Mesen-SX/Core/Cpu.Shared.h
2020-12-19 23:30:09 +03:00

1118 lines
19 KiB
C

void Cpu::PowerOn()
{
_state = {};
_state.PC = GetResetVector();
_state.SP = 0x1FF;
_state.PS = ProcFlags::IrqDisable;
_state.EmulationMode = true;
_state.NmiFlag = false;
_state.PrevNmiFlag = false;
_state.StopState = CpuStopState::Running;
_state.IrqSource = (uint8_t)IrqSource::None;
_state.PrevIrqSource = (uint8_t)IrqSource::None;
SetFlags(ProcFlags::MemoryMode8);
SetFlags(ProcFlags::IndexMode8);
}
void Cpu::Reset()
{
SetFlags(ProcFlags::IrqDisable | ProcFlags::MemoryMode8 | ProcFlags::IndexMode8);
ClearFlags(ProcFlags::Decimal);
_state.EmulationMode = true;
_state.DBR = 0;
_state.D = 0;
_state.K = 0;
_state.Y &= 0xFF;
_state.X &= 0xFF;
_state.CycleCount = 0;
_state.PC = GetResetVector();
SetSP(_state.SP);
_state.NmiFlag = false;
_state.PrevNmiFlag = false;
_state.StopState = CpuStopState::Running;
_state.IrqSource = (uint8_t)IrqSource::None;
_state.PrevIrqSource = (uint8_t)IrqSource::None;
}
void Cpu::RunOp()
{
switch (GetOpCode())
{
case 0x00: AddrMode_Imm8();
BRK();
break;
case 0x01: AddrMode_DirIdxIndX();
ORA();
break;
case 0x02: AddrMode_Imm8();
COP();
break;
case 0x03: AddrMode_StkRel();
ORA();
break;
case 0x04: AddrMode_Dir();
TSB();
break;
case 0x05: AddrMode_Dir();
ORA();
break;
case 0x06: AddrMode_Dir();
ASL();
break;
case 0x07: AddrMode_DirIndLng();
ORA();
break;
case 0x08: PHP();
break;
case 0x09: AddrMode_ImmM();
ORA();
break;
case 0x0A: AddrMode_Acc();
ASL_Acc();
break;
case 0x0B: PHD();
break;
case 0x0C: AddrMode_Abs();
TSB();
break;
case 0x0D: AddrMode_Abs();
ORA();
break;
case 0x0E: AddrMode_Abs();
ASL();
break;
case 0x0F: AddrMode_AbsLng();
ORA();
break;
case 0x10: AddrMode_Rel();
BPL();
break;
case 0x11: AddrMode_DirIndIdxY(false);
ORA();
break;
case 0x12: AddrMode_DirInd();
ORA();
break;
case 0x13: AddrMode_StkRelIndIdxY();
ORA();
break;
case 0x14: AddrMode_Dir();
TRB();
break;
case 0x15: AddrMode_DirIdxX();
ORA();
break;
case 0x16: AddrMode_DirIdxX();
ASL();
break;
case 0x17: AddrMode_DirIndLngIdxY();
ORA();
break;
case 0x18: AddrMode_Imp();
CLC();
break;
case 0x19: AddrMode_AbsIdxY(false);
ORA();
break;
case 0x1A: AddrMode_Acc();
INC_Acc();
break;
case 0x1B: AddrMode_Imp();
TCS();
break;
case 0x1C: AddrMode_Abs();
TRB();
break;
case 0x1D: AddrMode_AbsIdxX(false);
ORA();
break;
case 0x1E: AddrMode_AbsIdxX(true);
ASL();
break;
case 0x1F: AddrMode_AbsLngIdxX();
ORA();
break;
case 0x20: AddrMode_AbsJmp();
Idle();
JSR();
break;
case 0x21: AddrMode_DirIdxIndX();
AND();
break;
case 0x22: AddrMode_AbsLngJmp();
JSL();
break;
case 0x23: AddrMode_StkRel();
AND();
break;
case 0x24: AddrMode_Dir();
BIT();
break;
case 0x25: AddrMode_Dir();
AND();
break;
case 0x26: AddrMode_Dir();
ROL();
break;
case 0x27: AddrMode_DirIndLng();
AND();
break;
case 0x28: PLP();
break;
case 0x29: AddrMode_ImmM();
AND();
break;
case 0x2A: AddrMode_Acc();
ROL_Acc();
break;
case 0x2B: PLD();
break;
case 0x2C: AddrMode_Abs();
BIT();
break;
case 0x2D: AddrMode_Abs();
AND();
break;
case 0x2E: AddrMode_Abs();
ROL();
break;
case 0x2F: AddrMode_AbsLng();
AND();
break;
case 0x30: AddrMode_Rel();
BMI();
break;
case 0x31: AddrMode_DirIndIdxY(false);
AND();
break;
case 0x32: AddrMode_DirInd();
AND();
break;
case 0x33: AddrMode_StkRelIndIdxY();
AND();
break;
case 0x34: AddrMode_DirIdxX();
BIT();
break;
case 0x35: AddrMode_DirIdxX();
AND();
break;
case 0x36: AddrMode_DirIdxX();
ROL();
break;
case 0x37: AddrMode_DirIndLngIdxY();
AND();
break;
case 0x38: AddrMode_Imp();
SEC();
break;
case 0x39: AddrMode_AbsIdxY(false);
AND();
break;
case 0x3A: AddrMode_Acc();
DEC_Acc();
break;
case 0x3B: AddrMode_Imp();
TSC();
break;
case 0x3C: AddrMode_AbsIdxX(false);
BIT();
break;
case 0x3D: AddrMode_AbsIdxX(false);
AND();
break;
case 0x3E: AddrMode_AbsIdxX(true);
ROL();
break;
case 0x3F: AddrMode_AbsLngIdxX();
AND();
break;
case 0x40: RTI();
break;
case 0x41: AddrMode_DirIdxIndX();
EOR();
break;
case 0x42: AddrMode_Imm8();
WDM();
break;
case 0x43: AddrMode_StkRel();
EOR();
break;
case 0x44: AddrMode_BlkMov();
MVP();
break;
case 0x45: AddrMode_Dir();
EOR();
break;
case 0x46: AddrMode_Dir();
LSR();
break;
case 0x47: AddrMode_DirIndLng();
EOR();
break;
case 0x48: PHA();
break;
case 0x49: AddrMode_ImmM();
EOR();
break;
case 0x4A: AddrMode_Acc();
LSR_Acc();
break;
case 0x4B: PHK();
break;
case 0x4C: AddrMode_AbsJmp();
JMP();
break;
case 0x4D: AddrMode_Abs();
EOR();
break;
case 0x4E: AddrMode_Abs();
LSR();
break;
case 0x4F: AddrMode_AbsLng();
EOR();
break;
case 0x50: AddrMode_Rel();
BVC();
break;
case 0x51: AddrMode_DirIndIdxY(false);
EOR();
break;
case 0x52: AddrMode_DirInd();
EOR();
break;
case 0x53: AddrMode_StkRelIndIdxY();
EOR();
break;
case 0x54: AddrMode_BlkMov();
MVN();
break;
case 0x55: AddrMode_DirIdxX();
EOR();
break;
case 0x56: AddrMode_DirIdxX();
LSR();
break;
case 0x57: AddrMode_DirIndLngIdxY();
EOR();
break;
case 0x58: AddrMode_Imp();
CLI();
break;
case 0x59: AddrMode_AbsIdxY(false);
EOR();
break;
case 0x5A: PHY();
break;
case 0x5B: AddrMode_Imp();
TCD();
break;
case 0x5C: AddrMode_AbsLngJmp();
JML();
break;
case 0x5D: AddrMode_AbsIdxX(false);
EOR();
break;
case 0x5E: AddrMode_AbsIdxX(true);
LSR();
break;
case 0x5F: AddrMode_AbsLngIdxX();
EOR();
break;
case 0x60: RTS();
break;
case 0x61: AddrMode_DirIdxIndX();
ADC();
break;
case 0x62: AddrMode_RelLng();
PER();
break;
case 0x63: AddrMode_StkRel();
ADC();
break;
case 0x64: AddrMode_Dir();
STZ();
break;
case 0x65: AddrMode_Dir();
ADC();
break;
case 0x66: AddrMode_Dir();
ROR();
break;
case 0x67: AddrMode_DirIndLng();
ADC();
break;
case 0x68: PLA();
break;
case 0x69: AddrMode_ImmM();
ADC();
break;
case 0x6A: AddrMode_Acc();
ROR_Acc();
break;
case 0x6B: RTL();
break;
case 0x6C: AddrMode_AbsInd();
JMP();
break;
case 0x6D: AddrMode_Abs();
ADC();
break;
case 0x6E: AddrMode_Abs();
ROR();
break;
case 0x6F: AddrMode_AbsLng();
ADC();
break;
case 0x70: AddrMode_Rel();
BVS();
break;
case 0x71: AddrMode_DirIndIdxY(false);
ADC();
break;
case 0x72: AddrMode_DirInd();
ADC();
break;
case 0x73: AddrMode_StkRelIndIdxY();
ADC();
break;
case 0x74: AddrMode_DirIdxX();
STZ();
break;
case 0x75: AddrMode_DirIdxX();
ADC();
break;
case 0x76: AddrMode_DirIdxX();
ROR();
break;
case 0x77: AddrMode_DirIndLngIdxY();
ADC();
break;
case 0x78: AddrMode_Imp();
SEI();
break;
case 0x79: AddrMode_AbsIdxY(false);
ADC();
break;
case 0x7A: PLY();
break;
case 0x7B: AddrMode_Imp();
TDC();
break;
case 0x7C: AddrMode_AbsIdxXInd();
JMP();
break;
case 0x7D: AddrMode_AbsIdxX(false);
ADC();
break;
case 0x7E: AddrMode_AbsIdxX(true);
ROR();
break;
case 0x7F: AddrMode_AbsLngIdxX();
ADC();
break;
case 0x80: AddrMode_Rel();
BRA();
break;
case 0x81: AddrMode_DirIdxIndX();
STA();
break;
case 0x82: AddrMode_RelLng();
BRL();
break;
case 0x83: AddrMode_StkRel();
STA();
break;
case 0x84: AddrMode_Dir();
STY();
break;
case 0x85: AddrMode_Dir();
STA();
break;
case 0x86: AddrMode_Dir();
STX();
break;
case 0x87: AddrMode_DirIndLng();
STA();
break;
case 0x88: AddrMode_Imp();
DEY();
break;
case 0x89: AddrMode_ImmM();
BIT();
break;
case 0x8A: AddrMode_Imp();
TXA();
break;
case 0x8B: PHB();
break;
case 0x8C: AddrMode_Abs();
STY();
break;
case 0x8D: AddrMode_Abs();
STA();
break;
case 0x8E: AddrMode_Abs();
STX();
break;
case 0x8F: AddrMode_AbsLng();
STA();
break;
case 0x90: AddrMode_Rel();
BCC();
break;
case 0x91: AddrMode_DirIndIdxY(true);
STA();
break;
case 0x92: AddrMode_DirInd();
STA();
break;
case 0x93: AddrMode_StkRelIndIdxY();
STA();
break;
case 0x94: AddrMode_DirIdxX();
STY();
break;
case 0x95: AddrMode_DirIdxX();
STA();
break;
case 0x96: AddrMode_DirIdxY();
STX();
break;
case 0x97: AddrMode_DirIndLngIdxY();
STA();
break;
case 0x98: AddrMode_Imp();
TYA();
break;
case 0x99: AddrMode_AbsIdxY(true);
STA();
break;
case 0x9A: AddrMode_Imp();
TXS();
break;
case 0x9B: AddrMode_Imp();
TXY();
break;
case 0x9C: AddrMode_Abs();
STZ();
break;
case 0x9D: AddrMode_AbsIdxX(true);
STA();
break;
case 0x9E: AddrMode_AbsIdxX(true);
STZ();
break;
case 0x9F: AddrMode_AbsLngIdxX();
STA();
break;
case 0xA0: AddrMode_ImmX();
LDY();
break;
case 0xA1: AddrMode_DirIdxIndX();
LDA();
break;
case 0xA2: AddrMode_ImmX();
LDX();
break;
case 0xA3: AddrMode_StkRel();
LDA();
break;
case 0xA4: AddrMode_Dir();
LDY();
break;
case 0xA5: AddrMode_Dir();
LDA();
break;
case 0xA6: AddrMode_Dir();
LDX();
break;
case 0xA7: AddrMode_DirIndLng();
LDA();
break;
case 0xA8: AddrMode_Imp();
TAY();
break;
case 0xA9: AddrMode_ImmM();
LDA();
break;
case 0xAA: AddrMode_Imp();
TAX();
break;
case 0xAB: PLB();
break;
case 0xAC: AddrMode_Abs();
LDY();
break;
case 0xAD: AddrMode_Abs();
LDA();
break;
case 0xAE: AddrMode_Abs();
LDX();
break;
case 0xAF: AddrMode_AbsLng();
LDA();
break;
case 0xB0: AddrMode_Rel();
BCS();
break;
case 0xB1: AddrMode_DirIndIdxY(false);
LDA();
break;
case 0xB2: AddrMode_DirInd();
LDA();
break;
case 0xB3: AddrMode_StkRelIndIdxY();
LDA();
break;
case 0xB4: AddrMode_DirIdxX();
LDY();
break;
case 0xB5: AddrMode_DirIdxX();
LDA();
break;
case 0xB6: AddrMode_DirIdxY();
LDX();
break;
case 0xB7: AddrMode_DirIndLngIdxY();
LDA();
break;
case 0xB8: AddrMode_Imp();
CLV();
break;
case 0xB9: AddrMode_AbsIdxY(false);
LDA();
break;
case 0xBA: AddrMode_Imp();
TSX();
break;
case 0xBB: AddrMode_Imp();
TYX();
break;
case 0xBC: AddrMode_AbsIdxX(false);
LDY();
break;
case 0xBD: AddrMode_AbsIdxX(false);
LDA();
break;
case 0xBE: AddrMode_AbsIdxY(false);
LDX();
break;
case 0xBF: AddrMode_AbsLngIdxX();
LDA();
break;
case 0xC0: AddrMode_ImmX();
CPY();
break;
case 0xC1: AddrMode_DirIdxIndX();
CMP();
break;
case 0xC2: AddrMode_Imm8();
REP();
break;
case 0xC3: AddrMode_StkRel();
CMP();
break;
case 0xC4: AddrMode_Dir();
CPY();
break;
case 0xC5: AddrMode_Dir();
CMP();
break;
case 0xC6: AddrMode_Dir();
DEC();
break;
case 0xC7: AddrMode_DirIndLng();
CMP();
break;
case 0xC8: AddrMode_Imp();
INY();
break;
case 0xC9: AddrMode_ImmM();
CMP();
break;
case 0xCA: AddrMode_Imp();
DEX();
break;
case 0xCB: AddrMode_Imp();
WAI();
break;
case 0xCC: AddrMode_Abs();
CPY();
break;
case 0xCD: AddrMode_Abs();
CMP();
break;
case 0xCE: AddrMode_Abs();
DEC();
break;
case 0xCF: AddrMode_AbsLng();
CMP();
break;
case 0xD0: AddrMode_Rel();
BNE();
break;
case 0xD1: AddrMode_DirIndIdxY(false);
CMP();
break;
case 0xD2: AddrMode_DirInd();
CMP();
break;
case 0xD3: AddrMode_StkRelIndIdxY();
CMP();
break;
case 0xD4: AddrMode_Dir();
PEI();
break;
case 0xD5: AddrMode_DirIdxX();
CMP();
break;
case 0xD6: AddrMode_DirIdxX();
DEC();
break;
case 0xD7: AddrMode_DirIndLngIdxY();
CMP();
break;
case 0xD8: AddrMode_Imp();
CLD();
break;
case 0xD9: AddrMode_AbsIdxY(false);
CMP();
break;
case 0xDA: PHX();
break;
case 0xDB: AddrMode_Imp();
STP();
break;
case 0xDC: AddrMode_AbsIndLng();
JML();
break;
case 0xDD: AddrMode_AbsIdxX(false);
CMP();
break;
case 0xDE: AddrMode_AbsIdxX(true);
DEC();
break;
case 0xDF: AddrMode_AbsLngIdxX();
CMP();
break;
case 0xE0: AddrMode_ImmX();
CPX();
break;
case 0xE1: AddrMode_DirIdxIndX();
SBC();
break;
case 0xE2: AddrMode_Imm8();
SEP();
break;
case 0xE3: AddrMode_StkRel();
SBC();
break;
case 0xE4: AddrMode_Dir();
CPX();
break;
case 0xE5: AddrMode_Dir();
SBC();
break;
case 0xE6: AddrMode_Dir();
INC();
break;
case 0xE7: AddrMode_DirIndLng();
SBC();
break;
case 0xE8: AddrMode_Imp();
INX();
break;
case 0xE9: AddrMode_ImmM();
SBC();
break;
case 0xEA: AddrMode_Imp();
NOP();
break;
case 0xEB: AddrMode_Imp();
XBA();
break;
case 0xEC: AddrMode_Abs();
CPX();
break;
case 0xED: AddrMode_Abs();
SBC();
break;
case 0xEE: AddrMode_Abs();
INC();
break;
case 0xEF: AddrMode_AbsLng();
SBC();
break;
case 0xF0: AddrMode_Rel();
BEQ();
break;
case 0xF1: AddrMode_DirIndIdxY(false);
SBC();
break;
case 0xF2: AddrMode_DirInd();
SBC();
break;
case 0xF3: AddrMode_StkRelIndIdxY();
SBC();
break;
case 0xF4: AddrMode_Imm16();
PEA();
break;
case 0xF5: AddrMode_DirIdxX();
SBC();
break;
case 0xF6: AddrMode_DirIdxX();
INC();
break;
case 0xF7: AddrMode_DirIndLngIdxY();
SBC();
break;
case 0xF8: AddrMode_Imp();
SED();
break;
case 0xF9: AddrMode_AbsIdxY(false);
SBC();
break;
case 0xFA: PLX();
break;
case 0xFB: AddrMode_Imp();
XCE();
break;
case 0xFC: AddrMode_AbsIdxXInd();
JSR();
break;
case 0xFD: AddrMode_AbsIdxX(false);
SBC();
break;
case 0xFE: AddrMode_AbsIdxX(true);
INC();
break;
case 0xFF: AddrMode_AbsLngIdxX();
SBC();
break;
}
}
CpuState Cpu::GetState()
{
return _state;
}
uint64_t Cpu::GetCycleCount()
{
return _state.CycleCount;
}
void Cpu::SetNmiFlag(bool nmiFlag)
{
_state.NmiFlag = nmiFlag;
}
void Cpu::DetectNmiSignalEdge()
{
//"This edge detector polls the status of the NMI line during φ2 of each CPU cycle (i.e., during the
//second half of each cycle) and raises an internal signal if the input goes from being high during
//one cycle to being low during the next"
if (!_state.PrevNmiFlag && _state.NmiFlag)
{
_state.NeedNmi = true;
}
_state.PrevNmiFlag = _state.NmiFlag;
}
void Cpu::UpdateIrqNmiFlags()
{
if (!_state.IrqLock)
{
//"The internal signal goes high during φ1 of the cycle that follows the one where the edge is detected,
//and stays high until the NMI has been handled. "
_state.PrevNeedNmi = _state.NeedNmi;
_state.PrevIrqSource = _state.IrqSource && !CheckFlag(ProcFlags::IrqDisable);
}
_state.IrqLock = false;
}
void Cpu::SetIrqSource(IrqSource source)
{
_state.IrqSource |= (uint8_t)source;
}
bool Cpu::CheckIrqSource(IrqSource source)
{
if (_state.IrqSource & (uint8_t)source)
{
return true;
}
else
{
return false;
}
}
void Cpu::ClearIrqSource(IrqSource source)
{
_state.IrqSource &= ~(uint8_t)source;
}
uint32_t Cpu::GetProgramAddress(uint16_t addr)
{
return (_state.K << 16) | addr;
}
uint32_t Cpu::GetDataAddress(uint16_t addr)
{
return (_state.DBR << 16) | addr;
}
uint8_t Cpu::GetOpCode()
{
uint8_t opCode = ReadCode(_state.PC, MemoryOperationType::ExecOpCode);
_state.PC++;
return opCode;
}
void Cpu::IdleOrRead()
{
if (_state.PrevIrqSource)
{
ReadCode(_state.PC);
}
else
{
Idle();
}
}
uint8_t Cpu::ReadOperandByte()
{
uint8_t value = ReadCode(_state.PC, MemoryOperationType::ExecOperand);
_state.PC++;
return value;
}
uint16_t Cpu::ReadOperandWord()
{
uint8_t lsb = ReadOperandByte();
uint8_t msb = ReadOperandByte();
return (msb << 8) | lsb;
}
uint32_t Cpu::ReadOperandLong()
{
uint8_t b1 = ReadOperandByte();
uint8_t b2 = ReadOperandByte();
uint8_t b3 = ReadOperandByte();
return (b3 << 16) | (b2 << 8) | b1;
}
uint8_t Cpu::ReadCode(uint16_t addr, MemoryOperationType type)
{
return Read((_state.K << 16) | addr, type);
}
uint16_t Cpu::ReadCodeWord(uint16_t addr, MemoryOperationType type)
{
uint8_t lsb = ReadCode(addr);
uint8_t msb = ReadCode(addr + 1);
return (msb << 8) | lsb;
}
uint8_t Cpu::ReadData(uint32_t addr, MemoryOperationType type)
{
return Read(addr & 0xFFFFFF, type);
}
uint16_t Cpu::ReadDataWord(uint32_t addr, MemoryOperationType type)
{
uint8_t lsb = ReadData(addr);
uint8_t msb = ReadData(addr + 1);
return (msb << 8) | lsb;
}
uint32_t Cpu::ReadDataLong(uint32_t addr, MemoryOperationType type)
{
uint8_t b1 = ReadData(addr);
uint8_t b2 = ReadData(addr + 1);
uint8_t b3 = ReadData(addr + 2);
return (b3 << 16) | (b2 << 8) | b1;
}
void Cpu::WriteWord(uint32_t addr, uint16_t value, MemoryOperationType type)
{
Write(addr, (uint8_t)value);
Write((addr + 1) & 0xFFFFFF, (uint8_t)(value >> 8));
}
uint8_t Cpu::GetByteValue()
{
if (_immediateMode)
{
return (uint8_t)_operand;
}
else
{
return ReadData(_operand);
}
}
uint16_t Cpu::GetWordValue()
{
if (_immediateMode)
{
return (uint16_t)_operand;
}
else
{
return ReadDataWord(_operand);
}
}
void Cpu::PushByte(uint8_t value)
{
Write(_state.SP, value);
SetSP(_state.SP - 1);
}
uint8_t Cpu::PopByte()
{
SetSP(_state.SP + 1);
return ReadData(_state.SP);
}
void Cpu::PushWord(uint16_t value)
{
PushByte(value >> 8);
PushByte((uint8_t)value);
}
uint16_t Cpu::PopWord()
{
uint8_t lo = PopByte();
uint8_t hi = PopByte();
return lo | hi << 8;
}
uint16_t Cpu::GetDirectAddress(uint16_t offset, bool allowEmulationMode)
{
if (allowEmulationMode && _state.EmulationMode && (_state.D & 0xFF) == 0)
{
//TODO: Check if new instruction or not (PEI)
return (uint16_t)((_state.D & 0xFF00) | (offset & 0xFF));
}
else
{
return (uint16_t)(_state.D + offset);
}
}
uint16_t Cpu::GetDirectAddressIndirectWord(uint16_t offset, bool allowEmulationMode)
{
uint8_t lsb = ReadData(GetDirectAddress(offset + 0));
uint8_t msb = ReadData(GetDirectAddress(offset + 1));
return (msb << 8) | lsb;
}
uint32_t Cpu::GetDirectAddressIndirectLong(uint16_t offset, bool allowEmulationMode)
{
uint8_t b1 = ReadData(GetDirectAddress(offset + 0));
uint8_t b2 = ReadData(GetDirectAddress(offset + 1));
uint8_t b3 = ReadData(GetDirectAddress(offset + 2));
return (b3 << 16) | (b2 << 8) | b1;
}
void Cpu::SetSP(uint16_t sp)
{
if (_state.EmulationMode)
{
_state.SP = 0x100 | (sp & 0xFF);
}
else
{
_state.SP = sp;
}
}
void Cpu::SetPS(uint8_t ps)
{
_state.PS = ps;
if (CheckFlag(ProcFlags::IndexMode8))
{
//Truncate X/Y when 8-bit indexes are enabled
_state.Y &= 0xFF;
_state.X &= 0xFF;
}
}
void Cpu::SetRegister(uint8_t& reg, uint8_t value)
{
SetZeroNegativeFlags(value);
reg = value;
}
void Cpu::SetRegister(uint16_t& reg, uint16_t value, bool eightBitMode)
{
if (eightBitMode)
{
SetZeroNegativeFlags((uint8_t)value);
reg = (reg & 0xFF00) | (uint8_t)value;
}
else
{
SetZeroNegativeFlags(value);
reg = value;
}
}
void Cpu::SetZeroNegativeFlags(uint16_t value)
{
ClearFlags(ProcFlags::Zero | ProcFlags::Negative);
if (value == 0)
{
SetFlags(ProcFlags::Zero);
}
else if (value & 0x8000)
{
SetFlags(ProcFlags::Negative);
}
}
void Cpu::SetZeroNegativeFlags(uint8_t value)
{
ClearFlags(ProcFlags::Zero | ProcFlags::Negative);
if (value == 0)
{
SetFlags(ProcFlags::Zero);
}
else if (value & 0x80)
{
SetFlags(ProcFlags::Negative);
}
}
void Cpu::ClearFlags(uint8_t flags)
{
_state.PS &= ~flags;
}
void Cpu::SetFlags(uint8_t flags)
{
_state.PS |= flags;
}
bool Cpu::CheckFlag(uint8_t flag)
{
return (_state.PS & flag) == flag;
}
void Cpu::Serialize(Serializer& s)
{
s.Stream(
_state.A, _state.CycleCount, _state.D, _state.DBR, _state.EmulationMode, _state.IrqSource, _state.K,
_state.NmiFlag, _state.PC, _state.PrevIrqSource, _state.PrevNmiFlag, _state.PS, _state.SP, _state.StopState,
_state.X, _state.Y, _state.IrqLock, _state.NeedNmi, _state.PrevNeedNmi
);
}