/// <summary>
/// The INDR instruction.
/// </summary>
byte INDR()
{
FetchFinished();
var portNumber = Registers.C;
var address = Registers.HL;
var value = ProcessorAgent.ReadFromPort(portNumber);
ProcessorAgent.WriteToMemory(address.ToUShort(), value);
Registers.HL = address.Dec();
var counter = Registers.B;
counter = counter.Dec();
Registers.B = counter;
Registers.ZF = (counter == 0);
Registers.NF = 1;
Registers.SF = counter.GetBit(7);
SetFlags3and5From(counter);
if (counter != 0)
{
Registers.PC = Registers.PC.Sub(2);
return(21);
}
return(16);
}
/// <summary>
/// The LDIR instruction.
/// </summary>
byte LDIR()
{
FetchFinished();
var sourceAddress = Registers.HL;
var destAddress = Registers.DE;
var counter = Registers.BC;
var value = ProcessorAgent.ReadFromMemory(sourceAddress.ToUShort());
ProcessorAgent.WriteToMemory(destAddress.ToUShort(), value);
Registers.HL = sourceAddress.Inc();
Registers.DE = destAddress.Inc();
counter = counter.Dec();
Registers.BC = counter;
Registers.HF = 0;
Registers.NF = 0;
Registers.PF = (counter != 0);
var valuePlusA = value.Add(Registers.A).GetLowByte();
Registers.Flag3 = valuePlusA.GetBit(3);
Registers.Flag5 = valuePlusA.GetBit(1);
if (counter != 0)
{
Registers.PC = Registers.PC.Sub(2);
return(21);
}
return(16);
}
/// <summary>
/// The LDIR instruction.
/// </summary>
byte LDIR()
{
FetchFinished();
var sourceAddress = Registers.HL;
var destAddress = Registers.DE;
var counter = Registers.BC;
var value = ProcessorAgent.ReadFromMemory((ushort)sourceAddress);
ProcessorAgent.WriteToMemory((ushort)destAddress, value);
Registers.HL = (short)(sourceAddress + 1);
Registers.DE = (short)(destAddress + 1);
counter--;
Registers.BC = counter;
Registers.HF = 0;
Registers.NF = 0;
Registers.PF = (counter != 0);
var valuePlusA = (byte)(value + Registers.A);
Registers.Flag3 = valuePlusA.GetBit(3);
Registers.Flag5 = valuePlusA.GetBit(1);
if (counter != 0)
{
Registers.PC = (ushort)(Registers.PC - 2);
return(21);
}
return(16);
}
/// <summary>
/// The INDR instruction.
/// </summary>
byte INDR()
{
FetchFinished();
var portNumber = Registers.C;
var address = Registers.HL;
var value = ProcessorAgent.ReadFromPort(portNumber);
ProcessorAgent.WriteToMemory((ushort)address, value);
Registers.HL--;
var counter = Registers.B;
counter = (byte)(counter - 1);
Registers.B = counter;
Registers.ZF = (counter == 0);
Registers.NF = 1;
Registers.SF = counter.GetBit(7);
SetFlags3and5From(counter);
if (counter != 0)
{
Registers.PC = (ushort)(Registers.PC - 2);
return(21);
}
return(16);
}
/// <summary>
/// The LD IXH,n instruction.
/// </summary>
byte LD_IXH_n()
{
var value = ProcessorAgent.FetchNextOpcode();
FetchFinished();
Registers.IXH = value;
return(11);
}
/// <summary>
/// The IM 2 instruction.
/// </summary>
private byte IM_2()
{
FetchFinished();
ProcessorAgent.SetInterruptMode(2);
return(8);
}
/// <summary>
/// The OUT (C),0 instruction.
/// </summary>
byte OUT_C_0()
{
FetchFinished();
ProcessorAgent.WriteToPort(Registers.C, 0);
return(12);
}
/// <summary>
/// The LD L,n instruction.
/// </summary>
byte LD_L_n()
{
var value = ProcessorAgent.FetchNextOpcode();
FetchFinished();
Registers.L = value;
return(7);
}
/// <summary>
/// The JR d instruction.
/// </summary>
byte JR_d()
{
var offset = ProcessorAgent.FetchNextOpcode();
FetchFinished();
Registers.PC = (ushort)(Registers.PC + (SByte)offset);
return(12);
}
/// <summary>
/// The OUT (n),A instruction.
/// </summary>
byte OUT_n_A()
{
var portNumber = ProcessorAgent.FetchNextOpcode();
FetchFinished();
ProcessorAgent.WriteToPort(portNumber, Registers.A);
return(11);
}
/// <summary>
/// The IN A,(n) instruction.
/// </summary>
byte IN_A_n()
{
var portNumber = ProcessorAgent.FetchNextOpcode();
FetchFinished();
Registers.A = ProcessorAgent.ReadFromPort(portNumber);
return(11);
}
/// <summary>
/// The LD (nn),A instruction.
/// </summary>
private byte LD_aa_A()
{
var address = FetchWord().ToUShort();
FetchFinished();
ProcessorAgent.WriteToMemory(address, Registers.A);
return(13);
}
/// <summary>
/// The JR d instruction.
/// </summary>
byte JR_d()
{
var offset = ProcessorAgent.FetchNextOpcode();
FetchFinished();
Registers.PC = Registers.PC.AddSignedByte(offset);
return(12);
}
/// <summary>
/// The LD A,(nn) instruction.
/// </summary>
private byte LD_A_aa()
{
var address = FetchWord().ToUShort();
FetchFinished();
Registers.A = ProcessorAgent.ReadFromMemory(address);
return(13);
}
/// <summary>
/// The LD (HL),A instruction.
/// </summary>
byte LD_aHL_A()
{
FetchFinished();
var newValue = Registers.A;
var address = (ushort)Registers.HL;
ProcessorAgent.WriteToMemory(address, newValue);
return(7);
}
/// <summary>
/// The LD (DE),A instruction.
/// </summary>
byte LD_aDE_A()
{
FetchFinished();
var newValue = Registers.A;
var address = Registers.DE.ToUShort();
ProcessorAgent.WriteToMemory(address, newValue);
return(7);
}
/// <summary>
/// The LD L,(HL) instruction.
/// </summary>
byte LD_L_aHL()
{
FetchFinished();
var address = Registers.HL.ToUShort();
var oldValue = ProcessorAgent.ReadFromMemory(address);
Registers.L = oldValue;
return(7);
}
/// <summary>
/// The LD A,(HL) instruction.
/// </summary>
byte LD_A_aHL()
{
FetchFinished();
var address = (ushort)Registers.HL;
var oldValue = ProcessorAgent.ReadFromMemory(address);
Registers.A = oldValue;
return(7);
}
/// <summary>
/// The LD A,(DE) instruction.
/// </summary>
byte LD_A_aDE()
{
FetchFinished();
var address = Registers.DE.ToUShort();
var oldValue = ProcessorAgent.ReadFromMemory(address);
Registers.A = oldValue;
return(7);
}
/// <summary>
/// The LD (HL),n instruction.
/// </summary>
private byte LD_aHL_N()
{
var newValue = ProcessorAgent.FetchNextOpcode();
FetchFinished();
var address = (ushort)Registers.HL;
ProcessorAgent.WriteToMemory(address, newValue);
return(10);
}
/// <summary>
/// The LD (IY+n),L instruction.
/// </summary>
byte LD_aIY_plus_n_L()
{
var offset = ProcessorAgent.FetchNextOpcode();
FetchFinished();
var newValue = Registers.L;
var address = (ushort)(Registers.IY + (SByte)offset);
ProcessorAgent.WriteToMemory(address, newValue);
return(19);
}
/// <summary>
/// The LD L,(IY+n) instruction.
/// </summary>
byte LD_L_aIY_plus_n()
{
var offset = ProcessorAgent.FetchNextOpcode();
FetchFinished();
var address = (ushort)(Registers.IY + (SByte)offset);
var oldValue = ProcessorAgent.ReadFromMemory(address);
Registers.L = oldValue;
return(19);
}
/// <summary>
/// The LD (IY+n),L instruction.
/// </summary>
byte LD_aIY_plus_n_L()
{
var offset = ProcessorAgent.FetchNextOpcode();
FetchFinished();
var newValue = Registers.L;
var address = Registers.IY.ToUShort().Add(offset.ToSignedByte());
ProcessorAgent.WriteToMemory(address, newValue);
return(19);
}
/// <summary>
/// The LD L,(IY+n) instruction.
/// </summary>
byte LD_L_aIY_plus_n()
{
var offset = ProcessorAgent.FetchNextOpcode();
FetchFinished();
var address = Registers.IY.ToUShort().Add(offset.ToSignedByte());
var oldValue = ProcessorAgent.ReadFromMemory(address);
Registers.L = oldValue;
return(19);
}
/// <summary>
/// The PUSH DE instruction.
/// </summary>
private byte PUSH_DE()
{
FetchFinished();
var valueToPush = Registers.DE;
var sp = (ushort)(Registers.SP - 1);
ProcessorAgent.WriteToMemory(sp, valueToPush.GetHighByte());
sp--;
ProcessorAgent.WriteToMemory(sp, valueToPush.GetLowByte());
Registers.SP = (short)sp;
return(11);
}
/// <summary>
/// The PUSH DE instruction.
/// </summary>
private byte PUSH_DE()
{
FetchFinished();
var valueToPush = Registers.DE;
var sp = Registers.SP.Dec();
ProcessorAgent.WriteToMemory(sp.ToUShort(), valueToPush.GetHighByte());
sp = sp.Dec();
ProcessorAgent.WriteToMemory(sp.ToUShort(), valueToPush.GetLowByte());
Registers.SP = sp;
return(11);
}
/// <summary>
/// The RETI instruction.
/// </summary>
private byte RETI()
{
FetchFinished(isRet: true);
var sp = Registers.SP.ToUShort();
var newPC = NumberUtils.CreateShort(
ProcessorAgent.ReadFromMemory(sp),
ProcessorAgent.ReadFromMemory(sp.Inc()));
Registers.PC = newPC.ToUShort();
Registers.SP = Registers.SP.Add(2);
return(14);
}
/// <summary>
/// The BIT 7,(IY+n) instruction
/// </summary>
byte BIT_7_aIY_plus_n(byte offset)
{
FetchFinished();
var address = (ushort)(Registers.IY + (SByte)offset);
var oldValue = ProcessorAgent.ReadFromMemory(address);
var bitValue = oldValue.GetBit(7);
Registers.ZF = Registers.PF = ~bitValue;
Registers.SF = bitValue;
Registers.HF = 1;
Registers.NF = 0;
return(20);
}
/// <summary>
/// The IN F,(C) instruction.
/// </summary>
byte IN_F_C()
{
FetchFinished();
var value = ProcessorAgent.ReadFromPort(Registers.C);
Registers.SF = value.GetBit(7);
Registers.ZF = (value == 0);
Registers.NF = 0;
Registers.HF = 0;
Registers.PF = Parity[value];
SetFlags3and5From(value);
return(12);
}
/// <summary>
/// The POP BC instruction.
/// </summary>
private byte POP_BC()
{
FetchFinished();
var sp = Registers.SP.ToUShort();
var newBC = NumberUtils.CreateShort(
ProcessorAgent.ReadFromMemory(sp),
ProcessorAgent.ReadFromMemory(sp.Inc()));
Registers.BC = newBC;
Registers.SP = Registers.SP.Add(2);
return(10);
}
