public void InterruptServiceRoutine()
{
byte bIF = Memory.DirectRead(IF);
byte bIE = Memory.DirectRead(IE);
int f = IRQLookup[bIF & bIE & 0x1F]; //-1 means no interrupt
if (IME)
{
if (f != -1)
{
//2 Internal delays
Board.AdvanceSystemTime(); //4
Board.AdvanceSystemTime(); //8
//PUSH PC
Board.AdvanceSystemTime(); //12
Memory.Write((byte)(Registers.PC >> 8), --Registers.SP);
Board.AdvanceSystemTime(); //16
Memory.Write((byte)Registers.PC, --Registers.SP);
//SERVE
bIF = ServeIRQ(f, bIF);
Board.AdvanceSystemTime(); //20
Memory.DirectWrite(bIF, IF);
if (GetCPU().Halt)
{
Board.AdvanceSystemTime(); //24
GetCPU().Halt = false;
}
SetIME(false);
}
}
else
{
if (f != -1)
{
if (GetCPU().Halt)
{
Board.AdvanceSystemTime(); //4
GetCPU().Halt = false;
GetCPU().DoubleInstructionExecutionBug = DoubleInstructionEnable;
DoubleInstructionEnable = true;
}
}
else
{
DoubleInstructionEnable = false;
}
}
if (Schedule)
{
IME = true;
Schedule = false;
}
}
public void WriteByte(long address, byte b)
{
mmu.Write(b, (ushort)address);
}
