diff --git a/pom.xml b/pom.xml
index 85afb62..41d0a6a 100644
--- a/pom.xml
+++ b/pom.xml
@@ -80,6 +80,13 @@
             <version>${junit.version}</version>
             <scope>test</scope>
         </dependency>
+        <!-- https://mvnrepository.com/artifact/org.mockito/mockito-core -->
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <version>5.17.0</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>
@@ -113,6 +120,24 @@
                     </execution>
                 </executions>
             </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-dependency-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>properties</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <configuration>
+                    <argLine>@{argLine} -javaagent:${org.mockito:mockito-core:jar}</argLine>
+                </configuration>
+            </plugin>
         </plugins>
     </build>
 </project>
\ No newline at end of file
diff --git a/src/main/java/fabrik/simulator/pic16f84/Commands.java b/src/main/java/fabrik/simulator/pic16f84/Commands.java
index 8116fde..7fab199 100644
--- a/src/main/java/fabrik/simulator/pic16f84/Commands.java
+++ b/src/main/java/fabrik/simulator/pic16f84/Commands.java
@@ -4,6 +4,7 @@ import fabrik.simulator.pic16f84.interfaces.*;
 public class Commands extends PICComponent implements CommandInterface {
     private int wRegister;
     private long totalExecutionTime;
+    private double executionTimeMultiplier = 1;
 
     public Commands(){
         super();
@@ -22,7 +23,7 @@ public class Commands extends PICComponent implements CommandInterface {
     }
 
     public double getTotalExecutionTime() {
-        return (totalExecutionTime * frontendController.getExecutionTimeMultiplier());
+        return (totalExecutionTime * getExecutionTimeMultiplier());
     }
 
     public void resetTotalExecutionTime() {
@@ -248,8 +249,6 @@ public class Commands extends PICComponent implements CommandInterface {
         else{
             System.out.println("Nicht gefunden!");
         }
-
-
     }
 
     public void SLEEP() {
@@ -557,9 +556,39 @@ public class Commands extends PICComponent implements CommandInterface {
         }
     }
 
+    public double getExecutionTimeMultiplier(){
+        return executionTimeMultiplier;
+    }
+
+    public void setExecutionTimeMultiplier(String option){
+        switch (option) {
+            case "8 MHZ":
+                executionTimeMultiplier = 0.5;
+                break;
+
+            case "4 MHZ":
+                executionTimeMultiplier = 1;
+                break;
+            case "1 MHZ":
+                executionTimeMultiplier = 4;
+                break;
+            case "500 HZ":
+                executionTimeMultiplier = 8;
+                break;
+
+            case "100 HZ":
+                executionTimeMultiplier = 40;
+                break;
+
+            case "32 HZ":
+                executionTimeMultiplier = 125;
+                break;
+        }
+    }
+
+
     @Override
     public void initialize(PICComponents picComponents) {
-        System.out.println("Commands");
         super.initialize(picComponents);
     }
 }
diff --git a/src/main/java/fabrik/simulator/pic16f84/Controller_Frontend.java b/src/main/java/fabrik/simulator/pic16f84/Controller_Frontend.java
index 587b4a2..45ff56e 100644
--- a/src/main/java/fabrik/simulator/pic16f84/Controller_Frontend.java
+++ b/src/main/java/fabrik/simulator/pic16f84/Controller_Frontend.java
@@ -43,13 +43,6 @@ public class Controller_Frontend extends PICComponent implements FrontendControl
     private int [][] read;
     private int [] ind;
     private PICComponents picComponents;
-    private double executionTimeMultiplier = 1;
-
-
-
-    public double getExecutionTimeMultiplier(){
-        return executionTimeMultiplier;
-    }
 
     private boolean isBreakpointReached = false;
 
@@ -160,29 +153,7 @@ public class Controller_Frontend extends PICComponent implements FrontendControl
 
     private void updateExecutionTimeMultiplier() {
         String selectedOption = executionTimeComboBox.getValue();
-        switch (selectedOption) {
-            case "8 MHZ":
-                executionTimeMultiplier = 0.5;
-                break;
-
-            case "4 MHZ":
-                executionTimeMultiplier = 1;
-                break;
-            case "1 MHZ":
-                executionTimeMultiplier = 4;
-                break;
-            case "500 HZ":
-                executionTimeMultiplier = 8;
-                break;
-
-            case "100 HZ":
-                executionTimeMultiplier = 40;
-                break;
-
-            case "32 HZ":
-                executionTimeMultiplier = 125;
-                break;
-        }
+        commands.setExecutionTimeMultiplier(selectedOption);
     }
 
     @FXML
diff --git a/src/main/java/fabrik/simulator/pic16f84/EEPROM.java b/src/main/java/fabrik/simulator/pic16f84/EEPROM.java
index ddd3034..19791a1 100644
--- a/src/main/java/fabrik/simulator/pic16f84/EEPROM.java
+++ b/src/main/java/fabrik/simulator/pic16f84/EEPROM.java
@@ -36,6 +36,7 @@ public class EEPROM extends PICComponent implements EEPROMInterface {
     }
 
     public long read (int address) {
+        if (address < 0) return 0;
         FileReader reader;
         try {
             reader = new FileReader("eeprom.json");
@@ -60,6 +61,7 @@ public class EEPROM extends PICComponent implements EEPROMInterface {
     }
 
     public void write (int address, long data) {
+        if (address < 0) return;
         FileReader reader;
         try {
             reader = new FileReader("eeprom.json");
@@ -172,7 +174,6 @@ public class EEPROM extends PICComponent implements EEPROMInterface {
 
     @Override
     public void initialize(PICComponents picComponents) {
-        System.out.println("EEPROM");
         super.initialize(picComponents);
     }
 }
diff --git a/src/main/java/fabrik/simulator/pic16f84/PICComponent.java b/src/main/java/fabrik/simulator/pic16f84/PICComponent.java
index 1989679..f5fe00e 100644
--- a/src/main/java/fabrik/simulator/pic16f84/PICComponent.java
+++ b/src/main/java/fabrik/simulator/pic16f84/PICComponent.java
@@ -5,7 +5,7 @@ import fabrik.simulator.pic16f84.interfaces.*;
 public abstract class PICComponent {
     DataRegisterInterface dataRegister;
     EEPROMInterface eeprom;
-    PreScaler preScaler;
+    PreScalerInterface preScaler;
     IOPortInterface ioPorts;
     TimerInterface timer;
     InterruptInterface interrupts;
@@ -22,7 +22,7 @@ public abstract class PICComponent {
         dataRegister = (DataRegisterInterface) picComponents.getComponent(DataRegisterInterface.class);
         eeprom = (EEPROMInterface) picComponents.getComponent(EEPROMInterface.class);
         ioPorts = (IOPortInterface) picComponents.getComponent(IOPortInterface.class);
-        preScaler = (PreScaler) picComponents.getComponent(PreScalerInterface.class);
+        preScaler = (PreScalerInterface) picComponents.getComponent(PreScalerInterface.class);
         timer = (TimerInterface) picComponents.getComponent(TimerInterface.class);
         interrupts = (InterruptInterface) picComponents.getComponent(InterruptInterface.class);
         //table = (TableInterface) picComponents.getComponent(TableInterface.class);
diff --git a/src/main/java/fabrik/simulator/pic16f84/WatchdogTimer.java b/src/main/java/fabrik/simulator/pic16f84/WatchdogTimer.java
index 8c9f352..e1b3b7f 100644
--- a/src/main/java/fabrik/simulator/pic16f84/WatchdogTimer.java
+++ b/src/main/java/fabrik/simulator/pic16f84/WatchdogTimer.java
@@ -26,7 +26,7 @@ public class WatchdogTimer extends PICComponent implements WatchdogTimerInterfac
             }
             else {
                 rawtimer++;
-                realtimer = (long) (rawtimer * frontendController.getExecutionTimeMultiplier());
+                realtimer = (long) (rawtimer * commands.getExecutionTimeMultiplier());
             }
         }
     }
diff --git a/src/main/java/fabrik/simulator/pic16f84/interfaces/CommandInterface.java b/src/main/java/fabrik/simulator/pic16f84/interfaces/CommandInterface.java
index a05f745..4cbeacb 100644
--- a/src/main/java/fabrik/simulator/pic16f84/interfaces/CommandInterface.java
+++ b/src/main/java/fabrik/simulator/pic16f84/interfaces/CommandInterface.java
@@ -10,4 +10,10 @@ public interface CommandInterface extends PICComponentInterface {
     void decode(int i);
 
     void resetTotalExecutionTime();
+
+    void addExecutionTime(int i);
+
+    double getExecutionTimeMultiplier();
+
+    void setExecutionTimeMultiplier(String option);
 }
diff --git a/src/main/java/fabrik/simulator/pic16f84/interfaces/EEPROMInterface.java b/src/main/java/fabrik/simulator/pic16f84/interfaces/EEPROMInterface.java
index 776b4bd..4f4c49f 100644
--- a/src/main/java/fabrik/simulator/pic16f84/interfaces/EEPROMInterface.java
+++ b/src/main/java/fabrik/simulator/pic16f84/interfaces/EEPROMInterface.java
@@ -4,4 +4,8 @@ public interface EEPROMInterface extends PICComponentInterface {
     void registerTime(boolean b);
 
     void parse(int i, int content, int i1);
+
+    long read(int address);
+
+    void write (int address, long data);
 }
diff --git a/src/main/java/fabrik/simulator/pic16f84/interfaces/FrontendControllerInterface.java b/src/main/java/fabrik/simulator/pic16f84/interfaces/FrontendControllerInterface.java
index bc4364e..bc7aeb8 100644
--- a/src/main/java/fabrik/simulator/pic16f84/interfaces/FrontendControllerInterface.java
+++ b/src/main/java/fabrik/simulator/pic16f84/interfaces/FrontendControllerInterface.java
@@ -1,7 +1,6 @@
 package fabrik.simulator.pic16f84.interfaces;
 
 public interface FrontendControllerInterface extends PICComponentInterface {
-    double getExecutionTimeMultiplier();
 
     void sleep();
 
diff --git a/src/test/java/fabrik/simulator/pic16f84/CommandsTests.java b/src/test/java/fabrik/simulator/pic16f84/CommandsTests.java
new file mode 100644
index 0000000..a81e121
--- /dev/null
+++ b/src/test/java/fabrik/simulator/pic16f84/CommandsTests.java
@@ -0,0 +1,88 @@
+package fabrik.simulator.pic16f84;
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.Mockito.*;
+
+import fabrik.simulator.pic16f84.interfaces.*;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+
+class CommandsTests {
+    PICComponents picComponents;
+
+    public CommandsTests() {}
+
+    @BeforeEach
+    void resetComponents() {
+        picComponents = new PICComponents();
+    }
+
+    @Test
+    @DisplayName("Execution Time wird korrekt addiert")
+    void executionTimeIsAddedCorrectly() {
+        TimerInterface timerMock = mock(TimerInterface.class);
+        picComponents.registerComponent(TimerInterface.class, timerMock);
+
+        EEPROMInterface eepromMock = mock(EEPROMInterface.class);
+        picComponents.registerComponent(EEPROMInterface.class, eepromMock);
+
+        CommandInterface commands = new Commands();
+        picComponents.registerComponent(CommandInterface.class, commands);
+        picComponents.initAll();
+
+
+        commands.addExecutionTime(5);
+
+
+        assertEquals(5, commands.getTotalExecutionTime());
+    }
+
+    @Test
+    @DisplayName("Execution Time wird korrekt zurückgesetzt")
+    void executionTimeResetWorks() {
+        TimerInterface timerMock = mock(TimerInterface.class);
+        picComponents.registerComponent(TimerInterface.class, timerMock);
+
+        EEPROMInterface eepromMock = mock(EEPROMInterface.class);
+        picComponents.registerComponent(EEPROMInterface.class, eepromMock);
+
+        CommandInterface commands = new Commands();
+        picComponents.registerComponent(CommandInterface.class, commands);
+        picComponents.initAll();
+
+
+        commands.addExecutionTime(5);
+        commands.resetTotalExecutionTime();
+
+
+        assertEquals(0, commands.getTotalExecutionTime());
+    }
+
+    @Test
+    @DisplayName("Execution Time Faktor wird berücksichtigt")
+    void executionTimeMultiplierIsUsed() {
+        TimerInterface timerMock = mock(TimerInterface.class);
+        picComponents.registerComponent(TimerInterface.class, timerMock);
+
+        EEPROMInterface eepromMock = mock(EEPROMInterface.class);
+        picComponents.registerComponent(EEPROMInterface.class, eepromMock);
+
+        CommandInterface commands = new Commands();
+        picComponents.registerComponent(CommandInterface.class, commands);
+        picComponents.initAll();
+
+        commands.addExecutionTime(5);
+        commands.setExecutionTimeMultiplier("100 HZ");
+
+        assertEquals(5 * 40, commands.getTotalExecutionTime());
+    }
+
+    @Test
+    @DisplayName("Decode mit ungültigem Opcode wirft keine Exception")
+    void decodeInvalidOpcodeDoesNotCrash() {
+        CommandInterface commands = new Commands();
+
+        assertDoesNotThrow(() -> commands.decode(1));
+    }
+}
diff --git a/src/test/java/fabrik/simulator/pic16f84/DataRegisterTests.java b/src/test/java/fabrik/simulator/pic16f84/DataRegisterTests.java
new file mode 100644
index 0000000..b40c794
--- /dev/null
+++ b/src/test/java/fabrik/simulator/pic16f84/DataRegisterTests.java
@@ -0,0 +1,50 @@
+package fabrik.simulator.pic16f84;
+
+import fabrik.simulator.pic16f84.interfaces.*;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.mock;
+
+class DataRegisterTests {
+    PICComponents picComponents;
+
+    public DataRegisterTests() {}
+
+    @BeforeEach
+    void resetComponents() {
+        picComponents = new PICComponents();
+    }
+
+
+    @Test
+    @DisplayName("DataRegister wird durch Components initialisiert und enthält dann die korrekten Startwerte")
+    void registerGetsInitializedThroughComponents() {
+        IOPortInterface mockIOPorts = mock(IOPortInterface.class);
+        picComponents.registerComponent(IOPortInterface.class, mockIOPorts);
+
+        DataRegisterInterface dataRegister = new DataRegister();
+        picComponents.registerComponent(DataRegisterInterface.class, dataRegister);
+
+
+        picComponents.initAll();
+        int [] expected = {0, 0, 0, 24, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+                            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+                            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+                            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+                            0, 0, 0, 0, 0, 255, 0, 24, 0, 255, 255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+                            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+                            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+                            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+                            0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+
+        int [] actual = dataRegister.getDataRegister();
+
+        assertEquals(expected.length, actual.length);
+        for (int i = 0; i<expected.length; i++){
+            assertEquals(expected[i], actual[i]);
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/test/java/fabrik/simulator/pic16f84/EEPROMTests.java b/src/test/java/fabrik/simulator/pic16f84/EEPROMTests.java
new file mode 100644
index 0000000..604cc1a
--- /dev/null
+++ b/src/test/java/fabrik/simulator/pic16f84/EEPROMTests.java
@@ -0,0 +1,137 @@
+package fabrik.simulator.pic16f84;
+
+import fabrik.simulator.pic16f84.interfaces.CommandInterface;
+import fabrik.simulator.pic16f84.interfaces.DataRegisterInterface;
+import fabrik.simulator.pic16f84.interfaces.EEPROMInterface;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+
+import java.io.FileWriter;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.mock;
+
+
+class EEPROMTests {
+    PICComponents picComponents;
+    String savedEEPROM;
+
+    public EEPROMTests() {}
+
+    @BeforeEach
+    void resetComponentsAndReadEEPROM() throws IOException {
+        picComponents = new PICComponents();
+        savedEEPROM = Files.readString(Path.of("eeprom.json"));
+    }
+
+    @AfterEach
+    public void rewriteEEPROM() throws IOException {
+        FileWriter writer = new FileWriter("eeprom.json");
+        writer.write(savedEEPROM);
+        writer.close();
+    }
+
+    @Test
+    @DisplayName("EEPROM read gibt gültigen Wert zurück")
+    void eepromReadReturnsValidLong() throws IOException {
+        FileWriter writer = new FileWriter("eeprom.json");
+        writer.write("{\"0\": 255}");
+        writer.close();
+
+        DataRegisterInterface mockDataRegister = Mockito.mock(DataRegisterInterface.class);
+        picComponents.registerComponent(DataRegisterInterface.class, mockDataRegister);
+
+        EEPROMInterface eeprom = new EEPROM();
+        picComponents.registerComponent(EEPROMInterface.class, eeprom);
+        picComponents.initAll();
+
+
+        long value = eeprom.read(0);
+
+
+        assertEquals(255, value);
+    }
+
+
+    @Test
+    @DisplayName("EEPROM write schreibt an die korrekte Adresse in eeprom.json")
+    void eepromWritesCorrectly() throws IOException {
+        FileWriter writer = new FileWriter("eeprom.json");
+        writer.write("{}");
+        writer.close();
+
+        DataRegisterInterface mockDataRegister = Mockito.mock(DataRegisterInterface.class);
+        picComponents.registerComponent(DataRegisterInterface.class, mockDataRegister);
+
+        CommandInterface mockCommands = mock(CommandInterface.class);
+        picComponents.registerComponent(CommandInterface.class, mockCommands);
+
+        EEPROMInterface eeprom = new EEPROM();
+        picComponents.registerComponent(EEPROMInterface.class, eeprom);
+        picComponents.initAll();
+
+
+        eeprom.write(3, 123);
+
+
+        assertEquals("{\"3\":123}", Files.readString(Path.of("eeprom.json")));
+    }
+
+
+    @Test
+    @DisplayName("EEPROM write schreibt nicht an negative Adressen")
+    void eepromDoesntWriteNegative() throws IOException {
+        FileWriter writer = new FileWriter("eeprom.json");
+        writer.write("{}");
+        writer.close();
+
+        DataRegisterInterface mockDataRegister = Mockito.mock(DataRegisterInterface.class);
+        picComponents.registerComponent(DataRegisterInterface.class, mockDataRegister);
+
+        CommandInterface mockCommands = mock(CommandInterface.class);
+        picComponents.registerComponent(CommandInterface.class, mockCommands);
+
+        EEPROMInterface eeprom = new EEPROM();
+        picComponents.registerComponent(EEPROMInterface.class, eeprom);
+        picComponents.initAll();
+
+
+        eeprom.write(-1, 1);
+
+
+        assertEquals("{}", Files.readString(Path.of("eeprom.json")));
+    }
+
+
+    @Test
+    @DisplayName("EEPROM read mit negativem Wert liefert 0")
+    void eepromReadWithNegativeAddress() throws IOException {
+        FileWriter writer = new FileWriter("eeprom.json");
+        writer.write("{\"-1\":5}");
+        writer.close();
+
+        DataRegisterInterface mockDataRegister = Mockito.mock(DataRegisterInterface.class);
+        picComponents.registerComponent(DataRegisterInterface.class, mockDataRegister);
+
+        CommandInterface mockCommands = mock(CommandInterface.class);
+        picComponents.registerComponent(CommandInterface.class, mockCommands);
+
+        EEPROMInterface eeprom = new EEPROM();
+        picComponents.registerComponent(EEPROMInterface.class, eeprom);
+        picComponents.initAll();
+
+
+        long result = eeprom.read(-1);
+
+
+        assertEquals(0, result);
+    }
+
+}
\ No newline at end of file
diff --git a/src/test/java/fabrik/simulator/pic16f84/WatchDogTimerTests.java b/src/test/java/fabrik/simulator/pic16f84/WatchDogTimerTests.java
new file mode 100644
index 0000000..d6ee7d6
--- /dev/null
+++ b/src/test/java/fabrik/simulator/pic16f84/WatchDogTimerTests.java
@@ -0,0 +1,50 @@
+package fabrik.simulator.pic16f84;
+
+import fabrik.simulator.pic16f84.interfaces.*;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+class WatchDogTimerTests {
+    private PICComponents picComponents;
+
+    @BeforeEach
+    void resetComponents() {
+        picComponents = new PICComponents();
+    }
+
+    @Test
+    @DisplayName("WatchDogTimer testet ob er triggern soll, triggert korrekt nicht")
+    void watchDogIncrementWithoutTriggering() {
+        PreScalerInterface mockPreScaler = mock(PreScalerInterface.class);
+        when(
+                mockPreScaler.isPrescalerOnTimer()
+        ).thenReturn(
+                true
+        );
+        picComponents.registerComponent(PreScalerInterface.class, mockPreScaler);
+
+
+        CommandInterface mockCommands = mock(CommandInterface.class);
+        when(
+                mockCommands.getExecutionTimeMultiplier()
+        ).thenReturn(
+                1.0
+        );
+        picComponents.registerComponent(CommandInterface.class, mockCommands);
+
+        WatchdogTimerInterface watchDogTimer = new WatchdogTimer();
+        picComponents.registerComponent(WatchdogTimerInterface.class, watchDogTimer);
+        picComponents.initAll();
+
+        watchDogTimer.enable();
+        watchDogTimer.testAndTrigger();
+
+
+        assertEquals(1, watchDogTimer.get());
+    }
+}
\ No newline at end of file