diff --git a/src/main/java/de/neemann/digital/draw/library/ElementTypeDescriptionCustom.java b/src/main/java/de/neemann/digital/draw/library/ElementTypeDescriptionCustom.java
index 786ea641b..bdd251c33 100644
--- a/src/main/java/de/neemann/digital/draw/library/ElementTypeDescriptionCustom.java
+++ b/src/main/java/de/neemann/digital/draw/library/ElementTypeDescriptionCustom.java
@@ -18,11 +18,15 @@ import de.neemann.digital.draw.model.ModelCreator;
 import de.neemann.digital.draw.model.NetList;
 import de.neemann.digital.hdl.hgs.*;
 import de.neemann.digital.hdl.hgs.function.Function;
+import de.neemann.digital.hdl.hgs.refs.Reference;
+import de.neemann.digital.hdl.hgs.refs.ReferenceToStruct;
+import de.neemann.digital.hdl.hgs.refs.ReferenceToVar;
 import de.neemann.digital.lang.Lang;
 
 import java.io.File;
 import java.io.IOException;
 import java.util.HashMap;
+import java.util.TreeSet;
 
 /**
  * The description of a nested element.
@@ -36,6 +40,7 @@ public final class ElementTypeDescriptionCustom extends ElementTypeDescription {
     private String description;
     private NetList netList;
     private boolean isCustom = true;
+    private String declarationDefault;
 
     /**
      * Creates a new element
@@ -53,7 +58,7 @@ public final class ElementTypeDescriptionCustom extends ElementTypeDescription {
         addAttribute(Keys.ROTATE);
         addAttribute(Keys.LABEL);
         addAttribute(Keys.SHAPE_TYPE);
-        if (circuit.getAttributes().get(Keys.IS_GENERIC))
+        if (isGeneric())
             addAttribute(Keys.GENERIC);
     }
 
@@ -118,7 +123,7 @@ public final class ElementTypeDescriptionCustom extends ElementTypeDescription {
         if (depth > MAX_DEPTH)
             throw new NodeException(Lang.get("err_recursiveNestingAt_N0", circuit.getOrigin()));
 
-        if (circuit.getAttributes().get(Keys.IS_GENERIC)) {
+        if (isGeneric()) {
             try {
                 Context args;
                 if (containingVisualElement != null) {
@@ -201,4 +206,51 @@ public final class ElementTypeDescriptionCustom extends ElementTypeDescription {
         isCustom = false;
         return this;
     }
+
+    /**
+     * @return the generics field default value
+     */
+    public String getDeclarationDefault() {
+        if (declarationDefault == null)
+            declarationDefault = createDeclarationDefault();
+        return declarationDefault;
+    }
+
+    private String createDeclarationDefault() {
+        TreeSet<String> nameSet = new TreeSet<>();
+        for (VisualElement ve : circuit.getElements()) {
+            String gen = ve.getElementAttributes().get(Keys.GENERIC).trim();
+            try {
+                if (!gen.isEmpty()) {
+                    Parser p = new Parser(gen);
+                    p.enableRefReadCollection();
+                    p.parse(false);
+                    for (Reference r : p.getRefsRead()) {
+                        if (r instanceof ReferenceToStruct) {
+                            ReferenceToStruct st = (ReferenceToStruct) r;
+                            if (st.getParent() instanceof ReferenceToVar) {
+                                ReferenceToVar var = (ReferenceToVar) st.getParent();
+                                if (var.getName().equals("args")) {
+                                    nameSet.add(st.getName());
+                                }
+                            }
+                        }
+                    }
+                }
+            } catch (ParserException | IOException e) {
+                return "";
+            }
+        }
+        StringBuilder sb = new StringBuilder();
+        for (String name : nameSet)
+            sb.append(name).append(" := ;\n");
+        return sb.toString();
+    }
+
+    /**
+     * @return true if the circuit is generic
+     */
+    public boolean isGeneric() {
+        return circuit.getAttributes().get(Keys.IS_GENERIC);
+    }
 }
diff --git a/src/main/java/de/neemann/digital/gui/components/CircuitComponent.java b/src/main/java/de/neemann/digital/gui/components/CircuitComponent.java
index b74fa95e8..2f3bc8a24 100644
--- a/src/main/java/de/neemann/digital/gui/components/CircuitComponent.java
+++ b/src/main/java/de/neemann/digital/gui/components/CircuitComponent.java
@@ -1023,10 +1023,19 @@ public class CircuitComponent extends JComponent implements ChangedListener, Lib
         try {
             ArrayList<Key> list = getAttributeList(element);
             if (list.size() > 0) {
+                ElementTypeDescription elementType = library.getElementType(element.getElementName());
+
+                if (elementType instanceof ElementTypeDescriptionCustom) {
+                    ElementTypeDescriptionCustom customDescr = (ElementTypeDescriptionCustom) elementType;
+                    if (customDescr.isGeneric()) {
+                        if (element.getElementAttributes().get(Keys.GENERIC).isEmpty())
+                            element.getElementAttributes().set(Keys.GENERIC, customDescr.getDeclarationDefault());
+                    }
+                }
+
                 Point p = new Point(e.getX(), e.getY());
                 SwingUtilities.convertPointToScreen(p, CircuitComponent.this);
                 AttributeDialog attributeDialog = new AttributeDialog(parent, p, list, element.getElementAttributes()).setVisualElement(element);
-                ElementTypeDescription elementType = library.getElementType(element.getElementName());
                 if (elementType instanceof ElementTypeDescriptionCustom) {
                     attributeDialog.addButton(Lang.get("attr_openCircuitLabel"), new ToolTipAction(Lang.get("attr_openCircuit")) {
                         @Override
diff --git a/src/main/java/de/neemann/digital/hdl/hgs/Parser.java b/src/main/java/de/neemann/digital/hdl/hgs/Parser.java
index 5c62c3599..03bac503d 100644
--- a/src/main/java/de/neemann/digital/hdl/hgs/Parser.java
+++ b/src/main/java/de/neemann/digital/hdl/hgs/Parser.java
@@ -5,6 +5,7 @@
  */
 package de.neemann.digital.hdl.hgs;
 
+import de.neemann.digital.builder.tt2.TT2Exporter;
 import de.neemann.digital.core.Bits;
 import de.neemann.digital.hdl.hgs.function.FirstClassFunction;
 import de.neemann.digital.hdl.hgs.function.FirstClassFunctionCall;
@@ -55,6 +56,7 @@ public class Parser {
     }
 
 
+    private ArrayList<Reference> refRead;
     private final Tokenizer tok;
     private Context staticContext;
 
@@ -78,6 +80,20 @@ public class Parser {
         staticContext = new Context();
     }
 
+    /**
+     * If called all read references are collected.
+     */
+    public void enableRefReadCollection() {
+        refRead = new ArrayList<>();
+    }
+
+    /**
+     * @return returns the references read
+     */
+    public ArrayList<Reference> getRefsRead() {
+        return refRead;
+    }
+
     private Statement lino(Statement statement) {
         if (statement instanceof StatementWithLine)
             return statement;
@@ -517,6 +533,8 @@ public class Parser {
             case IDENT:
                 String name = tok.getIdent();
                 Reference r = parseReference(name);
+                if (refRead != null)
+                    refRead.add(r);
                 return r::get;
             case NUMBER:
                 long num = convToLong(tok.getIdent());
diff --git a/src/main/java/de/neemann/digital/hdl/hgs/refs/ReferenceToStruct.java b/src/main/java/de/neemann/digital/hdl/hgs/refs/ReferenceToStruct.java
index cedf2935d..17c101bd5 100644
--- a/src/main/java/de/neemann/digital/hdl/hgs/refs/ReferenceToStruct.java
+++ b/src/main/java/de/neemann/digital/hdl/hgs/refs/ReferenceToStruct.java
@@ -53,4 +53,17 @@ public class ReferenceToStruct implements Reference {
         return value;
     }
 
+    /**
+     * @return  the parent reference
+     */
+    public Reference getParent() {
+        return parent;
+    }
+
+    /**
+     * @return the struct field name
+     */
+    public String getName() {
+        return name;
+    }
 }
diff --git a/src/main/java/de/neemann/digital/hdl/hgs/refs/ReferenceToVar.java b/src/main/java/de/neemann/digital/hdl/hgs/refs/ReferenceToVar.java
index a8e45926e..8ba8f4ffd 100644
--- a/src/main/java/de/neemann/digital/hdl/hgs/refs/ReferenceToVar.java
+++ b/src/main/java/de/neemann/digital/hdl/hgs/refs/ReferenceToVar.java
@@ -42,4 +42,11 @@ public class ReferenceToVar implements Reference {
     public Object get(Context context) throws HGSEvalException {
         return context.getVar(name);
     }
+
+    /**
+     * @return the var name
+     */
+    public String getName() {
+        return name;
+    }
 }
diff --git a/src/test/resources/dig/test/generics/mainMem.dig b/src/test/resources/dig/test/generics/mainMem.dig
index 4494fc432..107545923 100644
--- a/src/test/resources/dig/test/generics/mainMem.dig
+++ b/src/test/resources/dig/test/generics/mainMem.dig
@@ -15,7 +15,7 @@
           <int>16</int>
         </entry>
       </elementAttributes>
-      <pos x="460" y="260"/>
+      <pos x="460" y="240"/>
     </visualElement>
     <visualElement>
       <elementName>In</elementName>
@@ -80,8 +80,11 @@ end loop
 
 # read data
 loop(n,1&lt;&lt;8)
-C   0   (n)  0   (n+2)
-end loop</dataString>
+0   0   (n)  0   (n+2)
+end loop
+
+0   0   (1&lt;&lt;8)  0   (2)
+</dataString>
           </testData>
         </entry>
       </elementAttributes>
@@ -92,8 +95,8 @@ end loop</dataString>
       <elementAttributes>
         <entry>
           <string>generic</string>
-          <string>bits:=int(16);
-addr:=8;</string>
+          <string>dataBits := 16;
+addrBits := 8;</string>
         </entry>
       </elementAttributes>
       <pos x="520" y="260"/>
@@ -105,8 +108,8 @@ addr:=8;</string>
       <p2 x="520" y="320"/>
     </wire>
     <wire>
-      <p1 x="460" y="260"/>
-      <p2 x="520" y="260"/>
+      <p1 x="460" y="240"/>
+      <p2 x="480" y="240"/>
     </wire>
     <wire>
       <p1 x="460" y="340"/>
@@ -116,6 +119,10 @@ addr:=8;</string>
       <p1 x="500" y="340"/>
       <p2 x="520" y="340"/>
     </wire>
+    <wire>
+      <p1 x="480" y="260"/>
+      <p2 x="520" y="260"/>
+    </wire>
     <wire>
       <p1 x="480" y="280"/>
       <p2 x="520" y="280"/>
@@ -140,6 +147,10 @@ addr:=8;</string>
       <p1 x="480" y="320"/>
       <p2 x="480" y="340"/>
     </wire>
+    <wire>
+      <p1 x="480" y="240"/>
+      <p2 x="480" y="260"/>
+    </wire>
     <wire>
       <p1 x="500" y="340"/>
       <p2 x="500" y="380"/>
diff --git a/src/test/resources/dig/test/generics/memLeaf.dig b/src/test/resources/dig/test/generics/memLeaf.dig
index 34ea4e024..b327bf6fa 100644
--- a/src/test/resources/dig/test/generics/memLeaf.dig
+++ b/src/test/resources/dig/test/generics/memLeaf.dig
@@ -13,7 +13,7 @@
       <elementAttributes>
         <entry>
           <string>generic</string>
-          <string>this.Bits=args.bits;</string>
+          <string>this.Bits=int(args.dataBits);</string>
         </entry>
       </elementAttributes>
       <pos x="560" y="140"/>
@@ -23,7 +23,7 @@
       <elementAttributes>
         <entry>
           <string>generic</string>
-          <string>this.Bits=args.bits;</string>
+          <string>this.Bits=int(args.dataBits);</string>
         </entry>
       </elementAttributes>
       <pos x="560" y="260"/>
@@ -33,7 +33,7 @@
       <elementAttributes>
         <entry>
           <string>generic</string>
-          <string>this.Bits=args.bits;</string>
+          <string>this.Bits=int(args.dataBits);</string>
         </entry>
       </elementAttributes>
       <pos x="660" y="160"/>
diff --git a/src/test/resources/dig/test/generics/memNode.dig b/src/test/resources/dig/test/generics/memNode.dig
index 6994fd7ae..dc3f52011 100644
--- a/src/test/resources/dig/test/generics/memNode.dig
+++ b/src/test/resources/dig/test/generics/memNode.dig
@@ -68,7 +68,7 @@
         <entry>
           <string>generic</string>
           <string>if (isPresent(args)) {
-  this.Bits=args.bits;
+  this.Bits=int(args.dataBits);
 }</string>
         </entry>
       </elementAttributes>
@@ -106,12 +106,12 @@
           <string>generic</string>
           <string>if (isPresent(args)) {
 
-  if (args.addr&lt;2)   {
+  if (args.addrBits&lt;2)   {
     panic(&quot;at least two address bits are necessary!&quot;);
   }
 
-  this.&apos;Input Splitting&apos;=&quot;&quot;+args.addr;
-  this.&apos;Output Splitting&apos;=(args.addr-1)+&quot;,1&quot;;
+  this.&apos;Input Splitting&apos;=&quot;&quot;+args.addrBits;
+  this.&apos;Output Splitting&apos;=(args.addrBits-1)+&quot;,1&quot;;
 }</string>
         </entry>
       </elementAttributes>
@@ -123,13 +123,13 @@
         <entry>
           <string>generic</string>
           <string>if (isPresent(args)) {
-  export bits:=args.bits;
-  export addr:=args.addr-1;
-  if (args.addr&gt;2) {
+  export dataBits:=args.dataBits;
+  export addrBits:=args.addrBits-1;
+  if (args.addrBits&gt;2) {
     setCircuit(&quot;memNode.dig&quot;);
   }
 } else {
-  export bits:=int(1);
+  export dataBits:=int(1);
 }</string>
         </entry>
       </elementAttributes>
@@ -141,13 +141,13 @@
         <entry>
           <string>generic</string>
           <string>if (isPresent(args)) {
-  export bits:=args.bits;
-  export addr:=args.addr-1;
-  if (args.addr&gt;2) {
+  export dataBits:=args.dataBits;
+  export addrBits:=args.addrBits-1;
+  if (args.addrBits&gt;2) {
     setCircuit(&quot;memNode.dig&quot;);
   }
 } else {
-  export bits:=int(1);
+  export dataBits:=int(1);
 }</string>
         </entry>
       </elementAttributes>
@@ -161,14 +161,14 @@
     </wire>
     <wire>
       <p1 x="300" y="320"/>
-      <p2 x="360" y="320"/>
+      <p2 x="340" y="320"/>
     </wire>
     <wire>
       <p1 x="320" y="160"/>
       <p2 x="520" y="160"/>
     </wire>
     <wire>
-      <p1 x="360" y="420"/>
+      <p1 x="340" y="420"/>
       <p2 x="640" y="420"/>
     </wire>
     <wire>
@@ -185,10 +185,10 @@
     </wire>
     <wire>
       <p1 x="240" y="200"/>
-      <p2 x="340" y="200"/>
+      <p2 x="360" y="200"/>
     </wire>
     <wire>
-      <p1 x="340" y="200"/>
+      <p1 x="360" y="200"/>
       <p2 x="400" y="200"/>
     </wire>
     <wire>
@@ -212,7 +212,7 @@
       <p2 x="520" y="300"/>
     </wire>
     <wire>
-      <p1 x="360" y="240"/>
+      <p1 x="340" y="240"/>
       <p2 x="380" y="240"/>
     </wire>
     <wire>
@@ -224,7 +224,7 @@
       <p2 x="520" y="340"/>
     </wire>
     <wire>
-      <p1 x="340" y="340"/>
+      <p1 x="360" y="340"/>
       <p2 x="400" y="340"/>
     </wire>
     <wire>
@@ -244,7 +244,7 @@
       <p2 x="620" y="220"/>
     </wire>
     <wire>
-      <p1 x="360" y="380"/>
+      <p1 x="340" y="380"/>
       <p2 x="400" y="380"/>
     </wire>
     <wire>
@@ -268,25 +268,25 @@
       <p2 x="500" y="440"/>
     </wire>
     <wire>
-      <p1 x="340" y="200"/>
-      <p2 x="340" y="340"/>
+      <p1 x="340" y="240"/>
+      <p2 x="340" y="320"/>
+    </wire>
+    <wire>
+      <p1 x="340" y="380"/>
+      <p2 x="340" y="420"/>
+    </wire>
+    <wire>
+      <p1 x="340" y="320"/>
+      <p2 x="340" y="380"/>
+    </wire>
+    <wire>
+      <p1 x="360" y="200"/>
+      <p2 x="360" y="340"/>
     </wire>
     <wire>
       <p1 x="600" y="220"/>
       <p2 x="600" y="320"/>
     </wire>
-    <wire>
-      <p1 x="360" y="240"/>
-      <p2 x="360" y="320"/>
-    </wire>
-    <wire>
-      <p1 x="360" y="380"/>
-      <p2 x="360" y="420"/>
-    </wire>
-    <wire>
-      <p1 x="360" y="320"/>
-      <p2 x="360" y="380"/>
-    </wire>
   </wires>
   <measurementOrdering/>
 </circuit>
\ No newline at end of file