fixed PC (#6)

Co-authored-by: Darkress <30271678+DarkressX@users.noreply.github.com>
Reviewed-on: darkress/pic16f84-sim#6

de/darkress/pic16f84sim/commands/Retlw.java

@@ -17,8 +17,6 @@ public class Retlw extends CommandUtils implements Command
     public void execute()
     {
         Memory.workingRegister = literal;
-        ProgramCounter.setPcFrom11BitLiteral(Stack.pop());
-        //TODO: This may need some rework since it does not really load all 13 Bit into the PC. Only 8 Bit are
-        // effectively set
+        ProgramCounter.setPcFromStack(Stack.pop());
     }
 }

de/darkress/pic16f84sim/commands/Return.java

@@ -8,8 +8,6 @@ public class Return extends CommandUtils implements Command
     @Override
     public void execute()
     {
-        ProgramCounter.setPcFrom11BitLiteral(Stack.pop());
-        //TODO: This may need some rework since it does not really load all 13 Bit into the PC. Only 8 Bit are
-        // effectively set
+        ProgramCounter.setPcFromStack(Stack.pop());
     }
 }

de/darkress/pic16f84sim/microcontroller/Memory.java

@@ -59,6 +59,10 @@ public class Memory
         }
         memory[address] = data;
         memory[address + 128] = data; //Ensure data is written to both banks to simulate mapping
+        if(address == 0x2) //Check if PCL is destination
+        {
+            ProgramCounter.loadPc();
+        }
     }
 
     private static int getDataFromIndirectAddress(int address)
@@ -75,6 +79,10 @@ public class Memory
         }
         memory[address % 128] = data; // else: Registers.Registers which are mapped
         memory[address % 128 + 128] = data; //Ensure data is written to both banks to simulate mapping
+        if(address == 0x2) //Check if PCL is destination
+        {
+            ProgramCounter.loadPc();
+        }
     }
 
     private static int getRegisterBank()

de/darkress/pic16f84sim/microcontroller/ProgramCounter.java

@@ -20,19 +20,20 @@ public class ProgramCounter
         pc = (pch) + pcl;
     }
 
+    public static void setPcFromStack(int stack)
+    {
+        pc = stack;
+        Memory.setPCL(pc & 0x00FF);
+    }
+
+    public static void loadPc()
+    {
+        pc = (Memory.getPCLATH() <<8) + Memory.getPCL();
+    }
+
     public static void incPC() //is called after every instruction execution
     {
-        int pcl = Memory.getPCL();
-        int pclath = Memory.getPCLATH();
-        if(pcl == 0xFF)
-        {
-            pclath++;
-            pcl = 0;
-        } else {
-            pcl++;
-        }
-        Memory.setPCL(pcl);
-        Memory.setPCLATH(pclath);
-        pc = (pclath <<8) + pcl;
+        pc++;
+        Memory.setPCL(pc & 0x00FF);
     }
 }