Mesen/Core/Fk23C.h

380 lines
10 KiB
C++

#pragma once
#include "stdafx.h"
#include "BaseMapper.h"
class Fk23C : public BaseMapper
{
private:
uint8_t _prgBankingMode;
uint8_t _outerChrBankSize;
bool _selectChrRam;
bool _mmc3ChrMode;
bool _cnromChrMode;
uint16_t _prgBaseBits;
uint8_t _chrBaseBits;
bool _extendedMmc3Mode;
uint8_t _wramBankSelect;
bool _ramInFirstChrBank;
bool _allowSingleScreenMirroring;
bool _fk23RegistersEnabled;
bool _wramConfigEnabled;
bool _wramEnabled;
bool _wramWriteProtected;
bool _invertPrgA14;
bool _invertChrA12;
uint8_t _currentRegister;
uint8_t _irqReloadValue;
uint8_t _irqCounter;
bool _irqReload;
bool _irqEnabled;
uint8_t _mirroringReg;
uint8_t _cnromChrReg;
uint8_t _mmc3Registers[12];
uint8_t _irqDelay;
A12Watcher _a12Watcher;
protected:
uint16_t GetPRGPageSize() override { return 0x2000; }
uint16_t GetCHRPageSize() override { return 0x0400; }
uint32_t GetChrRamSize() override { return 0x20000; } //only used for iNES 1.0 files w/ no DB entry
uint16_t GetChrRamPageSize() override { return 0x400; }
uint32_t GetWorkRamSize() override { return 0x8000; } //only used for iNES 1.0 files w/ no DB entry
uint32_t GetWorkRamPageSize() override { return 0x2000; }
void InitMapper() override
{
//$5000
_prgBankingMode = 0;
_outerChrBankSize = 0;
_selectChrRam = false;
_mmc3ChrMode = true;
//$5001 (mostly)
//Subtype 1, 1024 KiB PRG-ROM, 1024 KiB CHR-ROM: boot in second 512 KiB of PRG-ROM.
_prgBaseBits = (_prgSize == 1024*1024 && _prgSize == _chrRomSize) ? 0x20 : 0;
//$5002
_chrBaseBits = 0;
//$5003
_extendedMmc3Mode = false;
_cnromChrMode = false;
//$A001
_wramBankSelect = 0;
_ramInFirstChrBank = false;
_allowSingleScreenMirroring = false;
_wramConfigEnabled = false;
_fk23RegistersEnabled = false;
_wramEnabled = false;
_wramWriteProtected = false;
_currentRegister = 0;
_cnromChrReg = 0;
constexpr uint8_t initValues[12] = { 0,2,4,5,6,7,0,1,0xFE, 0xFF, 0xFF, 0xFF };
for(int i = 0; i < 12; i++) {
_mmc3Registers[i] = initValues[i];
}
_invertPrgA14 = false;
_invertChrA12 = false;
_mirroringReg = 0;
_irqCounter = 0;
_irqEnabled = false;
_irqReload = false;
_irqReloadValue = 0;
_irqDelay = 0;
AddRegisterRange(0x5000, 0x5FFF, MemoryOperation::Write);
UpdateState();
}
void Reset(bool softReset) override
{
if(softReset) {
if(_wramConfigEnabled && _selectChrRam && HasBattery()) {
_prgBaseBits = 0;
UpdateState();
}
}
}
void StreamState(bool saving) override
{
SnapshotInfo a12Watcher { &_a12Watcher };
ArrayInfo<uint8_t> regs { _mmc3Registers, 12 };
Stream(
_prgBankingMode, _outerChrBankSize, _selectChrRam, _mmc3ChrMode, _cnromChrMode, _prgBaseBits, _chrBaseBits, _extendedMmc3Mode,
_wramBankSelect, _ramInFirstChrBank, _allowSingleScreenMirroring, _fk23RegistersEnabled, _wramConfigEnabled, _wramEnabled, _wramWriteProtected,
_invertPrgA14, _invertChrA12, _currentRegister, _irqReloadValue,_irqCounter, _irqReload, _irqEnabled, _mirroringReg, _cnromChrReg,
_irqDelay, regs, a12Watcher
);
if(!saving) {
UpdateState();
}
}
void SelectCHRPage(uint16_t slot, uint16_t page, ChrMemoryType memoryType = ChrMemoryType::Default) override
{
bool useChrRam = !HasChrRom() || (_selectChrRam && _chrRamSize > 0) || (_wramConfigEnabled && _ramInFirstChrBank && page <= 7);
BaseMapper::SelectCHRPage(slot, page, useChrRam ? ChrMemoryType::ChrRam : ChrMemoryType::ChrRom);
}
void UpdatePrg()
{
switch(_prgBankingMode) {
case 0:
case 1:
case 2:
if(_extendedMmc3Mode) {
uint8_t swap = _invertPrgA14 ? 2 : 0;
uint16_t outer = (_prgBaseBits << 1);
SelectPRGPage(0 ^ swap, _mmc3Registers[6] | outer);
SelectPRGPage(1, _mmc3Registers[7] | outer);
SelectPRGPage(2 ^ swap, _mmc3Registers[8] | outer);
SelectPRGPage(3, _mmc3Registers[9] | outer);
} else {
uint8_t swap = _invertPrgA14 ? 2 : 0;
uint8_t innerMask = 0x3F >> _prgBankingMode;
uint16_t outer = (_prgBaseBits << 1) & ~innerMask;
SelectPRGPage(0 ^ swap, (_mmc3Registers[6] & innerMask) | outer);
SelectPRGPage(1, (_mmc3Registers[7] & innerMask) | outer);
SelectPRGPage(2 ^ swap, (0xFE & innerMask) | outer);
SelectPRGPage(3, (0xFF & innerMask) | outer);
}
break;
case 3:
SelectPrgPage2x(0, _prgBaseBits << 1);
SelectPrgPage2x(1, _prgBaseBits << 1);
break;
case 4:
SelectPrgPage4x(0, (_prgBaseBits & 0xFFE) << 1);
break;
default:
break;
}
}
void UpdateChr()
{
if(!_mmc3ChrMode) {
uint16_t innerMask = _cnromChrMode ? (_outerChrBankSize ? 1 : 3) : 0;
for(int i = 0; i < 8; i++) {
SelectCHRPage(i, (((_cnromChrReg & innerMask) | _chrBaseBits) << 3) + i);
}
} else {
uint8_t swap = _invertChrA12 ? 0x04 : 0;
if(_extendedMmc3Mode) {
uint16_t outer = (_chrBaseBits << 3);
SelectCHRPage(0 ^ swap, _mmc3Registers[0] | outer);
SelectCHRPage(1 ^ swap, _mmc3Registers[10] | outer);
SelectCHRPage(2 ^ swap, _mmc3Registers[1] | outer);
SelectCHRPage(3 ^ swap, _mmc3Registers[11] | outer);
SelectCHRPage(4 ^ swap, _mmc3Registers[2] | outer);
SelectCHRPage(5 ^ swap, _mmc3Registers[3] | outer);
SelectCHRPage(6 ^ swap, _mmc3Registers[4] | outer);
SelectCHRPage(7 ^ swap, _mmc3Registers[5] | outer);
} else {
uint8_t innerMask = (_outerChrBankSize ? 0x7F : 0xFF);
uint16_t outer = (_chrBaseBits << 3) & ~innerMask;
SelectCHRPage(0 ^ swap, ((_mmc3Registers[0] & 0xFE) & innerMask) | outer);
SelectCHRPage(1 ^ swap, ((_mmc3Registers[0] | 0x01) & innerMask) | outer);
SelectCHRPage(2 ^ swap, ((_mmc3Registers[1] & 0xFE) & innerMask) | outer);
SelectCHRPage(3 ^ swap, ((_mmc3Registers[1] | 0x01) & innerMask) | outer);
SelectCHRPage(4 ^ swap, (_mmc3Registers[2] & innerMask) | outer);
SelectCHRPage(5 ^ swap, (_mmc3Registers[3] & innerMask) | outer);
SelectCHRPage(6 ^ swap, (_mmc3Registers[4] & innerMask) | outer);
SelectCHRPage(7 ^ swap, (_mmc3Registers[5] & innerMask) | outer);
}
}
}
void UpdateState()
{
switch(_mirroringReg & (_allowSingleScreenMirroring ? 0x03 : 0x01)) {
case 0: SetMirroringType(MirroringType::Vertical); break;
case 1: SetMirroringType(MirroringType::Horizontal); break;
case 2: SetMirroringType(MirroringType::ScreenAOnly); break;
case 3: SetMirroringType(MirroringType::ScreenBOnly); break;
}
UpdatePrg();
UpdateChr();
if(_wramConfigEnabled) {
uint8_t nextBank = (_wramBankSelect + 1) & 0x03;
SetCpuMemoryMapping(0x4000, 0x5FFF, (nextBank & 0x02) >> 1, (nextBank & 0x01) ? PrgMemoryType::SaveRam : PrgMemoryType::WorkRam, MemoryAccessType::ReadWrite);
SetCpuMemoryMapping(0x6000, 0x7FFF, (_wramBankSelect & 0x02) >> 1, (_wramBankSelect & 0x01) ? PrgMemoryType::SaveRam : PrgMemoryType::WorkRam, MemoryAccessType::ReadWrite);
} else {
if(_wramEnabled) {
SetCpuMemoryMapping(0x6000, 0x7FFF, 0, PrgMemoryType::WorkRam, _wramWriteProtected ? MemoryAccessType::Read : MemoryAccessType::ReadWrite);
} else {
RemoveCpuMemoryMapping(0x6000, 0x7FFF);
}
RemoveCpuMemoryMapping(0x4000, 0x5FFF);
};
}
void WriteRegister(uint16_t addr, uint8_t value) override
{
if(addr < 0x8000) {
if(_fk23RegistersEnabled || !_wramConfigEnabled) {
uint16_t mask = 0x5010;
if((addr & mask) != mask) {
//not a register
return;
}
switch(addr & 0x03) {
case 0:
_prgBankingMode = value & 0x07;
_outerChrBankSize = (value & 0x10) >> 4;
_selectChrRam = (value & 0x20) != 0;
_mmc3ChrMode = (value & 0x40) == 0;
_prgBaseBits = (_prgBaseBits & ~0x180) | ((value & 0x80) << 1) | ((value & 0x08) << 4);
break;
case 1:
_prgBaseBits = (_prgBaseBits & ~0x7F) | (value & 0x7F);
break;
case 2:
_prgBaseBits = (_prgBaseBits & ~0x200) | ((value & 0x40) << 3);
_chrBaseBits = value;
_cnromChrReg = 0;
break;
case 3:
_extendedMmc3Mode = (value & 0x02) != 0;
_cnromChrMode = (value & 0x44) != 0;
break;
}
UpdateState();
} else {
//FK23C Registers disabled, $5000-$5FFF maps to the second 4 KiB of the 8 KiB WRAM bank 2
WritePrgRam(addr, value);
}
} else {
if(_cnromChrMode && (addr <= 0x9FFF || addr >= 0xC000)) {
_cnromChrReg = value & 0x03;
UpdateState();
}
switch(addr & 0xE001) {
case 0x8000:
if(_prgSize == 16384*1024 && (value == 0x46 || value == 0x47)) {
//Subtype 2, 16384 KiB PRG-ROM, no CHR-ROM: Like Subtype 0, but MMC3 registers $46 and $47 swapped.
value ^= 1;
}
_invertPrgA14 = (value & 0x40) != 0;
_invertChrA12 = (value & 0x80) != 0;
_currentRegister = value & 0x0F;
UpdateState();
break;
case 0x8001: {
uint8_t reg = _currentRegister & (_extendedMmc3Mode ? 0x0F : 0x07);
if(reg < 12) {
_mmc3Registers[_currentRegister & (_extendedMmc3Mode ? 0x0F : 0x07)] = value;
UpdateState();
}
break;
}
case 0xA000:
_mirroringReg = value & 0x03;
UpdateState();
break;
case 0xA001:
if((value & 0x20) == 0) {
//Ignore extra bits if bit 5 is not set
value &= 0xC0;
}
_wramBankSelect = (value & 0x03);
_ramInFirstChrBank = (value & 0x04) != 0;
_allowSingleScreenMirroring = (value & 0x08) != 0;
_wramConfigEnabled = (value & 0x20) != 0;
_fk23RegistersEnabled = (value & 0x40) != 0;
_wramWriteProtected = (value & 0x40) != 0;
_wramEnabled = (value & 0x80) != 0;
UpdateState();
break;
case 0xC000:
_irqReloadValue = value;
break;
case 0xC001:
_irqCounter = 0;
_irqReload = true;
break;
case 0xE000:
_irqEnabled = false;
_console->GetCpu()->ClearIrqSource(IRQSource::External);
break;
case 0xE001:
_irqEnabled = true;
break;
}
}
}
public:
void ProcessCpuClock() override
{
if(_irqDelay > 0) {
_irqDelay--;
if(_irqDelay == 0) {
_console->GetCpu()->SetIrqSource(IRQSource::External);
}
}
}
void NotifyVRAMAddressChange(uint16_t addr) override
{
switch(_a12Watcher.UpdateVramAddress(addr, _console->GetPpu()->GetFrameCycle())) {
case A12StateChange::None:
case A12StateChange::Fall:
break;
case A12StateChange::Rise:
if(_irqCounter == 0 || _irqReload) {
_irqCounter = _irqReloadValue;
} else {
_irqCounter--;
}
if(_irqCounter == 0 && _irqEnabled) {
_irqDelay = 2;
}
_irqReload = false;
break;
}
}
};