diff --git a/README.txt b/README.txt
index a1f3e8e7a..ad10d1bbc 100644
--- a/README.txt
+++ b/README.txt
@@ -344,6 +344,19 @@ language that are defined.
 	The $sizeof function is deprecated in favor of $bits, which is
 	the same thing, but included in the SystemVerilog definition.
 
+    $simtime
+	The $simtime system function returns as a 64bit value the
+	simulation time, unscaled by the time units of local
+	scope. This is different from the $time and $stime functions
+	which return the scaled times. This function is added for
+	regression testing of the compiler and run time, but can be
+	used by applications who really want the simulation time.
+
+	Note that the simulation time can be confusing if there are
+	lots of different `timescales within a design. It is not in
+	general possible to predict what the simulation precision will
+	turn out to be.
+
     Builtin system functions
 
 	Certain of the system functions have well defined meanings, so
diff --git a/elab_expr.cc b/elab_expr.cc
index eed522037..17a0991b1 100644
--- a/elab_expr.cc
+++ b/elab_expr.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: elab_expr.cc,v 1.66 2002/09/21 21:28:18 steve Exp $"
+#ident "$Id: elab_expr.cc,v 1.67 2002/12/21 00:55:57 steve Exp $"
 #endif
 
 # include "config.h"
@@ -215,6 +215,8 @@ NetExpr* PECallFunction::elaborate_sfunc_(Design*des, NetScope*scope) const
 
       if (strcmp(path_.peek_name(0), "$time") == 0)
 	    wid = 64;
+      if (strcmp(path_.peek_name(0), "$simtime") == 0)
+	    wid = 64;
       if (strcmp(path_.peek_name(0), "$stime") == 0)
 	    wid = 32;
 
@@ -885,6 +887,13 @@ NetExpr* PEUnary::elaborate_expr(Design*des, NetScope*scope, bool) const
 
 /*
  * $Log: elab_expr.cc,v $
+ * Revision 1.67  2002/12/21 00:55:57  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.66  2002/09/21 21:28:18  steve
  *  Allow constant bit selects out of range.
  *
diff --git a/ivl.def b/ivl.def
index 021fc6558..d40390f4b 100644
--- a/ivl.def
+++ b/ivl.def
@@ -120,6 +120,7 @@ ivl_scope_port
 ivl_scope_ports
 ivl_scope_sigs
 ivl_scope_sig
+ivl_scope_time_units
 ivl_scope_type
 ivl_scope_tname
 
diff --git a/ivl_target.h b/ivl_target.h
index 41139af6c..0545a774e 100644
--- a/ivl_target.h
+++ b/ivl_target.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: ivl_target.h,v 1.108 2002/10/23 01:47:17 steve Exp $"
+#ident "$Id: ivl_target.h,v 1.109 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 #ifdef __cplusplus
@@ -861,6 +861,11 @@ extern ivl_signal_t ivl_nexus_ptr_sig(ivl_nexus_ptr_t net);
  *    anything that can become and ivl_signal_t, include synthetic
  *    signals generated by the compiler.
  *
+ * ivl_scope_time_units
+ *    Scopes have their own intrinsic time units, typically from the
+ *    timescale compiler directive. This method returns the units as a
+ *    signed power of 10 value.
+ *
  * ivl_scope_type
  * ivl_scope_tname
  *    Scopes have a type and a type name. For example, if a scope is
@@ -891,6 +896,7 @@ extern unsigned     ivl_scope_sigs(ivl_scope_t net);
 extern ivl_signal_t ivl_scope_sig(ivl_scope_t net, unsigned idx);
 extern ivl_scope_type_t ivl_scope_type(ivl_scope_t net);
 extern const char*  ivl_scope_tname(ivl_scope_t net);
+extern int          ivl_scope_time_units(ivl_scope_t net);
 
 
 /* SIGNALS
@@ -1091,6 +1097,13 @@ _END_DECL
 
 /*
  * $Log: ivl_target.h,v $
+ * Revision 1.109  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.108  2002/10/23 01:47:17  steve
  *  Fix synth2 handling of aset/aclr signals where
  *  flip-flops are split by begin-end blocks.
diff --git a/t-dll-api.cc b/t-dll-api.cc
index f912255b3..91ef05794 100644
--- a/t-dll-api.cc
+++ b/t-dll-api.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: t-dll-api.cc,v 1.88 2002/10/23 01:47:17 steve Exp $"
+#ident "$Id: t-dll-api.cc,v 1.89 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 # include "config.h"
@@ -1157,6 +1157,12 @@ extern "C" ivl_signal_t ivl_scope_sig(ivl_scope_t net, unsigned idx)
       return net->sigs_[idx];
 }
 
+extern "C" int ivl_scope_time_units(ivl_scope_t net)
+{
+      assert(net);
+      return net->time_units;
+}
+
 extern "C" ivl_scope_type_t ivl_scope_type(ivl_scope_t net)
 {
       assert(net);
@@ -1585,6 +1591,13 @@ extern "C" ivl_statement_t ivl_stmt_sub_stmt(ivl_statement_t net)
 
 /*
  * $Log: t-dll-api.cc,v $
+ * Revision 1.89  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.88  2002/10/23 01:47:17  steve
  *  Fix synth2 handling of aset/aclr signals where
  *  flip-flops are split by begin-end blocks.
diff --git a/t-dll.cc b/t-dll.cc
index 18c6274f4..b8607c272 100644
--- a/t-dll.cc
+++ b/t-dll.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: t-dll.cc,v 1.100 2002/11/05 02:12:35 steve Exp $"
+#ident "$Id: t-dll.cc,v 1.101 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 # include "config.h"
@@ -435,6 +435,8 @@ void dll_target::add_root(ivl_design_s &des_, const NetScope *s)
       root_->mem_ = 0;
       root_->type_ = IVL_SCT_MODULE;
       root_->tname_ = root_->name_;
+      root_->time_units = s->time_unit();
+
       des_.nroots_++;
       if (des_.roots_)
 	    des_.roots_ = (ivl_scope_t *)realloc(des_.roots_, des_.nroots_ * sizeof(ivl_scope_t));
@@ -1776,6 +1778,7 @@ void dll_target::scope(const NetScope*net)
 	    scope->lpm_ = 0;
 	    scope->nmem_ = 0;
 	    scope->mem_ = 0;
+	    scope->time_units = net->time_unit();
 
 	    switch (net->type()) {
 		case NetScope::MODULE:
@@ -1981,6 +1984,13 @@ extern const struct target tgt_dll = { "dll", &dll_target_obj };
 
 /*
  * $Log: t-dll.cc,v $
+ * Revision 1.101  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.100  2002/11/05 02:12:35  steve
  *  Fix the call to FormatMessage under Windows.
  *
diff --git a/t-dll.h b/t-dll.h
index ba8d3dce3..54c4a1431 100644
--- a/t-dll.h
+++ b/t-dll.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: t-dll.h,v 1.95 2002/10/23 01:47:17 steve Exp $"
+#ident "$Id: t-dll.h,v 1.96 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 # include  "target.h"
@@ -500,6 +500,8 @@ struct ivl_scope_s {
 
       unsigned ports;
       ivl_signal_t*port;
+
+      signed int time_units :8;
 };
 
 /*
@@ -622,6 +624,13 @@ struct ivl_statement_s {
 
 /*
  * $Log: t-dll.h,v $
+ * Revision 1.96  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.95  2002/10/23 01:47:17  steve
  *  Fix synth2 handling of aset/aclr signals where
  *  flip-flops are split by begin-end blocks.
diff --git a/tgt-stub/stub.c b/tgt-stub/stub.c
index 1d5abf212..d53283f18 100644
--- a/tgt-stub/stub.c
+++ b/tgt-stub/stub.c
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: stub.c,v 1.70 2002/10/23 01:45:24 steve Exp $"
+#ident "$Id: stub.c,v 1.71 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 # include "config.h"
@@ -666,26 +666,28 @@ static int show_scope(ivl_scope_t net, void*x)
 
       switch (ivl_scope_type(net)) {
 	  case IVL_SCT_MODULE:
-	    fprintf(out, " module %s\n", ivl_scope_tname(net));
+	    fprintf(out, " module %s", ivl_scope_tname(net));
 	    break;
 	  case IVL_SCT_FUNCTION:
-	    fprintf(out, " function %s\n", ivl_scope_tname(net));
+	    fprintf(out, " function %s", ivl_scope_tname(net));
 	    break;
 	  case IVL_SCT_BEGIN:
-	    fprintf(out, " begin : %s\n", ivl_scope_tname(net));
+	    fprintf(out, " begin : %s", ivl_scope_tname(net));
 	    break;
 	  case IVL_SCT_FORK:
-	    fprintf(out, " fork : %s\n", ivl_scope_tname(net));
+	    fprintf(out, " fork : %s", ivl_scope_tname(net));
 	    break;
 	  case IVL_SCT_TASK:
-	    fprintf(out, " task %s\n", ivl_scope_tname(net));
+	    fprintf(out, " task %s", ivl_scope_tname(net));
 	    break;
 	  default:
-	    fprintf(out, " type(%u) %s\n", ivl_scope_type(net),
+	    fprintf(out, " type(%u) %s", ivl_scope_type(net),
 		    ivl_scope_tname(net));
 	    break;
       }
 
+      fprintf(out, " time units = 10e%d\n", ivl_scope_time_units(net));
+
       for (idx = 0 ;  idx < ivl_scope_events(net) ;  idx += 1)
 	    show_event(ivl_scope_event(net, idx));
 
@@ -728,6 +730,13 @@ int target_design(ivl_design_t des)
 
 /*
  * $Log: stub.c,v $
+ * Revision 1.71  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.70  2002/10/23 01:45:24  steve
  *  Fix synth2 handling of aset/aclr signals where
  *  flip-flops are split by begin-end blocks.
diff --git a/tgt-vvp/vvp_scope.c b/tgt-vvp/vvp_scope.c
index e85877872..ad6d94c8e 100644
--- a/tgt-vvp/vvp_scope.c
+++ b/tgt-vvp/vvp_scope.c
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: vvp_scope.c,v 1.81 2002/11/21 18:08:09 steve Exp $"
+#ident "$Id: vvp_scope.c,v 1.82 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 # include  "vvp_priv.h"
@@ -1547,12 +1547,16 @@ int draw_scope(ivl_scope_t net, ivl_scope_t parent)
 	      vvp_mangle_id(ivl_scope_name(net)), 
 	      type,
 	      vvp_mangle_name(ivl_scope_name(net)));
+
       if (parent) {
 	    fprintf(vvp_out, ", S_%s;\n",
 		    vvp_mangle_id(ivl_scope_name(parent)));
-      }
-      else
+      } else {
+
 	    fprintf(vvp_out, ";\n");
+      }
+
+      fprintf(vvp_out, " .timescale %d;\n", ivl_scope_time_units(net));
       
 	/* Scan the scope for logic devices. For each device, draw out
 	   a functor that connects pin 0 to the output, and the
@@ -1607,6 +1611,13 @@ int draw_scope(ivl_scope_t net, ivl_scope_t parent)
 
 /*
  * $Log: vvp_scope.c,v $
+ * Revision 1.82  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.81  2002/11/21 18:08:09  steve
  *  Better handling of select width of shifters.
  *
diff --git a/vpi/sys_lxt.c b/vpi/sys_lxt.c
index 0564d0519..d5dcfbec8 100644
--- a/vpi/sys_lxt.c
+++ b/vpi/sys_lxt.c
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: sys_lxt.c,v 1.12 2002/11/17 22:28:42 steve Exp $"
+#ident "$Id: sys_lxt.c,v 1.13 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 # include "config.h"
@@ -343,6 +343,7 @@ static int sys_dumpoff_calltf(char*name)
       if (dump_header_pending())
 	    return 0;
 
+      now.type = vpiSimTime;
       vpi_get_time(0, &now);
       if (now.low > vcd_cur_time)
             lt_set_time(dump_file, now.low);
@@ -368,6 +369,7 @@ static int sys_dumpon_calltf(char*name)
       if (dump_header_pending())
 	    return 0;
 
+      now.type = vpiSimTime;
       vpi_get_time(0, &now);
       if (now.low > vcd_cur_time)
             lt_set_time(dump_file, now.low);
@@ -388,6 +390,7 @@ static int sys_dumpall_calltf(char*name)
       if (dump_header_pending())
 	    return 0;
 
+      now.type = vpiSimTime;
       vpi_get_time(0, &now);
       if (now.low > vcd_cur_time)
             lt_set_time(dump_file, now.low);
@@ -817,6 +820,13 @@ void sys_lxt_register()
 
 /*
  * $Log: sys_lxt.c,v $
+ * Revision 1.13  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.12  2002/11/17 22:28:42  steve
  *  Close old file if $dumpfile is called again.
  *
diff --git a/vpi/sys_time.c b/vpi/sys_time.c
index 202662da6..c0b69b341 100644
--- a/vpi/sys_time.c
+++ b/vpi/sys_time.c
@@ -17,14 +17,25 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: sys_time.c,v 1.4 2002/08/12 01:35:05 steve Exp $"
+#ident "$Id: sys_time.c,v 1.5 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 # include "config.h"
 
 # include  "vpi_user.h"
+# include  <string.h>
 # include  <assert.h>
 
+static vpiHandle module_of_function(vpiHandle obj)
+{
+      while (vpi_get(vpiType, obj) != vpiModule) {
+	    obj = vpi_handle(vpiScope, obj);
+	    assert(obj);
+      }
+
+      return obj;
+}
+
 static int sys_time_sizetf(char*x)
 {
       return 64;
@@ -40,16 +51,39 @@ static int sys_time_calltf(char*name)
       s_vpi_value val;
       s_vpi_time  now;
       vpiHandle call_handle;
+      vpiHandle mod;
+      int units, prec;
+      long scale;
 
       call_handle = vpi_handle(vpiSysTfCall, 0);
       assert(call_handle);
 
+      mod = module_of_function(call_handle);
+
+      now.type = vpiSimTime;
       vpi_get_time(0, &now);
 
+	/* All the variants but $simtime return the time in units of
+	   the local scope. The $simtime function returns the
+	   simulation time. */
+      if (strcmp(name, "$simtime") == 0)
+	    units = vpi_get(vpiTimePrecision, 0);
+      else
+	    units = vpi_get(vpiTimeUnit, mod);
+
+      prec  = vpi_get(vpiTimePrecision, 0);
+      scale = 1;
+      while (units > prec) {
+	    scale *= 10;
+	    units -= 1;
+      }
+
       val.format = vpiIntVal;
       val.value.integer = now.low;
       assert(now.high == 0);
 
+      val.value.integer /= scale;
+
       vpi_put_value(call_handle, &val, 0, vpiNoDelay);
 
       return 0;
@@ -64,6 +98,7 @@ void sys_time_register()
       tf_data.calltf    = sys_time_calltf;
       tf_data.compiletf = 0;
       tf_data.sizetf    = sys_time_sizetf;
+      tf_data.user_data = "$time";
       vpi_register_systf(&tf_data);
 
       tf_data.type      = vpiSysFunc;
@@ -71,11 +106,27 @@ void sys_time_register()
       tf_data.calltf    = sys_time_calltf;
       tf_data.compiletf = 0;
       tf_data.sizetf    = sys_stime_sizetf;
+      tf_data.user_data = "$stime";
+      vpi_register_systf(&tf_data);
+
+      tf_data.type      = vpiSysFunc;
+      tf_data.tfname    = "$simtime";
+      tf_data.calltf    = sys_time_calltf;
+      tf_data.compiletf = 0;
+      tf_data.sizetf    = sys_time_sizetf;
+      tf_data.user_data = "$simtime";
       vpi_register_systf(&tf_data);
 }
 
 /*
  * $Log: sys_time.c,v $
+ * Revision 1.5  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.4  2002/08/12 01:35:05  steve
  *  conditional ident string using autoconfig.
  *
diff --git a/vpi/sys_vcd.c b/vpi/sys_vcd.c
index 98a437039..179d93713 100644
--- a/vpi/sys_vcd.c
+++ b/vpi/sys_vcd.c
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: sys_vcd.c,v 1.39 2002/11/17 22:28:42 steve Exp $"
+#ident "$Id: sys_vcd.c,v 1.40 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 # include "config.h"
@@ -315,6 +315,7 @@ static int sys_dumpoff_calltf(char*name)
       if (dump_header_pending())
 	    return 0;
 
+      now.type = vpiSimTime;
       vpi_get_time(0, &now);
       if (now.low > vcd_cur_time)
 	    fprintf(dump_file, "#%u\n", now.low);
@@ -342,6 +343,7 @@ static int sys_dumpon_calltf(char*name)
       if (dump_header_pending())
 	    return 0;
 
+      now.type = vpiSimTime;
       vpi_get_time(0, &now);
       if (now.low > vcd_cur_time)
 	    fprintf(dump_file, "#%u\n", now.low);
@@ -364,6 +366,7 @@ static int sys_dumpall_calltf(char*name)
       if (dump_header_pending())
 	    return 0;
 
+      now.type = vpiSimTime;
       vpi_get_time(0, &now);
       if (now.low > vcd_cur_time)
 	    fprintf(dump_file, "#%u\n", now.low);
@@ -849,6 +852,13 @@ void sys_vcd_register()
 
 /*
  * $Log: sys_vcd.c,v $
+ * Revision 1.40  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.39  2002/11/17 22:28:42  steve
  *  Close old file if $dumpfile is called again.
  *
diff --git a/vvp/compile.cc b/vvp/compile.cc
index 14f51231e..21c1a62e4 100644
--- a/vvp/compile.cc
+++ b/vvp/compile.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: compile.cc,v 1.146 2002/11/21 22:43:13 steve Exp $"
+#ident "$Id: compile.cc,v 1.147 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 # include  "arith.h"
@@ -418,6 +418,18 @@ bool vpi_handle_resolv_list_s::resolve(bool mes)
 
 void compile_vpi_lookup(vpiHandle *handle, char*label)
 {
+      if (strcmp(label, "$time") == 0) {
+	    *handle = vpip_sim_time(vpip_peek_current_scope());
+	    free(label);
+	    return;
+      }
+
+      if (strcmp(label, "$stime") == 0) {
+	    *handle = vpip_sim_time(vpip_peek_current_scope());
+	    free(label);
+	    return;
+      }
+
       struct vpi_handle_resolv_list_s*res
 	    = new struct vpi_handle_resolv_list_s;
 
@@ -576,8 +588,6 @@ void compile_vpi_symbol(const char*label, vpiHandle obj)
 void compile_init(void)
 {
       sym_vpi = new_symbol_table();
-      compile_vpi_symbol("$time",  vpip_sim_time());
-      compile_vpi_symbol("$stime", vpip_sim_time());
 
       sym_functors = new_symbol_table();
       functor_init();
@@ -1483,6 +1493,13 @@ void compile_net(char*label, char*name, int msb, int lsb, bool signed_flag,
 
 /*
  * $Log: compile.cc,v $
+ * Revision 1.147  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.146  2002/11/21 22:43:13  steve
  *  %set/x0 instruction to support bounds checking.
  *
diff --git a/vvp/compile.h b/vvp/compile.h
index a9aaf7368..4d45dc2b6 100644
--- a/vvp/compile.h
+++ b/vvp/compile.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: compile.h,v 1.45 2002/08/12 01:35:07 steve Exp $"
+#ident "$Id: compile.h,v 1.46 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 # include  <stdio.h>
@@ -116,6 +116,7 @@ extern void compile_shiftl(char*label, long width,
 extern void compile_shiftr(char*label, long width,
 			   unsigned argc, struct symb_s*argv);
 
+extern void compile_timescale(long units);
 
 extern void compile_vpi_symbol(const char*label, vpiHandle obj);
 extern void compile_vpi_lookup(vpiHandle *objref, char*label);
@@ -251,6 +252,13 @@ extern void compile_net(char*label, char*name,
 
 /*
  * $Log: compile.h,v $
+ * Revision 1.46  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.45  2002/08/12 01:35:07  steve
  *  conditional ident string using autoconfig.
  *
diff --git a/vvp/lexor.lex b/vvp/lexor.lex
index 862fc4ab5..292e7f9f7 100644
--- a/vvp/lexor.lex
+++ b/vvp/lexor.lex
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: lexor.lex,v 1.34 2002/06/21 04:58:55 steve Exp $"
+#ident "$Id: lexor.lex,v 1.35 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 # include  "parse_misc.h"
@@ -100,6 +100,7 @@
 ".shift/l"  { return K_SHIFTL; }
 ".shift/r"  { return K_SHIFTR; }
 ".thread"   { return K_THREAD; }
+".timescale" { return K_TIMESCALE; }
 ".ufunc"    { return K_UFUNC; }
 ".var"      { return K_VAR; }
 ".var/s"    { return K_VAR_S; }
@@ -173,6 +174,13 @@ int yywrap()
 
 /*
  * $Log: lexor.lex,v $
+ * Revision 1.35  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.34  2002/06/21 04:58:55  steve
  *  Add support for special integer vectors.
  *
diff --git a/vvp/parse.y b/vvp/parse.y
index 6f830f1c1..cb1b6d57c 100644
--- a/vvp/parse.y
+++ b/vvp/parse.y
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: parse.y,v 1.47 2002/06/21 04:58:55 steve Exp $"
+#ident "$Id: parse.y,v 1.48 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 # include  "parse_misc.h"
@@ -60,7 +60,7 @@ extern FILE*yyin;
 %token K_ARITH_DIV K_ARITH_MOD K_ARITH_MULT K_ARITH_SUB K_ARITH_SUM
 %token K_CMP_GE K_CMP_GT
 %token K_EVENT K_EVENT_OR K_FUNCTOR K_NET K_NET_S
-%token K_RESOLV K_SCOPE K_SHIFTL K_SHIFTR K_THREAD K_UFUNC
+%token K_RESOLV K_SCOPE K_SHIFTL K_SHIFTR K_THREAD K_TIMESCALE K_UFUNC
 %token K_UDP K_UDP_C K_UDP_S
 %token K_MEM K_MEM_P K_MEM_I
 %token K_FORCE 
@@ -295,6 +295,12 @@ statement
 	|         K_SCOPE T_SYMBOL ';'
 		{ compile_scope_recall($2); }
 
+
+	|         K_TIMESCALE T_NUMBER ';'
+		{ compile_timescale($2); }
+	|         K_TIMESCALE '-' T_NUMBER ';'
+		{ compile_timescale(-$3); }
+
   /* Thread statements declare a thread with its starting address. The
      starting address must already be defined. */
 
@@ -553,6 +559,13 @@ int compile_design(const char*path)
 
 /*
  * $Log: parse.y,v $
+ * Revision 1.48  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.47  2002/06/21 04:58:55  steve
  *  Add support for special integer vectors.
  *
diff --git a/vvp/vpi.txt b/vvp/vpi.txt
index d754bfa30..ba8cb3b8b 100644
--- a/vvp/vpi.txt
+++ b/vvp/vpi.txt
@@ -1,7 +1,7 @@
 /*
  * Copyright (c) 2001 Stephen Williams (steve@icarus.com)
  *
- *  $Id: vpi.txt,v 1.5 2001/03/20 06:16:24 steve Exp $
+ *  $Id: vpi.txt,v 1.6 2002/12/21 00:55:58 steve Exp $
  */
 
 
@@ -103,6 +103,7 @@ placed.
 A scope is created with a .scope directive, like so:
 
 	<label> .scope "name" [, <parent>];
+		.timescale <units>;
 
 The scope takes a string name as the first parameter. If there is an
 additional parameter, it is a label of the directive for the parent
@@ -114,6 +115,10 @@ scope. The vvp automatically constructs full names from the scope
 hierarchy, and runtime VPI code can access that full name with the
 vpiFullname reference.
 
+The .timescale directive changes the scope units from the simulation
+precision to the specified precision. The .timescale directive affects
+the current scope.
+
 Objects that place themselves in a scope place themselves in the
 current scope. The current scope is the one that was last mentioned by
 a .scope directive. If the wrong scope is current, the label on a
diff --git a/vvp/vpi_priv.cc b/vvp/vpi_priv.cc
index c8e126d56..3ec6dd246 100644
--- a/vvp/vpi_priv.cc
+++ b/vvp/vpi_priv.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: vpi_priv.cc,v 1.25 2002/12/11 23:55:22 steve Exp $"
+#ident "$Id: vpi_priv.cc,v 1.26 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 # include  "vpi_priv.h"
@@ -150,8 +150,8 @@ void vpi_get_time(vpiHandle obj, s_vpi_time*vp)
 {
       assert(vp);
 
-	// XXXX Cheat. Ignore timescale for the scope.
-      vp->type = vpiSimTime;
+	// Only vpiSimTime is supported, for now.
+      assert(vp->type == vpiSimTime);
       vp->high = 0;
       vp->low = schedule_simtime();
 }
@@ -369,6 +369,13 @@ extern "C" void vpi_sim_vcontrol(int operation, va_list ap)
 
 /*
  * $Log: vpi_priv.cc,v $
+ * Revision 1.26  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.25  2002/12/11 23:55:22  steve
  *  Add vpi_handle_by_name to the VPI interface,
  *  and bump the vpithunk magic number.
diff --git a/vvp/vpi_priv.h b/vvp/vpi_priv.h
index 856f91449..d06b1acfc 100644
--- a/vvp/vpi_priv.h
+++ b/vvp/vpi_priv.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: vpi_priv.h,v 1.40 2002/08/12 01:35:09 steve Exp $"
+#ident "$Id: vpi_priv.h,v 1.41 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 # include  "vpi_user.h"
@@ -128,19 +128,29 @@ struct __vpiCallback {
 extern struct __vpiCallback* new_vpi_callback();
 extern void callback_execute(struct __vpiCallback*cur);
 
+struct __vpiSystemTime {
+      struct __vpiHandle base;
+      struct __vpiScope *scope;
+};
+
 /*
- * Scopes are created by .scope statements in the source.
+ * Scopes are created by .scope statements in the source. These
+ * objects hold the items and properties that are knowably bound to a
+ * scope.
  */
 struct __vpiScope {
       struct __vpiHandle base;
       struct __vpiScope *scope;
 	/* The scope has a name. */
       const char*name;
-      /* Keep an array of internal scope items. */
+	/* The scope has a system time of its own. */
+      struct __vpiSystemTime scoped_time;
+	/* Keep an array of internal scope items. */
       struct __vpiHandle**intern;
       unsigned nintern;
 	/* Keep a list of threads in the scope. */
       vthread_t threads;
+      signed int time_units :8;
 };
 
 extern struct __vpiScope* vpip_peek_current_scope(void);
@@ -317,7 +327,7 @@ extern void vpip_execute_vpi_call(vthread_t thr, vpiHandle obj);
  * and to finish compilation in preparation for execution.
  */
 
-vpiHandle vpip_sim_time(void);
+vpiHandle vpip_sim_time(struct __vpiScope*scope);
 
 extern int vpip_get_time_precision(void);
 extern void vpip_set_time_precision(int pres);
@@ -374,6 +384,13 @@ extern char *need_result_buf(unsigned cnt, vpi_rbuf_t type);
 
 /*
  * $Log: vpi_priv.h,v $
+ * Revision 1.41  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.40  2002/08/12 01:35:09  steve
  *  conditional ident string using autoconfig.
  *
diff --git a/vvp/vpi_scope.cc b/vvp/vpi_scope.cc
index 6ab791733..eea689623 100644
--- a/vvp/vpi_scope.cc
+++ b/vvp/vpi_scope.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: vpi_scope.cc,v 1.21 2002/11/15 22:14:12 steve Exp $"
+#ident "$Id: vpi_scope.cc,v 1.22 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 # include  "compile.h"
@@ -43,17 +43,36 @@ vpiHandle vpip_make_root_iterator(void)
 				vpip_root_table_ptr, false);
 }
 
+static bool handle_is_scope(vpiHandle obj)
+{
+      return (obj->vpi_type->type_code == vpiModule)
+	    || (obj->vpi_type->type_code == vpiFunction)
+	    || (obj->vpi_type->type_code == vpiTask)
+	    || (obj->vpi_type->type_code == vpiNamedBegin)
+	    || (obj->vpi_type->type_code == vpiNamedFork);
+}
+
+static int scope_get(int code, vpiHandle obj)
+{
+      struct __vpiScope*ref = (struct __vpiScope*)obj;
+
+      assert(handle_is_scope(obj));
+
+      switch (code) {
+	  case vpiTimeUnit:
+	    return ref->time_units;
+      }
+
+      return 0;
+}
+
 static char* scope_get_str(int code, vpiHandle obj)
 {
       struct __vpiScope*ref = (struct __vpiScope*)obj;
       const char *n, *nn, *name = ref->name;
       char *rbuf = need_result_buf(strlen(name) + 1, RBUF_STR);
 
-      assert((obj->vpi_type->type_code == vpiModule)
-	     || (obj->vpi_type->type_code == vpiFunction)
-	     || (obj->vpi_type->type_code == vpiTask)
-	     || (obj->vpi_type->type_code == vpiNamedBegin)
-	     || (obj->vpi_type->type_code == vpiNamedFork));
+      assert(handle_is_scope(obj));
 
       switch (code) {
 	  case vpiFullName:
@@ -254,7 +273,7 @@ vpiHandle ipoint_get_scope(vvp_ipoint_t ipt)
 
 static const struct __vpirt vpip_scope_module_rt = {
       vpiModule,
-      0,
+      scope_get,
       scope_get_str,
       0,
       0,
@@ -302,6 +321,11 @@ static const struct __vpirt vpip_scope_fork_rt = {
       module_iter
 };
 
+/*
+ * The current_scope is a compile time concept. As the vvp source is
+ * compiled, items that have scope are placed in the current
+ * scope. The ".scope" directives select the scope that is current.
+ */
 static struct __vpiScope*current_scope = 0;
 
 static void attach_to_scope_(struct __vpiScope*scope, vpiHandle obj)
@@ -373,6 +397,10 @@ void compile_scope_decl(char*label, char*type, char*name, char*parent)
 	    struct __vpiScope*sp = (struct __vpiScope*) obj;
 	    attach_to_scope_(sp, &scope->base);
 	    scope->scope = (struct __vpiScope*)obj;
+
+	      /* Inherit time units from the parent scope. */
+	    scope->time_units = sp->time_units;
+
       } else {
 	    scope->scope = 0x0;
 
@@ -381,6 +409,9 @@ void compile_scope_decl(char*label, char*type, char*name, char*parent)
 		  realloc(vpip_root_table_ptr, cnt * sizeof(vpiHandle));
 	    vpip_root_table_ptr[vpip_root_table_cnt] = &scope->base;
 	    vpip_root_table_cnt = cnt;
+
+	      /* Root scopes inherit time_units from system precision. */
+	    scope->time_units = vpip_get_time_precision();
       }
 
       functor_set_scope(&current_scope->base);
@@ -393,6 +424,16 @@ void compile_scope_recall(char*symbol)
       functor_set_scope(&current_scope->base);
 }
 
+/*
+ * This function handles the ".timescale" directive in the vvp
+ * source. It sets in the current scope the specified units value.
+ */
+void compile_timescale(long units)
+{
+      assert(current_scope);
+      current_scope->time_units = units;
+}
+
 struct __vpiScope* vpip_peek_current_scope(void)
 {
       return current_scope;
@@ -406,6 +447,13 @@ void vpip_attach_to_current_scope(vpiHandle obj)
 
 /*
  * $Log: vpi_scope.cc,v $
+ * Revision 1.22  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.21  2002/11/15 22:14:12  steve
  *  Add vpiScope iterate on vpiScope objects.
  *
diff --git a/vvp/vpi_tasks.cc b/vvp/vpi_tasks.cc
index e7a130d47..f88652bec 100644
--- a/vvp/vpi_tasks.cc
+++ b/vvp/vpi_tasks.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: vpi_tasks.cc,v 1.16 2002/08/12 01:35:09 steve Exp $"
+#ident "$Id: vpi_tasks.cc,v 1.17 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 /*
@@ -176,7 +176,7 @@ static const struct __vpirt vpip_sysfunc_rt = {
       0,
       0,
       sysfunc_put_value,
-      0,
+      systask_handle,
       systask_iter
 };
 
@@ -344,6 +344,13 @@ void vpi_register_systf(const struct t_vpi_systf_data*ss)
 
 /*
  * $Log: vpi_tasks.cc,v $
+ * Revision 1.17  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.16  2002/08/12 01:35:09  steve
  *  conditional ident string using autoconfig.
  *
diff --git a/vvp/vpi_time.cc b/vvp/vpi_time.cc
index fe68f467c..9f9834f85 100644
--- a/vvp/vpi_time.cc
+++ b/vvp/vpi_time.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2001-2002 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: vpi_time.cc,v 1.8 2002/08/12 01:35:09 steve Exp $"
+#ident "$Id: vpi_time.cc,v 1.9 2002/12/21 00:55:58 steve Exp $"
 #endif
 
 # include  "vpi_priv.h"
@@ -25,7 +25,17 @@
 # include  <stdio.h>
 # include  <assert.h>
 
+/*
+ * The $time system function is supported in VPI contexts (i.e. an
+ * argument to a system task/function) as a magical time variable. The
+ * VPI sees it as a vpiTimeVar object, but reads from it get the
+ * current value instead of some assigned value.
+ */
 
+/*
+ * vpi_time_precision is the precision of the simulation clock. It is
+ * set by the :vpi_time_precision directive in the vvp source file.
+ */
 static int vpi_time_precision = 0;
 
 void vpip_time_to_timestruct(struct t_vpi_time*ts, vvp_time64_t ti)
@@ -42,10 +52,6 @@ vvp_time64_t vpip_timestruct_to_time(const struct t_vpi_time*ts)
       return ti;
 }
 
-static struct __vpiSystemTime {
-      struct __vpiHandle base;
-      struct t_vpi_time value;
-} time_handle;
 
 static int timevar_get(int code, vpiHandle ref)
 {
@@ -66,20 +72,31 @@ static int timevar_get(int code, vpiHandle ref)
 static void timevar_get_value(vpiHandle ref, s_vpi_value*vp)
 {
       static char buf_obj[128];
-      assert(ref == &time_handle.base);
+
+	/* Keep a persistent structure for passing time values back to
+	   the caller. */
+      static struct t_vpi_time time_value;
+
+      struct __vpiSystemTime*rfp = reinterpret_cast<struct __vpiSystemTime*>(ref);
       unsigned long x, num_bits;
+      vvp_time64_t simtime = schedule_simtime();
+      int units = rfp->scope->time_units;
+      while (units > vpi_time_precision) {
+	    simtime /= 10;
+	    units -= 1;
+      }
 
       switch (vp->format) {
 	  case vpiObjTypeVal:
 	  case vpiTimeVal:
-	    vp->value.time = &time_handle.value;
+	    vp->value.time = &time_value;
 	    vp->value.time->type = vpiSimTime;
-	    vpip_time_to_timestruct(vp->value.time, schedule_simtime());
+	    vpip_time_to_timestruct(vp->value.time, simtime);
 	    vp->format = vpiTimeVal;
 	    break;
 
 	  case vpiBinStrVal:
-	    x = schedule_simtime();
+	    x = simtime;
 	    num_bits = 8 * sizeof(unsigned long);
 
 	    buf_obj[num_bits] = 0;
@@ -92,17 +109,17 @@ static void timevar_get_value(vpiHandle ref, s_vpi_value*vp)
 	    break;
 
 	  case vpiDecStrVal:
-	    sprintf(buf_obj, "%lu", schedule_simtime());
+	    sprintf(buf_obj, "%lu", simtime);
 	    vp->value.str = buf_obj;
 	    break;
 
 	  case vpiOctStrVal:
-	    sprintf(buf_obj, "%lo", schedule_simtime());
+	    sprintf(buf_obj, "%lo", simtime);
 	    vp->value.str = buf_obj;
 	    break;
 
 	  case vpiHexStrVal:
-	    sprintf(buf_obj, "%lx", schedule_simtime());
+	    sprintf(buf_obj, "%lx", simtime);
 	    vp->value.str = buf_obj;
 	    break;
 
@@ -123,10 +140,11 @@ static const struct __vpirt vpip_system_time_rt = {
 };
 
 
-vpiHandle vpip_sim_time(void)
+vpiHandle vpip_sim_time(struct __vpiScope*scope)
 {
-      time_handle.base.vpi_type = &vpip_system_time_rt;
-      return &time_handle.base;
+      scope->scoped_time.base.vpi_type = &vpip_system_time_rt;
+      scope->scoped_time.scope = scope;
+      return &scope->scoped_time.base;
 }
 
 int vpip_get_time_precision(void)
@@ -142,6 +160,13 @@ void vpip_set_time_precision(int pre)
 
 /*
  * $Log: vpi_time.cc,v $
+ * Revision 1.9  2002/12/21 00:55:58  steve
+ *  The $time system task returns the integer time
+ *  scaled to the local units. Change the internal
+ *  implementation of vpiSystemTime the $time functions
+ *  to properly account for this. Also add $simtime
+ *  to get the simulation time.
+ *
  * Revision 1.8  2002/08/12 01:35:09  steve
  *  conditional ident string using autoconfig.
  *