implemented Clrwdt Instruction

Co-authored-by: Darkress <30271678+DarkressX@users.noreply.github.com>
Reviewed-on: darkress/pic16f84-sim#33

de/darkress/pic16f84sim/Main.java

@@ -5,6 +5,7 @@ import de.darkress.pic16f84sim.decoder.CommandDecoder;
 import de.darkress.pic16f84sim.microcontroller.Cycles;
 import de.darkress.pic16f84sim.microcontroller.Memory;
 import de.darkress.pic16f84sim.microcontroller.ProgramCounter;
+import de.darkress.pic16f84sim.microcontroller.Watchdog;
 import de.darkress.pic16f84sim.parser.Parser;
 
 import java.util.concurrent.TimeUnit;
@@ -13,18 +14,30 @@ class Main
 {
     public static void main(String[] args) throws InterruptedException {
 
-        Command[] program = Parser.parser("de/darkress/pic16f84sim/TestPrograms/TPicSim7.LST");
+        Command[] program = Parser.parser("de/darkress/pic16f84sim/TestPrograms/TPicSim11.LST");
 
         Memory.initMemory();
 
         while(ProgramCounter.getPc() < 1024)
         {
+            if((Memory.getRegister(0x03) & 0x10) == 0x00) { // Checking WDT in Status Register
+                System.out.println("Resetting device");
+                Watchdog.resetProgram();
+            }
             System.out.println("Command: " + program[ProgramCounter.getPc()].toString());
             program[ProgramCounter.getPc()].execute();
 
             System.out.println(Integer.toHexString(Memory.workingRegister) + " " + Cycles.getCycles());
             System.out.println(Integer.toHexString(Memory.getOption()) + " " + Integer.toHexString(Memory.getTimer()));
+
+            System.out.println(Integer.toHexString(Memory.getRegister(0x20)) + " " + Integer.toHexString(Memory.getRegister(0x21)));
+            System.out.println(Integer.toHexString(Memory.getRegister(0x22)) + " " + Integer.toHexString(Memory.getRegister(0x23)));
+
             System.out.println(Integer.toHexString(Memory.getPCLATH()) + " " + Integer.toHexString(Memory.getPCL()) + "\n");
+
+            if(ProgramCounter.getPc() == 0x10) {
+                System.out.println(Memory.getRegister(0x20));
+            }
         }
     }
 }

de/darkress/pic16f84sim/commands/Clrwdt.java

@@ -0,0 +1,24 @@
+package de.darkress.pic16f84sim.commands;
+
+import de.darkress.pic16f84sim.microcontroller.*;
+
+public class Clrwdt extends LiteralCommandUtils implements Command
+{
+
+    public Clrwdt()
+    {
+    }
+
+    @Override
+    public void execute()
+    {
+        ProgramCounter.incPC();
+        Cycles.incCycles();
+
+        Memory.setRegister(0x03, Memory.getRegister(0x03) | 0x18);
+        if(Timer.getPrescalerAssignment()) {
+            Timer.resetTimeToTimerIncrease();
+            Watchdog.resetWatchdogTimer();
+        }
+    }
+}

de/darkress/pic16f84sim/decoder/CommandDecoder.java

@@ -97,7 +97,7 @@ public class CommandDecoder
 
         if (input == 0x0064)
         {
-            //clrwdt();
+            return new Clrwdt();
         }
 
         if (input == 0x0009)

de/darkress/pic16f84sim/microcontroller/Cycles.java

@@ -5,7 +5,7 @@ public class Cycles {
 
     public static void incCycles()
     {
-        Timer.increaseTimer();
+        Timer.decreasePrescaler();
         cycles++;
     }
 

de/darkress/pic16f84sim/microcontroller/Memory.java

@@ -54,7 +54,8 @@ public class Memory
             setDataFromIndirectAddress(indirectAddress, data);
             return;
         }
-        if(address == 0x01) //Reset PrescalerCounter if change on Option or Timer Register
+        if(address == 0x01 && !Timer.getPrescalerAssignment()) //Reset PrescalerCounter if change on Option or Timer
+            // Register
         {
             Timer.resetTimeToTimerIncrease();
             Timer.setCyclesToTimerIncrease(Timer.getCyclesToTimerIncrease() - 1); //Decrease by one to account for
@@ -86,7 +87,7 @@ public class Memory
 
     private static void setDataFromIndirectAddress(int address, int data)
     {
-        if(address == 0x81 || address == 0x01) //Reset PrescalerCounter if change on Option or Timer Register
+        if((address == 0x81 || address == 0x01) && !Timer.getPrescalerAssignment()) //Reset PrescalerCounter if change on Option or Timer Register
         {
             Timer.resetTimeToTimerIncrease();
             Timer.setCyclesToTimerIncrease(Timer.getCyclesToTimerIncrease() - 1); //Decrease by one to account for

de/darkress/pic16f84sim/microcontroller/ProgramCounter.java

@@ -36,4 +36,9 @@ public class ProgramCounter
         pc++;
         Memory.setPCL(pc & 0x00FF);
     }
+
+    public static void resetProgramCounter() {
+        pc = 0;
+        Memory.setPCL(0x0);
+    }
 }

de/darkress/pic16f84sim/microcontroller/Timer.java

@@ -24,7 +24,7 @@ public class Timer
         cyclesToTimerIncrease = getPrescalerFactor();
     }
 
-    private static boolean getPrescalerAsssignment() {
+    public static boolean getPrescalerAssignment() {
         return (Memory.getOption() & 0x08) == 0x08;
     }
 
@@ -32,7 +32,7 @@ public class Timer
         final int MULTIPLIER = 2;
         int prescalerPower = Memory.getOption() & 0x07;
         int prescaler = (int)Math.pow(2, prescalerPower);
-        if(!getPrescalerAsssignment())
+        if(!getPrescalerAssignment())
         {
             return prescaler * MULTIPLIER;
         }
@@ -50,17 +50,27 @@ public class Timer
         Memory.setTimer(timerRegister);
     }
 
-    public static void increaseTimer()
+    public static void decreasePrescaler()
     {
-        if(!timerEnabled())
-        {
-            return;
+        if(getPrescalerAssignment()) { // Assigned to WatchdogTimer
+            cyclesToTimerIncrease--;
+            if(cyclesToTimerIncrease == 0) {
+                resetTimeToTimerIncrease();
+                Watchdog.decreaseWatchdogTimer();
+            }
+        } else {
+            Watchdog.decreaseWatchdogTimer();
         }
-        cyclesToTimerIncrease--;
-        if(cyclesToTimerIncrease == 0)
-        {
-            resetTimeToTimerIncrease();
-            increaseTimerRegister();
+        if(timerEnabled()) {
+            if(!getPrescalerAssignment()) { // Assigned to timer0
+                cyclesToTimerIncrease--;
+                if(cyclesToTimerIncrease == 0) {
+                    resetTimeToTimerIncrease();
+                    Timer.increaseTimerRegister();
+                }
+            } else {
+                Timer.increaseTimerRegister();
+            }
         }
     }
 }

de/darkress/pic16f84sim/microcontroller/Watchdog.java

@@ -0,0 +1,36 @@
+package de.darkress.pic16f84sim.microcontroller;
+
+public class Watchdog
+{
+    private static int watchdogTimer = 18000;
+    public static int getWatchdogTimer()
+    {
+        return watchdogTimer;
+    }
+
+    public static void resetWatchdogTimer() {
+        watchdogTimer = 18000;
+    }
+
+    public static void decreaseWatchdogTimer()
+    {
+        watchdogTimer--;
+        checkWatchdog();
+    }
+
+    private static void checkWatchdog()
+    {
+        if(watchdogTimer == 0)
+        {
+            System.out.println("Watchdog Time-Out");
+            Memory.setRegister(0x03, Memory.getRegister(0x03) & 0xEF); //Clear !TO in StatusReg
+        }
+    }
+
+    public static void resetProgram()
+    {
+        Memory.setRegister(0x03, Memory.getRegister(0x03) | 0x10);
+        watchdogTimer = 18000;
+    }
+
+}