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6502: added RDY pin, required for C64 and possibly others

This commit is contained in:
saxxonpike 2013-08-15 06:08:21 +00:00
parent af9bbd9ae4
commit 459368dd5b
3 changed files with 798 additions and 339 deletions
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523
BizHawk.Emulation/CPUs/MOS 6502X/Execute.cs
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File diff suppressed because it is too large Load Diff

3
BizHawk.Emulation/CPUs/MOS 6502X/MOS6502X.cs
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@ -27,6 +27,7 @@ namespace BizHawk.Emulation.CPUs.M6502
mi = 0; mi = 0;
opcode = 256; opcode = 256;
iflag_pending = true; iflag_pending = true;
RDY = true;
} }
public void NESSoftReset() public void NESSoftReset()
@ -82,6 +83,7 @@ namespace BizHawk.Emulation.CPUs.M6502
public bool IRQ; public bool IRQ;
public bool NMI; public bool NMI;
public bool RDY;
public void SyncState(Serializer ser) public void SyncState(Serializer ser)
{ {
@ -94,6 +96,7 @@ namespace BizHawk.Emulation.CPUs.M6502
ser.Sync("S", ref S); ser.Sync("S", ref S);
ser.Sync("NMI", ref NMI); ser.Sync("NMI", ref NMI);
ser.Sync("IRQ", ref IRQ); ser.Sync("IRQ", ref IRQ);
ser.Sync("RDY", ref RDY);
ser.Sync("TotalExecutedCycles", ref TotalExecutedCycles); ser.Sync("TotalExecutedCycles", ref TotalExecutedCycles);
ser.Sync("opcode", ref opcode); ser.Sync("opcode", ref opcode);
ser.Sync("opcode2", ref opcode2); ser.Sync("opcode2", ref opcode2);

43
BizHawk.Emulation/Computers/Commodore64/MOS/MOS6510.cs
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@ -13,14 +13,9 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
private MOS6502X cpu; private MOS6502X cpu;
private List<GCHandle> disposeList = new List<GCHandle>(); private List<GCHandle> disposeList = new List<GCHandle>();
private bool freezeCpu; //private bool freezeCpu;
private bool pinNMILast; private bool pinNMILast;
private LatchedPort port; private LatchedPort port;
private bool unusedPin0;
private bool unusedPin1;
private uint unusedPinTTL0;
private uint unusedPinTTL1;
private uint unusedPinTTLCycles;
public Func<int, byte> PeekMemory; public Func<int, byte> PeekMemory;
public Action<int, byte> PokeMemory; public Action<int, byte> PokeMemory;
@ -43,9 +38,6 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
cpu.ReadMemory = Read; cpu.ReadMemory = Read;
cpu.WriteMemory = Write; cpu.WriteMemory = Write;
// todo: verify this value (I only know that unconnected bits fade after a number of cycles)
unusedPinTTLCycles = 40;
// perform hard reset // perform hard reset
HardReset(); HardReset();
} }
@ -74,10 +66,6 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
// NMI is high on startup (todo: verify) // NMI is high on startup (todo: verify)
pinNMILast = true; pinNMILast = true;
// reset unused IO pin TTLs
unusedPinTTL0 = 0;
unusedPinTTL1 = 0;
} }
// ------------------------------------ // ------------------------------------
@ -88,8 +76,8 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
public void ExecutePhase2() public void ExecutePhase2()
{ {
if (ReadAEC() && !freezeCpu) cpu.RDY = ReadRDY();
{
// the 6502 core expects active high // the 6502 core expects active high
// so we reverse the polarity here // so we reverse the polarity here
bool thisNMI = ReadNMI(); bool thisNMI = ReadNMI();
@ -103,21 +91,6 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
cpu.ExecuteOne(); cpu.ExecuteOne();
} }
// unfreeze cpu if BA is high
if (ReadRDY()) freezeCpu = false;
// process unused pin TTL
if (unusedPinTTL0 == 0)
unusedPin0 = false;
else
unusedPinTTL0--;
if (unusedPinTTL1 == 0)
unusedPin1 = false;
else
unusedPinTTL1--;
}
// ------------------------------------ // ------------------------------------
public ushort PC public ushort PC
@ -162,10 +135,6 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
public byte Read(ushort addr) public byte Read(ushort addr)
{ {
// cpu freezes after first read when RDY is low
if (!ReadRDY())
freezeCpu = true;
if (addr == 0x0000) if (addr == 0x0000)
return port.Direction; return port.Direction;
else if (addr == 0x0001) else if (addr == 0x0001)
@ -177,13 +146,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
public void SyncState(Serializer ser) public void SyncState(Serializer ser)
{ {
cpu.SyncState(ser); cpu.SyncState(ser);
ser.Sync("freezeCpu", ref freezeCpu);
ser.Sync("pinNMILast", ref pinNMILast); ser.Sync("pinNMILast", ref pinNMILast);
ser.Sync("unusedPin0", ref unusedPin0);
ser.Sync("unusedPin1", ref unusedPin1);
ser.Sync("unusedPinTTL0", ref unusedPinTTL0);
ser.Sync("unusedPinTTL1", ref unusedPinTTL1);
ser.Sync("unusedPinTTLCycles", ref unusedPinTTLCycles);
} }
public void Write(ushort addr, byte val) public void Write(ushort addr, byte val)