implemented subwf Instruction

Co-authored-by: Darkress <30271678+DarkressX@users.noreply.github.com>
Reviewed-on: darkress/pic16f84-sim#21

de/darkress/pic16f84sim/Main.java

@@ -12,9 +12,9 @@ class Main
     public static void main(String[] args) {
 
         ArrayList<Command> program = new ArrayList<>();
-        Memory.clearCarryBit();
-        Memory.setRegister(0x14, 0B11110000); //240 << 224
-        program.add(CommandDecoder.decode(0x0D94));
+        Memory.workingRegister = 0x01;
+        Memory.setRegister(0x14, 0x01); //240 << 224
+        program.add(CommandDecoder.decode(0x0294));
         for(int i = 0; i < program.size(); i++)
         {
             program.get(ProgramCounter.getPc()).execute();

de/darkress/pic16f84sim/commands/Rlf.java

@@ -18,15 +18,14 @@ public class Rlf extends FileRegisterCommandUtils implements Command
     public void execute()
     {
         int register = Memory.getRegister(address);
-        int carry = Memory.getCarryBit();
-        int tmp = carry;
-        carry = register >>7;
-        register = ((register <<1) + tmp) & 0xFF;
+        int newCarry = register >>7;
+        int oldCarry = Memory.getCarryBit();
+        register = ((register <<1) + oldCarry) & 0xFF;
 
-        if(carry == 1)
+        if(newCarry == 1)
         {
             Memory.setCarryBit();
-        } else if(carry == 0){
+        } else if(newCarry == 0){
             Memory.clearCarryBit();
         }
 

de/darkress/pic16f84sim/commands/Rrf.java

@@ -0,0 +1,35 @@
+package de.darkress.pic16f84sim.commands;
+
+import de.darkress.pic16f84sim.microcontroller.Memory;
+import de.darkress.pic16f84sim.microcontroller.ProgramCounter;
+
+public class Rrf extends FileRegisterCommandUtils implements Command
+{
+    private final int address;
+    private final boolean destinationBit;
+
+    public Rrf(int input)
+    {
+        address = input & 0x007F;
+        destinationBit = checkDestinationBit(input);
+    }
+
+    @Override
+    public void execute()
+    {
+        int register = Memory.getRegister(address);
+        int newCarry = register & 0x01;
+        int oldCarry = Memory.getCarryBit();
+        register = (oldCarry << 7) + (register >>1);
+
+        if(newCarry == 1)
+        {
+            Memory.setCarryBit();
+        } else if(newCarry == 0){
+            Memory.clearCarryBit();
+        }
+
+        writeToDestination(destinationBit, address, register);
+        ProgramCounter.incPC();
+    }
+}

de/darkress/pic16f84sim/commands/Subwf.java

@@ -0,0 +1,49 @@
+package de.darkress.pic16f84sim.commands;
+
+import de.darkress.pic16f84sim.microcontroller.Memory;
+import de.darkress.pic16f84sim.microcontroller.ProgramCounter;
+
+public class Subwf extends FileRegisterCommandUtils implements Command
+{
+    private final int address;
+    private final boolean destinationBit;
+
+    public Subwf(int input)
+    {
+        address = input & 0x007F;
+        destinationBit = checkDestinationBit(input);
+    }
+
+    @Override
+    protected void checkCarryBit(int result)
+    {
+        if(result <= 255){
+            Memory.clearCarryBit();
+        } else{
+            Memory.setCarryBit();
+        }
+    }
+
+    @Override
+    protected void checkDigitCarryBit(int literal)
+    {
+        if(((literal & 0x0F) - (Memory.workingRegister & 0x0F)) < 0){
+            Memory.clearDigitCarryBit();
+        } else{
+            Memory.setDigitCarryBit();
+        }
+    }
+
+    @Override
+    public void execute()
+    {
+        int result = Memory.getRegister(address) - Memory.workingRegister + 256;
+
+        checkZeroBit(result);
+        checkCarryBit(result);
+        checkDigitCarryBit(Memory.getRegister(address));
+
+        writeToDestination(destinationBit, address, result % 256);
+        ProgramCounter.incPC();
+    }
+}

de/darkress/pic16f84sim/decoder/CommandDecoder.java

@@ -29,11 +29,9 @@ public class CommandDecoder
             case 0xD00:
                 return new Rlf(input);
             case 0xC00:
-                //rrf();
-                break;
+                return new Rrf(input);
             case 0x200:
-                //subwf();
-                break;
+                return new Subwf(input);
             case 0xE00:
                 //swapf();
                 break;