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