Counters are able to act as program counters via the remote interface, closes #426

distribution/ReleaseNotes.txt

@@ -3,6 +3,7 @@ Release Notes
 Head, planned as v0.25
 - move the "lib" folder from the "examples" folder to the root folder.
 - Reordering of the cells in the K-Map
+- Counters are able to act as program counters via the remote interface.
 - 74193 was added
 
 v0.24, released on 1. Feb. 2020

src/main/java/de/neemann/digital/core/memory/Counter.java

@@ -14,7 +14,7 @@ import static de.neemann.digital.core.element.PinInfo.input;
 /**
  * A simple counter.
  */
-public class Counter extends Node implements Element {
+public class Counter extends Node implements Element, ProgramCounter {
 
     /**
      * The counters {@link ElementTypeDescription}
@@ -25,13 +25,15 @@ public class Counter extends Node implements Element {
             .addAttribute(Keys.BITS)
             .addAttribute(Keys.INVERTER_CONFIG)
             .addAttribute(Keys.LABEL)
-            .addAttribute(Keys.VALUE_IS_PROBE);
+            .addAttribute(Keys.VALUE_IS_PROBE)
+            .addAttribute(Keys.IS_PROGRAM_COUNTER);
 
     private final ObservableValue out;
     private final ObservableValue ovf;
     private final long maxValue;
     private final boolean probe;
     private final String label;
+    private final boolean isProgramCounter;
     private ObservableValue clockIn;
     private ObservableValue clrIn;
     private ObservableValue enable;
@@ -52,6 +54,7 @@ public class Counter extends Node implements Element {
         maxValue = Bits.mask(bits);
         probe = attributes.get(Keys.VALUE_IS_PROBE);
         label = attributes.getLabel();
+        isProgramCounter = attributes.get(Keys.IS_PROGRAM_COUNTER);
     }
 
     @Override
@@ -92,7 +95,6 @@ public class Counter extends Node implements Element {
         return ovs(out, ovf);
     }
 
-
     @Override
     public void registerNodes(Model model) {
         super.registerNodes(model);
@@ -105,4 +107,13 @@ public class Counter extends Node implements Element {
             }));
     }
 
+    @Override
+    public boolean isProgramCounter() {
+        return isProgramCounter;
+    }
+
+    @Override
+    public long getProgramCounter() {
+        return counter;
+    }
 }

src/main/java/de/neemann/digital/core/memory/CounterPreset.java

@@ -17,7 +17,7 @@ import static de.neemann.digital.core.element.PinInfo.input;
 /**
  * A simple counter.
  */
-public class CounterPreset extends Node implements Element {
+public class CounterPreset extends Node implements Element, ProgramCounter {
 
     /**
      * The counters {@link ElementTypeDescription}
@@ -35,7 +35,8 @@ public class CounterPreset extends Node implements Element {
             .addAttribute(Keys.MAX_VALUE)
             .addAttribute(Keys.INVERTER_CONFIG)
             .addAttribute(Keys.LABEL)
-            .addAttribute(Keys.VALUE_IS_PROBE);
+            .addAttribute(Keys.VALUE_IS_PROBE)
+            .addAttribute(Keys.IS_PROGRAM_COUNTER);
 
     private final ObservableValue out;
     private final ObservableValue ovf;
@@ -43,6 +44,7 @@ public class CounterPreset extends Node implements Element {
     private final boolean probe;
     private final String label;
     private final int bits;
+    private final boolean isProgramCounter;
     private ObservableValue clockIn;
     private ObservableValue clrIn;
     private ObservableValue enable;
@@ -72,6 +74,7 @@ public class CounterPreset extends Node implements Element {
 
         probe = attributes.get(Keys.VALUE_IS_PROBE);
         label = attributes.getLabel();
+        isProgramCounter = attributes.get(Keys.IS_PROGRAM_COUNTER);
     }
 
     @Override
@@ -145,4 +148,13 @@ public class CounterPreset extends Node implements Element {
             }));
     }
 
+    @Override
+    public boolean isProgramCounter() {
+        return isProgramCounter;
+    }
+
+    @Override
+    public long getProgramCounter() {
+        return counter;
+    }
 }

src/main/java/de/neemann/digital/core/memory/ProgramCounter.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2020 Helmut Neemann.
+ * Use of this source code is governed by the GPL v3 license
+ * that can be found in the LICENSE file.
+ */
+package de.neemann.digital.core.memory;
+
+/**
+ * This interface is implemented by all components which are able to act as a program counter.
+ */
+public interface ProgramCounter {
+
+    /**
+     * @return true if this component is used as the program counter
+     */
+    boolean isProgramCounter();
+
+    /**
+     * @return the value of the program counter
+     */
+    long getProgramCounter();
+
+}

src/main/java/de/neemann/digital/core/memory/Register.java

@@ -17,7 +17,7 @@ import static de.neemann.digital.core.element.PinInfo.input;
 /**
  * A simple register.
  */
-public class Register extends Node implements Element, Countable {
+public class Register extends Node implements Element, Countable, ProgramCounter {
 
     /**
      * The registers {@link ElementTypeDescription}
@@ -92,17 +92,13 @@ public class Register extends Node implements Element, Countable {
             }));
     }
 
-    /**
+    @Override
-     * @return true if this register is the program counter
-     */
     public boolean isProgramCounter() {
         return isProgramCounter;
     }
 
-    /**
+    @Override
-     * @return the value of this register
+    public long getProgramCounter() {
-     */
-    public long getValue() {
         return value;
     }
 

src/main/java/de/neemann/digital/gui/Main.java

@@ -15,7 +15,7 @@ import de.neemann.digital.core.element.ElementAttributes;
 import de.neemann.digital.core.element.Keys;
 import de.neemann.digital.core.io.Button;
 import de.neemann.digital.core.io.*;
-import de.neemann.digital.core.memory.Register;
+import de.neemann.digital.core.memory.ProgramCounter;
 import de.neemann.digital.core.stats.Statistics;
 import de.neemann.digital.core.wiring.AsyncSeq;
 import de.neemann.digital.core.wiring.Clock;
@@ -1777,9 +1777,9 @@ public final class Main extends JFrame implements ClosingWindowListener.ConfirmS
         private long address;
 
         private void getProgramROMAddress(Model model) {
-            List<Register> roms = model.findNode(Register.class, Register::isProgramCounter);
+            List<Node> programCounters = model.findNode(n -> n instanceof ProgramCounter && ((ProgramCounter) n).isProgramCounter());
-            if (roms.size() == 1)
+            if (programCounters.size() == 1)
-                address = roms.get(0).getValue();
+                address = ((ProgramCounter) programCounters.get(0)).getProgramCounter();
             else
                 address = -1;
         }