implemented Clrf Instruction

Co-authored-by: darkress <github@darkress.xyz>
Reviewed-on: darkress/pic16f84-sim#15

de/darkress/pic16f84sim/Main.java

@@ -12,11 +12,9 @@ class Main
     public static void main(String[] args) {
 
         ArrayList<Command> program = new ArrayList<>();
-        int input1 = 0x27FF;
-        program.add(CommandDecoder.decode(0x3011)); //Write 0x11 to W
-        Memory.setRegister(0x14, 0x14);
-        program.add(CommandDecoder.decode(0x0994));
-        for(int i = 0; i < 2; i++)
+        Memory.setRegister(0x14, 0xFF);
+        program.add(CommandDecoder.decode(0x0194));
+        for(int i = 0; i < program.size(); i++)
         {
             program.get(ProgramCounter.getPc()).execute();
         }

de/darkress/pic16f84sim/commands/Clrf.java

@@ -0,0 +1,27 @@
+package de.darkress.pic16f84sim.commands;
+
+import de.darkress.pic16f84sim.microcontroller.Memory;
+import de.darkress.pic16f84sim.microcontroller.ProgramCounter;
+
+public class Clrf extends FileRegisterCommandUtils implements Command
+{
+    private final int address;
+    private final boolean destinationBit;
+
+    public Clrf(int input)
+    {
+        address = input & 0x007F;
+        destinationBit = true;
+    }
+
+    @Override
+    public void execute()
+    {
+        final int result = 0;
+
+        checkZeroBit(result);
+
+        writeToDestination(destinationBit, address, result);
+        ProgramCounter.incPC();
+    }
+}

de/darkress/pic16f84sim/commands/Clrw.java

@@ -0,0 +1,18 @@
+package de.darkress.pic16f84sim.commands;
+
+import de.darkress.pic16f84sim.microcontroller.Memory;
+import de.darkress.pic16f84sim.microcontroller.ProgramCounter;
+
+public class Clrw extends FileRegisterCommandUtils implements Command
+{
+    @Override
+    public void execute()
+    {
+        final int result = 0;
+
+        checkZeroBit(result);
+
+        Memory.workingRegister = result;
+        ProgramCounter.incPC();
+    }
+}

de/darkress/pic16f84sim/commands/Decf.java

@@ -0,0 +1,27 @@
+package de.darkress.pic16f84sim.commands;
+
+import de.darkress.pic16f84sim.microcontroller.Memory;
+import de.darkress.pic16f84sim.microcontroller.ProgramCounter;
+
+public class Decf extends FileRegisterCommandUtils implements Command
+{
+    private final int address;
+    private final boolean destinationBit;
+
+    public Decf(int input)
+    {
+        address = input & 0x007F;
+        destinationBit = checkDestinationBit(input);
+    }
+
+    @Override
+    public void execute()
+    {
+        int result = Memory.getRegister(address) + 255; // Allow underflow
+
+        checkZeroBit(result);
+
+        writeToDestination(destinationBit, address, result % 256); // Catch underflow
+        ProgramCounter.incPC();
+    }
+}

de/darkress/pic16f84sim/commands/Decfsz.java

@@ -0,0 +1,33 @@
+package de.darkress.pic16f84sim.commands;
+
+import de.darkress.pic16f84sim.microcontroller.Memory;
+import de.darkress.pic16f84sim.microcontroller.ProgramCounter;
+
+public class Decfsz extends FileRegisterCommandUtils implements Command
+{
+    private final int address;
+    private final boolean destinationBit;
+
+    public Decfsz(int input)
+    {
+        address = input & 0x007F;
+        destinationBit = checkDestinationBit(input);
+    }
+
+    @Override
+    public void execute()
+    {
+        int result = Memory.getRegister(address) + 255; // Allow underflow
+
+        checkZeroBit(result);
+
+        writeToDestination(destinationBit, address, result % 256); // Catch underflow
+
+        if((result % 256) == 0)
+        {
+            Nop nop = new Nop();
+            nop.execute();
+        }
+        ProgramCounter.incPC();
+    }
+}

de/darkress/pic16f84sim/commands/Incf.java

@@ -0,0 +1,27 @@
+package de.darkress.pic16f84sim.commands;
+
+import de.darkress.pic16f84sim.microcontroller.Memory;
+import de.darkress.pic16f84sim.microcontroller.ProgramCounter;
+
+public class Incf extends FileRegisterCommandUtils implements Command
+{
+    private final int address;
+    private final boolean destinationBit;
+
+    public Incf(int input)
+    {
+        address = input & 0x007F;
+        destinationBit = checkDestinationBit(input);
+    }
+
+    @Override
+    public void execute()
+    {
+        int result = Memory.getRegister(address) + 1; // Allow underflow
+
+        checkZeroBit(result);
+
+        writeToDestination(destinationBit, address, result % 256); // Catch underflow
+        ProgramCounter.incPC();
+    }
+}

de/darkress/pic16f84sim/commands/Incfsz.java

@@ -0,0 +1,33 @@
+package de.darkress.pic16f84sim.commands;
+
+import de.darkress.pic16f84sim.microcontroller.Memory;
+import de.darkress.pic16f84sim.microcontroller.ProgramCounter;
+
+public class Incfsz extends FileRegisterCommandUtils implements Command
+{
+    private final int address;
+    private final boolean destinationBit;
+
+    public Incfsz(int input)
+    {
+        address = input & 0x007F;
+        destinationBit = checkDestinationBit(input);
+    }
+
+    @Override
+    public void execute()
+    {
+        int result = Memory.getRegister(address) + 1;
+
+        checkZeroBit(result);
+
+        writeToDestination(destinationBit, address, result % 256);
+
+        if((result % 256) == 0)
+        {
+            Nop nop = new Nop();
+            nop.execute();
+        }
+        ProgramCounter.incPC();
+    }
+}

de/darkress/pic16f84sim/commands/Nop.java

@@ -0,0 +1,14 @@
+package de.darkress.pic16f84sim.commands;
+
+import de.darkress.pic16f84sim.microcontroller.ProgramCounter;
+
+public class Nop extends LiteralCommandUtils implements Command
+{
+
+    @Override
+    public void execute()
+    {
+        // Do nothing, just increment the PC
+        ProgramCounter.incPC();
+    }
+}

de/darkress/pic16f84sim/decoder/CommandDecoder.java

@@ -15,17 +15,13 @@ public class CommandDecoder
             case 0x900:
                 return new Comf(input);
             case 0x300:
-                //decf();
-                break;
+                return new Decf(input);
             case 0xB00:
-                //decfsz();
-                break;
+                return new Decfsz(input);
             case 0xA00:
-                //incf();
-                break;
+                return new Incf(input);
             case 0xF00:
-                //incfsz();
-                break;
+                return new Incfsz(input);
             case 0x400:
                 //iorwf();
                 break;
@@ -58,11 +54,9 @@ public class CommandDecoder
         switch(input & 0x3F80)
         {
             case 0x180:
-                //clrf();
-                break;
+                return new Clrf(input);
             case 0x100:
-                //clrw();
-                break;
+                return new Clrw();
             case 0x80:
                 //movwf();
                 break;
@@ -112,7 +106,7 @@ public class CommandDecoder
 
         if ((input | 0x0060) == 0x0060)
         {
-            //nop();
+            return new Nop();
         }
 
         if (input == 0x0064)