protected void ValidateEffectiveAddress(EffectiveAddressMode mode, IEnumerable <EffectiveAddressMode> allowed)
{
if (allowed.Any(m => m == mode) == false)
{
throw new InvalidOpCodeException();
}
}
protected string GetAssemblyForEffectiveAddress(EffectiveAddressMode mode, uint ea, byte xn)
{
switch (mode)
{
case EffectiveAddressMode.Immediate:
switch (this.Size)
{
case Size.Long:
return($"#{(int)ea}");
case Size.Word:
return($"#{(short)ea}");
case Size.Byte:
return($"#{(byte)ea}");
default:
throw new NotImplementedException();
}
case EffectiveAddressMode.AbsoluteWord:
return($"0x{ea:X4}");
case EffectiveAddressMode.AbsoluteLong:
return($"${ea:X8}");
case EffectiveAddressMode.AddressWithDisplacement:
return($"(${(short)ea:X4},A{xn})");
case EffectiveAddressMode.ProgramCounterWithDisplacement:
return($"(${(short)ea:X4},PC)");
case EffectiveAddressMode.Address:
return($"(A{xn})");
case EffectiveAddressMode.AddressPostIncrement:
return($"(A{xn})+");
case EffectiveAddressMode.AddressPreDecrement:
return($"-(A{xn})");
case EffectiveAddressMode.DataRegister:
return($"D{xn}");
case EffectiveAddressMode.AddressRegister:
return($"A{xn}");
default:
throw new NotImplementedException(mode.ToString());
}
}
/// <summary>
/// MOVEM will write to the register instead of the referenced address.
/// </summary>
/// <param name="ea">Effective Address Mode.</param>
/// <param name="Xn">Xn value.</param>
/// <param name="value">Value to write.</param>
protected void WriteValueToEffectiveAddress(EffectiveAddressMode ea, uint Xn, uint value)
{
switch (ea)
{
case EffectiveAddressMode.AddressPostIncrement:
switch (this.Size)
{
case Size.Byte:
this.state.WriteAReg((byte)Xn, value);
break;
case Size.Word:
this.state.WriteAReg((byte)Xn, value);
break;
case Size.Long:
this.state.WriteAReg((byte)Xn, value);
break;
default:
throw new InvalidStateException();
}
break;
case EffectiveAddressMode.Address:
switch (this.Size)
{
case Size.Byte:
this.state.WriteAReg((byte)Xn, value);
break;
case Size.Word:
this.state.WriteAReg((byte)Xn, value);
break;
case Size.Long:
this.state.WriteAReg((byte)Xn, value);
break;
default:
throw new InvalidStateException();
}
break;
default:
throw new InvalidStateException();
}
}
protected string GetDescriptionForEffectiveAddress(EffectiveAddressMode mode, uint ea, byte xn)
{
switch (mode)
{
//case EffectiveAddressMode.Immediate:
// switch (Size)
// {
// case Size.Long:
// return string.Format("#{0}", (int)ea);
// case Size.Word:
// return string.Format("#{0}", (short)ea);
// default:
// throw new NotImplementedException();
// }
case EffectiveAddressMode.AbsoluteWord:
return($"0x{ea:X4}");
//case EffectiveAddressMode.AbsoluteLong:
// return string.Format("0x{0:X8}", ea);
//case EffectiveAddressMode.AddressWithDisplacement:
// return $"(d16, A{xn})";
case EffectiveAddressMode.ProgramCounterWithDisplacement:
return($"(d16, PC)");
//case EffectiveAddressMode.Address:
// return string.Format("(A{0})", xn);
//case EffectiveAddressMode.Address_PostIncremenet:
// return string.Format("(A{0}+)", xn);
//case EffectiveAddressMode.DataRegister:
// return string.Format("D{0}", xn);
//case EffectiveAddressMode.AddressRegister:
// return string.Format("A{0}", xn);
default:
throw new NotImplementedException(mode.ToString());
}
}
protected uint ReadAddressForEffectiveAddress(EffectiveAddressMode mode, uint ea, byte xn)
{
switch (mode)
{
// get the address stored in the address register
case EffectiveAddressMode.Address:
return(this.state.ReadAReg((byte)xn));
// get the address stored in the address register plus the displacement
case EffectiveAddressMode.AddressWithDisplacement:
return(this.state.ReadAReg((byte)xn) + ea);
// get the address stored in the program counter plus the displacement
case EffectiveAddressMode.ProgramCounterWithDisplacement:
return(this.state.PC + ea - 2);
case EffectiveAddressMode.AbsoluteWord:
return((uint)this.ReadDataUsingPC(this.Size));
default:
throw new InvalidStateException();
}
}
protected uint FetchEffectiveAddress(EffectiveAddressMode ea, byte Xn)
{
switch (ea)
{
// get the address data immediately following the opcode
case EffectiveAddressMode.AbsoluteLong:
return((uint)this.ReadDataUsingPC(Size.Long));
// get the address data immediately following the opcode
case EffectiveAddressMode.AbsoluteWord:
return((uint)this.ReadDataUsingPC(Size.Long));
// get the immediate value follwoing the opcode
case EffectiveAddressMode.Immediate:
return((uint)this.ReadDataUsingPC(this.Size));
// get the address register number
case EffectiveAddressMode.Address:
return(Xn);
// get the address register number
case EffectiveAddressMode.AddressRegister:
return(Xn);
// get the data register number
case EffectiveAddressMode.DataRegister:
return(Xn);
// get the displacement word immediately following the opcode
case EffectiveAddressMode.AddressWithDisplacement:
return((uint)this.ReadDataUsingPC(Size.Word));
// get the displacement word immediately following the opcode
case EffectiveAddressMode.ProgramCounterWithDisplacement:
return((uint)this.ReadDataUsingPC(Size.Word));
// get the reg value
case EffectiveAddressMode.AddressPostIncrement:
switch (this.Size)
{
case Size.Byte:
return(this.state.ReadAReg(Xn));
case Size.Word:
return(this.state.ReadAReg(Xn));
case Size.Long:
return(this.state.ReadAReg(Xn));
default:
throw new InvalidStateException();
}
// get the reg value
case EffectiveAddressMode.AddressPreDecrement:
switch (this.Size)
{
case Size.Byte:
return(this.state.ReadAReg(Xn));
case Size.Word:
return(this.state.ReadAReg(Xn));
case Size.Long:
return(this.state.ReadAReg(Xn));
default:
throw new InvalidStateException();
}
default:
throw new NotImplementedException(ea.ToString());
}
}
protected void WriteValueToEffectiveAddress(EffectiveAddressMode ea, uint effectiveAddress, uint Xn, uint value, bool addressProcessed)
{
switch (ea)
{
// write the value at the address to the specified data register
case EffectiveAddressMode.DataRegister:
switch (this.Size)
{
case Size.Byte:
this.state.WriteDReg((byte)Xn, (uint)(byte)value);
break;
case Size.Word:
this.state.WriteDReg((byte)Xn, (uint)(short)value);
break;
case Size.Long:
this.state.WriteDReg((byte)Xn, (uint)value);
break;
default:
throw new InvalidStateException();
}
break;
// write the value to the specified address register
case EffectiveAddressMode.AddressRegister:
this.state.WriteAReg((byte)Xn, value);
break;
// write the value to the specified address register
case EffectiveAddressMode.AddressPostIncrement:
switch (this.Size)
{
case Size.Byte:
this.state.WriteByte(effectiveAddress, (byte)value);
break;
case Size.Word:
this.state.WriteWord(effectiveAddress, (ushort)value);
break;
case Size.Long:
this.state.WriteLong(effectiveAddress, (uint)value);
break;
default:
throw new InvalidStateException();
}
break;
case EffectiveAddressMode.AddressPreDecrement:
switch (this.Size)
{
case Size.Long:
var regl = this.state.ReadAReg((byte)Xn);
if (!addressProcessed)
{
regl -= 4;
this.state.WriteAReg((byte)Xn, regl);
}
this.state.WriteLong(regl, value);
break;
case Size.Word:
var regw = this.state.ReadAReg((byte)Xn);
if (!addressProcessed)
{
regw -= 2;
this.state.WriteAReg((byte)Xn, regw);
}
this.state.WriteWord(regw, (ushort)value);
break;
case Size.Byte:
var regb = this.state.ReadAReg((byte)Xn);
if (!addressProcessed)
{
regb -= 1;
this.state.WriteAReg((byte)Xn, regb);
}
this.state.WriteByte(regb, (byte)value);
break;
default:
throw new InvalidStateException();
}
break;
// write value to address specified in An
case EffectiveAddressMode.Address:
switch (this.Size)
{
case Size.Byte:
this.state.WriteByte(this.state.ReadAReg((byte)Xn), (byte)value);
break;
case Size.Word:
this.state.WriteWord(this.state.ReadAReg((byte)Xn), (ushort)value);
break;
case Size.Long:
this.state.WriteLong(this.state.ReadAReg((byte)Xn), (uint)value);
break;
default:
throw new InvalidStateException();
}
break;
case EffectiveAddressMode.AddressWithDisplacement:
switch (this.Size)
{
case Size.Byte:
var addrb = this.state.ReadAReg((byte)Xn);
if (!addressProcessed)
{
addrb += effectiveAddress;
}
this.state.WriteByte(addrb, (byte)value);
break;
case Size.Word:
throw new NotImplementedException();
case Size.Long:
throw new NotImplementedException();
default:
throw new InvalidStateException();
}
break;
default:
throw new NotImplementedException(ea.ToString());
}
}
/// <summary>
/// Write the value to the location indicated by the effective address.
/// </summary>
/// <param name="ea"></param>
/// <param name="Xn"></param>
/// <param name="value"></param>
protected void WriteValueToEffectiveAddress(EffectiveAddressMode ea, uint Xn, uint value)
{
this.WriteValueToEffectiveAddress(ea, this.EffectiveAddress, Xn, value, false);
}
protected uint ReadValueForEffectiveAddress(EffectiveAddressMode mode, uint ea, byte xn)
{
switch (mode)
{
// get the immediate value
case EffectiveAddressMode.Immediate:
return(ea);
// get the data in memory pointed to by the address register
case EffectiveAddressMode.Address:
switch (this.Size)
{
case Size.Long:
return(this.state.ReadLong(this.state.ReadAReg(xn)));
case Size.Word:
return(this.state.ReadWord(this.state.ReadAReg(xn)));
case Size.Byte:
return(this.state.ReadByte(this.state.ReadAReg(xn)));
default:
throw new InvalidStateException();
}
// get the data in memory pointed to by the address register (post increment register)
case EffectiveAddressMode.AddressPostIncrement:
switch (this.Size)
{
case Size.Long:
var regl = this.state.ReadAReg(xn);
var l = this.state.ReadLong(regl);
this.state.WriteAReg(xn, regl + 4);
return(l);
case Size.Word:
var regw = this.state.ReadAReg(xn);
var w = this.state.ReadWord(regw);
this.state.WriteAReg(xn, regw + 2);
return(w);
case Size.Byte:
var regb = this.state.ReadAReg(xn);
var b = this.state.ReadByte(regb);
this.state.WriteAReg(xn, regb + 1);
return(b);
default:
throw new InvalidStateException();
}
// get the data in memory pointed to by the address register (pre decrement register)
case EffectiveAddressMode.AddressPreDecrement:
switch (this.Size)
{
case Size.Long:
var regl = this.state.ReadAReg(xn);
regl -= 4;
var l = this.state.ReadLong(regl);
this.state.WriteAReg(xn, regl);
return(l);
case Size.Word:
var regw = this.state.ReadAReg(xn);
regw -= 2;
var w = this.state.ReadWord(regw);
this.state.WriteAReg(xn, regw);
return(w);
case Size.Byte:
var regb = this.state.ReadAReg(xn);
regb -= 1;
var b = this.state.ReadByte(regb);
this.state.WriteAReg(xn, regb);
return(b);
default:
throw new InvalidStateException();
}
// get the number stored in the address register
case EffectiveAddressMode.AddressRegister:
return(this.state.ReadAReg(xn));
// get the number stored in the data register
case EffectiveAddressMode.DataRegister:
return(this.state.ReadDReg(xn));
// get the value from memory using the provided long address
// TODO: should this return only LONG?
case EffectiveAddressMode.AbsoluteLong:
switch (this.Size)
{
case Size.Long:
return(this.state.ReadLong(ea));
case Size.Word:
return(this.state.ReadWord(ea));
default:
throw new InvalidStateException();
}
// get the value from memory using the provided long address
// TODO: should this return only WORD?
case EffectiveAddressMode.AbsoluteWord:
switch (this.Size)
{
case Size.Long:
return(this.state.ReadLong(ea));
case Size.Word:
return(this.state.ReadWord(ea));
default:
throw new InvalidStateException();
}
// get the data addressed by the contents of the address register + displacement
case EffectiveAddressMode.AddressWithDisplacement:
var ad = (uint)(this.state.ReadAReg(xn) + (short)ea);
switch (this.Size)
{
case Size.Long:
return(this.state.ReadLong(ad));
case Size.Word:
return(this.state.ReadWord(ad));
case Size.Byte:
return(this.state.ReadByte(ad));
default:
throw new InvalidStateException();
}
// get the data addressed by PC + displacement (-2 so it is from opcode address)
case EffectiveAddressMode.ProgramCounterWithDisplacement:
var pcd = (uint)(this.state.PC - 2 + (short)ea);
switch (this.Size)
{
case Size.Long:
return(this.state.ReadLong(pcd));
case Size.Word:
return(this.state.ReadWord(pcd));
case Size.Byte:
return(this.state.ReadByte(pcd));
default:
throw new InvalidStateException();
}
default:
throw new NotImplementedException(mode.ToString());
}
}