BizHawk/BizHawk.Emulation.Cores/Computers/Commodore64/MOS/Chip6510.cs

237 lines
4.4 KiB
C#

using System;
using BizHawk.Common;
using BizHawk.Emulation.Common;
using BizHawk.Emulation.Cores.Components.M6502;
namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
{
// an extension of the 6502 processor
public sealed partial class Chip6510
{
// ------------------------------------
private readonly MOS6502X _cpu;
private bool _pinNmiLast;
private LatchedPort _port;
private bool _thisNmi;
public Func<int, int> PeekMemory;
public Action<int, int> PokeMemory;
public Func<bool> ReadAec;
public Func<bool> ReadIrq;
public Func<bool> ReadNmi;
public Func<bool> ReadRdy;
public Func<int, int> ReadMemory;
public Func<int> ReadPort;
public Action<int, int> WriteMemory;
public Action<int, int> WriteMemoryPort;
public Action DebuggerStep;
// ------------------------------------
public Chip6510()
{
// configure cpu r/w
_cpu = new MOS6502X
{
DummyReadMemory = CpuRead,
ReadMemory = CpuRead,
WriteMemory = CpuWrite,
PeekMemory = CpuPeek
};
// perform hard reset
HardReset();
}
public string TraceHeader => "6510: PC, machine code, mnemonic, operands, registers (A, X, Y, P, SP), flags (NVTBDIZCR)";
public Action<TraceInfo> TraceCallback
{
get { return _cpu.TraceCallback; }
set { _cpu.TraceCallback = value; }
}
public void SetOverflow()
{
}
private byte CpuPeek(ushort addr)
{
return unchecked((byte)Peek(addr));
}
private byte CpuRead(ushort addr)
{
return unchecked((byte)Read(addr));
}
private void CpuWrite(ushort addr, byte val)
{
Write(addr, val);
}
public void HardReset()
{
_cpu.NESSoftReset();
_port = new LatchedPort
{
Direction = 0x00,
Latch = 0xFF
};
_pinNmiLast = true;
}
// ------------------------------------
public void ExecutePhase()
{
_cpu.RDY = ReadRdy();
if (ReadAec())
{
_cpu.IRQ = !ReadIrq();
_pinNmiLast = _thisNmi;
_thisNmi = ReadNmi();
_cpu.NMI |= _pinNmiLast && !_thisNmi;
_cpu.ExecuteOne();
}
else
{
LagCycles++;
}
}
public int LagCycles;
internal bool AtInstructionStart()
{
return _cpu.AtInstructionStart();
}
// ------------------------------------
public ushort Pc
{
get
{
return _cpu.PC;
}
set
{
_cpu.PC = value;
}
}
public int A
{
get { return _cpu.A; }
set { _cpu.A = unchecked((byte)value); }
}
public int X
{
get { return _cpu.X; }
set { _cpu.X = unchecked((byte)value); }
}
public int Y
{
get { return _cpu.Y; }
set { _cpu.Y = unchecked((byte)value); }
}
public int S
{
get { return _cpu.S; }
set { _cpu.S = unchecked((byte)value); }
}
public bool FlagC => _cpu.FlagC;
public bool FlagZ => _cpu.FlagZ;
public bool FlagI => _cpu.FlagI;
public bool FlagD => _cpu.FlagD;
public bool FlagB => _cpu.FlagB;
public bool FlagV => _cpu.FlagV;
public bool FlagN => _cpu.FlagN;
public bool FlagT => _cpu.FlagT;
public int Peek(int addr)
{
switch (addr)
{
case 0x0000:
return _port.Direction;
case 0x0001:
return PortData;
default:
return PeekMemory(addr);
}
}
public void Poke(int addr, int val)
{
switch (addr)
{
case 0x0000:
_port.Direction = val;
break;
case 0x0001:
_port.Latch = val;
break;
default:
PokeMemory(addr, val);
break;
}
}
public int PortData => _port.ReadInput(ReadPort());
public int Read(int addr)
{
switch (addr)
{
case 0x0000:
return _port.Direction;
case 0x0001:
return PortData;
default:
return ReadMemory(addr);
}
}
public void SyncState(Serializer ser)
{
ser.BeginSection("Chip6510Cpu");
_cpu.SyncState(ser);
ser.EndSection();
ser.Sync("_pinNmiLast", ref _pinNmiLast);
ser.BeginSection("_port");
_port.SyncState(ser);
ser.EndSection();
ser.Sync("_thisNmi", ref _thisNmi);
ser.Sync("LagCycles", ref LagCycles);
}
public void Write(int addr, int val)
{
switch (addr)
{
case 0x0000:
_port.Direction = val;
WriteMemoryPort(addr, val);
break;
case 0x0001:
_port.Latch = val;
WriteMemoryPort(addr, val);
break;
default:
WriteMemory(addr, val);
break;
}
}
}
}