implemented timer, opcode decoding

ass2/Machine.h

@@ -2,6 +2,8 @@
 #define MACHINE_H
 
 #include <cstdint>
+#include <thread>
+#include <atomic>
 
 #include "Device.h"
 
@@ -24,6 +26,11 @@ class Machine {
     int PC;    // Program Counter (24-bit)
     int SW;    // Status Word (24-bit)
 
+    // timer simulation
+    std::atomic<bool> running;
+    std::thread* timerThread;
+    int speed;  // kHz
+
    public:
     Machine();
     ~Machine();
@@ -62,12 +69,31 @@ class Machine {
 
     int getByte(int addr) const;
     void setByte(int addr, int val);
-    
+
     int getWord(int addr) const;
     void setWord(int addr, int val);
 
     Device* getDevice(int num) const;
     void setDevice(int num, Device* device);
+
+    // error handling
+    void notImplemented(const char* mnemonic);
+    void invalidOpcode(int opcode);
+    void invalidAddressing();
+
+    // execution
+    int fetch();
+    void execute();
+    bool execF1(int opcode);
+    bool execF2(int opcode, int operand);
+    bool execSICF3F4(int opcode, int ni, int operand);
+
+    // timer simulation
+    void start();
+    void stop();
+    bool isRunning() const;
+    int getSpeed() const;
+    void setSpeed(int kHz);
 };
 
 #endif  // MACHINE_H