private void InternalAddressBus_SendTo(InternalAddressBusConnection target)
{
switch (target)
{
case InternalAddressBusConnection.AddressBus:
Address.SetValue(InternalAddressBus);
break;
case InternalAddressBusConnection.PC:
PC = InternalAddressBus;
break;
case InternalAddressBusConnection.WZ:
WZ = InternalAddressBus;
break;
default:
throw new NotImplementedException();
}
if (TraceMicroInstructions)
{
TraceMicroInstruction(new MicroInstruction(Z80MicroInstructionTypes.InternalAddressBusSendTo, target));
if (target == InternalAddressBusConnection.AddressBus)
{
TraceMicroInstruction(new MicroInstruction(Z80MicroInstructionTypes.BusConnectorSetValue, target));
}
}
}
private void InternalAddressBus_SampleFromAndDecrement(InternalAddressBusConnection source)
{
switch (source)
{
case InternalAddressBusConnection.WZ:
InternalAddressBus_SampleFrom(InternalAddressBusConnection.WZ);
Register16_Decrement(InternalAddressBusConnection.WZ);
break;
default:
throw new NotImplementedException();
}
}
private void InternalAddressBus_DecrementAndSampleFrom(InternalAddressBusConnection source)
{
switch (source)
{
case InternalAddressBusConnection.SP:
// The stack pointer is automatically decremented before its contents are transferred to the address lines
Register16_Decrement(Register16.SP);
InternalAddressBus_SampleFrom(InternalAddressBusConnection.SP);
break;
default:
throw new NotImplementedException();
}
}
private void Register16_Decrement(InternalAddressBusConnection register)
{
switch (register)
{
case InternalAddressBusConnection.PC:
PC = (ushort)(PC - 1);
break;
case InternalAddressBusConnection.WZ:
WZ = (ushort)(WZ - 1);
break;
default:
throw new NotImplementedException();
}
if (TraceMicroInstructions)
{
TraceMicroInstruction(new MicroInstruction(Z80MicroInstructionTypes.Register16Decrement, register));
}
}
private void InternalAddressBus_SampleFrom(InternalAddressBusConnection source)
{
switch (source)
{
case InternalAddressBusConnection.PC:
InternalAddressBus = PC;
break;
case InternalAddressBusConnection.SP:
InternalAddressBus = SP;
break;
case InternalAddressBusConnection.WZ:
InternalAddressBus = WZ;
break;
case InternalAddressBusConnection.IX:
InternalAddressBus = IX;
break;
case InternalAddressBusConnection.IY:
InternalAddressBus = IY;
break;
case InternalAddressBusConnection.IandR:
// During every first machine cycle (beginning of an instruction or part of it, prefixes have their
// own M1 two), the memory refresh cycle is issued. The whole I+R register is put on the address
// bus, and the RFSH pin is lowered. It is unclear whether the Z80 increases the R register before
// or after putting I+R on the bus.
InternalAddressBus = (ushort)((I << 8) + R);
break;
default:
throw new NotImplementedException();
}
if (TraceMicroInstructions)
{
TraceMicroInstruction(new MicroInstruction(Z80MicroInstructionTypes.InternalAddressBusSampleFrom, source));
}
}
private void InternalAddressBus_SampleFromAndIncrement(InternalAddressBusConnection source)
{
switch (source)
{
case InternalAddressBusConnection.PC:
// The PC is automatically incremented after its contents have been transferred to the address lines
InternalAddressBus_SampleFrom(InternalAddressBusConnection.PC);
Register16_Increment(InternalAddressBusConnection.PC);
break;
case InternalAddressBusConnection.SP:
// The stack pointer is automatically incremented after its contents have been transferred to the address lines
InternalAddressBus_SampleFrom(InternalAddressBusConnection.SP);
Register16_Increment(InternalAddressBusConnection.SP);
break;
case InternalAddressBusConnection.WZ:
InternalAddressBus_SampleFrom(InternalAddressBusConnection.WZ);
Register16_Increment(InternalAddressBusConnection.WZ);
break;
case InternalAddressBusConnection.IandR:
// During every first machine cycle (beginning of an instruction or part of it, prefixes have their
// own M1 two), the memory refresh cycle is issued. The whole I+R register is put on the address
// bus, and the RFSH pin is lowered. It is unclear whether the Z80 increases the R register before
// or after putting I+R on the bus.
InternalAddressBus_SampleFrom(InternalAddressBusConnection.IandR);
// The R register is increased at every first machine cycle (M1). Bit 7 of the register is never
// changed by this.
RegisterR_Increment();
break;
default:
throw new NotImplementedException();
}
}
private void InternalAddressBus_SendTo(InternalAddressBusConnection target)
{
switch (target)
{
case InternalAddressBusConnection.AddressBus:
Address.SetValue(InternalAddressBus);
break;
case InternalAddressBusConnection.PC:
PC = InternalAddressBus;
break;
case InternalAddressBusConnection.WZ:
WZ = InternalAddressBus;
break;
default:
throw new NotImplementedException();
}
if (TraceMicroInstructions)
{
TraceMicroInstruction(new MicroInstruction(Z80MicroInstructionTypes.InternalAddressBusSendTo, target));
if (target == InternalAddressBusConnection.AddressBus)
{
TraceMicroInstruction(new MicroInstruction(Z80MicroInstructionTypes.BusConnectorSetValue, target));
}
}
}
private void InternalAddressBus_SampleFromAndIncrement(InternalAddressBusConnection source)
{
switch (source)
{
case InternalAddressBusConnection.PC:
// The PC is automatically incremented after its contents have been transferred to the address lines
InternalAddressBus_SampleFrom(InternalAddressBusConnection.PC);
Register16_Increment(InternalAddressBusConnection.PC);
break;
case InternalAddressBusConnection.SP:
// The stack pointer is automatically incremented after its contents have been transferred to the address lines
InternalAddressBus_SampleFrom(InternalAddressBusConnection.SP);
Register16_Increment(InternalAddressBusConnection.SP);
break;
case InternalAddressBusConnection.WZ:
InternalAddressBus_SampleFrom(InternalAddressBusConnection.WZ);
Register16_Increment(InternalAddressBusConnection.WZ);
break;
case InternalAddressBusConnection.IandR:
// During every first machine cycle (beginning of an instruction or part of it, prefixes have their
// own M1 two), the memory refresh cycle is issued. The whole I+R register is put on the address
// bus, and the RFSH pin is lowered. It is unclear whether the Z80 increases the R register before
// or after putting I+R on the bus.
InternalAddressBus_SampleFrom(InternalAddressBusConnection.IandR);
// The R register is increased at every first machine cycle (M1). Bit 7 of the register is never
// changed by this.
RegisterR_Increment();
break;
default:
throw new NotImplementedException();
}
}
private void InternalAddressBus_SampleFromAndDecrement(InternalAddressBusConnection source)
{
switch (source)
{
case InternalAddressBusConnection.WZ:
InternalAddressBus_SampleFrom(InternalAddressBusConnection.WZ);
Register16_Decrement(InternalAddressBusConnection.WZ);
break;
default:
throw new NotImplementedException();
}
}
private void InternalAddressBus_SampleFrom(InternalAddressBusConnection source)
{
switch (source)
{
case InternalAddressBusConnection.PC:
InternalAddressBus = PC;
break;
case InternalAddressBusConnection.SP:
InternalAddressBus = SP;
break;
case InternalAddressBusConnection.WZ:
InternalAddressBus = WZ;
break;
case InternalAddressBusConnection.IX:
InternalAddressBus = IX;
break;
case InternalAddressBusConnection.IY:
InternalAddressBus = IY;
break;
case InternalAddressBusConnection.IandR:
// During every first machine cycle (beginning of an instruction or part of it, prefixes have their
// own M1 two), the memory refresh cycle is issued. The whole I+R register is put on the address
// bus, and the RFSH pin is lowered. It is unclear whether the Z80 increases the R register before
// or after putting I+R on the bus.
InternalAddressBus = (ushort)((I << 8) + R);
break;
default:
throw new NotImplementedException();
}
if (TraceMicroInstructions)
{
TraceMicroInstruction(new MicroInstruction(Z80MicroInstructionTypes.InternalAddressBusSampleFrom, source));
}
}
private void InternalAddressBus_DecrementAndSampleFrom(InternalAddressBusConnection source)
{
switch (source)
{
case InternalAddressBusConnection.SP:
// The stack pointer is automatically decremented before its contents are transferred to the address lines
Register16_Decrement(Register16.SP);
InternalAddressBus_SampleFrom(InternalAddressBusConnection.SP);
break;
default:
throw new NotImplementedException();
}
}
private void Register16_Increment(InternalAddressBusConnection register)
{
switch (register)
{
case InternalAddressBusConnection.PC:
PC = (ushort)(PC + 1);
break;
case InternalAddressBusConnection.SP:
SP = (ushort)(SP + 1);
break;
case InternalAddressBusConnection.WZ:
WZ = (ushort)(WZ + 1);
break;
default:
throw new NotImplementedException();
}
if (TraceMicroInstructions)
{
TraceMicroInstruction(new MicroInstruction(Z80MicroInstructionTypes.Register16Increment, register));
}
}
