mirror of
https://github.com/MoleskiCoder/EightBitNet.git
synced 2024-12-23 17:31:33 +00:00
841 lines
32 KiB
C#
841 lines
32 KiB
C#
// <copyright file="Intel8080.cs" company="Adrian Conlon">
|
|
// Copyright (c) Adrian Conlon. All rights reserved.
|
|
// </copyright>
|
|
|
|
namespace EightBit
|
|
{
|
|
using System;
|
|
|
|
public class Intel8080 : IntelProcessor
|
|
{
|
|
private readonly Register16 af = new Register16();
|
|
private readonly Register16 intermediate = new Register16();
|
|
|
|
private readonly InputOutput ports;
|
|
|
|
private bool interruptEnable = false;
|
|
|
|
public Intel8080(Bus bus, InputOutput ports)
|
|
: base(bus) => this.ports = ports;
|
|
|
|
public event EventHandler<EventArgs> ExecutingInstruction;
|
|
|
|
public event EventHandler<EventArgs> ExecutedInstruction;
|
|
|
|
public override Register16 AF
|
|
{
|
|
get
|
|
{
|
|
this.af.Low = (byte)((this.af.Low | (byte)Bits.Bit1) & (int)~(Bits.Bit5 | Bits.Bit3));
|
|
return this.af;
|
|
}
|
|
}
|
|
|
|
public override Register16 BC { get; } = new Register16((int)Mask.Mask16);
|
|
|
|
public override Register16 DE { get; } = new Register16((int)Mask.Mask16);
|
|
|
|
public override Register16 HL { get; } = new Register16((int)Mask.Mask16);
|
|
|
|
public override int Execute()
|
|
{
|
|
var decoded = this.GetDecodedOpCode(this.OpCode);
|
|
|
|
var x = decoded.X;
|
|
var y = decoded.Y;
|
|
var z = decoded.Z;
|
|
|
|
var p = decoded.P;
|
|
var q = decoded.Q;
|
|
|
|
this.Execute(x, y, z, p, q);
|
|
|
|
return this.Cycles;
|
|
}
|
|
|
|
public override int Step()
|
|
{
|
|
this.ResetCycles();
|
|
this.OnExecutingInstruction();
|
|
if (this.Powered)
|
|
{
|
|
if (this.RESET.Lowered())
|
|
{
|
|
this.HandleRESET();
|
|
}
|
|
else if (this.INT.Lowered())
|
|
{
|
|
this.HandleINT();
|
|
}
|
|
else if (this.Halted)
|
|
{
|
|
this.Execute(0); // NOP
|
|
}
|
|
else
|
|
{
|
|
this.Execute(this.FetchByte());
|
|
}
|
|
}
|
|
|
|
this.OnExecutedInstruction();
|
|
return this.Cycles;
|
|
}
|
|
|
|
protected virtual void OnExecutingInstruction() => this.ExecutingInstruction?.Invoke(this, EventArgs.Empty);
|
|
|
|
protected virtual void OnExecutedInstruction() => this.ExecutedInstruction?.Invoke(this, EventArgs.Empty);
|
|
|
|
protected override void HandleRESET()
|
|
{
|
|
base.HandleRESET();
|
|
this.DisableInterrupts();
|
|
this.Tick(3);
|
|
}
|
|
|
|
protected override void HandleINT()
|
|
{
|
|
base.HandleINT();
|
|
this.RaiseHALT();
|
|
if (this.interruptEnable)
|
|
{
|
|
this.DisableInterrupts();
|
|
this.Execute(this.Bus.Data);
|
|
this.Tick(3);
|
|
}
|
|
}
|
|
|
|
private static byte SetFlag(byte f, StatusBits flag) => SetFlag(f, (byte)flag);
|
|
|
|
private static byte SetFlag(byte f, StatusBits flag, int condition) => SetFlag(f, (byte)flag, condition);
|
|
|
|
private static byte SetFlag(byte f, StatusBits flag, bool condition) => SetFlag(f, (byte)flag, condition);
|
|
|
|
private static byte ClearFlag(byte f, StatusBits flag) => ClearFlag(f, (byte)flag);
|
|
|
|
private static byte ClearFlag(byte f, StatusBits flag, int condition) => ClearFlag(f, (byte)flag, condition);
|
|
|
|
private static byte AdjustSign(byte input, byte value) => SetFlag(input, StatusBits.SF, value & (byte)StatusBits.SF);
|
|
|
|
private static byte AdjustZero(byte input, byte value) => ClearFlag(input, StatusBits.ZF, value);
|
|
|
|
private static byte AdjustParity(byte input, byte value) => SetFlag(input, StatusBits.PF, EvenParity(value));
|
|
|
|
private static byte AdjustSZ(byte input, byte value)
|
|
{
|
|
input = AdjustSign(input, value);
|
|
return AdjustZero(input, value);
|
|
}
|
|
|
|
private static byte AdjustSZP(byte input, byte value)
|
|
{
|
|
input = AdjustSZ(input, value);
|
|
return AdjustParity(input, value);
|
|
}
|
|
|
|
private static byte AdjustAuxiliaryCarryAdd(byte input, byte before, byte value, int calculation) => SetFlag(input, StatusBits.AC, CalculateHalfCarryAdd(before, value, calculation));
|
|
|
|
private static byte AdjustAuxiliaryCarrySub(byte input, byte before, byte value, int calculation) => ClearFlag(input, StatusBits.AC, CalculateHalfCarrySub(before, value, calculation));
|
|
|
|
private void DisableInterrupts() => this.interruptEnable = false;
|
|
|
|
private void EnableInterrupts() => this.interruptEnable = true;
|
|
|
|
private byte R(int r)
|
|
{
|
|
switch (r)
|
|
{
|
|
case 0:
|
|
return this.B;
|
|
case 1:
|
|
return this.C;
|
|
case 2:
|
|
return this.D;
|
|
case 3:
|
|
return this.E;
|
|
case 4:
|
|
return this.H;
|
|
case 5:
|
|
return this.L;
|
|
case 6:
|
|
return this.BusRead(this.HL.Word);
|
|
case 7:
|
|
return this.A;
|
|
default:
|
|
throw new ArgumentOutOfRangeException(nameof(r));
|
|
}
|
|
}
|
|
|
|
private void R(int r, byte value)
|
|
{
|
|
switch (r)
|
|
{
|
|
case 0:
|
|
this.B = value;
|
|
break;
|
|
case 1:
|
|
this.C = value;
|
|
break;
|
|
case 2:
|
|
this.D = value;
|
|
break;
|
|
case 3:
|
|
this.E = value;
|
|
break;
|
|
case 4:
|
|
this.H = value;
|
|
break;
|
|
case 5:
|
|
this.L = value;
|
|
break;
|
|
case 6:
|
|
this.BusWrite(this.HL.Word, value);
|
|
break;
|
|
case 7:
|
|
this.A = value;
|
|
break;
|
|
default:
|
|
throw new ArgumentOutOfRangeException(nameof(r));
|
|
}
|
|
}
|
|
|
|
private Register16 RP(int rp)
|
|
{
|
|
switch (rp)
|
|
{
|
|
case 0:
|
|
return this.BC;
|
|
case 1:
|
|
return this.DE;
|
|
case 2:
|
|
return this.HL;
|
|
case 3:
|
|
return this.SP;
|
|
default:
|
|
throw new ArgumentOutOfRangeException(nameof(rp));
|
|
}
|
|
}
|
|
|
|
private Register16 RP2(int rp)
|
|
{
|
|
switch (rp)
|
|
{
|
|
case 0:
|
|
return this.BC;
|
|
case 1:
|
|
return this.DE;
|
|
case 2:
|
|
return this.HL;
|
|
case 3:
|
|
return this.AF;
|
|
default:
|
|
throw new ArgumentOutOfRangeException(nameof(rp));
|
|
}
|
|
}
|
|
|
|
private void Execute(int x, int y, int z, int p, int q)
|
|
{
|
|
switch (x)
|
|
{
|
|
case 0:
|
|
switch (z)
|
|
{
|
|
case 0: // Relative jumps and assorted ops
|
|
switch (y)
|
|
{
|
|
case 0: // NOP
|
|
this.Tick(4);
|
|
break;
|
|
}
|
|
|
|
break;
|
|
case 1: // 16-bit load immediate/add
|
|
switch (q)
|
|
{
|
|
case 0: // LD rp,nn
|
|
this.RP(p).Word = this.FetchWord().Word;
|
|
this.Tick(10);
|
|
break;
|
|
case 1: // ADD HL,rp
|
|
this.Add(this.RP(p));
|
|
this.Tick(11);
|
|
break;
|
|
default:
|
|
throw new NotSupportedException("Invalid operation mode");
|
|
}
|
|
|
|
break;
|
|
case 2: // Indirect loading
|
|
switch (q)
|
|
{
|
|
case 0:
|
|
switch (p)
|
|
{
|
|
case 0: // LD (BC),A
|
|
this.BusWrite(this.BC, this.A);
|
|
this.Tick(7);
|
|
break;
|
|
case 1: // LD (DE),A
|
|
this.BusWrite(this.DE, this.A);
|
|
this.Tick(7);
|
|
break;
|
|
case 2: // LD (nn),HL
|
|
this.Bus.Address.Word = this.FetchWord().Word;
|
|
this.SetWord(this.HL);
|
|
this.Tick(16);
|
|
break;
|
|
case 3: // LD (nn),A
|
|
this.Bus.Address.Word = this.FetchWord().Word;
|
|
this.BusWrite(this.A);
|
|
this.Tick(13);
|
|
break;
|
|
default:
|
|
throw new NotSupportedException("Invalid operation mode");
|
|
}
|
|
|
|
break;
|
|
case 1:
|
|
switch (p)
|
|
{
|
|
case 0: // LD A,(BC)
|
|
this.A = this.BusRead(this.BC);
|
|
this.Tick(7);
|
|
break;
|
|
case 1: // LD A,(DE)
|
|
this.A = this.BusRead(this.DE);
|
|
this.Tick(7);
|
|
break;
|
|
case 2: // LD HL,(nn)
|
|
this.Bus.Address.Word = this.FetchWord().Word;
|
|
this.HL.Word = this.GetWord().Word;
|
|
this.Tick(16);
|
|
break;
|
|
case 3: // LD A,(nn)
|
|
this.Bus.Address.Word = this.FetchWord().Word;
|
|
this.A = this.BusRead();
|
|
this.Tick(13);
|
|
break;
|
|
default:
|
|
throw new NotSupportedException("Invalid operation mode");
|
|
}
|
|
|
|
break;
|
|
default:
|
|
throw new NotSupportedException("Invalid operation mode");
|
|
}
|
|
|
|
break;
|
|
case 3: // 16-bit INC/DEC
|
|
switch (q)
|
|
{
|
|
case 0: // INC rp
|
|
++this.RP(p).Word;
|
|
break;
|
|
case 1: // DEC rp
|
|
--this.RP(p).Word;
|
|
break;
|
|
default:
|
|
throw new NotSupportedException("Invalid operation mode");
|
|
}
|
|
|
|
this.Tick(6);
|
|
break;
|
|
case 4: // 8-bit INC
|
|
this.R(y, this.Increment(this.R(y)));
|
|
this.Tick(4);
|
|
break;
|
|
case 5: // 8-bit DEC
|
|
this.R(y, this.Decrement(this.R(y)));
|
|
this.Tick(4);
|
|
if (y == 6)
|
|
{
|
|
this.Tick(7);
|
|
}
|
|
|
|
break;
|
|
case 6: // 8-bit load immediate
|
|
this.R(y, this.FetchByte());
|
|
this.Tick(7);
|
|
if (y == 6)
|
|
{
|
|
this.Tick(3);
|
|
}
|
|
|
|
break;
|
|
case 7: // Assorted operations on accumulator/flags
|
|
switch (y)
|
|
{
|
|
case 0:
|
|
this.A = this.RLC(this.A);
|
|
break;
|
|
case 1:
|
|
this.A = this.RRC(this.A);
|
|
break;
|
|
case 2:
|
|
this.A = this.RL(this.A);
|
|
break;
|
|
case 3:
|
|
this.A = this.RR(this.A);
|
|
break;
|
|
case 4:
|
|
this.DAA();
|
|
break;
|
|
case 5:
|
|
this.CMA();
|
|
break;
|
|
case 6:
|
|
this.STC();
|
|
break;
|
|
case 7:
|
|
this.CMC();
|
|
break;
|
|
default:
|
|
throw new NotSupportedException("Invalid operation mode");
|
|
}
|
|
|
|
this.Tick(4);
|
|
break;
|
|
default:
|
|
throw new NotSupportedException("Invalid operation mode");
|
|
}
|
|
|
|
break;
|
|
case 1: // 8-bit loading
|
|
if (z == 6 && y == 6)
|
|
{
|
|
this.Halt(); // Exception (replaces LD (HL), (HL))
|
|
}
|
|
else
|
|
{
|
|
this.R(y, this.R(z));
|
|
if ((y == 6) || (z == 6))
|
|
{
|
|
this.Tick(3); // M operations
|
|
}
|
|
}
|
|
|
|
this.Tick(4);
|
|
break;
|
|
case 2: // Operate on accumulator and register/memory location
|
|
switch (y)
|
|
{
|
|
case 0: // ADD A,r
|
|
this.Add(this.R(z));
|
|
break;
|
|
case 1: // ADC A,r
|
|
this.ADC(this.R(z));
|
|
break;
|
|
case 2: // SUB r
|
|
this.SUB(this.R(z));
|
|
break;
|
|
case 3: // SBC A,r
|
|
this.SBB(this.R(z));
|
|
break;
|
|
case 4: // AND r
|
|
this.AndR(this.R(z));
|
|
break;
|
|
case 5: // XOR r
|
|
this.XorR(this.R(z));
|
|
break;
|
|
case 6: // OR r
|
|
this.OrR(this.R(z));
|
|
break;
|
|
case 7: // CP r
|
|
this.Compare(this.R(z));
|
|
break;
|
|
default:
|
|
throw new NotSupportedException("Invalid operation mode");
|
|
}
|
|
|
|
this.Tick(4);
|
|
if (z == 6)
|
|
{
|
|
this.Tick(3);
|
|
}
|
|
|
|
break;
|
|
case 3:
|
|
switch (z)
|
|
{
|
|
case 0: // Conditional return
|
|
if (this.ReturnConditionalFlag(y))
|
|
{
|
|
this.Tick(6);
|
|
}
|
|
|
|
this.Tick(5);
|
|
break;
|
|
case 1: // POP & various ops
|
|
switch (q)
|
|
{
|
|
case 0: // POP rp2[p]
|
|
this.RP2(p).Word = this.PopWord().Word;
|
|
this.Tick(10);
|
|
break;
|
|
case 1:
|
|
switch (p)
|
|
{
|
|
case 0: // RET
|
|
this.Return();
|
|
this.Tick(10);
|
|
break;
|
|
case 2: // JP HL
|
|
this.Jump(this.HL.Word);
|
|
this.Tick(4);
|
|
break;
|
|
case 3: // LD SP,HL
|
|
this.SP.Word = this.HL.Word;
|
|
this.Tick(4);
|
|
break;
|
|
}
|
|
|
|
break;
|
|
default:
|
|
throw new NotSupportedException("Invalid operation mode");
|
|
}
|
|
|
|
break;
|
|
case 2: // Conditional jump
|
|
this.JumpConditionalFlag(y);
|
|
this.Tick(10);
|
|
break;
|
|
case 3: // Assorted operations
|
|
switch (y)
|
|
{
|
|
case 0: // JP nn
|
|
this.Jump(this.FetchWord().Word);
|
|
this.Tick(10);
|
|
break;
|
|
case 2: // OUT (n),A
|
|
this.WritePort(this.FetchByte());
|
|
this.Tick(11);
|
|
break;
|
|
case 3: // IN A,(n)
|
|
this.A = this.ReadPort(this.FetchByte());
|
|
this.Tick(11);
|
|
break;
|
|
case 4: // EX (SP),HL
|
|
this.XHTL();
|
|
this.Tick(19);
|
|
break;
|
|
case 5: // EX DE,HL
|
|
(this.DE.Word, this.HL.Word) = (this.HL.Word, this.DE.Word);
|
|
this.Tick(4);
|
|
break;
|
|
case 6: // DI
|
|
this.DisableInterrupts();
|
|
this.Tick(4);
|
|
break;
|
|
case 7: // EI
|
|
this.EnableInterrupts();
|
|
this.Tick(4);
|
|
break;
|
|
}
|
|
|
|
break;
|
|
case 4: // Conditional call: CALL cc[y], nn
|
|
if (this.CallConditionalFlag(y))
|
|
{
|
|
this.Tick(7);
|
|
}
|
|
|
|
this.Tick(10);
|
|
break;
|
|
case 5: // PUSH & various ops
|
|
switch (q)
|
|
{
|
|
case 0: // PUSH rp2[p]
|
|
this.PushWord(this.RP2(p));
|
|
this.Tick(11);
|
|
break;
|
|
case 1:
|
|
switch (p)
|
|
{
|
|
case 0: // CALL nn
|
|
this.Call(this.FetchWord().Word);
|
|
this.Tick(17);
|
|
break;
|
|
}
|
|
|
|
break;
|
|
default:
|
|
throw new NotSupportedException("Invalid operation mode");
|
|
}
|
|
|
|
break;
|
|
case 6: // Operate on accumulator and immediate operand: alu[y] n
|
|
switch (y)
|
|
{
|
|
case 0: // ADD A,n
|
|
this.Add(this.FetchByte());
|
|
break;
|
|
case 1: // ADC A,n
|
|
this.ADC(this.FetchByte());
|
|
break;
|
|
case 2: // SUB n
|
|
this.SUB(this.FetchByte());
|
|
break;
|
|
case 3: // SBC A,n
|
|
this.SBB(this.FetchByte());
|
|
break;
|
|
case 4: // AND n
|
|
this.AndR(this.FetchByte());
|
|
break;
|
|
case 5: // XOR n
|
|
this.XorR(this.FetchByte());
|
|
break;
|
|
case 6: // OR n
|
|
this.OrR(this.FetchByte());
|
|
break;
|
|
case 7: // CP n
|
|
this.Compare(this.FetchByte());
|
|
break;
|
|
default:
|
|
throw new NotSupportedException("Invalid operation mode");
|
|
}
|
|
|
|
this.Tick(7);
|
|
break;
|
|
case 7: // Restart: RST y * 8
|
|
this.Restart((byte)(y << 3));
|
|
this.Tick(11);
|
|
break;
|
|
default:
|
|
throw new NotSupportedException("Invalid operation mode");
|
|
}
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
private byte Increment(byte operand)
|
|
{
|
|
this.F = AdjustSZP(this.F, ++operand);
|
|
this.F = ClearFlag(this.F, StatusBits.AC, LowNibble(operand));
|
|
return operand;
|
|
}
|
|
|
|
private byte Decrement(byte operand)
|
|
{
|
|
this.F = AdjustSZP(this.F, --operand);
|
|
this.F = SetFlag(this.F, StatusBits.AC, LowNibble(operand) != (byte)Mask.Mask4);
|
|
return operand;
|
|
}
|
|
|
|
private bool JumpConditionalFlag(int flag)
|
|
{
|
|
switch (flag)
|
|
{
|
|
case 0: // NZ
|
|
return this.JumpConditional((this.F & (byte)StatusBits.ZF) == 0);
|
|
case 1: // Z
|
|
return this.JumpConditional((this.F & (byte)StatusBits.ZF) != 0);
|
|
case 2: // NC
|
|
return this.JumpConditional((this.F & (byte)StatusBits.CF) == 0);
|
|
case 3: // C
|
|
return this.JumpConditional((this.F & (byte)StatusBits.CF) != 0);
|
|
case 4: // PO
|
|
return this.JumpConditional((this.F & (byte)StatusBits.PF) == 0);
|
|
case 5: // PE
|
|
return this.JumpConditional((this.F & (byte)StatusBits.PF) != 0);
|
|
case 6: // P
|
|
return this.JumpConditional((this.F & (byte)StatusBits.SF) == 0);
|
|
case 7: // M
|
|
return this.JumpConditional((this.F & (byte)StatusBits.SF) != 0);
|
|
default:
|
|
throw new ArgumentOutOfRangeException(nameof(flag));
|
|
}
|
|
}
|
|
|
|
private bool ReturnConditionalFlag(int flag)
|
|
{
|
|
switch (flag)
|
|
{
|
|
case 0: // NZ
|
|
return this.ReturnConditional((this.F & (byte)StatusBits.ZF) == 0);
|
|
case 1: // Z
|
|
return this.ReturnConditional((this.F & (byte)StatusBits.ZF) != 0);
|
|
case 2: // NC
|
|
return this.ReturnConditional((this.F & (byte)StatusBits.CF) == 0);
|
|
case 3: // C
|
|
return this.ReturnConditional((this.F & (byte)StatusBits.CF) != 0);
|
|
case 4: // PO
|
|
return this.ReturnConditional((this.F & (byte)StatusBits.PF) == 0);
|
|
case 5: // PE
|
|
return this.ReturnConditional((this.F & (byte)StatusBits.PF) != 0);
|
|
case 6: // P
|
|
return this.ReturnConditional((this.F & (byte)StatusBits.SF) == 0);
|
|
case 7: // M
|
|
return this.ReturnConditional((this.F & (byte)StatusBits.SF) != 0);
|
|
default:
|
|
throw new ArgumentOutOfRangeException(nameof(flag));
|
|
}
|
|
}
|
|
|
|
private bool CallConditionalFlag(int flag)
|
|
{
|
|
switch (flag)
|
|
{
|
|
case 0: // NZ
|
|
return this.CallConditional((this.F & (byte)StatusBits.ZF) == 0);
|
|
case 1: // Z
|
|
return this.CallConditional((this.F & (byte)StatusBits.ZF) != 0);
|
|
case 2: // NC
|
|
return this.CallConditional((this.F & (byte)StatusBits.CF) == 0);
|
|
case 3: // C
|
|
return this.CallConditional((this.F & (byte)StatusBits.CF) != 0);
|
|
case 4: // PO
|
|
return this.CallConditional((this.F & (byte)StatusBits.PF) == 0);
|
|
case 5: // PE
|
|
return this.CallConditional((this.F & (byte)StatusBits.PF) != 0);
|
|
case 6: // P
|
|
return this.CallConditional((this.F & (byte)StatusBits.SF) == 0);
|
|
case 7: // M
|
|
return this.CallConditional((this.F & (byte)StatusBits.SF) != 0);
|
|
default:
|
|
throw new ArgumentOutOfRangeException(nameof(flag));
|
|
}
|
|
}
|
|
|
|
private void Add(Register16 value)
|
|
{
|
|
var result = this.HL.Word + value.Word;
|
|
this.HL.Word = (ushort)result;
|
|
this.F = SetFlag(this.F, StatusBits.CF, result & (int)Bits.Bit16);
|
|
}
|
|
|
|
private void Add(byte value, int carry = 0)
|
|
{
|
|
this.intermediate.Word = (ushort)(this.A + value + carry);
|
|
|
|
this.F = AdjustAuxiliaryCarryAdd(this.F, this.A, value, this.intermediate.Low);
|
|
|
|
this.A = this.intermediate.Low;
|
|
|
|
this.F = SetFlag(this.F, StatusBits.CF, this.intermediate.High & (byte)StatusBits.CF);
|
|
this.F = AdjustSZP(this.F, this.A);
|
|
}
|
|
|
|
private void ADC(byte value) => this.Add(value, this.F & (byte)StatusBits.CF);
|
|
|
|
private byte Subtract(byte operand, byte value, int carry = 0)
|
|
{
|
|
this.intermediate.Word = (ushort)(operand - value - carry);
|
|
|
|
this.F = AdjustAuxiliaryCarrySub(this.F, operand, value, this.intermediate.Word);
|
|
|
|
var result = this.intermediate.Low;
|
|
|
|
this.F = SetFlag(this.F, StatusBits.CF, this.intermediate.High & (byte)StatusBits.CF);
|
|
this.F = AdjustSZP(this.F, result);
|
|
|
|
return result;
|
|
}
|
|
|
|
private void SUB(byte value, int carry = 0) => this.A = this.Subtract(this.A, value, carry);
|
|
|
|
private void SBB(byte value) => this.SUB(value, this.F & (byte)StatusBits.CF);
|
|
|
|
private void AndR(byte value)
|
|
{
|
|
this.F = SetFlag(this.F, StatusBits.AC, (this.A | value) & (int)Bits.Bit3);
|
|
this.F = ClearFlag(this.F, StatusBits.CF);
|
|
this.F = AdjustSZP(this.F, this.A &= value);
|
|
}
|
|
|
|
private void XorR(byte value)
|
|
{
|
|
this.F = ClearFlag(this.F, StatusBits.AC | StatusBits.CF);
|
|
this.F = AdjustSZP(this.F, this.A ^= value);
|
|
}
|
|
|
|
private void OrR(byte value)
|
|
{
|
|
this.F = ClearFlag(this.F, StatusBits.AC | StatusBits.CF);
|
|
this.F = AdjustSZP(this.F, this.A |= value);
|
|
}
|
|
|
|
private void Compare(byte value) => this.Subtract(this.A, value);
|
|
|
|
private byte RLC(byte operand)
|
|
{
|
|
var carry = operand & (byte)Bits.Bit7;
|
|
this.F = SetFlag(this.F, StatusBits.CF, carry);
|
|
return (byte)((operand << 1) | (carry >> 7));
|
|
}
|
|
|
|
private byte RRC(byte operand)
|
|
{
|
|
var carry = operand & (byte)Bits.Bit0;
|
|
this.F = SetFlag(this.F, StatusBits.CF, carry);
|
|
return (byte)((operand >> 1) | (carry << 7));
|
|
}
|
|
|
|
private byte RL(byte operand)
|
|
{
|
|
var carry = this.F & (byte)StatusBits.CF;
|
|
this.F = SetFlag(this.F, StatusBits.CF, operand & (byte)Bits.Bit7);
|
|
return (byte)((operand << 1) | carry);
|
|
}
|
|
|
|
private byte RR(byte operand)
|
|
{
|
|
var carry = this.F & (byte)StatusBits.CF;
|
|
this.F = SetFlag(this.F, StatusBits.CF, operand & (byte)Bits.Bit0);
|
|
return (byte)((operand >> 1) | (carry << 7));
|
|
}
|
|
|
|
private void DAA()
|
|
{
|
|
var before = this.A;
|
|
var carry = (this.F & (byte)StatusBits.CF) != 0;
|
|
byte addition = 0;
|
|
if (((this.F & (byte)StatusBits.AC) != 0) || (LowNibble(before) > (byte)9))
|
|
{
|
|
addition = 0x6;
|
|
}
|
|
|
|
if (((this.F & (byte)StatusBits.CF) != 0) || HighNibble(before) > 9 || (HighNibble(before) >= 9 && LowNibble(before) > 9))
|
|
{
|
|
addition |= 0x60;
|
|
carry = true;
|
|
}
|
|
|
|
this.Add(addition);
|
|
this.F = SetFlag(this.F, StatusBits.CF, carry);
|
|
}
|
|
|
|
private void CMA() => this.A = (byte)~this.A;
|
|
|
|
private void STC() => this.F = SetFlag(this.F, StatusBits.CF);
|
|
|
|
private void CMC() => this.F = ClearFlag(this.F, StatusBits.CF, this.F & (byte)StatusBits.CF);
|
|
|
|
private void XHTL()
|
|
{
|
|
this.MEMPTR.Low = this.BusRead(this.SP);
|
|
this.BusWrite(this.L);
|
|
this.L = this.MEMPTR.Low;
|
|
++this.Bus.Address.Word;
|
|
this.MEMPTR.High = this.BusRead();
|
|
this.BusWrite(this.H);
|
|
this.H = this.MEMPTR.High;
|
|
}
|
|
|
|
private void WritePort(byte port)
|
|
{
|
|
this.Bus.Address.Word = new Register16(port, this.A).Word;
|
|
this.Bus.Data = this.A;
|
|
this.WritePort();
|
|
}
|
|
|
|
private void WritePort() => this.ports.Write(this.Bus.Address.Low, this.Bus.Data);
|
|
|
|
private byte ReadPort(byte port)
|
|
{
|
|
this.Bus.Address.Word = new Register16(port, this.A).Word;
|
|
return this.ReadPort();
|
|
}
|
|
|
|
private byte ReadPort() => this.Bus.Data = this.ports.Read(this.Bus.Address.Low);
|
|
}
|
|
} |