public static ushort GetIndirectY(MOS6502 CPU)
{
intermediateAddress = CPU.ReadNextByte();
CPU.IncrementPC();
var baseAddress = intermediateAddress == 0xFF
? (ushort)(CPU.ReadByteAt(0xFF) | CPU.ReadByteAt(0x00) << 8)
: CPU.ReadShortAt((ushort)intermediateAddress);
var finalAddress = (ushort)(baseAddress + CPU.Registers.Y);
if (AddressingMode.NotSamePage(baseAddress, CPU.Registers.Y))
{
CPU.CycleFinished();
}
return(finalAddress);
}
public static bool WasSamePage(ushort a1, byte a2) => AddressingMode.WasSamePage(a1, (sbyte)a2);
public static ushort GetAddressedOperand(MOS6502 CPU, OpcodeContainer container)
{
operandValue = 0;
intermediateAddress = 0;
address = 0;
switch (container.AddressingMode)
{
case AddressingModes.Implied:
address = 0x0000;
CPU.CycleFinished();
break;
case AddressingModes.Accumulator:
address = 0x0000;
CPU.CycleFinished();
break;
case AddressingModes.Immediate:
address = AddressingMode.GetImmediate(CPU);
break;
case AddressingModes.Absolute:
address = AddressingMode.GetAbsolute(CPU);
break;
case AddressingModes.AbsoluteX:
address = AddressingMode.GetAbsoluteX(CPU);
break;
case AddressingModes.AbsoluteXWrite:
address = AddressingMode.GetAbsoluteXWrite(CPU);
break;
case AddressingModes.AbsoluteY:
address = AddressingMode.GetAbsoluteY(CPU);
break;
case AddressingModes.Indirect:
address = AddressingMode.GetIndirect(CPU);
break;
case AddressingModes.IndirectX:
address = AddressingMode.GetIndirectX(CPU);
break;
case AddressingModes.IndirectY:
address = AddressingMode.GetIndirectY(CPU);
break;
case AddressingModes.IndirectYWrite:
address = AddressingMode.GetIndirectYWrite(CPU);
break;
case AddressingModes.ZeroPage:
address = AddressingMode.GetZeroPage(CPU);
break;
case AddressingModes.ZeroPageX:
address = AddressingMode.GetZeroPageX(CPU);
break;
case AddressingModes.ZeroPageY:
address = AddressingMode.GetZeroPageY(CPU);
break;
case AddressingModes.Relative:
address = AddressingMode.GetRelative(CPU);
break;
default:
throw new InvalidOperationException();
}
if (MOS6502.IsDebug)
{
CPU.LastAccessedAddress = AddressingMode.GetAddressAsString(CPU, container);
}
return(address);
}