implemented Goto Instruction; Increment ProgramCounter;

Co-authored-by: Darkress <30271678+DarkressX@users.noreply.github.com>
Reviewed-on: darkress/pic16f84-sim#1

de/darkress/pic16f84sim/Main.java

@@ -3,16 +3,23 @@ package de.darkress.pic16f84sim;
 import de.darkress.pic16f84sim.commands.Command;
 import de.darkress.pic16f84sim.decoder.CommandDecoder;
 import de.darkress.pic16f84sim.microcontroller.Memory;
+import de.darkress.pic16f84sim.microcontroller.ProgramCounter;
+
 import java.util.ArrayList;
 
 class Main
 {
     public static void main(String[] args) {
+
         ArrayList<Command> program = new ArrayList<>();
         Memory.workingRegister = 0xAA;
-        int input1 = 0x3AFF;
+        int input1 = 0x2FFF;
         program.add(CommandDecoder.decode(input1));
+
+        Memory.setPCLATH(0xFF);
         program.get(0).execute();
 
+        //ProgramCounter.incPC();
+
     }
 }

de/darkress/pic16f84sim/commands/Addlw.java

@@ -1,6 +1,7 @@
 package de.darkress.pic16f84sim.commands;
 
 import de.darkress.pic16f84sim.microcontroller.Memory;
+import de.darkress.pic16f84sim.microcontroller.ProgramCounter;
 
 public class Addlw extends CommandUtils implements Command
 {
@@ -21,5 +22,6 @@ public class Addlw extends CommandUtils implements Command
         checkDigitCarryBit(literal);
 
         Memory.workingRegister = result % 256;
+        ProgramCounter.incPC();
     }
 }

de/darkress/pic16f84sim/commands/Goto.java

@@ -0,0 +1,20 @@
+package de.darkress.pic16f84sim.commands;
+
+import de.darkress.pic16f84sim.microcontroller.Memory;
+import de.darkress.pic16f84sim.microcontroller.ProgramCounter;
+
+public class Goto extends CommandUtils implements Command
+{
+    private final int literal;
+
+    public Goto(int input)
+    {
+        literal = input & 0x07FF;
+    }
+
+    @Override
+    public void execute()
+    {
+        ProgramCounter.setPcForGotoCall(literal);
+    }
+}

de/darkress/pic16f84sim/decoder/CommandDecoder.java

@@ -103,8 +103,7 @@ public class CommandDecoder
                 //call();
                 break;
             case 0x2800:
-                //goto();
-                break;
+                return new Goto(input);
         }
 
         switch(input & 0x3C00)

de/darkress/pic16f84sim/microcontroller/Memory.java

@@ -91,6 +91,28 @@ public class Memory
         return memory[0x4];
     }
 
+    public static int getPCL()
+    {
+        return memory[0x2];
+    }
+
+    public static void setPCL(int data)
+    {
+        memory[0x2] = data;
+        memory[0x82] = data;
+    }
+
+    public static int getPCLATH()
+    {
+        return memory[0xA] & 0x1F;
+    }
+
+    public static void setPCLATH(int data)
+    {
+        memory[0xA] = data & 0x1F;
+        memory[0x8A] = data & 0x1F;
+    }
+
     public static boolean getZeroBit()
     {
         return (memory[0x03] & 0x04) == 0x04;
@@ -99,6 +121,7 @@ public class Memory
     public static void setZeroBit()
     {
         memory[0x03] |= 0x04;
+        memory[0x83] |= 0x04;
     }
 
     public static void clearZeroBit()
@@ -114,6 +137,7 @@ public class Memory
     public static void setDigitCarryBit()
     {
         memory[0x03] |= 0x02;
+        memory[0x83] |= 0x02;
     }
 
     public static void clearDigitCarryBit()
@@ -129,6 +153,7 @@ public class Memory
     public static void setCarryBit()
     {
         memory[0x03] |= 0x01;
+        memory[0x83] |= 0x01;
     }
 
     public static void clearCarryBit()

de/darkress/pic16f84sim/microcontroller/ProgramCounter.java

@@ -4,20 +4,35 @@ public class ProgramCounter
 
     //This class is not actual part of the µC. It is a storage for the current value of the PC
 {
-    private static int PC = 0;
+    private static int pc = 0;
 
-    public static int getPC()
+    public static int getPc()
     {
-        return PC;
+        return pc;
     }
 
-    public static void setPC(int PC)
+    public static void setPcForGotoCall(int data)
     {
-        ProgramCounter.PC = PC;
+        int pcl = data & 0x00FF;
+        int pch = Memory.getPCLATH();
+        pch = ((pch & 0xF8) <<8) + (data & 0x700);
+        Memory.setPCL(pcl);
+        pc = (pch) + pcl;
     }
 
-    public static void incPC()
+    public static void incPC() //is called after every instruction execution
     {
-        PC++;
+        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;
     }
 }