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Resurrect the Register16 class. This (or something *very* much like it) is going to be necessary to add a Z80 emulator (reference access to the high/low parts of 16-bit registers).

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Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
This commit is contained in:
Adrian Conlon
2019-02-14 23:01:31 +00:00
parent b61d884679
commit 63db46a7bc
12 changed files with 336 additions and 195 deletions
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102
EightBit/IntelProcessor.cs
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@@ -10,14 +10,15 @@ namespace EightBit
{
private readonly IntelOpCodeDecoded[] decodedOpCodes = new IntelOpCodeDecoded[0x100];
private Register16 sp = new Register16((ushort)Mask.Mask16);
private Register16 memptr = new Register16((ushort)Mask.Mask16);
private PinLevel haltLine;
protected IntelProcessor(Bus bus)
: base(bus)
{
this.SP = (ushort)Mask.Mask16;
this.MEMPTR = (ushort)Mask.Mask16;
for (int i = 0; i < 0x100; ++i)
{
this.decodedOpCodes[i] = new IntelOpCodeDecoded((byte)i);
@@ -32,43 +33,43 @@ namespace EightBit
public event EventHandler<EventArgs> LoweredHALT;
public ushort SP { get; set; }
public ushort MEMPTR { get; set; }
public abstract ushort AF { get; set; }
public byte A { get => Chip.HighByte(this.AF); set => this.AF = (ushort)(Chip.LowerPart(this.AF) | Chip.PromoteByte(value)); }
public byte F { get => Chip.LowByte(this.AF); set => this.AF = (ushort)(Chip.HigherPart(this.AF) | value); }
public abstract ushort BC { get; set; }
public byte B { get => Chip.HighByte(this.BC); set => this.BC = (ushort)(Chip.LowerPart(this.BC) | Chip.PromoteByte(value)); }
public byte C { get => Chip.LowByte(this.BC); set => this.BC = (ushort)(Chip.HigherPart(this.BC) | value); }
public abstract ushort DE { get; set; }
public byte D { get => Chip.HighByte(this.DE); set => this.DE = (ushort)(Chip.LowerPart(this.DE) | Chip.PromoteByte(value)); }
public byte E { get => Chip.LowByte(this.DE); set => this.DE = (ushort)(Chip.HigherPart(this.DE) | value); }
public abstract ushort HL { get; set; }
public byte H { get => Chip.HighByte(this.HL); set => this.HL = (ushort)(Chip.LowerPart(this.HL) | Chip.PromoteByte(value)); }
public byte L { get => Chip.LowByte(this.HL); set => this.HL = (ushort)(Chip.HigherPart(this.HL) | value); }
protected bool Halted => this.HALT().Lowered();
public ref Register16 SP() => ref this.sp;
public ref Register16 MEMPTR() => ref this.memptr;
public abstract ref Register16 AF();
public ref byte A() => ref this.AF().High;
public ref byte F() => ref this.AF().Low;
public abstract ref Register16 BC();
public ref byte B() => ref this.BC().High;
public ref byte C() => ref this.BC().Low;
public abstract ref Register16 DE();
public ref byte D() => ref this.DE().High;
public ref byte E() => ref this.DE().Low;
public abstract ref Register16 HL();
public ref byte H() => ref this.HL().High;
public ref byte L() => ref this.HL().Low;
public ref PinLevel HALT() => ref this.haltLine;
public override void RaisePOWER()
{
base.RaisePOWER();
this.RaiseHALT();
this.SP = this.AF = this.BC = this.DE = this.HL = (ushort)Mask.Mask16;
this.SP().Word = this.AF().Word = this.BC().Word = this.DE().Word = this.HL().Word = (ushort)Mask.Mask16;
}
public virtual void RaiseHALT()
@@ -96,40 +97,41 @@ namespace EightBit
protected override void HandleRESET()
{
base.HandleRESET();
this.PC = 0;
this.PC().Word = 0;
}
protected sealed override void Push(byte value) => this.Bus.Write(--this.SP, value);
protected sealed override void Push(byte value) => this.Bus.Write(--this.SP(), value);
protected sealed override byte Pop() => this.Bus.Read(this.SP++);
protected sealed override byte Pop() => this.Bus.Read(this.SP()++);
protected sealed override ushort GetWord()
protected sealed override Register16 GetWord()
{
var returned = base.GetWord();
this.MEMPTR = this.Bus.Address;
this.MEMPTR().Word = this.Bus.Address().Word;
return returned;
}
protected sealed override void SetWord(ushort value)
protected sealed override void SetWord(Register16 value)
{
base.SetWord(value);
this.MEMPTR = this.Bus.Address;
this.MEMPTR().Word = this.Bus.Address().Word;
}
////
protected void Restart(byte address)
{
this.MEMPTR = address;
this.Call(this.MEMPTR);
this.MEMPTR().Low = address;
this.MEMPTR().High = 0;
this.Call(this.MEMPTR().Word);
}
protected bool CallConditional(bool condition)
{
this.MEMPTR = this.FetchWord();
this.MEMPTR().Word = this.FetchWord().Word;
if (condition)
{
this.Call(this.MEMPTR);
this.Call(this.MEMPTR().Word);
}
return condition;
@@ -137,10 +139,10 @@ namespace EightBit
protected bool JumpConditional(bool condition)
{
this.MEMPTR = this.FetchWord();
this.MEMPTR().Word = this.FetchWord().Word;
if (condition)
{
this.Jump(this.MEMPTR);
this.Jump(this.MEMPTR().Word);
}
return condition;
@@ -158,8 +160,8 @@ namespace EightBit
protected void JumpRelative(sbyte offset)
{
this.MEMPTR = (ushort)(this.PC + offset);
this.Jump(this.MEMPTR);
this.MEMPTR().Word = (ushort)(this.PC().Word + offset);
this.Jump(this.MEMPTR().Word);
}
protected bool JumpRelativeConditional(bool condition)
@@ -176,18 +178,18 @@ namespace EightBit
protected override sealed void Return()
{
base.Return();
this.MEMPTR = this.PC;
this.MEMPTR().Word = this.PC().Word;
}
protected void Halt()
{
--this.PC;
--this.PC();
this.LowerHALT();
}
protected void Proceed()
{
++this.PC;
++this.PC();
this.RaiseHALT();
}
}