diff --git a/parse.y b/parse.y
index cc1e8118d..298e824b6 100644
--- a/parse.y
+++ b/parse.y
@@ -171,6 +171,21 @@ static PECallFunction*make_call_function(perm_string tn, PExpr*arg1, PExpr*arg2)
       return tmp;
 }
 
+static named_number_t* make_named_number(perm_string name)
+{
+      named_number_t*res = new named_number_t;
+      res->name = name;
+      return res;
+}
+
+static named_number_t* make_named_number(perm_string name, const verinum&val)
+{
+      named_number_t*res = new named_number_t;
+      res->name = name;
+      res->parm = val;
+      return res;
+}
+
 %}
 
 %union {
@@ -206,6 +221,9 @@ static PECallFunction*make_call_function(perm_string tn, PExpr*arg1, PExpr*arg2)
       LexicalScope::range_t* value_range;
       vector<Module::port_t*>*mports;
 
+      named_number_t* named_number;
+      list<named_number_t>* named_numbers;
+
       named_pexpr_t*named_pexpr;
       svector<named_pexpr_t*>*named_pexprs;
       struct parmvalue_t*parmvalue;
@@ -230,6 +248,7 @@ static PECallFunction*make_call_function(perm_string tn, PExpr*arg1, PExpr*arg2)
       PTaskFuncArg function_type;
 
       net_decl_assign_t*net_decl_assign;
+      enum_type_t*enum_type;
 
       verinum* number;
 
@@ -357,6 +376,10 @@ static PECallFunction*make_call_function(perm_string tn, PExpr*arg1, PExpr*arg2)
 %type <value_range> parameter_value_ranges_opt
 %type <expr> value_range_expression
 
+%type <named_number> enum_name
+%type <named_numbers> enum_name_list
+%type <enum_type> enum_data_type
+
 %type <wires> task_item task_item_list task_item_list_opt
 %type <wires> task_port_item task_port_decl task_port_decl_list
 %type <wires> function_item function_item_list
@@ -549,6 +572,13 @@ block_item_decl
        if ($1) delete $1;
      }
 
+  /* Enum data types are possible here. */
+
+  | attribute_list_opt enum_data_type register_variable_list ';'
+      { pform_set_enum(@2, $2, $3);
+	if ($1) delete $1;
+      }
+
   /* real declarations are fairly simple as there is no range of
      signed flag in the declaration. Create the real as a NetNet::REG
      with real value. Note that real and realtime are interchangeable
@@ -611,6 +641,67 @@ block_item_decls_opt
 	|
 	;
 
+  /* The structure for an enumeration data type is the keyword "enum",
+     followed by the enumeration values in curly braces. Also allow
+     for an optional base type. The default base type is "int", but it
+     can be any of the integral or vector types. */
+
+enum_data_type
+  : K_enum '{' enum_name_list '}'
+      { enum_type_t*enum_type = new enum_type_t;
+	enum_type->names .reset($3);
+	enum_type->base_type = IVL_VT_BOOL;
+	enum_type->signed_flag = true;
+	enum_type->range.reset( make_range_from_width(32) );
+	$$ = enum_type;
+      }
+  | K_enum atom2_type signed_unsigned_opt '{' enum_name_list '}'
+      { enum_type_t*enum_type = new enum_type_t;
+	enum_type->names .reset($5);
+	enum_type->base_type = IVL_VT_BOOL;
+	enum_type->signed_flag = $3;
+	enum_type->range.reset( make_range_from_width($2) );
+	$$ = enum_type;
+      }
+  | K_enum K_integer signed_unsigned_opt '{' enum_name_list '}'
+      { enum_type_t*enum_type = new enum_type_t;
+	enum_type->names .reset($5);
+	enum_type->base_type = IVL_VT_LOGIC;
+	enum_type->signed_flag = $3;
+	enum_type->range.reset( make_range_from_width(integer_width) );
+	$$ = enum_type;
+      }
+  ;
+
+enum_name_list
+  : enum_name
+      { list<named_number_t>*lst = new list<named_number_t>;
+	lst->push_back(*$1);
+	delete $1;
+	$$ = lst;
+      }
+  | enum_name_list ',' enum_name
+      { list<named_number_t>*lst = $1;
+	lst->push_back(*$3);
+	delete $3;
+	$$ = lst;
+      }
+  ;
+
+enum_name
+  : IDENTIFIER
+      { perm_string name = lex_strings.make($1);
+	delete[]$1;
+	$$ = make_named_number(name);
+      }
+  | IDENTIFIER '=' number
+      { perm_string name = lex_strings.make($1);
+	delete[]$1;
+	$$ = make_named_number(name, *$3);
+	delete $3;
+      }
+  ;
+
 case_item
 	: expression_list_proper ':' statement_or_null
 		{ PCase::Item*tmp = new PCase::Item;
diff --git a/pform.cc b/pform.cc
index 6591622e6..010e8d260 100644
--- a/pform.cc
+++ b/pform.cc
@@ -2463,6 +2463,15 @@ void pform_set_integer_2atom(uint64_t width, bool signed_flag, list<perm_string>
       delete names;
 }
 
+void pform_set_enum(const struct vlltype&li, enum_type_t*enum_type, list<perm_string>*names)
+{
+      cerr << li.text << ":" << li.first_line << ": "
+	   << "sorry: enum types not supported yet." << endl;
+      error_count += 1;
+      delete enum_type;
+      delete names;
+}
+
 svector<PWire*>* pform_make_udp_input_ports(list<perm_string>*names)
 {
       svector<PWire*>*out = new svector<PWire*>(names->size());
diff --git a/pform.h b/pform.h
index fa5debc72..9cce000a5 100644
--- a/pform.h
+++ b/pform.h
@@ -35,6 +35,7 @@
 # include  <iostream>
 # include  <string>
 # include  <list>
+# include  <memory>
 # include  <cstdio>
 
 /*
@@ -83,9 +84,10 @@ extern bool pform_library_flag;
 /* This is information about port name information for named port
    connections. */
 
-//typedef struct named<PExpr*> named_pexpr_t;
 typedef named<PExpr*> named_pexpr_t;
 
+typedef named<verinum> named_number_t;
+
 struct parmvalue_t {
       svector<PExpr*>*by_order;
       svector<named_pexpr_t*>*by_name;
@@ -93,12 +95,20 @@ struct parmvalue_t {
 
 struct str_pair_t { ivl_drive_t str0, str1; };
 
+
 struct net_decl_assign_t {
       perm_string name;
       PExpr*expr;
       struct net_decl_assign_t*next;
 };
 
+struct enum_type_t {
+      ivl_variable_type_t base_type;
+      bool signed_flag;
+      auto_ptr< svector<PExpr*> > range;
+      auto_ptr< list<named_number_t> > names;
+};
+
 /* The lgate is gate instantiation information. */
 struct lgate {
       lgate(int =0)
@@ -277,6 +287,8 @@ extern void pform_set_reg_time(list<perm_string>*names);
 
 extern void pform_set_integer_2atom(uint64_t width, bool signed_flag, list<perm_string>*names);
 
+extern void pform_set_enum(const struct vlltype&li, enum_type_t*enum_type, list<perm_string>*names);
+
   /* pform_set_attrib and pform_set_type_attrib exist to support the
      $attribute syntax, which can only set string values to
      attributes. The functions keep the value strings that are