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https://github.com/MoleskiCoder/EightBitNet.git
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Layout into regions
This commit is contained in:
Adrian Conlon
parent
301cd0c1e2
commit
0f9fdd95d5
725
M6502/M6502.cs
725
M6502/M6502.cs
@ -4,106 +4,34 @@
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namespace EightBit
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{
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using System;
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public class M6502(Bus bus) : LittleEndianProcessor(bus)
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{
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private const byte IRQvector = 0xfe; // IRQ vector
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private const byte RSTvector = 0xfc; // RST vector
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private const byte NMIvector = 0xfa; // NMI vector
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private readonly Register16 intermediate = new();
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private byte fixedPage;
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private PinLevel nmiLine = PinLevel.Low;
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private PinLevel soLine = PinLevel.Low;
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private PinLevel syncLine = PinLevel.Low;
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private PinLevel rdyLine = PinLevel.Low;
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private PinLevel rwLine = PinLevel.Low;
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#region Instruction execution events
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public event EventHandler<EventArgs>? ExecutingInstruction;
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public event EventHandler<EventArgs>? ExecutedInstruction;
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protected virtual void OnExecutedInstruction() => this.ExecutedInstruction?.Invoke(this, EventArgs.Empty);
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protected virtual void OnExecutingInstruction() => this.ExecutingInstruction?.Invoke(this, EventArgs.Empty);
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public event EventHandler<EventArgs>? RaisingNMI;
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#endregion
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public event EventHandler<EventArgs>? RaisedNMI;
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#region Pin controls
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public event EventHandler<EventArgs>? LoweringNMI;
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public event EventHandler<EventArgs>? LoweredNMI;
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public event EventHandler<EventArgs>? RaisingSO;
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public event EventHandler<EventArgs>? RaisedSO;
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public event EventHandler<EventArgs>? LoweringSO;
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public event EventHandler<EventArgs>? LoweredSO;
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public event EventHandler<EventArgs>? RaisingSYNC;
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public event EventHandler<EventArgs>? RaisedSYNC;
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public event EventHandler<EventArgs>? LoweringSYNC;
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public event EventHandler<EventArgs>? LoweredSYNC;
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public event EventHandler<EventArgs>? RaisingRDY;
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public event EventHandler<EventArgs>? RaisedRDY;
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public event EventHandler<EventArgs>? LoweringRDY;
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public event EventHandler<EventArgs>? LoweredRDY;
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public event EventHandler<EventArgs>? RaisingRW;
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public event EventHandler<EventArgs>? RaisedRW;
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public event EventHandler<EventArgs>? LoweringRW;
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public event EventHandler<EventArgs>? LoweredRW;
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#region NMI pin
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public ref PinLevel NMI => ref this.nmiLine;
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private PinLevel nmiLine = PinLevel.Low;
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public event EventHandler<EventArgs>? RaisingNMI;
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public event EventHandler<EventArgs>? RaisedNMI;
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public event EventHandler<EventArgs>? LoweringNMI;
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public event EventHandler<EventArgs>? LoweredNMI;
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protected virtual void OnRaisingNMI() => this.RaisingNMI?.Invoke(this, EventArgs.Empty);
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protected virtual void OnRaisedNMI() => this.RaisedNMI?.Invoke(this, EventArgs.Empty);
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protected virtual void OnLoweringNMI() => this.LoweringNMI?.Invoke(this, EventArgs.Empty);
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protected virtual void OnLoweredNMI() => this.LoweredNMI?.Invoke(this, EventArgs.Empty);
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public ref PinLevel SO => ref this.soLine;
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public ref PinLevel SYNC => ref this.syncLine;
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public ref PinLevel RDY => ref this.rdyLine;
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public ref PinLevel RW => ref this.rwLine;
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public byte X { get; set; }
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public byte Y { get; set; }
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public byte A { get; set; }
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public byte S { get; set; }
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public byte P { get; set; }
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private int InterruptMasked => this.P & (byte)StatusBits.IF;
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private int Decimal => this.P & (byte)StatusBits.DF;
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private int Negative => NegativeTest(this.P);
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private int Zero => ZeroTest(this.P);
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private int Overflow => OverflowTest(this.P);
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private int Carry => CarryTest(this.P);
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private static int NegativeTest(byte data) => data & (byte)StatusBits.NF;
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private static int ZeroTest(byte data) => data & (byte)StatusBits.ZF;
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private static int OverflowTest(byte data) => data & (byte)StatusBits.VF;
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private static int CarryTest(byte data) => data & (byte)StatusBits.CF;
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[System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1030:Use events where appropriate", Justification = "The word 'raise' is used in an electrical sense")]
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public virtual void RaiseNMI()
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@ -126,6 +54,23 @@ namespace EightBit
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}
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}
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#endregion
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#region SO pin
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public ref PinLevel SO => ref this.soLine;
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private PinLevel soLine = PinLevel.Low;
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public event EventHandler<EventArgs>? RaisingSO;
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public event EventHandler<EventArgs>? RaisedSO;
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public event EventHandler<EventArgs>? LoweringSO;
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public event EventHandler<EventArgs>? LoweredSO;
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protected virtual void OnRaisingSO() => this.RaisingSO?.Invoke(this, EventArgs.Empty);
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protected virtual void OnRaisedSO() => this.RaisedSO?.Invoke(this, EventArgs.Empty);
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protected virtual void OnLoweringSO() => this.LoweringSO?.Invoke(this, EventArgs.Empty);
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protected virtual void OnLoweredSO() => this.LoweredSO?.Invoke(this, EventArgs.Empty);
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[System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1030:Use events where appropriate", Justification = "The word 'raise' is used in an electrical sense")]
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public virtual void RaiseSO()
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{
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@ -147,6 +92,52 @@ namespace EightBit
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}
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}
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#endregion
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#region SYNC pin
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public ref PinLevel SYNC => ref this.syncLine;
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private PinLevel syncLine = PinLevel.Low;
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public event EventHandler<EventArgs>? RaisingSYNC;
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public event EventHandler<EventArgs>? RaisedSYNC;
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public event EventHandler<EventArgs>? LoweringSYNC;
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public event EventHandler<EventArgs>? LoweredSYNC;
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protected virtual void OnRaisingSYNC() => this.RaisingSYNC?.Invoke(this, EventArgs.Empty);
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protected virtual void OnRaisedSYNC() => this.RaisedSYNC?.Invoke(this, EventArgs.Empty);
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protected virtual void OnLoweringSYNC() => this.LoweringSYNC?.Invoke(this, EventArgs.Empty);
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protected virtual void OnLoweredSYNC() => this.LoweredSYNC?.Invoke(this, EventArgs.Empty);
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[System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1030:Use events where appropriate", Justification = "The word 'raise' is used in an electrical sense")]
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protected virtual void RaiseSYNC()
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{
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this.OnRaisingSYNC();
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this.SYNC.Raise();
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this.OnRaisedSYNC();
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}
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protected virtual void LowerSYNC()
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{
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this.OnLoweringSYNC();
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this.SYNC.Lower();
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this.OnLoweredSYNC();
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}
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#endregion
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#region RDY pin
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public ref PinLevel RDY => ref this.rdyLine;
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private PinLevel rdyLine = PinLevel.Low;
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public event EventHandler<EventArgs>? RaisingRDY;
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public event EventHandler<EventArgs>? RaisedRDY;
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public event EventHandler<EventArgs>? LoweringRDY;
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public event EventHandler<EventArgs>? LoweredRDY;
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protected virtual void OnRaisingRDY() => this.RaisingRDY?.Invoke(this, EventArgs.Empty);
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protected virtual void OnRaisedRDY() => this.RaisedRDY?.Invoke(this, EventArgs.Empty);
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protected virtual void OnLoweringRDY() => this.LoweringRDY?.Invoke(this, EventArgs.Empty);
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protected virtual void OnLoweredRDY() => this.LoweredRDY?.Invoke(this, EventArgs.Empty);
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[System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1030:Use events where appropriate", Justification = "The word 'raise' is used in an electrical sense")]
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public virtual void RaiseRDY()
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{
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@ -168,6 +159,21 @@ namespace EightBit
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}
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}
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#endregion
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#region RW pin
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public ref PinLevel RW => ref this.rwLine;
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private PinLevel rwLine = PinLevel.Low;
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public event EventHandler<EventArgs>? RaisingRW;
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public event EventHandler<EventArgs>? RaisedRW;
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public event EventHandler<EventArgs>? LoweringRW;
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public event EventHandler<EventArgs>? LoweredRW;
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protected virtual void OnRaisingRW() => this.RaisingRW?.Invoke(this, EventArgs.Empty);
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protected virtual void OnRaisedRW() => this.RaisedRW?.Invoke(this, EventArgs.Empty);
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protected virtual void OnLoweringRW() => this.LoweringRW?.Invoke(this, EventArgs.Empty);
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protected virtual void OnLoweredRW() => this.LoweredRW?.Invoke(this, EventArgs.Empty);
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[System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1030:Use events where appropriate", Justification = "The word 'raise' is used in an electrical sense")]
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public virtual void RaiseRW()
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{
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@ -189,6 +195,164 @@ namespace EightBit
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}
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}
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#endregion
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protected override void OnRaisedPOWER()
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{
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this.X = (byte)Bits.Bit7;
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this.Y = 0;
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this.A = 0;
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this.P = (byte)StatusBits.RF;
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this.S = (byte)Mask.Eight;
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this.LowerSYNC();
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this.LowerRW();
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base.OnRaisedPOWER();
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}
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#endregion
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#region Interrupts
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private const byte IRQvector = 0xfe; // IRQ vector
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private const byte RSTvector = 0xfc; // RST vector
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private const byte NMIvector = 0xfa; // NMI vector
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enum InterruptSource { hardware, software };
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enum InterruptType { reset, non_reset };
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private void Interrupt(byte vector, InterruptSource source = InterruptSource.hardware, InterruptType type = InterruptType.non_reset)
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{
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if (type == InterruptType.reset)
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{
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this.DummyPush();
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this.DummyPush();
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this.DummyPush();
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}
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else
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{
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this.PushWord(this.PC);
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this.Push((byte)(this.P | (source == InterruptSource.hardware ? 0 : (byte)StatusBits.BF)));
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}
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this.SetFlag(StatusBits.IF); // Disable IRQ
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this.Jump(this.GetWordPaged(0xff, vector).Word);
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}
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#region Interrupt etc. handlers
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protected override sealed void HandleRESET()
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{
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this.RaiseRESET();
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this.Interrupt(RSTvector, InterruptSource.hardware, InterruptType.reset);
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}
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protected override sealed void HandleINT()
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{
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this.RaiseINT();
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this.Interrupt(IRQvector);
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}
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private void HandleNMI()
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{
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this.RaiseNMI();
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this.Interrupt(NMIvector);
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}
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private void HandleSO()
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{
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this.RaiseSO();
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this.SetFlag(StatusBits.VF);
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}
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#endregion
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#endregion
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#region Registers
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public byte X { get; set; }
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public byte Y { get; set; }
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public byte A { get; set; }
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public byte S { get; set; }
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public byte P { get; set; }
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#endregion
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#region Processor state helpers
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private int InterruptMasked => this.P & (byte)StatusBits.IF;
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private int Decimal => this.P & (byte)StatusBits.DF;
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private int Negative => NegativeTest(this.P);
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private int Zero => ZeroTest(this.P);
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private int Overflow => OverflowTest(this.P);
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private int Carry => CarryTest(this.P);
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private static int NegativeTest(byte data) => data & (byte)StatusBits.NF;
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private static int ZeroTest(byte data) => data & (byte)StatusBits.ZF;
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private static int OverflowTest(byte data) => data & (byte)StatusBits.VF;
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private static int CarryTest(byte data) => data & (byte)StatusBits.CF;
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#endregion
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#region Bit/state twiddling
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#region Bit twiddling
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private static byte SetBit(byte f, StatusBits flag) => SetBit(f, (byte)flag);
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private static byte SetBit(byte f, StatusBits flag, int condition) => SetBit(f, (byte)flag, condition);
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private static byte SetBit(byte f, StatusBits flag, bool condition) => SetBit(f, (byte)flag, condition);
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private static byte ClearBit(byte f, StatusBits flag) => ClearBit(f, (byte)flag);
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private static byte ClearBit(byte f, StatusBits flag, int condition) => ClearBit(f, (byte)flag, condition);
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#endregion
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#region State flag twiddling
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private void SetFlag(StatusBits flag)
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{
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this.P = SetBit(this.P, flag);
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}
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private void SetFlag(StatusBits which, int condition)
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{
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this.P = SetBit(this.P, which, condition);
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}
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private void SetFlag(StatusBits which, bool condition)
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{
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this.P = SetBit(this.P, which, condition);
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}
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private void ResetFlag(StatusBits which)
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{
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this.P = ClearBit(this.P, which);
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}
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private void ResetFlag(StatusBits which, int condition)
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{
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this.P = ClearBit(this.P, which, condition);
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}
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#endregion
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#endregion
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#region Cycle wastage
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private void Swallow() => this.MemoryRead(this.PC);
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private void SwallowStack() => this.MemoryRead(this.S, 1);
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private void SwallowFetch() => this.FetchByte();
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#endregion
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#region Core instruction dispatching
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public override void Execute()
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{
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switch (this.OpCode)
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@ -210,7 +374,7 @@ namespace EightBit
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case 0x0e: this.AM_Absolute(); this.ModifyWrite(this.ASL()); break; // ASL (absolute)
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case 0x0f: this.AM_Absolute(); this.SLO(); break; // *SLO (absolute)
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case 0x10: this.Branch(this.Negative == 0); break; // BPL (relative)
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case 0x10: this.BranchNot(this.Negative); break; // BPL (relative)
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case 0x11: this.AM_IndirectIndexedY(); this.OrR(); break; // ORA (indirect indexed Y)
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case 0x12: this.Jam(); break; // *JAM
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case 0x13: this.Address_IndirectIndexedY(); this.FixupR(); this.SLO(); break; // *SLO (indirect indexed Y)
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@ -278,7 +442,7 @@ namespace EightBit
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case 0x4e: this.AM_Absolute(); this.ModifyWrite(this.LSR()); break; // LSR (absolute)
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case 0x4f: this.AM_Absolute(); this.SRE(); break; // *SRE (absolute)
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case 0x50: this.Branch(this.Overflow == 0); break; // BVC (relative)
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case 0x50: this.BranchNot(this.Overflow); break; // BVC (relative)
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case 0x51: this.AM_IndirectIndexedY(); this.EorR(); break; // EOR (indirect indexed Y)
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case 0x52: this.Jam(); break; // *JAM
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case 0x53: this.Address_IndirectIndexedY(); this.FixupR(); this.SRE(); break; // *SRE (indirect indexed Y)
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@ -346,7 +510,7 @@ namespace EightBit
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case 0x8e: this.Address_Absolute(); this.MemoryWrite(this.X); break; // STX (absolute)
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case 0x8f: this.Address_Absolute(); this.MemoryWrite((byte)(this.A & this.X)); break; // *SAX (absolute)
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case 0x90: this.Branch(this.Carry == 0); break; // BCC (relative)
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case 0x90: this.BranchNot(this.Carry); break; // BCC (relative)
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case 0x91: this.Address_IndirectIndexedY(); this.Fixup(); this.MemoryWrite(this.A); break; // STA (indirect indexed Y)
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case 0x92: this.Jam(); break; // *JAM
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case 0x93: this.Address_IndirectIndexedY(); this.Fixup(); this.SHA(); break; // *SHA (indirect indexed, Y)
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@ -414,7 +578,7 @@ namespace EightBit
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case 0xce: this.AM_Absolute(); this.ModifyWrite(this.DEC()); break; // DEC (absolute)
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case 0xcf: this.AM_Absolute(); this.DCP(); break; // *DCP (absolute)
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case 0xd0: this.Branch(this.Zero == 0); break; // BNE (relative)
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case 0xd0: this.BranchNot(this.Zero); break; // BNE (relative)
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case 0xd1: this.AM_IndirectIndexedY(); this.CMP(this.A); break; // CMP (indirect indexed Y)
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case 0xd2: this.Jam(); break; // *JAM
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case 0xd3: this.Address_IndirectIndexedY(); this.FixupR(); this.DCP(); break; // *DCP (indirect indexed Y)
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@ -507,7 +671,6 @@ namespace EightBit
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private void FetchInstruction()
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{
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// Instruction fetch beginning
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this.LowerSYNC();
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@ -523,100 +686,9 @@ namespace EightBit
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this.RaiseSYNC();
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}
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protected virtual void OnExecutingInstruction() => this.ExecutingInstruction?.Invoke(this, EventArgs.Empty);
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#endregion
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protected virtual void OnExecutedInstruction() => this.ExecutedInstruction?.Invoke(this, EventArgs.Empty);
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protected virtual void OnRaisingNMI() => this.RaisingNMI?.Invoke(this, EventArgs.Empty);
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protected virtual void OnRaisedNMI() => this.RaisedNMI?.Invoke(this, EventArgs.Empty);
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protected virtual void OnLoweringNMI() => this.LoweringNMI?.Invoke(this, EventArgs.Empty);
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protected virtual void OnLoweredNMI() => this.LoweredNMI?.Invoke(this, EventArgs.Empty);
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protected virtual void OnRaisingSO() => this.RaisingSO?.Invoke(this, EventArgs.Empty);
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protected virtual void OnRaisedSO() => this.RaisedSO?.Invoke(this, EventArgs.Empty);
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protected virtual void OnLoweringSO() => this.LoweringSO?.Invoke(this, EventArgs.Empty);
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protected virtual void OnLoweredSO() => this.LoweredSO?.Invoke(this, EventArgs.Empty);
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protected virtual void OnRaisingSYNC() => this.RaisingSYNC?.Invoke(this, EventArgs.Empty);
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||||
protected virtual void OnRaisedSYNC() => this.RaisedSYNC?.Invoke(this, EventArgs.Empty);
|
||||
|
||||
protected virtual void OnLoweringSYNC() => this.LoweringSYNC?.Invoke(this, EventArgs.Empty);
|
||||
|
||||
protected virtual void OnLoweredSYNC() => this.LoweredSYNC?.Invoke(this, EventArgs.Empty);
|
||||
|
||||
protected virtual void OnRaisingRDY() => this.RaisingRDY?.Invoke(this, EventArgs.Empty);
|
||||
|
||||
protected virtual void OnRaisedRDY() => this.RaisedRDY?.Invoke(this, EventArgs.Empty);
|
||||
|
||||
protected virtual void OnLoweringRDY() => this.LoweringRDY?.Invoke(this, EventArgs.Empty);
|
||||
|
||||
protected virtual void OnLoweredRDY() => this.LoweredRDY?.Invoke(this, EventArgs.Empty);
|
||||
|
||||
protected virtual void OnRaisingRW() => this.RaisingRW?.Invoke(this, EventArgs.Empty);
|
||||
|
||||
protected virtual void OnRaisedRW() => this.RaisedRW?.Invoke(this, EventArgs.Empty);
|
||||
|
||||
protected virtual void OnLoweringRW() => this.LoweringRW?.Invoke(this, EventArgs.Empty);
|
||||
|
||||
protected virtual void OnLoweredRW() => this.LoweredRW?.Invoke(this, EventArgs.Empty);
|
||||
|
||||
protected override void OnRaisedPOWER()
|
||||
{
|
||||
this.X = (byte)Bits.Bit7;
|
||||
this.Y = 0;
|
||||
this.A = 0;
|
||||
this.P = (byte)StatusBits.RF;
|
||||
this.S = (byte)Mask.Eight;
|
||||
this.LowerSYNC();
|
||||
this.LowerRW();
|
||||
base.OnRaisedPOWER();
|
||||
}
|
||||
|
||||
protected override byte Pop()
|
||||
{
|
||||
this.RaiseStack();
|
||||
return this.MemoryRead();
|
||||
}
|
||||
|
||||
protected override void Push(byte value)
|
||||
{
|
||||
this.LowerStack();
|
||||
this.MemoryWrite(value);
|
||||
}
|
||||
|
||||
[System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1030:Use events where appropriate", Justification = "The word 'raise' is used in an electrical sense")]
|
||||
protected virtual void RaiseSYNC()
|
||||
{
|
||||
this.OnRaisingSYNC();
|
||||
this.SYNC.Raise();
|
||||
this.OnRaisedSYNC();
|
||||
}
|
||||
|
||||
protected virtual void LowerSYNC()
|
||||
{
|
||||
this.OnLoweringSYNC();
|
||||
this.SYNC.Lower();
|
||||
this.OnLoweredSYNC();
|
||||
}
|
||||
|
||||
protected override sealed void HandleRESET()
|
||||
{
|
||||
this.RaiseRESET();
|
||||
this.Interrupt(RSTvector, InterruptSource.hardware, InterruptType.reset);
|
||||
}
|
||||
|
||||
protected override sealed void HandleINT()
|
||||
{
|
||||
this.RaiseINT();
|
||||
this.Interrupt(IRQvector);
|
||||
}
|
||||
#region Bus/Memory access
|
||||
|
||||
protected override sealed void BusWrite()
|
||||
{
|
||||
@ -630,74 +702,39 @@ namespace EightBit
|
||||
return this.ReadFromBus();
|
||||
}
|
||||
|
||||
private static byte SetBit(byte f, StatusBits flag) => SetBit(f, (byte)flag);
|
||||
|
||||
private static byte SetBit(byte f, StatusBits flag, int condition) => SetBit(f, (byte)flag, condition);
|
||||
|
||||
private static byte SetBit(byte f, StatusBits flag, bool condition) => SetBit(f, (byte)flag, condition);
|
||||
|
||||
private static byte ClearBit(byte f, StatusBits flag) => ClearBit(f, (byte)flag);
|
||||
|
||||
private static byte ClearBit(byte f, StatusBits flag, int condition) => ClearBit(f, (byte)flag, condition);
|
||||
|
||||
// Status flag operations
|
||||
|
||||
private void SetFlag(StatusBits flag)
|
||||
private byte ReadFromBus()
|
||||
{
|
||||
this.P = SetBit(this.P, flag);
|
||||
this.RaiseRW();
|
||||
return base.BusRead();
|
||||
}
|
||||
|
||||
private void SetFlag(StatusBits which, int condition)
|
||||
private void WriteToBus()
|
||||
{
|
||||
this.P = SetBit(this.P, which, condition);
|
||||
this.LowerRW();
|
||||
base.BusWrite();
|
||||
}
|
||||
|
||||
private void SetFlag(StatusBits which, bool condition)
|
||||
private void ModifyWrite(byte data)
|
||||
{
|
||||
this.P = SetBit(this.P, which, condition);
|
||||
// The read will have already taken place...
|
||||
this.MemoryWrite();
|
||||
this.MemoryWrite(data);
|
||||
}
|
||||
|
||||
private void ResetFlag(StatusBits which)
|
||||
#endregion
|
||||
|
||||
#region Stack access
|
||||
|
||||
protected override byte Pop()
|
||||
{
|
||||
this.P = ClearBit(this.P, which);
|
||||
this.RaiseStack();
|
||||
return this.MemoryRead();
|
||||
}
|
||||
|
||||
private void ResetFlag(StatusBits which, int condition)
|
||||
protected override void Push(byte value)
|
||||
{
|
||||
this.P = ClearBit(this.P, which, condition);
|
||||
}
|
||||
|
||||
private void HandleNMI()
|
||||
{
|
||||
this.RaiseNMI();
|
||||
this.Interrupt(NMIvector);
|
||||
}
|
||||
|
||||
private void HandleSO()
|
||||
{
|
||||
this.RaiseSO();
|
||||
this.P |= (byte)StatusBits.VF;
|
||||
}
|
||||
|
||||
enum InterruptSource { hardware, software };
|
||||
|
||||
enum InterruptType { reset, non_reset };
|
||||
|
||||
private void Interrupt(byte vector, InterruptSource source = InterruptSource.hardware, InterruptType type = InterruptType.non_reset)
|
||||
{
|
||||
if (type == InterruptType.reset)
|
||||
{
|
||||
this.DummyPush();
|
||||
this.DummyPush();
|
||||
this.DummyPush();
|
||||
}
|
||||
else
|
||||
{
|
||||
this.PushWord(this.PC);
|
||||
this.Push((byte)(this.P | (source == InterruptSource.hardware ? 0 : (byte)StatusBits.BF)));
|
||||
}
|
||||
this.SetFlag(StatusBits.IF); // Disable IRQ
|
||||
this.Jump(this.GetWordPaged(0xff, vector).Word);
|
||||
this.LowerStack();
|
||||
this.MemoryWrite(value);
|
||||
}
|
||||
|
||||
private void UpdateStack(byte position)
|
||||
@ -716,20 +753,43 @@ namespace EightBit
|
||||
this.Tick(); // In place of the memory write
|
||||
}
|
||||
|
||||
private byte ReadFromBus()
|
||||
#endregion
|
||||
|
||||
#region Addressing modes
|
||||
|
||||
#region Address page fixup
|
||||
|
||||
private byte fixedPage;
|
||||
|
||||
private void MaybeFixup()
|
||||
{
|
||||
this.RaiseRW();
|
||||
return base.BusRead();
|
||||
if (this.Bus.Address.High != this.fixedPage)
|
||||
{
|
||||
this.Fixup();
|
||||
}
|
||||
}
|
||||
|
||||
private void WriteToBus()
|
||||
private void Fixup()
|
||||
{
|
||||
this.LowerRW();
|
||||
base.BusWrite();
|
||||
this.MemoryRead();
|
||||
this.Bus.Address.High = this.fixedPage;
|
||||
}
|
||||
|
||||
private void MaybeFixupR()
|
||||
{
|
||||
this.MaybeFixup();
|
||||
this.MemoryRead();
|
||||
}
|
||||
|
||||
// Addressing modes
|
||||
private void FixupR()
|
||||
{
|
||||
this.Fixup();
|
||||
this.MemoryRead();
|
||||
}
|
||||
|
||||
#endregion
|
||||
|
||||
#region Address resolution
|
||||
|
||||
private void NoteFixedAddress(int address)
|
||||
{
|
||||
@ -797,7 +857,9 @@ namespace EightBit
|
||||
this.NoteFixedAddress(this.Bus.Address.Word + Y);
|
||||
}
|
||||
|
||||
// Addressing modes, with read
|
||||
#endregion
|
||||
|
||||
#region Address and read
|
||||
|
||||
private void AM_Immediate()
|
||||
{
|
||||
@ -853,15 +915,13 @@ namespace EightBit
|
||||
this.MaybeFixupR();
|
||||
}
|
||||
|
||||
private void AdjustZero(byte datum) => this.ResetFlag(StatusBits.ZF, datum);
|
||||
#endregion
|
||||
|
||||
private void AdjustNegative(byte datum) => this.SetFlag(StatusBits.NF, NegativeTest(datum));
|
||||
#endregion
|
||||
|
||||
private void AdjustNZ(byte datum)
|
||||
{
|
||||
this.AdjustZero(datum);
|
||||
this.AdjustNegative(datum);
|
||||
}
|
||||
#region Branching
|
||||
|
||||
private void BranchNot(int condition) => this.Branch(condition == 0);
|
||||
|
||||
private void Branch(int condition) => this.Branch(condition != 0);
|
||||
|
||||
@ -878,6 +938,20 @@ namespace EightBit
|
||||
}
|
||||
}
|
||||
|
||||
#endregion
|
||||
|
||||
#region Data flag adjustment
|
||||
|
||||
private void AdjustZero(byte datum) => this.ResetFlag(StatusBits.ZF, datum);
|
||||
|
||||
private void AdjustNegative(byte datum) => this.SetFlag(StatusBits.NF, NegativeTest(datum));
|
||||
|
||||
private void AdjustNZ(byte datum)
|
||||
{
|
||||
this.AdjustZero(datum);
|
||||
this.AdjustNegative(datum);
|
||||
}
|
||||
|
||||
private byte Through() => this.Through(this.Bus.Data);
|
||||
|
||||
private byte Through(int data) => this.Through((byte)data);
|
||||
@ -888,14 +962,11 @@ namespace EightBit
|
||||
return data;
|
||||
}
|
||||
|
||||
private void ModifyWrite(byte data)
|
||||
{
|
||||
// The read will have already taken place...
|
||||
this.MemoryWrite();
|
||||
this.MemoryWrite(data);
|
||||
}
|
||||
#endregion
|
||||
|
||||
// Flag adjustment
|
||||
#region Instruction implementations
|
||||
|
||||
#region Instructions with BCD effects
|
||||
|
||||
private void AdjustOverflow_add(byte operand)
|
||||
{
|
||||
@ -911,45 +982,9 @@ namespace EightBit
|
||||
this.SetFlag(StatusBits.VF, NegativeTest((byte)((operand ^ data) & (operand ^ intermediate))));
|
||||
}
|
||||
|
||||
// Miscellaneous
|
||||
#region Addition/subtraction
|
||||
|
||||
private void MaybeFixup()
|
||||
{
|
||||
if (this.Bus.Address.High != this.fixedPage)
|
||||
{
|
||||
this.Fixup();
|
||||
}
|
||||
}
|
||||
|
||||
private void Fixup()
|
||||
{
|
||||
this.MemoryRead();
|
||||
this.Bus.Address.High = this.fixedPage;
|
||||
}
|
||||
|
||||
private void MaybeFixupR()
|
||||
{
|
||||
this.MaybeFixup();
|
||||
this.MemoryRead();
|
||||
}
|
||||
|
||||
private void FixupR()
|
||||
{
|
||||
this.Fixup();
|
||||
this.MemoryRead();
|
||||
}
|
||||
|
||||
// Chew up a cycle
|
||||
|
||||
private void Swallow() => this.MemoryRead(this.PC);
|
||||
|
||||
private void SwallowStack() => this.MemoryRead(this.S, 1);
|
||||
|
||||
private void SwallowFetch() => this.FetchByte();
|
||||
|
||||
// Instruction implementations
|
||||
|
||||
// Instructions with BCD effects
|
||||
#region Subtraction
|
||||
|
||||
private void SBC()
|
||||
{
|
||||
@ -992,6 +1027,10 @@ namespace EightBit
|
||||
return (byte)(PromoteNibble(high) | LowNibble(low));
|
||||
}
|
||||
|
||||
#endregion
|
||||
|
||||
#region Addition
|
||||
|
||||
private void ADC()
|
||||
{
|
||||
if (this.Decimal != 0)
|
||||
@ -1041,7 +1080,11 @@ namespace EightBit
|
||||
this.A = (byte)(LowerNibble(LowByte(low)) | HigherNibble(this.intermediate.Low));
|
||||
}
|
||||
|
||||
// Undocumented compound instructions (with BCD effects)
|
||||
#endregion
|
||||
|
||||
#endregion
|
||||
|
||||
#region ARR (undocument instruction)
|
||||
|
||||
private void ARR()
|
||||
{
|
||||
@ -1079,6 +1122,11 @@ namespace EightBit
|
||||
this.SetFlag(StatusBits.VF, OverflowTest((byte)(this.A ^ (this.A << 1))));
|
||||
}
|
||||
|
||||
#endregion
|
||||
|
||||
#endregion
|
||||
|
||||
#region Bitwise operations
|
||||
|
||||
private void OrR() => this.A = this.Through(this.A | this.Bus.Data);
|
||||
|
||||
@ -1094,6 +1142,8 @@ namespace EightBit
|
||||
this.AdjustNegative(data);
|
||||
}
|
||||
|
||||
#endregion
|
||||
|
||||
private void CMP(byte first)
|
||||
{
|
||||
var second = Bus.Data;
|
||||
@ -1102,6 +1152,7 @@ namespace EightBit
|
||||
ResetFlag(StatusBits.CF, this.intermediate.High);
|
||||
}
|
||||
|
||||
#region Increment/decrement
|
||||
|
||||
private byte DEC() => this.DEC(this.Bus.Data);
|
||||
|
||||
@ -1111,6 +1162,10 @@ namespace EightBit
|
||||
|
||||
private byte INC(byte value) => this.Through(value + 1);
|
||||
|
||||
#endregion
|
||||
|
||||
#region Stack operations
|
||||
|
||||
private void JSR()
|
||||
{
|
||||
this.intermediate.Low = this.FetchByte();
|
||||
@ -1120,12 +1175,12 @@ namespace EightBit
|
||||
this.PC.Word = this.intermediate.Word;
|
||||
}
|
||||
|
||||
private void PHP() => this.Push((byte)(this.P | (byte)StatusBits.BF));
|
||||
private void PHP() => this.Push(SetBit(this.P, StatusBits.BF));
|
||||
|
||||
private void PLP()
|
||||
{
|
||||
this.SwallowStack();
|
||||
this.P = (byte)((this.Pop() | (byte)StatusBits.RF) & (byte)~StatusBits.BF);
|
||||
this.P = ClearBit(SetBit(this.Pop(), StatusBits.RF), StatusBits.BF);
|
||||
}
|
||||
|
||||
private void RTI()
|
||||
@ -1141,6 +1196,12 @@ namespace EightBit
|
||||
this.SwallowFetch();
|
||||
}
|
||||
|
||||
#endregion
|
||||
|
||||
#region Shift/rotate operations
|
||||
|
||||
#region Shift
|
||||
|
||||
private byte ASL() => this.ASL(this.Bus.Data);
|
||||
|
||||
private byte ASL(byte value)
|
||||
@ -1149,14 +1210,6 @@ namespace EightBit
|
||||
return this.Through(value << 1);
|
||||
}
|
||||
|
||||
private byte ROL() => this.ROL(this.Bus.Data);
|
||||
|
||||
private byte ROL(byte value)
|
||||
{
|
||||
var carryIn = this.Carry;
|
||||
return this.Through(this.ASL(value) | carryIn);
|
||||
}
|
||||
|
||||
private byte LSR() => this.LSR(this.Bus.Data);
|
||||
|
||||
private byte LSR(byte value)
|
||||
@ -1165,6 +1218,18 @@ namespace EightBit
|
||||
return this.Through(value >> 1);
|
||||
}
|
||||
|
||||
#endregion
|
||||
|
||||
#region Rotate
|
||||
|
||||
private byte ROL() => this.ROL(this.Bus.Data);
|
||||
|
||||
private byte ROL(byte value)
|
||||
{
|
||||
var carryIn = this.Carry;
|
||||
return this.Through(this.ASL(value) | carryIn);
|
||||
}
|
||||
|
||||
private byte ROR() => this.ROR(this.Bus.Data);
|
||||
|
||||
private byte ROR(byte value)
|
||||
@ -1173,7 +1238,27 @@ namespace EightBit
|
||||
return this.Through(this.LSR(value) | (carryIn << 7));
|
||||
}
|
||||
|
||||
// Undocumented compound instructions
|
||||
#endregion
|
||||
|
||||
#endregion
|
||||
|
||||
#region Undocumented instructions
|
||||
|
||||
#region Undocumented instructions with fixup effects
|
||||
|
||||
private void StoreFixupEffect(byte data)
|
||||
{
|
||||
var fixedAddress = (byte)(this.Bus.Address.High + 1);
|
||||
this.MemoryWrite((byte)(data & fixedAddress));
|
||||
}
|
||||
|
||||
private void SHA() => this.StoreFixupEffect((byte)(this.A & this.X));
|
||||
|
||||
private void SYA() => this.StoreFixupEffect(this.Y);
|
||||
|
||||
private void SXA() => this.StoreFixupEffect(this.X);
|
||||
|
||||
#endregion
|
||||
|
||||
private void ANC()
|
||||
{
|
||||
@ -1187,7 +1272,6 @@ namespace EightBit
|
||||
this.ResetFlag(StatusBits.CF, this.intermediate.High);
|
||||
}
|
||||
|
||||
|
||||
private void Jam()
|
||||
{
|
||||
this.Bus.Address.Word = this.PC.Word--;
|
||||
@ -1195,17 +1279,6 @@ namespace EightBit
|
||||
this.MemoryRead();
|
||||
}
|
||||
|
||||
private void StoreFixupEffect(byte data)
|
||||
{
|
||||
var fixedAddress = (byte)(this.Bus.Address.High + 1);
|
||||
this.MemoryWrite((byte)(data & fixedAddress));
|
||||
}
|
||||
|
||||
private void SHA() => this.StoreFixupEffect((byte)(this.A & this.X));
|
||||
|
||||
private void SYA() => this.StoreFixupEffect(this.Y);
|
||||
|
||||
private void SXA() => this.StoreFixupEffect(this.X);
|
||||
|
||||
private void TAS()
|
||||
{
|
||||
@ -1260,5 +1333,9 @@ namespace EightBit
|
||||
this.ModifyWrite(this.DEC());
|
||||
this.CMP(this.A);
|
||||
}
|
||||
|
||||
#endregion
|
||||
|
||||
#endregion
|
||||
}
|
||||
}
|
||||
Loading…
x
Reference in New Issue
Block a user