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Refactored a little, but no functional changes

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Adrian Conlon
2025-05-06 21:41:32 +01:00
parent db1da4f506
commit 62f42ef46f
1 changed files with 117 additions and 69 deletions
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186
Z80/Z80.cs
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@@ -5,7 +5,6 @@
namespace Z80
{
using EightBit;
using System.Diagnostics;
public class Z80 : IntelProcessor
{
@@ -51,7 +50,6 @@ namespace Z80
public bool IFF2 { get; set; }
public byte Q { get; set; } // Previously modified instruction status register
private byte _modifiedF; // In-flight status register. Used to build "Q"
@@ -193,7 +191,7 @@ namespace Z80
this.DisableInterrupts();
this.IM = 0;
this.REFRESH = new(0);
this.REFRESH = 0;
this.IV = (byte)Mask.Eight;
this.IX.Word = this.IY.Word = (ushort)Mask.Sixteen;
@@ -306,9 +304,9 @@ namespace Z80
// seven bits of the system’s address bus can be used as a _refresh address to the system’s
// dynamic memories.
private PinLevel _rfshLine = PinLevel.Low;
private PinLevel _refreshLine = PinLevel.Low;
public ref PinLevel RFSH => ref this._rfshLine;
public ref PinLevel RFSH => ref this._refreshLine;
[System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1030:Use events where appropriate", Justification = "The word 'raise' is used in an electrical sense")]
public virtual void RaiseRFSH()
@@ -343,9 +341,9 @@ namespace Z80
public event EventHandler<EventArgs>? LoweredMREQ;
private PinLevel _mreqLine = PinLevel.Low;
private PinLevel _memoryRequestLine = PinLevel.Low;
public ref PinLevel MREQ => ref this._mreqLine;
public ref PinLevel MREQ => ref this._memoryRequestLine;
[System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1030:Use events where appropriate", Justification = "The word 'raise' is used in an electrical sense")]
public virtual void RaiseMREQ()
@@ -380,9 +378,9 @@ namespace Z80
public event EventHandler<EventArgs>? LoweredIORQ;
private PinLevel _iorqLine = PinLevel.Low;
private PinLevel _ioRequestLine = PinLevel.Low;
public ref PinLevel IORQ => ref this._iorqLine;
public ref PinLevel IORQ => ref this._ioRequestLine;
[System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1030:Use events where appropriate", Justification = "The word 'raise' is used in an electrical sense")]
public virtual void RaiseIORQ()
@@ -1928,7 +1926,6 @@ namespace Z80
}
this.AdjustStatusFlags((byte)((this.F & (byte)(StatusBits.CF | StatusBits.NF)) | (this.A > 0x99 ? (byte)StatusBits.CF : 0) | HalfCarryTest((byte)(this.A ^ updated))));
this.AdjustSZPXY(this.A = updated);
}
@@ -1976,6 +1973,8 @@ namespace Z80
this.Tick(3);
}
#region Block instructions
private void RepeatBlockInstruction()
{
this.DecrementPC();
@@ -1984,6 +1983,8 @@ namespace Z80
this.AdjustXY(this.PC.High);
}
#region Block compare
private void BlockCompare()
{
_ = this.MemoryRead(this.HL);
@@ -2003,6 +2004,8 @@ namespace Z80
this.Tick(5);
}
#region Block compare single
private void CPI()
{
this.BlockCompare();
@@ -2010,6 +2013,17 @@ namespace Z80
++this.MEMPTR.Word;
}
private void CPD()
{
this.BlockCompare();
--this.HL.Word;
--this.MEMPTR.Word;
}
#endregion
#region Block compare repeated
private void CPIR()
{
this.CPI();
@@ -2020,13 +2034,6 @@ namespace Z80
}
}
private void CPD()
{
this.BlockCompare();
--this.HL.Word;
--this.MEMPTR.Word;
}
private void CPDR()
{
this.CPD();
@@ -2042,6 +2049,12 @@ namespace Z80
}
}
#endregion
#endregion
#region Block load
private void BlockLoad()
{
this.MemoryRead(this.HL);
@@ -2056,6 +2069,8 @@ namespace Z80
this.SetBit(StatusBits.PF, --this.BC.Word);
}
#region Block load single
private void LDI()
{
this.BlockLoad();
@@ -2063,6 +2078,17 @@ namespace Z80
++this.DE.Word;
}
private void LDD()
{
this.BlockLoad();
--this.HL.Word;
--this.DE.Word;
}
#endregion
#region Block load repeated
private void LDIR()
{
this.LDI();
@@ -2073,13 +2099,6 @@ namespace Z80
this.Tick(5);
}
private void LDD()
{
this.BlockLoad();
--this.HL.Word;
--this.DE.Word;
}
private void LDDR()
{
this.LDD();
@@ -2090,24 +2109,21 @@ namespace Z80
this.Tick(5);
}
#endregion
#endregion
#region Block input/output
private void AdjustBlockRepeatFlagsIO()
{
var previousParity = this.Parity() >> 2;
Debug.Assert(previousParity < 2);
if (this.Carry() != 0)
{
if (SignTest(this.Bus.Data) != 0)
{
var parity = previousParity ^ (EvenParity((byte)((byte)(this.B - 1) & (byte)Mask.Three)) ? 1 : 0) ^ 1;
this.SetBit(StatusBits.PF, parity != 0);
this.SetBit(StatusBits.HC, (this.B & (byte)Mask.Four) == 0);
}
else
{
var parity = previousParity ^ (EvenParity((byte)((byte)(this.B + 1) & (byte)Mask.Three)) ? 1 : 0) ^ 1;
this.SetBit(StatusBits.PF, parity != 0);
this.SetBit(StatusBits.HC, (this.B & (byte)Mask.Four) == (int)Mask.Four);
}
var negative = SignTest(this.Bus.Data) != 0;
var direction = (byte)(this.B + (negative ? -1 : +1));
var parity = (this.Parity() >> 2) ^ (EvenParity((byte)(direction & (byte)Mask.Three)) ? 1 : 0) ^ 1;
this.SetBit(StatusBits.PF, parity != 0);
this.SetBit(StatusBits.HC, (this.B & (byte)Mask.Four) == (negative ? 0 : (int)Mask.Four));
}
else
{
@@ -2115,20 +2131,31 @@ namespace Z80
}
}
private void AdjustBlockInputOutputFlags(int basis)
{
this.SetBit(StatusBits.HC | StatusBits.CF, basis > 0xff);
this.AdjustParity((byte)((basis & (int)Mask.Three) ^ this.B));
}
private void AdjustBlockInFlagsIncrement()
{
var basis = (byte)(this.C + 1) + this.Bus.Data;
this.SetBit(StatusBits.CF | StatusBits.HC, basis > 0xff);
this.AdjustParity((byte)(basis & (byte)Mask.Three ^ this.B));
AdjustBlockInputOutputFlags((byte)(this.C + 1) + this.Bus.Data);
}
private void AdjustBlockInFlagsDecrement()
{
var basis = (byte)(this.C - 1) + this.Bus.Data;
this.SetBit(StatusBits.CF | StatusBits.HC, basis > 0xff);
this.AdjustParity((byte)(basis & (byte)Mask.Three ^ this.B));
AdjustBlockInputOutputFlags((byte)(this.C - 1) + this.Bus.Data);
}
private void AdjustBlockOutFlags()
{
// HL needs to have been incremented or decremented prior to this call
this.SetBit(StatusBits.NF, SignTest(this.Bus.Data));
AdjustBlockInputOutputFlags(this.L + this.Bus.Data);
}
#region Block input
private void BlockIn()
{
this.Tick();
@@ -2140,9 +2167,11 @@ namespace Z80
this.MemoryUpdate(1);
this.Tick();
this.AdjustSZXY(--this.B);
this.SetBit(StatusBits.NF, (this.Bus.Data & (byte)StatusBits.SF) != 0);
this.SetBit(StatusBits.NF, this.Bus.Data & (byte)StatusBits.SF);
}
#region Block input single
private void INI()
{
this.BlockIn();
@@ -2151,6 +2180,18 @@ namespace Z80
++this.MEMPTR.Word;
}
private void IND()
{
this.BlockIn();
this.AdjustBlockInFlagsDecrement();
--this.HL.Word;
--this.MEMPTR.Word;
}
#endregion
#region Block input repeated
private void INIR()
{
this.INI();
@@ -2162,14 +2203,6 @@ namespace Z80
}
}
private void IND()
{
this.BlockIn();
this.AdjustBlockInFlagsDecrement();
--this.HL.Word;
--this.MEMPTR.Word;
}
private void INDR()
{
this.IND();
@@ -2181,6 +2214,12 @@ namespace Z80
}
}
#endregion
#endregion
#region Block output
private void BlockOut()
{
this.Tick();
@@ -2191,14 +2230,7 @@ namespace Z80
this.WritePort();
}
private void AdjustBlockOutFlags()
{
// HL needs to have been incremented or decremented prior to this call
var value = this.Bus.Data;
this.SetBit(StatusBits.NF, value & (byte)Bits.Bit7);
this.SetBit(StatusBits.HC | StatusBits.CF, this.L + value > 0xff);
this.AdjustParity((byte)(((value + this.L) & (int)Mask.Three) ^ this.B));
}
#region Block output single
private void OUTI()
{
@@ -2208,6 +2240,18 @@ namespace Z80
++this.MEMPTR.Word;
}
private void OUTD()
{
this.BlockOut();
--this.HL.Word;
this.AdjustBlockOutFlags();
--this.MEMPTR.Word;
}
#endregion
#region Block output repeated
private void OTIR()
{
this.OUTI();
@@ -2219,14 +2263,6 @@ namespace Z80
}
}
private void OUTD()
{
this.BlockOut();
--this.HL.Word;
this.AdjustBlockOutFlags();
--this.MEMPTR.Word;
}
private void OTDR()
{
this.OUTD();
@@ -2238,6 +2274,14 @@ namespace Z80
}
}
#endregion
#endregion
#endregion
#endregion
private void NEG()
{
this.SetBit(StatusBits.PF, this.A == (byte)Bits.Bit7);
@@ -2284,6 +2328,8 @@ namespace Z80
this.ClearBit(StatusBits.NF | StatusBits.HC);
}
#region Input/output port control
private void WritePort(byte port)
{
this.Bus.Address.Assign(port, this.Bus.Data = this.A);
@@ -2323,5 +2369,7 @@ namespace Z80
this.RaiseIORQ();
this.Tick();
}
#endregion
}
}