Stack

src/main/java/fabrik/simulator/pic16f84/Controller_FileSelect.java

@@ -44,6 +44,7 @@ public class Controller_FileSelect {
                     System.out.println("W: " + Commands.get_wRegister());
                     System.out.println("C: " + DataRegister.getCarryFlag());
                     System.out.println("DC: " + DataRegister.getDigitCarryFlag());
+                    System.out.println("StackPointer: " + ProgramStack.getStackPointer());
                     System.out.println(ProgramStack.getStack());
                     System.out.printf(Arrays.toString(DataRegister.getDataRegister()));
                     DataRegister.increasePC();

src/main/java/fabrik/simulator/pic16f84/ProgramStack.java

@@ -1,25 +1,42 @@
 package fabrik.simulator.pic16f84;
 
-import java.util.ArrayDeque;
+import java.util.ArrayList;
-import java.util.Deque;
+import java.util.List;
 
 public class ProgramStack {
-    private static Deque<Integer> returnStack = new ArrayDeque<>();
+    private static List<Integer> returnStack = new ArrayList<>(8);
+    private static int stackIndex = 0;
 
-    public static void push(int value) {
+    private static void incIndex(){
-        if (returnStack.size() != 7)
+        if (stackIndex == 7){
-            returnStack.push(value);
+            stackIndex = 0;
-        else {
+        }
-            System.out.println("Stack overflow");
+        else{
+            stackIndex++;
+        }
     }
 
+    public static void push(int value) {
+        if (returnStack.size() != 8) {
+            returnStack.add(value);
+            incIndex();
+        }
+        else {
+            returnStack.set(stackIndex, value);
+            incIndex();
+        }
     }
 
     public static int pop() {
-        return returnStack.pop();
+        stackIndex =  (stackIndex > 0) ? --stackIndex : 7;
+        return returnStack.get(stackIndex)-1;
     }
 
-    public static Deque<Integer> getStack() {
+    public static int getStackPointer(){
+        return stackIndex;
+    }
+
+    public static List<Integer> getStack() {
         return returnStack;
     }
 }