diff --git a/src/main/java/de/neemann/digital/core/io/PinControl.java b/src/main/java/de/neemann/digital/core/io/PinControl.java
index be9b3f3de..040e56984 100644
--- a/src/main/java/de/neemann/digital/core/io/PinControl.java
+++ b/src/main/java/de/neemann/digital/core/io/PinControl.java
@@ -26,7 +26,8 @@ public class PinControl extends Node implements Element {
      */
     public static final ElementTypeDescription DESCRIPTION = new ElementTypeDescription(PinControl.class, input("wr"), input("oe"))
             .addAttribute(Keys.ROTATE)
-            .addAttribute(Keys.BITS);
+            .addAttribute(Keys.BITS)
+            .addAttribute(Keys.MIRROR);
 
     private final int bits;
     private final ObservableValue rdValue;
@@ -46,7 +47,7 @@ public class PinControl extends Node implements Element {
     public PinControl(ElementAttributes attr) {
         bits = attr.getBits();
         rdValue = new ObservableValue("rd", bits).setPinDescription(DESCRIPTION);
-        outWriteValue = new ObservableValue("out", bits).setPinDescription(DESCRIPTION).setBidirectional();
+        outWriteValue = new ObservableValue("pin", bits).setPinDescription(DESCRIPTION).setBidirectional();
     }
 
     @Override
diff --git a/src/main/java/de/neemann/digital/hdl/model2/HDLModel.java b/src/main/java/de/neemann/digital/hdl/model2/HDLModel.java
index 5dd57e3ef..59d294d05 100644
--- a/src/main/java/de/neemann/digital/hdl/model2/HDLModel.java
+++ b/src/main/java/de/neemann/digital/hdl/model2/HDLModel.java
@@ -180,10 +180,17 @@ public class HDLModel implements Iterable<HDLCircuit> {
     private <N extends HDLNode> N addInputsOutputs(N node, VisualElement v, HDLCircuit c) throws HDLException {
         for (Pin p : v.getPins()) {
             HDLNet net = c.getNetOfPin(p);
-            if (p.getDirection().equals(PinDescription.Direction.input))
-                node.addPort(new HDLPort(p.getName(), net, HDLPort.Direction.IN, 0));
-            else
-                node.addPort(new HDLPort(p.getName(), net, HDLPort.Direction.OUT, node.getBits(p.getName())));
+            switch (p.getDirection()) {
+                case input:
+                    node.addPort(new HDLPort(p.getName(), net, HDLPort.Direction.IN, 0));
+                    break;
+                case output:
+                    node.addPort(new HDLPort(p.getName(), net, HDLPort.Direction.OUT, node.getBits(p.getName())));
+                    break;
+                case both:
+                    node.addPort(new HDLPort(p.getName(), net, HDLPort.Direction.INOUT, node.getBits(p.getName())));
+                    break;
+            }
         }
         return node;
     }
diff --git a/src/main/java/de/neemann/digital/hdl/model2/HDLNet.java b/src/main/java/de/neemann/digital/hdl/model2/HDLNet.java
index 67ccd90e3..4a1ae5253 100644
--- a/src/main/java/de/neemann/digital/hdl/model2/HDLNet.java
+++ b/src/main/java/de/neemann/digital/hdl/model2/HDLNet.java
@@ -7,6 +7,7 @@ package de.neemann.digital.hdl.model2;
 
 import de.neemann.digital.hdl.model2.expression.ExprConstant;
 import de.neemann.digital.hdl.printer.CodePrinter;
+import de.neemann.digital.hdl.vhdl2.VHDLTestBenchCreator;
 import de.neemann.digital.lang.Lang;
 
 import java.io.IOException;
@@ -18,8 +19,9 @@ import java.util.ArrayList;
  */
 public class HDLNet implements Printable, HasName {
     private final boolean userNamed;
+    private final ArrayList<HDLPort> inputs;
+    private final ArrayList<HDLPort> inOutputs;
     private String name;
-    private ArrayList<HDLPort> inputs;
     private HDLPort output;
     private boolean needsVariable = true;
     private boolean isInput;
@@ -32,6 +34,7 @@ public class HDLNet implements Printable, HasName {
     public HDLNet(String name) {
         this.name = name;
         inputs = new ArrayList<>();
+        inOutputs = new ArrayList<>();
         userNamed = name != null;
     }
 
@@ -49,16 +52,24 @@ public class HDLNet implements Printable, HasName {
      * @throws HDLException HDLException
      */
     public void addPort(HDLPort hdlPort) throws HDLException {
-        if (hdlPort.getDirection().equals(HDLPort.Direction.OUT)) {
-            if (output != null) {
-                String netName = name;
-                if (netName == null)
-                    netName = Lang.get("err_unnamedNet");
-                throw new HDLException(Lang.get("err_hdlMultipleOutputsConnectedToNet_N_N_N", netName, output, hdlPort));
-            }
-            output = hdlPort;
-        } else
-            inputs.add(hdlPort);
+        switch (hdlPort.getDirection()) {
+            case OUT:
+                if (output != null) {
+                    String netName = name;
+                    if (netName == null)
+                        netName = Lang.get("err_unnamedNet");
+                    throw new HDLException(Lang.get("err_hdlMultipleOutputsConnectedToNet_N_N_N", netName, output, hdlPort));
+                }
+                output = hdlPort;
+                break;
+            case IN:
+                inputs.add(hdlPort);
+                break;
+            case INOUT:
+                inOutputs.add(hdlPort);
+                break;
+
+        }
     }
 
     /**
@@ -81,11 +92,25 @@ public class HDLNet implements Printable, HasName {
     }
 
     void fixBits() throws HDLException {
-        if (output == null)
-            throw new HDLException("no output connected to net");
-        final int bits = output.getBits();
-        if (bits == 0)
-            throw new HDLException("no bit number set for output " + output.getName());
+        int bits = 0;
+        if (output == null) {
+            if (inOutputs.isEmpty())
+                throw new HDLException("no output connected to net");
+            else {
+                for (HDLPort p : inOutputs) {
+                    if (p.getBits() > 0) {
+                        bits = p.getBits();
+                        break;
+                    }
+                }
+                if (bits == 0)
+                    throw new HDLException("no bit number set for inOutputs " + inOutputs);
+            }
+        } else {
+            bits = output.getBits();
+            if (bits == 0)
+                throw new HDLException("no bit number set for output " + output.getName());
+        }
 
         for (HDLPort i : inputs)
             i.setBits(bits);
@@ -96,6 +121,8 @@ public class HDLNet implements Printable, HasName {
      * @return the constant if this net is a constant, null otherwise
      */
     public ExprConstant isConstant() {
+        if (output == null)
+            return null;
         return ExprConstant.isConstant(output.getParent());
     }
 
@@ -161,8 +188,16 @@ public class HDLNet implements Printable, HasName {
     /**
      * @return the number of bits on this net
      */
-    public int getBits() {
-        return output.getBits();
+    public int getBits() throws HDLException {
+        if (output != null)
+            return output.getBits();
+
+        for (HDLPort p : inOutputs) {
+            if (p.getBits() > 0) {
+                return p.getBits();
+            }
+        }
+        throw new HDLException("no bit number set for inOutputs " + inOutputs);
     }
 
     /**
diff --git a/src/main/java/de/neemann/digital/hdl/model2/HDLNode.java b/src/main/java/de/neemann/digital/hdl/model2/HDLNode.java
index d1b343274..b0b625140 100644
--- a/src/main/java/de/neemann/digital/hdl/model2/HDLNode.java
+++ b/src/main/java/de/neemann/digital/hdl/model2/HDLNode.java
@@ -9,6 +9,7 @@ import de.neemann.digital.core.element.ElementAttributes;
 import de.neemann.digital.hdl.model2.expression.Expression;
 import de.neemann.digital.hdl.model2.expression.Visitor;
 import de.neemann.digital.hdl.printer.CodePrinter;
+import de.neemann.digital.hdl.vhdl2.VHDLTestBenchCreator;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -22,6 +23,7 @@ public abstract class HDLNode {
     private final HDLModel.BitProvider bitProvider;
     private final ArrayList<HDLPort> inputs;
     private final ArrayList<HDLPort> outputs;
+    private final ArrayList<HDLPort> inOutputs;
     private String hdlEntityName;
 
     /**
@@ -37,6 +39,7 @@ public abstract class HDLNode {
         this.bitProvider = bitProvider;
         inputs = new ArrayList<>();
         outputs = new ArrayList<>();
+        inOutputs = new ArrayList<>();
     }
 
     /**
@@ -46,10 +49,17 @@ public abstract class HDLNode {
      * @return this for chained calls
      */
     public HDLNode addPort(HDLPort port) {
-        if (port.getDirection().equals(HDLPort.Direction.OUT))
-            outputs.add(port);
-        else
-            inputs.add(port);
+        switch (port.getDirection()) {
+            case IN:
+                inputs.add(port);
+                break;
+            case OUT:
+                outputs.add(port);
+                break;
+            case INOUT:
+                inOutputs.add(port);
+                break;
+        }
 
         port.setParent(this);
 
@@ -96,6 +106,13 @@ public abstract class HDLNode {
         return outputs;
     }
 
+    /**
+     * @return the list of inOutputs
+     */
+    public ArrayList<HDLPort> getInOutputs() {
+        return inOutputs;
+    }
+
     int getBits(String name) {
         return bitProvider.getBits(name);
     }
@@ -111,6 +128,10 @@ public abstract class HDLNode {
         printWithLocal(out, inputs);
         out.print("out");
         printWithLocal(out, outputs);
+        if (!inOutputs.isEmpty()) {
+            out.print("inOut");
+            printWithLocal(out, inOutputs);
+        }
     }
 
     private void printWithLocal(CodePrinter out, ArrayList<HDLPort> ports) throws IOException {
@@ -177,6 +198,8 @@ public abstract class HDLNode {
             p.rename(renaming);
         for (HDLPort p : inputs)
             p.rename(renaming);
+        for (HDLPort p : inOutputs)
+            p.rename(renaming);
     }
 
     /**
diff --git a/src/main/java/de/neemann/digital/hdl/model2/HDLPort.java b/src/main/java/de/neemann/digital/hdl/model2/HDLPort.java
index 3e64b16d3..22b8dd391 100644
--- a/src/main/java/de/neemann/digital/hdl/model2/HDLPort.java
+++ b/src/main/java/de/neemann/digital/hdl/model2/HDLPort.java
@@ -30,7 +30,11 @@ public class HDLPort implements Printable, HasName {
          * Caution: a circuits input components port has type OUT because it defines a value,
          * seen from inside the node.
          */
-        OUT
+        OUT,
+        /**
+         * Bidirectional port
+         */
+        INOUT
     }
 
     private String name;
diff --git a/src/main/java/de/neemann/digital/hdl/vhdl2/VHDLCreator.java b/src/main/java/de/neemann/digital/hdl/vhdl2/VHDLCreator.java
index aa6519012..3af1433d1 100644
--- a/src/main/java/de/neemann/digital/hdl/vhdl2/VHDLCreator.java
+++ b/src/main/java/de/neemann/digital/hdl/vhdl2/VHDLCreator.java
@@ -250,6 +250,11 @@ public class VHDLCreator {
                 sep.check();
                 out.print(o.getName()).print(" => ").print(o.getNet().getName());
             }
+        for (HDLPort o : node.getInOutputs())
+            if (o.getNet() != null) {
+                sep.check();
+                out.print(o.getName()).print(" => ").print(o.getNet().getName());
+            }
         out.println(");").dec().dec();
     }
 
diff --git a/src/main/resources/lang/lang_de.xml b/src/main/resources/lang/lang_de.xml
index 76112b696..9ec4fa634 100644
--- a/src/main/resources/lang/lang_de.xml
+++ b/src/main/resources/lang/lang_de.xml
@@ -362,7 +362,7 @@
     <string name="elem_PinControl_pin_wr">Die auszugebenden Daten</string>
     <string name="elem_PinControl_pin_oe">Aktiviert die Ausgabe</string>
     <string name="elem_PinControl_pin_rd">Die zu lesenden Daten.</string>
-    <string name="elem_PinControl_pin_out">Der Anschluss für den eigentlichen Pin. Hier sollte nur noch ein einzelner
+    <string name="elem_PinControl_pin_pin">Der Anschluss für den eigentlichen Pin. Hier sollte nur noch ein einzelner
         Eingang angeschlossen werden.
     </string>
 
diff --git a/src/main/resources/lang/lang_en.xml b/src/main/resources/lang/lang_en.xml
index cac2712ec..76791481c 100644
--- a/src/main/resources/lang/lang_en.xml
+++ b/src/main/resources/lang/lang_en.xml
@@ -371,7 +371,7 @@
     <string name="elem_PinControl_pin_wr">The data to be output.</string>
     <string name="elem_PinControl_pin_oe">Activates the output.</string>
     <string name="elem_PinControl_pin_rd">The data to be read.</string>
-    <string name="elem_PinControl_pin_out">The connector for the actual pin. Only a single input should be connected
+    <string name="elem_PinControl_pin_pin">The connector for the actual pin. Only a single input should be connected
         here.
     </string>
 
diff --git a/src/main/resources/vhdl/DIG_PinControl.tem b/src/main/resources/vhdl/DIG_PinControl.tem
new file mode 100644
index 000000000..8d0b84cc6
--- /dev/null
+++ b/src/main/resources/vhdl/DIG_PinControl.tem
@@ -0,0 +1,64 @@
+LIBRARY ieee;
+USE ieee.std_logic_1164.all;
+<?
+  if (elem.Bits=1) {
+      export entityName:="PinControl";  ?>
+
+LIBRARY ieee;
+USE ieee.std_logic_1164.ALL;
+
+ENTITY PinControl IS
+    PORT(
+        pin  : INOUT STD_LOGIC;
+        oe   : IN STD_LOGIC;
+        wr   : IN STD_LOGIC;
+        rd   : OUT STD_LOGIC);
+END PinControl;
+
+ARCHITECTURE Behavioral OF PinControl IS
+BEGIN
+    PROCESS (oe, pin, wr)      -- Behavioral representation
+        BEGIN                  -- of tri-states.
+        IF( oe = '0') THEN
+            pin <= 'Z';
+            rd <= pin;
+        ELSE
+            pin <= wr;
+            rd <= wr;
+        END IF;
+    END PROCESS;
+END Behavioral;
+
+<? } else {
+      export entityName:="PinControl_BUS"; ?>
+
+LIBRARY ieee;
+USE ieee.std_logic_1164.ALL;
+
+ENTITY PinControl_BUS IS
+    GENERIC (
+      Bits: integer );<? vhdl.registerGeneric("Bits"); ?>
+    PORT(
+        pin  : INOUT std_logic_vector((Bits-1) downto 0);
+        oe   : IN STD_LOGIC;
+        wr   : IN std_logic_vector((Bits-1) downto 0);
+        rd   : OUT std_logic_vector((Bits-1) downto 0));
+END PinControl_BUS;
+
+ARCHITECTURE Behavioral OF PinControl_BUS IS
+BEGIN
+    PROCESS (oe, pin, wr)      -- Behavioral representation
+        BEGIN                  -- of tri-states.
+        IF( oe = '0') THEN
+            pin <= (others => 'Z');
+            rd <= pin;
+        ELSE
+            pin <= wr;
+            rd <= wr;
+        END IF;
+    END PROCESS;
+END Behavioral;
+
+<?
+  }
+?>
diff --git a/src/test/java/de/neemann/digital/hdl/vhdl2/VHDLSimulatorTest.java b/src/test/java/de/neemann/digital/hdl/vhdl2/VHDLSimulatorTest.java
index a3ebabaf3..e04f3e47b 100644
--- a/src/test/java/de/neemann/digital/hdl/vhdl2/VHDLSimulatorTest.java
+++ b/src/test/java/de/neemann/digital/hdl/vhdl2/VHDLSimulatorTest.java
@@ -14,6 +14,7 @@ import de.neemann.digital.draw.library.ElementNotFoundException;
 import de.neemann.digital.gui.Settings;
 import de.neemann.digital.hdl.model2.HDLException;
 import de.neemann.digital.hdl.printer.CodePrinter;
+import de.neemann.digital.hdl.printer.CodePrinterStr;
 import de.neemann.digital.integration.FileScanner;
 import de.neemann.digital.integration.Resources;
 import de.neemann.digital.integration.TestExamples;
@@ -32,9 +33,9 @@ public class VHDLSimulatorTest extends TestCase {
     private static final String GHDL = System.getProperty("ghdl", "ghdl");
     private int testBenches;
 
-    /*
+    //*
     public void testDebug() throws Exception {
-        File file = new File(Resources.getRoot(), "dig/test/vhdl/lut2.dig");
+        File file = new File(Resources.getRoot(), "/dig/test/pinControl/simple.dig");
 
         ToBreakRunner br = new ToBreakRunner(file);
         System.out.println(new VHDLGenerator(br.getLibrary(), new CodePrinterStr(true)).export(br.getCircuit()));
diff --git a/src/test/java/de/neemann/digital/integration/TestExamples.java b/src/test/java/de/neemann/digital/integration/TestExamples.java
index 2c9a374e8..d043be59c 100644
--- a/src/test/java/de/neemann/digital/integration/TestExamples.java
+++ b/src/test/java/de/neemann/digital/integration/TestExamples.java
@@ -43,8 +43,8 @@ public class TestExamples extends TestCase {
      */
     public void testTestExamples() throws Exception {
         File examples = new File(Resources.getRoot(), "/dig/test");
-        assertEquals(184, new FileScanner(this::check).scan(examples));
-        assertEquals(172, testCasesInFiles);
+        assertEquals(185, new FileScanner(this::check).scan(examples));
+        assertEquals(173, testCasesInFiles);
     }
 
     /**
diff --git a/src/test/resources/dig/test/pinControl/simple.dig b/src/test/resources/dig/test/pinControl/simple.dig
new file mode 100644
index 000000000..77048e635
--- /dev/null
+++ b/src/test/resources/dig/test/pinControl/simple.dig
@@ -0,0 +1,182 @@
+<?xml version="1.0" encoding="utf-8"?>
+<circuit>
+  <version>1</version>
+  <attributes/>
+  <visualElements>
+    <visualElement>
+      <elementName>In</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Label</string>
+          <string>wr_0</string>
+        </entry>
+        <entry>
+          <string>Bits</string>
+          <int>4</int>
+        </entry>
+      </elementAttributes>
+      <pos x="340" y="140"/>
+    </visualElement>
+    <visualElement>
+      <elementName>In</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Label</string>
+          <string>oe</string>
+        </entry>
+      </elementAttributes>
+      <pos x="340" y="220"/>
+    </visualElement>
+    <visualElement>
+      <elementName>PinControl</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Bits</string>
+          <int>4</int>
+        </entry>
+      </elementAttributes>
+      <pos x="380" y="180"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Out</elementName>
+      <elementAttributes>
+        <entry>
+          <string>rotation</string>
+          <rotation rotation="2"/>
+        </entry>
+        <entry>
+          <string>Label</string>
+          <string>rd_0</string>
+        </entry>
+        <entry>
+          <string>Bits</string>
+          <int>4</int>
+        </entry>
+      </elementAttributes>
+      <pos x="340" y="180"/>
+    </visualElement>
+    <visualElement>
+      <elementName>In</elementName>
+      <elementAttributes>
+        <entry>
+          <string>rotation</string>
+          <rotation rotation="2"/>
+        </entry>
+        <entry>
+          <string>Label</string>
+          <string>wr_1</string>
+        </entry>
+        <entry>
+          <string>Bits</string>
+          <int>4</int>
+        </entry>
+      </elementAttributes>
+      <pos x="520" y="140"/>
+    </visualElement>
+    <visualElement>
+      <elementName>PinControl</elementName>
+      <elementAttributes>
+        <entry>
+          <string>mirror</string>
+          <boolean>true</boolean>
+        </entry>
+        <entry>
+          <string>rotation</string>
+          <rotation rotation="2"/>
+        </entry>
+        <entry>
+          <string>Bits</string>
+          <int>4</int>
+        </entry>
+      </elementAttributes>
+      <pos x="480" y="180"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Out</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Label</string>
+          <string>rd_1</string>
+        </entry>
+        <entry>
+          <string>Bits</string>
+          <int>4</int>
+        </entry>
+      </elementAttributes>
+      <pos x="520" y="180"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Not</elementName>
+      <elementAttributes/>
+      <pos x="400" y="220"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Testcase</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Testdata</string>
+          <testData>
+            <dataString>oe wr_0 rd_0 wr_1 rd_1
+1   1     x   x    1
+1   2     x   x    2
+0   x     1   1    x
+0   x     2   2    x
+</dataString>
+          </testData>
+        </entry>
+      </elementAttributes>
+      <pos x="380" y="80"/>
+    </visualElement>
+  </visualElements>
+  <wires>
+    <wire>
+      <p1 x="360" y="220"/>
+      <p2 x="380" y="200"/>
+    </wire>
+    <wire>
+      <p1 x="500" y="140"/>
+      <p2 x="480" y="160"/>
+    </wire>
+    <wire>
+      <p1 x="360" y="140"/>
+      <p2 x="380" y="160"/>
+    </wire>
+    <wire>
+      <p1 x="420" y="180"/>
+      <p2 x="440" y="180"/>
+    </wire>
+    <wire>
+      <p1 x="340" y="180"/>
+      <p2 x="380" y="180"/>
+    </wire>
+    <wire>
+      <p1 x="480" y="180"/>
+      <p2 x="520" y="180"/>
+    </wire>
+    <wire>
+      <p1 x="440" y="220"/>
+      <p2 x="480" y="220"/>
+    </wire>
+    <wire>
+      <p1 x="340" y="220"/>
+      <p2 x="360" y="220"/>
+    </wire>
+    <wire>
+      <p1 x="360" y="220"/>
+      <p2 x="400" y="220"/>
+    </wire>
+    <wire>
+      <p1 x="500" y="140"/>
+      <p2 x="520" y="140"/>
+    </wire>
+    <wire>
+      <p1 x="340" y="140"/>
+      <p2 x="360" y="140"/>
+    </wire>
+    <wire>
+      <p1 x="480" y="200"/>
+      <p2 x="480" y="220"/>
+    </wire>
+  </wires>
+  <measurementOrdering/>
+</circuit>
\ No newline at end of file