trace_flag_off.out b/test_regress/t/t_trace_flag_off.out
new file mode 100644
index 000000000..680eb2bcf
--- /dev/null
+++ b/test_regress/t/t_trace_flag_off.out
@@ -0,0 +1,2 @@
+-Info: t/t_trace_flag_off.v:9: $dumpvar ignored, as Verilated without --trace
+*-* All Finished *-*
diff --git a/test_regress/t/t_trace_flag_off.pl b/test_regress/t/t_trace_flag_off.pl
new file mode 100755
index 000000000..bc3f03af6
--- /dev/null
+++ b/test_regress/t/t_trace_flag_off.pl
@@ -0,0 +1,22 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+# Test that without --trace we get a message when turning on traces
+scenarios(vlt => 1);
+
+compile(
+    );
+
+execute(
+    expect_filename => $Self->{golden_filename},
+    fails => 0,
+    );
+
+ok(1);
+1;
diff --git a/test_regress/t/t_trace_flag_off.v b/test_regress/t/t_trace_flag_off.v
new file mode 100644
index 000000000..b8348526f
--- /dev/null
+++ b/test_regress/t/t_trace_flag_off.v
@@ -0,0 +1,13 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2020 by Wilson Snyder.
+
+module t(/*AUTOARG*/);
+   initial begin
+      $dumpfile("/should/not/be/opened");
+      $dumpvars();
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+endmodule
diff --git a/test_regress/t/t_trace_two_a.v b/test_regress/t/t_trace_two_a.v
index da58afecc..86533cc90 100644
--- a/test_regress/t/t_trace_two_a.v
+++ b/test_regress/t/t_trace_two_a.v
@@ -3,6 +3,9 @@
 // This file ONLY is placed into the Public Domain, for any use,
 // without warranty, 2020 by Wilson Snyder.
 
+`define CONCAT(a, b) a``b
+`define STRINGIFY(x) `"x`"
+
 module t (/*AUTOARG*/
    // Inputs
    clk
@@ -15,11 +18,55 @@ module t (/*AUTOARG*/
 
    sub sub ();
 
+   // verilator tracing_off
+   string  filename;
+   // verilator tracing_on
+
+   initial begin
+`ifdef TEST_FST
+      filename = {`STRINGIFY(`TEST_OBJ_DIR), "/simx.fst"};
+`else
+      filename = {`STRINGIFY(`TEST_OBJ_DIR), "/simx.vcd"};
+`endif
+
+`ifdef TEST_DUMP
+      $dumpfile(filename);
+      $dumpvars(0, top);
+      $dumplimit(10 * 1024 * 1024);
+`elsif TEST_DUMPPORTS
+      $dumpports(top, filename);
+      $dumpportslimit(10 * 1024 * 1024, filename);
+`endif
+   end
+
    always @ (posedge clk) begin
       if (cyc != 0) begin
          cyc <= cyc + 1;
          c_trace_on <= cyc + 2;
-         if (cyc == 10) begin
+         if (cyc == 3) begin
+`ifdef TEST_DUMP
+            $dumpoff;
+`elsif TEST_DUMPPORTS
+            $dumpportsoff(filename);
+`endif
+         end
+         else if (cyc == 5) begin
+`ifdef TEST_DUMP
+            $dumpall;
+            $dumpflush;
+`elsif TEST_DUMPPORTS
+            $dumpportsall(filename);
+            $dumpportsflush(filename);
+`endif
+         end
+         else if (cyc == 7) begin
+`ifdef TEST_DUMP
+            $dumpon;
+`elsif TEST_DUMPPORTS
+            $dumpportson(filename);
+`endif
+         end
+         else if (cyc == 10) begin
             $write("*-* All Finished *-*\n");
             $finish;
          end
diff --git a/test_regress/t/t_trace_two_hdr_cc.cpp b/test_regress/t/t_trace_two_cc.cpp
similarity index 72%
rename from test_regress/t/t_trace_two_hdr_cc.cpp
rename to test_regress/t/t_trace_two_cc.cpp
index 9b8bcf395..3eb7c0baa 100644
--- a/test_regress/t/t_trace_two_hdr_cc.cpp
+++ b/test_regress/t/t_trace_two_cc.cpp
@@ -9,7 +9,13 @@
 #include VM_PREFIX_INCLUDE
 #include "Vt_trace_two_b.h"
 #include "verilated.h"
-#include "verilated_vcd_c.h"
+#ifdef TEST_HDR_TRACE
+# ifdef TEST_FST
+#  include "verilated_fst_c.h"
+# else
+#  include "verilated_vcd_c.h"
+# endif
+#endif
 
 // Compile in place
 #include "Vt_trace_two_b.cpp"
@@ -26,18 +32,28 @@ int main(int argc, char** argv, char** env) {
     double sim_time = 1100;
     Verilated::commandArgs(argc, argv);
     Verilated::debug(0);
+    Verilated::traceEverOn(true);
     srand48(5);
     ap = new VM_PREFIX("topa");
     bp = new Vt_trace_two_b("topb");
-    ap->eval();
-    bp->eval();
+    ap->eval_step();
+    bp->eval_step();
+    ap->eval_end_step();
+    bp->eval_end_step();
 
-#if VM_TRACE
+#ifdef TEST_HDR_TRACE
     Verilated::traceEverOn(true);
+# ifdef TEST_FST
+    VerilatedFstC* tfp = new VerilatedFstC;
+    ap->trace(tfp, 99);
+    bp->trace(tfp, 99);
+    tfp->open(VL_STRINGIFY(TEST_OBJ_DIR) "/simx.fst");
+# else
     VerilatedVcdC* tfp = new VerilatedVcdC;
     ap->trace(tfp, 99);
     bp->trace(tfp, 99);
     tfp->open(VL_STRINGIFY(TEST_OBJ_DIR) "/simx.vcd");
+# endif
     if (tfp) tfp->dump(main_time);
 #endif
     {
@@ -48,11 +64,13 @@ int main(int argc, char** argv, char** env) {
     while (sc_time_stamp() < sim_time && !Verilated::gotFinish()) {
         ap->clk = !ap->clk;
         bp->clk = ap->clk;
-        ap->eval();
-        bp->eval();
-#if VM_TRACE
+        ap->eval_step();
+        bp->eval_step();
+        ap->eval_end_step();
+        bp->eval_end_step();
+#ifdef TEST_HDR_TRACE
         if (tfp) tfp->dump(main_time);
-#endif  // VM_TRACE
+#endif
         main_time += 5;
     }
     if (!Verilated::gotFinish()) {
@@ -60,9 +78,9 @@ int main(int argc, char** argv, char** env) {
     }
     ap->final();
     bp->final();
-#if VM_TRACE
+#ifdef TEST_HDR_TRACE
     if (tfp) tfp->close();
-#endif  // VM_TRACE
+#endif
 
     VL_DO_DANGLING(delete ap, ap);
     VL_DO_DANGLING(delete bp, bp);
diff --git a/test_regress/t/t_trace_two_dump_cc.out b/test_regress/t/t_trace_two_dump_cc.out
new file mode 100644
index 000000000..466b4c432
--- /dev/null
+++ b/test_regress/t/t_trace_two_dump_cc.out
@@ -0,0 +1,102 @@
+$version Generated by VerilatedVcd $end
+$date Sun Mar  1 20:48:56 2020
+ $end
+$timescale   1ns $end
+
+ $scope module topa $end
+  $var wire  1 3 clk $end
+  $scope module t $end
+   $var wire 32 + c_trace_on [31:0] $end
+   $var wire  1 3 clk $end
+   $var wire 32 # cyc [31:0] $end
+   $scope module sub $end
+    $var wire 32 ; inside_sub_a [31:0] $end
+   $upscope $end
+  $upscope $end
+ $upscope $end
+$enddefinitions $end
+
+
+#0
+b00000000000000000000000000000001 #
+b00000000000000000000000000000000 +
+03
+b00000000000000000000000000000001 ;
+#0
+#10
+#10
+b00000000000000000000000000000010 #
+b00000000000000000000000000000011 +
+13
+#15
+#15
+03
+#20
+#20
+b00000000000000000000000000000011 #
+b00000000000000000000000000000100 +
+13
+#25
+#25
+03
+#30
+#30
+b00000000000000000000000000000100 #
+b00000000000000000000000000000101 +
+13
+#35
+#35
+03
+#40
+#40
+b00000000000000000000000000000101 #
+b00000000000000000000000000000110 +
+13
+#45
+#45
+03
+#50
+#50
+b00000000000000000000000000000110 #
+b00000000000000000000000000000111 +
+13
+#55
+#55
+03
+#60
+#60
+b00000000000000000000000000000111 #
+b00000000000000000000000000001000 +
+13
+#65
+#65
+03
+#70
+#70
+b00000000000000000000000000001000 #
+b00000000000000000000000000001001 +
+13
+#75
+#75
+03
+#80
+#80
+b00000000000000000000000000001001 #
+b00000000000000000000000000001010 +
+13
+#85
+#85
+03
+#90
+#90
+b00000000000000000000000000001010 #
+b00000000000000000000000000001011 +
+13
+#95
+#95
+03
+#100
+#100
+b00000000000000000000000000001011 #
+b00000000000000000000000000001100 +
+13
diff --git a/test_regress/t/t_trace_two_dump_cc.pl b/test_regress/t/t_trace_two_dump_cc.pl
new file mode 100755
index 000000000..2d3e34fd4
--- /dev/null
+++ b/test_regress/t/t_trace_two_dump_cc.pl
@@ -0,0 +1,40 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+# Test tracing with two models instanced
+scenarios(vlt_all => 1);
+
+top_filename("t_trace_two_a.v");
+
+compile(
+    make_main => 0,
+    verilator_make_gmake => 0,
+    top_filename => 't_trace_two_b.v',
+    VM_PREFIX => 'Vt_trace_two_b',
+    verilator_flags2 => ['-trace'],
+    );
+
+compile(
+    make_main => 0,
+    top_filename => 't_trace_two_a.v',
+    verilator_flags2 => ['-exe', '-trace', "$Self->{t_dir}/t_trace_two_cc.cpp"],
+    v_flags2 => ['+define+TEST_DUMP'],
+    );
+
+execute(
+    check_finished => 1,
+    );
+
+if ($Self->{vlt_all}) {
+    file_grep("$Self->{obj_dir}/simx.vcd", qr/\$enddefinitions/x);
+    vcd_identical("$Self->{obj_dir}/simx.vcd", $Self->{golden_filename});
+}
+
+ok(1);
+1;
diff --git a/test_regress/t/t_trace_two_dump_sc.out b/test_regress/t/t_trace_two_dump_sc.out
new file mode 100644
index 000000000..a9f2fe8aa
--- /dev/null
+++ b/test_regress/t/t_trace_two_dump_sc.out
@@ -0,0 +1,81 @@
+$version Generated by VerilatedVcd $end
+$date Sun Mar  1 20:49:13 2020
+ $end
+$timescale   1ps $end
+
+ $scope module topa $end
+  $scope module t $end
+   $var wire 32 3 c_trace_on [31:0] $end
+   $var wire  1 # clk $end
+   $var wire 32 + cyc [31:0] $end
+   $scope module sub $end
+    $var wire 32 ; inside_sub_a [31:0] $end
+   $upscope $end
+  $upscope $end
+ $upscope $end
+$enddefinitions $end
+
+
+#0
+0#
+b00000000000000000000000000000001 +
+b00000000000000000000000000000000 3
+b00000000000000000000000000000001 ;
+#10000
+1#
+b00000000000000000000000000000010 +
+b00000000000000000000000000000011 3
+#15000
+0#
+#20000
+1#
+b00000000000000000000000000000011 +
+b00000000000000000000000000000100 3
+#25000
+0#
+#30000
+1#
+b00000000000000000000000000000100 +
+b00000000000000000000000000000101 3
+#35000
+0#
+#40000
+1#
+b00000000000000000000000000000101 +
+b00000000000000000000000000000110 3
+#45000
+0#
+#50000
+1#
+b00000000000000000000000000000110 +
+b00000000000000000000000000000111 3
+#55000
+0#
+#60000
+1#
+b00000000000000000000000000000111 +
+b00000000000000000000000000001000 3
+#65000
+0#
+#70000
+1#
+b00000000000000000000000000001000 +
+b00000000000000000000000000001001 3
+#75000
+0#
+#80000
+1#
+b00000000000000000000000000001001 +
+b00000000000000000000000000001010 3
+#85000
+0#
+#90000
+1#
+b00000000000000000000000000001010 +
+b00000000000000000000000000001011 3
+#95000
+0#
+#100000
+1#
+b00000000000000000000000000001011 +
+b00000000000000000000000000001100 3
diff --git a/test_regress/t/t_trace_two_dump_sc.pl b/test_regress/t/t_trace_two_dump_sc.pl
new file mode 100755
index 000000000..6579e2cec
--- /dev/null
+++ b/test_regress/t/t_trace_two_dump_sc.pl
@@ -0,0 +1,45 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+scenarios(simulator => 1);
+
+if (!$Self->have_sc) {
+    skip("No SystemC installed");
+}
+else {
+    top_filename("t_trace_two_a.v");
+
+    compile(
+        make_main => 0,
+        verilator_make_gmake => 0,
+        top_filename => 't_trace_two_b.v',
+        VM_PREFIX => 'Vt_trace_two_b',
+        verilator_flags2 => ['-sc -trace'],
+        );
+
+    compile(
+        make_main => 0,
+        top_filename => 't_trace_two_a.v',
+        verilator_flags2 => ['-sc', '-exe', '-trace',
+                             "$Self->{t_dir}/t_trace_two_sc.cpp"],
+        v_flags2 => ['+define+TEST_DUMP'],
+        );
+
+    execute(
+        check_finished => 1,
+        );
+
+    if ($Self->{vlt_all}) {
+        file_grep("$Self->{obj_dir}/simx.vcd", qr/\$enddefinitions/x);
+        vcd_identical("$Self->{obj_dir}/simx.vcd", $Self->{golden_filename});
+    }
+}
+
+ok(1);
+1;
diff --git a/test_regress/t/t_trace_two_dumpfst_cc.out b/test_regress/t/t_trace_two_dumpfst_cc.out
new file mode 100755
index 000000000..9141e9a39
--- /dev/null
+++ b/test_regress/t/t_trace_two_dumpfst_cc.out
@@ -0,0 +1,83 @@
+$date
+	Sun Mar  1 21:31:56 2020
+
+$end
+$version
+	fstWriter
+$end
+$timescale
+	1ns
+$end
+$scope module topa $end
+$var wire 1 ! clk $end
+$scope module t $end
+$var wire 1 ! clk $end
+$var integer 32 " cyc $end
+$var integer 32 # c_trace_on $end
+$scope module sub $end
+$var integer 32 $ inside_sub_a $end
+$upscope $end
+$upscope $end
+$upscope $end
+$enddefinitions $end
+$dumpvars
+#0
+0!
+#10
+1!
+b00000000000000000000000000000011 #
+b00000000000000000000000000000010 "
+#15
+0!
+#20
+1!
+b00000000000000000000000000000011 "
+b00000000000000000000000000000100 #
+#25
+0!
+#30
+1!
+b00000000000000000000000000000101 #
+b00000000000000000000000000000100 "
+#35
+0!
+#40
+1!
+b00000000000000000000000000000101 "
+b00000000000000000000000000000110 #
+#45
+0!
+#50
+1!
+b00000000000000000000000000000111 #
+b00000000000000000000000000000110 "
+#55
+0!
+#60
+1!
+b00000000000000000000000000000111 "
+b00000000000000000000000000001000 #
+#65
+0!
+#70
+1!
+b00000000000000000000000000001001 #
+b00000000000000000000000000001000 "
+#75
+0!
+#80
+1!
+b00000000000000000000000000001001 "
+b00000000000000000000000000001010 #
+#85
+0!
+#90
+1!
+b00000000000000000000000000001011 #
+b00000000000000000000000000001010 "
+#95
+0!
+#100
+1!
+b00000000000000000000000000001011 "
+b00000000000000000000000000001100 #
diff --git a/test_regress/t/t_trace_two_dumpfst_cc.pl b/test_regress/t/t_trace_two_dumpfst_cc.pl
new file mode 100755
index 000000000..f19d777c0
--- /dev/null
+++ b/test_regress/t/t_trace_two_dumpfst_cc.pl
@@ -0,0 +1,42 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+# Test tracing with two models instanced
+scenarios(vlt_all => 1);
+
+top_filename("t_trace_two_a.v");
+
+compile(
+    make_main => 0,
+    verilator_make_gmake => 0,
+    top_filename => 't_trace_two_b.v',
+    VM_PREFIX => 'Vt_trace_two_b',
+    verilator_flags2 => ['--trace-fst-thread -DTEST_FST'],
+    );
+
+compile(
+    make_main => 0,
+    top_filename => 't_trace_two_a.v',
+    verilator_flags2 => ['-exe', '--trace-fst-thread',
+                         '-DTEST_FST',
+                         "$Self->{t_dir}/t_trace_two_cc.cpp"],
+    v_flags2 => ['+define+TEST_DUMP'],
+    );
+
+execute(
+    check_finished => 1,
+    );
+
+if ($Self->{vlt_all}) {
+    fst2vcd($Self->trace_filename, "$Self->{obj_dir}/simx-fst2vcd.vcd");
+    vcd_identical("$Self->{obj_dir}/simx-fst2vcd.vcd", $Self->{golden_filename});
+}
+
+ok(1);
+1;
diff --git a/test_regress/t/t_trace_two_hdr_cc.pl b/test_regress/t/t_trace_two_hdr_cc.pl
index 3601322e4..1fbe3fd38 100755
--- a/test_regress/t/t_trace_two_hdr_cc.pl
+++ b/test_regress/t/t_trace_two_hdr_cc.pl
@@ -23,7 +23,8 @@ compile(
 compile(
     make_main => 0,
     top_filename => 't_trace_two_a.v',
-    verilator_flags2 => ['-exe', '-trace', "$Self->{t_dir}/t_trace_two_hdr_cc.cpp"],
+    make_flags => 'CPPFLAGS_ADD=-DTEST_HDR_TRACE=1',
+    verilator_flags2 => ['-exe', '-trace', "$Self->{t_dir}/t_trace_two_cc.cpp"],
     );
 
 execute(
diff --git a/test_regress/t/t_trace_two_hdr_sc.pl b/test_regress/t/t_trace_two_hdr_sc.pl
index 3c8de5b0b..7cbd882a0 100755
--- a/test_regress/t/t_trace_two_hdr_sc.pl
+++ b/test_regress/t/t_trace_two_hdr_sc.pl
@@ -26,8 +26,9 @@ else {
     compile(
         make_main => 0,
         top_filename => 't_trace_two_a.v',
+        make_flags => 'CPPFLAGS_ADD=-DTEST_HDR_TRACE',
         verilator_flags2 => ['-sc', '-exe', '-trace',
-                             "$Self->{t_dir}/t_trace_two_hdr_sc.cpp"],
+                             "$Self->{t_dir}/t_trace_two_sc.cpp"],
         );
 
     execute(
diff --git a/test_regress/t/t_trace_two_hdrfst_cc.out b/test_regress/t/t_trace_two_hdrfst_cc.out
new file mode 100755
index 000000000..a7289d36e
Binary files /dev/null and b/test_regress/t/t_trace_two_hdrfst_cc.out differ
diff --git a/test_regress/t/t_trace_two_hdrfst_cc.pl b/test_regress/t/t_trace_two_hdrfst_cc.pl
new file mode 100755
index 000000000..514eca86d
--- /dev/null
+++ b/test_regress/t/t_trace_two_hdrfst_cc.pl
@@ -0,0 +1,42 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+# Test tracing with two models instanced
+scenarios(vlt_all => 1);
+
+top_filename("t_trace_two_a.v");
+
+compile(
+    make_main => 0,
+    verilator_make_gmake => 0,
+    top_filename => 't_trace_two_b.v',
+    VM_PREFIX => 'Vt_trace_two_b',
+    verilator_flags2 => ['--trace-fst-thread'],
+    );
+
+compile(
+    make_main => 0,
+    top_filename => 't_trace_two_a.v',
+    make_flags => 'CPPFLAGS_ADD="-DTEST_HDR_TRACE=1 -DTEST_FST=1"',
+    verilator_flags2 => ['-exe', '--trace-fst-thread',
+                         '-DTEST_FST',
+                         "$Self->{t_dir}/t_trace_two_cc.cpp"],
+    );
+
+execute(
+    check_finished => 1,
+    );
+
+if ($Self->{vlt_all}) {
+    fst2vcd($Self->trace_filename, "$Self->{obj_dir}/simx-fst2vcd.vcd");
+    vcd_identical("$Self->{obj_dir}/simx-fst2vcd.vcd", $Self->{golden_filename});
+}
+
+ok(1);
+1;
diff --git a/test_regress/t/t_trace_two_port_cc.out b/test_regress/t/t_trace_two_port_cc.out
new file mode 100644
index 000000000..dd2f3213c
--- /dev/null
+++ b/test_regress/t/t_trace_two_port_cc.out
@@ -0,0 +1,102 @@
+$version Generated by VerilatedVcd $end
+$date Sun Mar  1 21:32:13 2020
+ $end
+$timescale   1ns $end
+
+ $scope module topa $end
+  $var wire  1 3 clk $end
+  $scope module t $end
+   $var wire 32 + c_trace_on [31:0] $end
+   $var wire  1 3 clk $end
+   $var wire 32 # cyc [31:0] $end
+   $scope module sub $end
+    $var wire 32 ; inside_sub_a [31:0] $end
+   $upscope $end
+  $upscope $end
+ $upscope $end
+$enddefinitions $end
+
+
+#0
+b00000000000000000000000000000001 #
+b00000000000000000000000000000000 +
+03
+b00000000000000000000000000000001 ;
+#0
+#10
+#10
+b00000000000000000000000000000010 #
+b00000000000000000000000000000011 +
+13
+#15
+#15
+03
+#20
+#20
+b00000000000000000000000000000011 #
+b00000000000000000000000000000100 +
+13
+#25
+#25
+03
+#30
+#30
+b00000000000000000000000000000100 #
+b00000000000000000000000000000101 +
+13
+#35
+#35
+03
+#40
+#40
+b00000000000000000000000000000101 #
+b00000000000000000000000000000110 +
+13
+#45
+#45
+03
+#50
+#50
+b00000000000000000000000000000110 #
+b00000000000000000000000000000111 +
+13
+#55
+#55
+03
+#60
+#60
+b00000000000000000000000000000111 #
+b00000000000000000000000000001000 +
+13
+#65
+#65
+03
+#70
+#70
+b00000000000000000000000000001000 #
+b00000000000000000000000000001001 +
+13
+#75
+#75
+03
+#80
+#80
+b00000000000000000000000000001001 #
+b00000000000000000000000000001010 +
+13
+#85
+#85
+03
+#90
+#90
+b00000000000000000000000000001010 #
+b00000000000000000000000000001011 +
+13
+#95
+#95
+03
+#100
+#100
+b00000000000000000000000000001011 #
+b00000000000000000000000000001100 +
+13
diff --git a/test_regress/t/t_trace_two_port_cc.pl b/test_regress/t/t_trace_two_port_cc.pl
new file mode 100755
index 000000000..31abb926b
--- /dev/null
+++ b/test_regress/t/t_trace_two_port_cc.pl
@@ -0,0 +1,40 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+# Test tracing with two models instanced
+scenarios(vlt_all => 1);
+
+top_filename("t_trace_two_a.v");
+
+compile(
+    make_main => 0,
+    verilator_make_gmake => 0,
+    top_filename => 't_trace_two_b.v',
+    VM_PREFIX => 'Vt_trace_two_b',
+    verilator_flags2 => ['-trace'],
+    );
+
+compile(
+    make_main => 0,
+    top_filename => 't_trace_two_a.v',
+    verilator_flags2 => ['-exe', '-trace', "$Self->{t_dir}/t_trace_two_cc.cpp"],
+    v_flags2 => ['+define+TEST_DUMPPORTS'],
+    );
+
+execute(
+    check_finished => 1,
+    );
+
+if ($Self->{vlt_all}) {
+    file_grep("$Self->{obj_dir}/simx.vcd", qr/\$enddefinitions/x);
+    vcd_identical("$Self->{obj_dir}/simx.vcd", $Self->{golden_filename});
+}
+
+ok(1);
+1;
diff --git a/test_regress/t/t_trace_two_port_sc.out b/test_regress/t/t_trace_two_port_sc.out
new file mode 100644
index 000000000..af8668106
--- /dev/null
+++ b/test_regress/t/t_trace_two_port_sc.out
@@ -0,0 +1,81 @@
+$version Generated by VerilatedVcd $end
+$date Sun Mar  1 21:32:22 2020
+ $end
+$timescale   1ps $end
+
+ $scope module topa $end
+  $scope module t $end
+   $var wire 32 3 c_trace_on [31:0] $end
+   $var wire  1 # clk $end
+   $var wire 32 + cyc [31:0] $end
+   $scope module sub $end
+    $var wire 32 ; inside_sub_a [31:0] $end
+   $upscope $end
+  $upscope $end
+ $upscope $end
+$enddefinitions $end
+
+
+#0
+0#
+b00000000000000000000000000000001 +
+b00000000000000000000000000000000 3
+b00000000000000000000000000000001 ;
+#10000
+1#
+b00000000000000000000000000000010 +
+b00000000000000000000000000000011 3
+#15000
+0#
+#20000
+1#
+b00000000000000000000000000000011 +
+b00000000000000000000000000000100 3
+#25000
+0#
+#30000
+1#
+b00000000000000000000000000000100 +
+b00000000000000000000000000000101 3
+#35000
+0#
+#40000
+1#
+b00000000000000000000000000000101 +
+b00000000000000000000000000000110 3
+#45000
+0#
+#50000
+1#
+b00000000000000000000000000000110 +
+b00000000000000000000000000000111 3
+#55000
+0#
+#60000
+1#
+b00000000000000000000000000000111 +
+b00000000000000000000000000001000 3
+#65000
+0#
+#70000
+1#
+b00000000000000000000000000001000 +
+b00000000000000000000000000001001 3
+#75000
+0#
+#80000
+1#
+b00000000000000000000000000001001 +
+b00000000000000000000000000001010 3
+#85000
+0#
+#90000
+1#
+b00000000000000000000000000001010 +
+b00000000000000000000000000001011 3
+#95000
+0#
+#100000
+1#
+b00000000000000000000000000001011 +
+b00000000000000000000000000001100 3
diff --git a/test_regress/t/t_trace_two_port_sc.pl b/test_regress/t/t_trace_two_port_sc.pl
new file mode 100755
index 000000000..177f24f65
--- /dev/null
+++ b/test_regress/t/t_trace_two_port_sc.pl
@@ -0,0 +1,45 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+scenarios(simulator => 1);
+
+if (!$Self->have_sc) {
+    skip("No SystemC installed");
+}
+else {
+    top_filename("t_trace_two_a.v");
+
+    compile(
+        make_main => 0,
+        verilator_make_gmake => 0,
+        top_filename => 't_trace_two_b.v',
+        VM_PREFIX => 'Vt_trace_two_b',
+        verilator_flags2 => ['-sc -trace'],
+        );
+
+    compile(
+        make_main => 0,
+        top_filename => 't_trace_two_a.v',
+        verilator_flags2 => ['-sc', '-exe', '-trace',
+                             "$Self->{t_dir}/t_trace_two_sc.cpp"],
+        v_flags2 => ['+define+TEST_DUMPPORTS'],
+        );
+
+    execute(
+        check_finished => 1,
+        );
+
+    if ($Self->{vlt_all}) {
+        file_grep("$Self->{obj_dir}/simx.vcd", qr/\$enddefinitions/x);
+        vcd_identical("$Self->{obj_dir}/simx.vcd", $Self->{golden_filename});
+    }
+}
+
+ok(1);
+1;
diff --git a/test_regress/t/t_trace_two_portfst_cc.out b/test_regress/t/t_trace_two_portfst_cc.out
new file mode 100755
index 000000000..ec99d954e
--- /dev/null
+++ b/test_regress/t/t_trace_two_portfst_cc.out
@@ -0,0 +1,83 @@
+$date
+	Sun Mar  1 21:32:04 2020
+
+$end
+$version
+	fstWriter
+$end
+$timescale
+	1ns
+$end
+$scope module topa $end
+$var wire 1 ! clk $end
+$scope module t $end
+$var wire 1 ! clk $end
+$var integer 32 " cyc $end
+$var integer 32 # c_trace_on $end
+$scope module sub $end
+$var integer 32 $ inside_sub_a $end
+$upscope $end
+$upscope $end
+$upscope $end
+$enddefinitions $end
+$dumpvars
+#0
+0!
+#10
+1!
+b00000000000000000000000000000011 #
+b00000000000000000000000000000010 "
+#15
+0!
+#20
+1!
+b00000000000000000000000000000011 "
+b00000000000000000000000000000100 #
+#25
+0!
+#30
+1!
+b00000000000000000000000000000101 #
+b00000000000000000000000000000100 "
+#35
+0!
+#40
+1!
+b00000000000000000000000000000101 "
+b00000000000000000000000000000110 #
+#45
+0!
+#50
+1!
+b00000000000000000000000000000111 #
+b00000000000000000000000000000110 "
+#55
+0!
+#60
+1!
+b00000000000000000000000000000111 "
+b00000000000000000000000000001000 #
+#65
+0!
+#70
+1!
+b00000000000000000000000000001001 #
+b00000000000000000000000000001000 "
+#75
+0!
+#80
+1!
+b00000000000000000000000000001001 "
+b00000000000000000000000000001010 #
+#85
+0!
+#90
+1!
+b00000000000000000000000000001011 #
+b00000000000000000000000000001010 "
+#95
+0!
+#100
+1!
+b00000000000000000000000000001011 "
+b00000000000000000000000000001100 #
diff --git a/test_regress/t/t_trace_two_portfst_cc.pl b/test_regress/t/t_trace_two_portfst_cc.pl
new file mode 100755
index 000000000..cb21e0f34
--- /dev/null
+++ b/test_regress/t/t_trace_two_portfst_cc.pl
@@ -0,0 +1,42 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003-2020 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+# Test tracing with two models instanced
+scenarios(vlt_all => 1);
+
+top_filename("t_trace_two_a.v");
+
+compile(
+    make_main => 0,
+    verilator_make_gmake => 0,
+    top_filename => 't_trace_two_b.v',
+    VM_PREFIX => 'Vt_trace_two_b',
+    verilator_flags2 => ['--trace-fst-thread'],
+    );
+
+compile(
+    make_main => 0,
+    top_filename => 't_trace_two_a.v',
+    verilator_flags2 => ['-exe', '--trace-fst-thread',
+                         '-DTEST_FST',
+                         "$Self->{t_dir}/t_trace_two_cc.cpp"],
+    v_flags2 => ['+define+TEST_DUMPPORTS'],
+    );
+
+execute(
+    check_finished => 1,
+    );
+
+if ($Self->{vlt_all}) {
+    fst2vcd($Self->trace_filename, "$Self->{obj_dir}/simx-fst2vcd.vcd");
+    vcd_identical("$Self->{obj_dir}/simx-fst2vcd.vcd", $Self->{golden_filename});
+}
+
+ok(1);
+1;
diff --git a/test_regress/t/t_trace_two_hdr_sc.cpp b/test_regress/t/t_trace_two_sc.cpp
similarity index 93%
rename from test_regress/t/t_trace_two_hdr_sc.cpp
rename to test_regress/t/t_trace_two_sc.cpp
index dce33a0e1..c3c1d12ac 100644
--- a/test_regress/t/t_trace_two_hdr_sc.cpp
+++ b/test_regress/t/t_trace_two_sc.cpp
@@ -9,7 +9,9 @@
 #include VM_PREFIX_INCLUDE
 #include "Vt_trace_two_b.h"
 #include "verilated.h"
-#include "verilated_vcd_c.h"
+#ifdef TEST_HDR_TRACE
+# include "verilated_vcd_sc.h"
+#endif
 
 // Compile in place
 #include "Vt_trace_two_b.cpp"
@@ -20,7 +22,6 @@
 // General headers
 #include "verilated.h"
 #include "systemc.h"
-#include "verilated_vcd_sc.h"
 
 VM_PREFIX* ap;
 Vt_trace_two_b* bp;
@@ -29,6 +30,7 @@ int sc_main(int argc, char** argv) {
     sc_signal<bool> clk;
     sc_time sim_time(1100, SC_NS);
     Verilated::commandArgs(argc, argv);
+    Verilated::traceEverOn(true);
     Verilated::debug(0);
     srand48(5);
     ap = new VM_PREFIX("topa");
@@ -36,8 +38,7 @@ int sc_main(int argc, char** argv) {
     ap->clk(clk);
     bp->clk(clk);
 
-#if VM_TRACE
-    Verilated::traceEverOn(true);
+#ifdef TEST_HDR_TRACE
     VerilatedVcdSc* tfp = new VerilatedVcdSc;
     ap->trace(tfp, 99);
     bp->trace(tfp, 99);
@@ -64,9 +65,9 @@ int sc_main(int argc, char** argv) {
     }
     ap->final();
     bp->final();
-#if VM_TRACE
+#ifdef TEST_HDR_TRACE
     if (tfp) tfp->close();
-#endif  // VM_TRACE
+#endif
 
     VL_DO_DANGLING(delete ap, ap);
     VL_DO_DANGLING(delete bp, bp);