private int GetAddress(AddressModes addressMode, int SignatureBytes, RegisterBankNumber Bank)
{
int addr = 0;
int ptr = 0;
switch (addressMode)
{
// The address will not be used in Immediate or Implied mode, but
case AddressModes.Immediate:
return(ADDRESS_IMMEDIATE);
case AddressModes.Implied:
return(ADDRESS_IMPLIED);
case AddressModes.Absolute:
return(Bank.GetLongAddress(SignatureBytes));
case AddressModes.AbsoluteLong:
return(SignatureBytes);
case AddressModes.AbsoluteIndexedWithX:
return(Bank.GetLongAddress(SignatureBytes + cpu.X.Value));
case AddressModes.AbsoluteLongIndexedWithX:
return(SignatureBytes + cpu.X.Value);
case AddressModes.AbsoluteIndexedWithY:
return(SignatureBytes + cpu.Y.Value);
case AddressModes.AbsoluteLongIndexedWithY:
return(Bank.GetLongAddress(SignatureBytes + cpu.X.Value));
case AddressModes.DirectPage:
return(cpu.DirectPage.GetLongAddress(SignatureBytes));
case AddressModes.DirectPageIndexedWithX:
return(cpu.DirectPage.GetLongAddress(SignatureBytes + cpu.X.Value));
case AddressModes.DirectPageIndexedWithY:
return(cpu.DirectPage.GetLongAddress(SignatureBytes + cpu.Y.Value));
case AddressModes.DirectPageIndexedIndirectWithX:
addr = cpu.DirectPage.GetLongAddress(SignatureBytes) + cpu.X.Value;
ptr = cpu.Memory.ReadWord(addr);
return(cpu.ProgramBank.GetLongAddress(ptr));
case AddressModes.DirectPageIndirect:
addr = cpu.DirectPage.GetLongAddress(SignatureBytes);
ptr = cpu.Memory.ReadWord(addr);
return(cpu.ProgramBank.GetLongAddress(ptr));
case AddressModes.DirectPageIndirectIndexedWithY:
addr = cpu.DirectPage.GetLongAddress(SignatureBytes);
ptr = cpu.Memory.ReadWord(addr) + cpu.Y.Value;
return(cpu.ProgramBank.GetLongAddress(ptr));
case AddressModes.DirectPageIndirectLong:
addr = cpu.DirectPage.GetLongAddress(SignatureBytes);
ptr = cpu.Memory.ReadLong(addr);
return(ptr);
case AddressModes.DirectPageIndirectLongIndexedWithY:
addr = cpu.DirectPage.GetLongAddress(SignatureBytes);
ptr = cpu.Memory.ReadLong(addr) + cpu.Y.Value;
return(cpu.ProgramBank.GetLongAddress(ptr));
case AddressModes.ProgramCounterRelative:
ptr = MakeSignedByte((byte)SignatureBytes);
addr = cpu.PC.Value + ptr;
return(addr);
case AddressModes.ProgramCounterRelativeLong:
ptr = MakeSignedInt((UInt16)SignatureBytes);
addr = cpu.PC.Value + ptr;
return(addr);
case AddressModes.StackImplied:
//case AddressModes.StackAbsolute:
return(0);
case AddressModes.StackDirectPageIndirect:
return(cpu.DirectPage.GetLongAddress(SignatureBytes));
case AddressModes.StackRelative:
return(cpu.Stack.Value + SignatureBytes);
case AddressModes.StackRelativeIndirectIndexedWithY:
return(cpu.Stack.Value + SignatureBytes + cpu.Y.Value);
case AddressModes.StackProgramCounterRelativeLong:
return(SignatureBytes);
// Jump and JSR indirect references vectors located in Bank 0
case AddressModes.JmpAbsoluteIndirect:
addr = SignatureBytes;
ptr = cpu.Memory.ReadWord(addr);
return(cpu.ProgramBank.GetLongAddress(ptr));
case AddressModes.JmpAbsoluteIndirectLong:
addr = SignatureBytes;
ptr = cpu.Memory.ReadLong(addr);
return(ptr);
case AddressModes.JmpAbsoluteIndexedIndirectWithX:
addr = SignatureBytes + cpu.X.Value;
ptr = cpu.Memory.ReadWord(addr);
return(cpu.ProgramBank.GetLongAddress(ptr));
case AddressModes.Accumulator:
return(0);
default:
throw new NotImplementedException("GetAddress() Address mode not implemented: " + addressMode.ToString());
}
}