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Resurrect the Register16 class. This (or something *very* much like it) is going to be necessary to add a Z80 emulator (reference access to the high/low parts of 16-bit registers).

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Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
This commit is contained in:
Adrian Conlon
2019-02-14 23:01:31 +00:00
parent b61d884679
commit 63db46a7bc
12 changed files with 336 additions and 195 deletions
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M6502/Disassembly.cs
+2 -2
View File
@@ -56,7 +56,7 @@ namespace EightBit
output.Append(" ");
var next = this.bus.Peek((ushort)(current + 1));
var relative = (ushort)(this.processor.PC + 2 + (sbyte)next);
var relative = (ushort)(this.processor.PC().Word + 2 + (sbyte)next);
var aaa = (cell & 0b11100000) >> 5;
var bbb = (cell & 0b00011100) >> 2;
@@ -550,7 +550,7 @@ namespace EightBit
private ushort GetWord(ushort absolute)
{
return this.processor.PeekWord(absolute);
return this.processor.PeekWord(absolute).Word;
}
private string Dump_Byte(ushort absolute)
M6502/M6502.Test/Board.cs
+3 -3
View File
@@ -52,7 +52,7 @@ namespace M6502.Test
var programFilename = this.configuration.Program;
var programPath = this.configuration.RomDirectory + "/" + this.configuration.Program;
var loadAddress = this.configuration.LoadAddress;
this.ram.Load(programPath, loadAddress);
this.ram.Load(programPath, loadAddress.Word);
if (this.configuration.DebugMode)
{
@@ -72,7 +72,7 @@ namespace M6502.Test
private void CPU_ExecutedInstruction(object sender, System.EventArgs e)
{
var pc = this.CPU.PC;
var pc = this.CPU.PC().Word;
if (this.oldPC != pc)
{
this.oldPC = pc;
@@ -89,7 +89,7 @@ namespace M6502.Test
private void CPU_ExecutingInstruction(object sender, System.EventArgs e)
{
var address = this.CPU.PC;
var address = this.CPU.PC().Word;
var cell = this.Peek(address);
var output = new StringBuilder();
M6502/M6502.Test/Configuration.cs
+4 -4
View File
@@ -8,8 +8,8 @@ namespace M6502.Test
internal class Configuration
{
private readonly ushort loadAddress = 0x400;
private readonly ushort startAddress = 0x400;
private readonly Register16 loadAddress = new Register16(0x400);
private readonly Register16 startAddress = new Register16(0x400);
private readonly string romDirectory = "roms";
private readonly string program = "6502_functional_test.bin";
private bool debugMode = false;
@@ -24,9 +24,9 @@ namespace M6502.Test
set => this.debugMode = value;
}
public ushort LoadAddress { get => this.loadAddress; }
public Register16 LoadAddress { get => this.loadAddress; }
public ushort StartAddress { get => this.startAddress; }
public Register16 StartAddress { get => this.startAddress; }
public string RomDirectory { get => this.romDirectory; }
M6502/M6502.cs
+55 -52
View File
@@ -233,7 +233,7 @@ namespace EightBit
case 0x49: this.A = this.EorR(this.A, this.AM_Immediate()); break; // EOR (immediate)
case 0x4a: this.BusRead(); this.A = this.LSR(this.A); break; // LSR A (implied)
case 0x4b: this.ASR(this.AM_Immediate()); break; // *ASR (immediate)
case 0x4c: this.Jump(this.Address_Absolute()); break; // JMP (absolute)
case 0x4c: this.Jump(this.Address_Absolute().Word); break; // JMP (absolute)
case 0x4d: this.A = this.EorR(this.A, this.AM_Absolute()); break; // EOR (absolute)
case 0x4e: this.BusReadModifyWrite(this.LSR(this.AM_Absolute())); break; // LSR (absolute)
case 0x4f: this.SRE(this.AM_Absolute()); break; // *SRE (absolute)
@@ -267,7 +267,7 @@ namespace EightBit
case 0x69: this.A = this.ADC(this.A, this.AM_Immediate()); break; // ADC (immediate)
case 0x6a: this.BusRead(); this.A = this.ROR(this.A); break; // ROR A (implied)
case 0x6b: this.ARR(this.AM_Immediate()); break; // *ARR (immediate)
case 0x6c: this.Jump(this.Address_Indirect()); break; // JMP (indirect)
case 0x6c: this.Jump(this.Address_Indirect().Word); break; // JMP (indirect)
case 0x6d: this.A = this.ADC(this.A, this.AM_Absolute()); break; // ADC (absolute)
case 0x6e: this.BusReadModifyWrite(this.ROR(this.AM_Absolute())); break; // ROR (absolute)
case 0x6f: this.RRA(this.AM_Absolute()); break; // *RRA (absolute)
@@ -290,9 +290,9 @@ namespace EightBit
case 0x7f: this.RRA(this.AM_AbsoluteX()); break; // *RRA (absolute, X)
case 0x80: this.AM_Immediate(); break; // *NOP (immediate)
case 0x81: this.BusWrite(this.Address_IndexedIndirectX(), this.A); break; // STA (indexed indirect X)
case 0x81: this.BusWrite(this.Address_IndexedIndirectX().Word, this.A); break; // STA (indexed indirect X)
case 0x82: this.AM_Immediate(); break; // *NOP (immediate)
case 0x83: this.BusWrite(this.Address_IndexedIndirectX(), (byte)(this.A & this.X)); break; // *SAX (indexed indirect X)
case 0x83: this.BusWrite(this.Address_IndexedIndirectX().Word, (byte)(this.A & this.X)); break; // *SAX (indexed indirect X)
case 0x84: this.BusWrite(this.Address_ZeroPage(), this.Y); break; // STY (zero page)
case 0x85: this.BusWrite(this.Address_ZeroPage(), this.A); break; // STA (zero page)
case 0x86: this.BusWrite(this.Address_ZeroPage(), this.X); break; // STX (zero page)
@@ -301,10 +301,10 @@ namespace EightBit
case 0x89: this.AM_Immediate(); break; // *NOP (immediate)
case 0x8a: this.BusRead(); this.A = this.Through(this.X); break; // TXA (implied)
case 0x8b: break;
case 0x8c: this.BusWrite(this.Address_Absolute(), this.Y); break; // STY (absolute)
case 0x8d: this.BusWrite(this.Address_Absolute(), this.A); break; // STA (absolute)
case 0x8e: this.BusWrite(this.Address_Absolute(), this.X); break; // STX (absolute)
case 0x8f: this.BusWrite(this.Address_Absolute(), (byte)(this.A & this.X)); break; // *SAX (absolute)
case 0x8c: this.BusWrite(this.Address_Absolute().Word, this.Y); break; // STY (absolute)
case 0x8d: this.BusWrite(this.Address_Absolute().Word, this.A); break; // STA (absolute)
case 0x8e: this.BusWrite(this.Address_Absolute().Word, this.X); break; // STX (absolute)
case 0x8f: this.BusWrite(this.Address_Absolute().Word, (byte)(this.A & this.X)); break; // *SAX (absolute)
case 0x90: this.Branch(this.Carry == 0); break; // BCC (relative)
case 0x91: this.AM_IndirectIndexedY(); this.BusWrite(this.A); break; // STA (indirect indexed Y)
@@ -443,7 +443,7 @@ namespace EightBit
if (this.RDY().Raised())
{
this.LowerSYNC(); // Instruction fetch beginning
this.OpCode = this.Bus.Read(this.PC++); // can't use fetchByte
this.OpCode = this.Bus.Read(this.PC()++); // can't use fetchByte
if (this.RESET().Lowered())
{
this.HandleRESET();
@@ -567,19 +567,19 @@ namespace EightBit
var software = !hardware;
if (reset)
{
this.DummyPush(Chip.HighByte(this.PC));
this.DummyPush(Chip.LowByte(this.PC));
this.DummyPush(this.PC().High);
this.DummyPush(this.PC().Low);
this.DummyPush(this.P);
}
else
{
this.PushWord(this.PC);
this.PushWord(this.PC());
this.Push((byte)(this.P | (int)(software ? StatusBits.BF : 0)));
}
this.P = SetFlag(this.P, StatusBits.IF); // Disable IRQ
var vector = reset ? RSTvector : (nmi ? NMIvector : IRQvector);
this.Jump(this.GetWordPaged(0xff, vector));
this.Jump(this.GetWordPaged(0xff, vector).Word);
this.handlingRESET = this.handlingNMI = this.handlingINT = false;
}
@@ -587,19 +587,20 @@ namespace EightBit
{
this.Tick();
this.Bus.Data = value;
this.Bus.Address = Chip.MakeWord(this.S--, 1);
this.Bus.Address().Low = this.S--;
this.Bus.Address().High = 1;
}
private ushort Address_Absolute() => this.FetchWord();
private Register16 Address_Absolute() => this.FetchWord();
private byte Address_ZeroPage() => this.FetchByte();
private ushort Address_ZeroPageIndirect() => this.GetWordPaged(0, this.Address_ZeroPage());
private Register16 Address_ZeroPageIndirect() => this.GetWordPaged(0, this.Address_ZeroPage());
private ushort Address_Indirect()
private Register16 Address_Indirect()
{
var address = this.Address_Absolute();
return this.GetWordPaged(Chip.HighByte(address), Chip.LowByte(address));
return this.GetWordPaged(address.High, address.Low);
}
private byte Address_ZeroPageX()
@@ -616,42 +617,42 @@ namespace EightBit
return Chip.LowByte(address + this.Y);
}
private Tuple<ushort, byte> Address_AbsoluteX()
private Tuple<Register16, byte> Address_AbsoluteX()
{
var address = this.Address_Absolute();
var page = HighByte(address);
address += this.X;
return new Tuple<ushort, byte>(address, page);
var page = address.High;
address.Word += this.X;
return new Tuple<Register16, byte>(address, page);
}
private Tuple<ushort, byte> Address_AbsoluteY()
private Tuple<Register16, byte> Address_AbsoluteY()
{
var address = this.Address_Absolute();
var page = HighByte(address);
address += this.Y;
return new Tuple<ushort, byte>(address, page);
var page = address.High;
address.Word += this.Y;
return new Tuple<Register16, byte>(address, page);
}
private ushort Address_IndexedIndirectX() => this.GetWordPaged(0, this.Address_ZeroPageX());
private Register16 Address_IndexedIndirectX() => this.GetWordPaged(0, this.Address_ZeroPageX());
private Tuple<ushort, byte> Address_IndirectIndexedY()
private Tuple<Register16, byte> Address_IndirectIndexedY()
{
var address = this.Address_ZeroPageIndirect();
var page = Chip.HighByte(address);
address += this.Y;
return new Tuple<ushort, byte>(address, page);
var page = address.High;
address.Word += this.Y;
return new Tuple<Register16, byte>(address, page);
}
private ushort Address_relative_byte()
{
var offset = (sbyte)this.FetchByte();
this.intermediate = (ushort)(this.PC + offset);
this.intermediate = (ushort)(this.PC().Word + offset);
return this.intermediate;
}
private byte AM_Immediate() => this.FetchByte();
private byte AM_Absolute() => this.BusRead(this.Address_Absolute());
private byte AM_Absolute() => this.BusRead(this.Address_Absolute().Word);
private byte AM_ZeroPage() => this.BusRead(this.Address_ZeroPage());
@@ -660,10 +661,10 @@ namespace EightBit
var crossed = this.Address_AbsoluteX();
var address = crossed.Item1;
var page = crossed.Item2;
var possible = this.BusRead(Chip.LowByte(address), page);
if ((behaviour == PageCrossingBehavior.AlwaysReadTwice) || (page != Chip.HighByte(address)))
var possible = this.BusRead(address.Low, page);
if ((behaviour == PageCrossingBehavior.AlwaysReadTwice) || (page != address.High))
{
possible = this.BusRead(address);
possible = this.BusRead(address.Word);
}
return possible;
@@ -674,10 +675,10 @@ namespace EightBit
var crossed = this.Address_AbsoluteY();
var address = crossed.Item1;
var page = crossed.Item2;
var possible = this.BusRead(Chip.LowByte(address), page);
if (page != Chip.HighByte(address))
var possible = this.BusRead(address.Low, page);
if (page != address.High)
{
possible = this.BusRead(address);
possible = this.BusRead(address.Word);
}
return possible;
@@ -687,17 +688,17 @@ namespace EightBit
private byte AM_ZeroPageY() => this.BusRead(this.Address_ZeroPageY());
private byte AM_IndexedIndirectX() => this.BusRead(this.Address_IndexedIndirectX());
private byte AM_IndexedIndirectX() => this.BusRead(this.Address_IndexedIndirectX().Word);
private byte AM_IndirectIndexedY()
{
var crossed = this.Address_IndirectIndexedY();
var address = crossed.Item1;
var page = crossed.Item2;
var possible = this.BusRead(LowByte(address), page);
if (page != Chip.HighByte(address))
var possible = this.BusRead(address.Low, page);
if (page != address.High)
{
possible = this.BusRead(address);
possible = this.BusRead(address.Word);
}
return possible;
@@ -719,11 +720,11 @@ namespace EightBit
if (condition)
{
this.BusRead();
var page = HighByte(this.PC);
var page = this.PC().High;
this.Jump(destination);
if (Chip.HighByte(this.PC) != page)
if (this.PC().High != page)
{
this.BusRead(Chip.LowByte(this.PC), page);
this.BusRead(this.PC().Low, page);
}
}
}
@@ -864,8 +865,10 @@ namespace EightBit
{
var low = this.FetchByte();
this.BusRead(this.S, 1); // dummy read
this.PushWord(this.PC);
this.PC = Chip.MakeWord(low, this.FetchByte());
this.PushWord(this.PC());
var high = this.FetchByte();
this.PC().Low = low;
this.PC().High = high;
}
private byte LSR(byte value)
@@ -977,8 +980,8 @@ namespace EightBit
var crossed = this.Address_AbsoluteX();
var address = crossed.Item1;
var page = crossed.Item2;
this.BusRead(Chip.LowByte(address), page);
this.BusWrite(address, this.A);
this.BusRead(address.Low, page);
this.BusWrite(address.Word, this.A);
}
private void STA_AbsoluteY()
@@ -986,8 +989,8 @@ namespace EightBit
var crossed = this.Address_AbsoluteY();
var address = crossed.Item1;
var page = crossed.Item2;
this.BusRead(Chip.LowByte(address), page);
this.BusWrite(address, this.A);
this.BusRead(address.Low, page);
this.BusWrite(address.Word, this.A);
}
}
}