cpu/cpu - Implement stop mode

cpu/cpu.cpp

@@ -54,6 +54,8 @@ Cpu::Cpu(Mem_device* bus)
 
 void Cpu::step()
 {
+  if(stopped) return;
+
   if(!handleInterrupts()) // if no isr has been called, decode an instruction
     {
       if (halted)
@@ -82,6 +84,7 @@ void Cpu::reset()
   state.IF = 0;
 
   halted = false;
+  stopped = false;
 }
 
 u8 Cpu::readPC8()

cpu/cpu.h

@@ -92,6 +92,7 @@ struct Cpu_state {
   u8 IF;
 
   bool halted;
+  bool stopped;
 
   void setAF(u16 v);
   u16 getAF();