Addlw instruction (#4)

* Added addlw command

* Write to program list

* Included CommandUtils as helpter class. Sorted classes into packages

* Revert changes on HelloWorld

* Revert "Revert changes on HelloWorld"

This reverts commit a08a336864fb2aa2bbc5a4e37ca360765774965e.

* Added example execution of Addlw command

HelloWorld.java

@@ -1,7 +1,14 @@
+import commands.Command;
+import decoder.CommandDecoder;
 
+import java.util.ArrayList;
 
 class HelloWorld {
     public static void main(String[] args) {
-        System.out.println(Parser.parser("TPicSim2.LST"));
+        //System.out.println(Parser.Parser.parser("TPicSim2.LST"));
+        ArrayList<Command> program = new ArrayList<>();
+        int input1 = 0x3EFF;
+        program.add(CommandDecoder.decode(input1));
+        program.get(0).execute();
     }
 }

commands/Addlw.java

@@ -0,0 +1,25 @@
+package commands;
+
+import registers.Memory;
+
+public class Addlw extends CommandUtils implements Command
+{
+    private final int literal;
+
+    public Addlw(int input)
+    {
+        literal = input & 0x00FF;
+    }
+
+    @Override
+    public void execute()
+    {
+        int result = literal + Memory.workingRegister;
+
+        checkZeroBit(result);
+        checkCarryBit(result);
+        checkDigitCarryBit(result, literal);
+
+        Memory.workingRegister = result % 256;
+    }
+}

commands/Command.java

@@ -0,0 +1,6 @@
+package commands;
+
+public interface Command
+{
+    void execute();
+}

commands/CommandUtils.java

@@ -0,0 +1,33 @@
+package commands;
+
+import registers.Memory;
+
+public class CommandUtils
+{
+    protected void checkZeroBit(int result)
+    {
+        if(result == 0){
+            Memory.setZeroBit();
+        } else{
+            Memory.clearZeroBit();
+        }
+    }
+
+    protected void checkCarryBit(int result)
+    {
+        if(result > 255){
+            Memory.setCarryBit();
+        } else{
+            Memory.clearCarryBit();
+        }
+    }
+
+    protected void checkDigitCarryBit(int result, int literal)
+    {
+        if(((Memory.workingRegister & 0x0F) + (literal & 0x0F)) > 15){
+            Memory.setDigitCarryBit();
+        } else{
+            Memory.clearDigitCarryBit();
+        }
+    }
+}

decoder/CommandDecoder.java

@@ -1,6 +1,11 @@
+package decoder;
+
+import commands.Addlw;
+import commands.Command;
+
 public class CommandDecoder
 {
-    public CommandDecoder(int input)
+    public static Command decode(int input)
     {
         switch(input & 0x3F00)
         {
@@ -90,7 +95,8 @@ public class CommandDecoder
         {
             case 0x3E00:
                 //addlw();
-                break;
+                return new Addlw(input);
+                //break;
             case 0x3C00:
                 //sublw();
                 break;
@@ -141,5 +147,8 @@ public class CommandDecoder
         {
             //sleep();
         }
+
+        System.out.println("No command matched");
+        return null;
     }
 }

parser/Parser.java

@@ -1,11 +1,14 @@
+package parser;
+
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.util.ArrayList;
+import java.util.List;
 import java.util.Scanner;
 
 public class Parser
 {
-    public static ArrayList<Integer> parser(String filePath)
+    public static List<Integer> parser(String filePath)
     {
         ArrayList<Integer> program = new ArrayList<>();
         try {

registers/Memory.java

@@ -1,9 +1,11 @@
+package registers;
+
 import java.util.Arrays;
 
-public class Registers
+public class Memory
 {
     private static final int MEMORY_SIZE = 0xFF;  //Addressable Memory
-    public static final int workingRegister = 0;
+    public static int workingRegister = 0;
     private static final int[] memory = new int[MEMORY_SIZE];
     private static final int[] bank0UniqueSpecialRegister = new int[] {0x01,0x05,0x06,0x08,0x09}; //and many more
     private static final int[] bank1UniqueSpecialRegister = new int[] {0x81,0x85,0x86,0x88,0x89}; //and many more
@@ -50,7 +52,7 @@ public class Registers
         {
             return memory[address];
         }
-        return memory[address % 128]; // else: Registers which are mapped
+        return memory[address % 128]; // else: Registers.Registers which are mapped
     }
 
     private static void setDataFromIndirectAddress(int address, int data)
@@ -59,7 +61,7 @@ public class Registers
         {
             memory[address] = data;
         }
-        memory[address % 128] = data; // else: Registers which are mapped
+        memory[address % 128] = data; // else: Registers.Registers which are mapped
     }
 
     private static int getRegisterBank()