diff options
Diffstat (limited to 'Noddybox.Emulation.EightBit.Z80/Z80Cpu.cs')
| -rw-r--r-- | Noddybox.Emulation.EightBit.Z80/Z80Cpu.cs | 179 |
1 files changed, 117 insertions, 62 deletions
diff --git a/Noddybox.Emulation.EightBit.Z80/Z80Cpu.cs b/Noddybox.Emulation.EightBit.Z80/Z80Cpu.cs index d967bb9..1583ae0 100644 --- a/Noddybox.Emulation.EightBit.Z80/Z80Cpu.cs +++ b/Noddybox.Emulation.EightBit.Z80/Z80Cpu.cs @@ -1,4 +1,7 @@ -using System;
+//
+// Copyright (c) 2012 Ian Cowburn
+//
+using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
@@ -22,13 +25,13 @@ namespace Noddybox.Emulation.EightBit.Z80 private enum Z80Flags
{
None = 0x00,
- Carry = 0x01, - Neg = 0x02, - PV = 0x04, - Hidden3 = 0x08, - HalfCarry = 0x10, - Hidden5 = 0x20, - Zero = 0x40, + Carry = 0x01,
+ Neg = 0x02,
+ PV = 0x04,
+ Hidden3 = 0x08,
+ HalfCarry = 0x10,
+ Hidden5 = 0x20,
+ Zero = 0x40,
Sign = 0x80
};
@@ -38,11 +41,12 @@ namespace Noddybox.Emulation.EightBit.Z80 // Lookup tables
//
- private Z80Flags[] PSZtable = new Z80Flags[512]; - private Z80Flags[] SZtable = new Z80Flags[512]; - private Z80Flags[] Ptable = new Z80Flags[512]; - private Z80Flags[] Stable = new Z80Flags[512]; + private Z80Flags[] PSZtable = new Z80Flags[512];
+ private Z80Flags[] SZtable = new Z80Flags[512];
+ private Z80Flags[] Ptable = new Z80Flags[512];
+ private Z80Flags[] Stable = new Z80Flags[512];
private Z80Flags[] Ztable = new Z80Flags[512];
+ private Z80Flags[] H35table = new Z80Flags[256];
// Machine accessors
//
@@ -53,17 +57,14 @@ namespace Noddybox.Emulation.EightBit.Z80 // Main registers
//
private byte A;
- private byte F;
- private byte R;
- private byte IFF1;
- private byte IFF2;
+ private Z80Flags F;
private IRegister16 BC = Register16Factory.Create();
private IRegister16 DE = Register16Factory.Create();
private IRegister16 HL = Register16Factory.Create();
private IRegister16 IX = Register16Factory.Create();
private IRegister16 IY = Register16Factory.Create();
- private IRegister16 SP = Register16Factory.Create();
- private IRegister16 PC = Register16Factory.Create();
+ private ushort SP;
+ private ushort PC;
// Alternate registers
//
@@ -72,6 +73,15 @@ namespace Noddybox.Emulation.EightBit.Z80 private IRegister16 DE_ = Register16Factory.Create();
private IRegister16 HL_ = Register16Factory.Create();
+ // Auxilliary registers and flags
+ //
+ private byte I;
+ private byte R;
+ private bool IFF1;
+ private bool IFF2;
+ private int IM;
+ private bool HALT;
+
#endregion
#region ICpu Members
@@ -87,7 +97,29 @@ namespace Noddybox.Emulation.EightBit.Z80 public void Reset()
{
- // TODO: Initial register settings.
+ PC = 0;
+ A = 0xff;
+ F = (Z80Flags)0xff;
+
+ BC.Value = 0xffff;
+ DE.Value = 0xffff;
+ HL.Value = 0xffff;
+ AF_.Value = 0xffff;
+ BC_.Value = 0xffff;
+ DE_.Value = 0xffff;
+ HL_.Value = 0xffff;
+
+ IX.Value = 0xffff;
+ IY.Value = 0xffff;
+
+ SP = 0xffff;
+
+ IFF1 = false;
+ IFF2 = false;
+ IM = 0;
+ I = 0;
+ R = 0;
+ HALT = false;
}
public void Step()
@@ -97,16 +129,23 @@ namespace Noddybox.Emulation.EightBit.Z80 public void Run()
{
- // TODO: Run for a frame
+ while(!clock.FrameDone)
+ {
+ Step();
+ }
}
public void MaskableInterrupt(byte value)
{
+ clock.Add(2);
+
// TODO: INT
}
public void NonMaskableInterrupt(byte value)
{
+ clock.Add(2);
+
// TODO: NMI
}
@@ -118,48 +157,64 @@ namespace Noddybox.Emulation.EightBit.Z80 {
// Setup lookup tables
//
- for(int f = 0; f < 256; f++) - { - Z80Flags p = Z80Flags.None; - Z80Flags z = Z80Flags.None; - Z80Flags s = Z80Flags.None; - int parity = 0; - - for(int b=0; b < 8; b++) - { - if ((f & (1<<b)) == (1<<b)) - { - parity++; - } - } - - if ((parity & 1) == 1) - { - p = Z80Flags.PV; - } - - if (f == 0) - { - z = Z80Flags.Zero; - } - - if ((f & 0x80) == 0x80) - { - s = Z80Flags.Sign; - } - - Ptable[f] = p; - Stable[f] = s; - Ztable[f] = z; - SZtable[f] =z|s; - PSZtable[f] = z|s|p; - - Ptable[f+256] = Ptable[f]|Z80Flags.Carry; - Stable[f+256] = Stable[f]|Z80Flags.Carry; - Ztable[f+256] = Ztable[f]|Z80Flags.Carry; - SZtable[f+256] = SZtable[f]|Z80Flags.Carry; - PSZtable[f+256] = PSZtable[f]|Z80Flags.Carry; - } + for(int f = 0; f < 256; f++)
+ {
+ Z80Flags p = Z80Flags.None;
+ Z80Flags z = Z80Flags.None;
+ Z80Flags s = Z80Flags.None;
+ Z80Flags h3 = Z80Flags.None;
+ Z80Flags h5 = Z80Flags.None;
+
+ int parity = 0;
+
+ for(int b=0; b < 8; b++)
+ {
+ if ((f & (1<<b)) == (1<<b))
+ {
+ parity++;
+ }
+ }
+
+ if ((parity & 1) == 1)
+ {
+ p = Z80Flags.PV;
+ }
+
+ if (f == 0)
+ {
+ z = Z80Flags.Zero;
+ }
+
+ if ((f & 0x80) == 0x80)
+ {
+ s = Z80Flags.Sign;
+ }
+
+ if ((f & (int)Z80Flags.Hidden3) == (int)Z80Flags.Hidden3)
+ {
+ h3 = Z80Flags.Hidden3;
+ }
+
+ if ((f & (int)Z80Flags.Hidden5) == (int)Z80Flags.Hidden5)
+ {
+ h5 = Z80Flags.Hidden5;
+ }
+
+ Ptable[f] = p;
+ Stable[f] = s;
+ Ztable[f] = z;
+ SZtable[f] =z | s;
+ PSZtable[f] = z | s | p;
+ H35table[f] = h3 | h5;
+
+ Ptable[f+256] = Ptable[f] | Z80Flags.Carry;
+ Stable[f+256] = Stable[f] | Z80Flags.Carry;
+ Ztable[f+256] = Ztable[f] | Z80Flags.Carry;
+ SZtable[f+256] = SZtable[f] | Z80Flags.Carry;
+ PSZtable[f+256] = PSZtable[f] | Z80Flags.Carry;
+ }
+
+ Reset();
}
#endregion
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